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2014 WASTEWATER TREATMENT PLANT FACILITY PLAN June 2015 Prepared by J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. Ste. 201 Kennewick, WA 99336 ---PAGE BREAK--- ---PAGE BREAK--- Chapter 0 EXECUTIVE 1 ES-1 Purpose 1 ES-2 Discharge Permit 1 ES-3 WWTP Evaluation 2 ES-4 Alternatives Evaluation and Selected 3 ES-5 Capital Improvement Plan 5 Chapter 1 – BACKGROUND INFORMATION 1-1 1.1 Introduction and Facility History 1-1 1.2 Study Scope 1-5 1.3 Compliance with Washington Department of Ecology and WAC Facility Plan Requirements 1-6 Chapter 2 – Existing Environment 2-1 2.1 Public Health 2-1 2.2 Physical 2-1 2.2.1 Topography 2-1 2.2.2 Climate 2-1 2.2.3 Geology 2-2 2.2.4 Soils 2-2 2.3 Study Boundary 2-3 2.4 Sensitive Areas 2-4 2.4.1 Flood Plains 2-4 2.4.2 Shorelines 2-5 2.4.3 Wetlands 2-5 2.4.4 Prime or Unique 2-5 2.4.5 Archeological and Historical Sites 2-5 2.4.6 Wild and Scenic Rivers Act 2-6 2.5 Species and Habitats 2-6 2.5.1 ESA Listed Species for the APE 2-6 2.6 SERP 2-6 Chapter 3 – Flows and Loads 3-1 3.1 Introduction 3-1 3.2 Existing Influent WWTP Flow and Loads 3-1 3.2.1 Flows 3-1 3.2.2 Biochemical Oxygen Demand (BOD) 3-4 3.2.3 Total Suspended Solids (TSS) 3-6 3.2.4 Total Kjeldahl Nitrogen (TKN) 3-7 3.2.5 Total Phosphorus 3-8 3.2.5 Summary of Current Flows and Loads 3-9 3.3 Projected Flows and Loads for Year 2034 3-10 3.4 Temperature 3-13 Chapter 4 – discharge standards 4-1 4.1 Federal Water Quality Standards 4-1 4.2 Washington State Surface Water Quality Standards (WQS) 4-1 4.2.1 303(d) List 4-2 4.2.2 Temperature TMDL 4-3 ---PAGE BREAK--- 4.2.3 Dissolved Gas TMDL 4-3 4.2.4 Future 4-3 4.3 Existing Discharge Standards 4-4 4.4 Expected Future Discharge Standards 4-5 Chapter 5 – Existing Wastewater Treatment Facilities evaluation 5-1 5.1 Introduction and Facility History 5-1 5.2 Unit Process Treatment Evaluation 5-4 5.2.1 Headworks (Influent Screening) 5-4 5.2.2 Influent Parshall Flume 5-5 5.2.3 Influent Pump Station 5-5 5.2.4 Grit Removal 5-6 5.2.5 HRT Cells 5-6 5.2.6 Intermediate 5-9 5.2.7 Intermediate Clarifier RAS / WAS Pumping 5-12 5.2.8 Flash Mix / Flocculation 5-13 5.2.9 Final Clarifiers 5-15 5.2.10 UV Disinfection 5-16 5.2.11 Effluent Palmer Bowlus Flume, Effluent Pump Station, and Outfall 5-18 5.2.12 Aerated Sludge Lagoons 5-19 5.2.13 Hydraulic Capacity 5-20 5.3 Ancillary Support 5-20 5.3.1 Plant Water 5-20 5.3.2 Supervisory Control and Data Acquisition (SCADA) 5-20 5.3.3 Standby Power / Power Distribution 5-21 5.4 Overall Performance 5-21 5.5 Reliability Considerations 5-25 5.6 Facility Summary and Remaining Capacity 5-26 Chapter 6 – Alternatives to Meet Facilities Goals: Liquid Stream 6-1 6.1 Introduction 6-1 6.2 No Action Alternative 6-1 6.2.1 Headworks (Influent Screening) – No Action 6-1 6.2.2 Influent Parshall Flume – No Action 6-1 6.2.3 Influent Pump Station – No Action 6-1 6.2.4 HRT Cells – No Action 6-1 6.2.5 Intermediate Clarifiers – No Action 6-3 6.2.6 Intermediate Clarifier RAS / WAS Pump Station – No Action 6-5 6.2.7 Flash Mix / Flocculation – No Action 6-5 6.2.8 Final Clarifiers – No Action 6-5 6.2.9 UV Disinfection – No Action 6-5 6.2.10 Effluent Palmer Bowlus Flume, Effluent Pump Station, and Outfall – No Action 6-6 6.2.11 Aerated Sludge Lagoons – No Action 6-6 6.2.12 Hydraulic Capacity – No Action 6-6 6.2.13 Ancillary Support Facilities – No Action 6-6 6.2.14 Summary of No Action Alternative 6-8 6.3 General Facility Upgrades 6-12 ---PAGE BREAK--- 6.4 Biological Treatment Alternatives 6-12 6.4.1 Alternative 1 – No Action 6-13 6.4.2 Alternative 2 – Retain Existing HRT Cells and Add Mechanical Aeration 6-13 6.4.3 Alternative 3 – Add a Third HRT Cell with Mechanical Aeration 6-14 6.4.4 Alternative 4 – Retain Existing HRT Cells and Retrofit with Diffused Aeration 6-14 6.4.5 Alternative 5 – New Concrete Aeration Basins with Fine Bubble Aeration 6-15 6.4.6 Summary of Biological Treatment Alternatives 6-16 6.5 UV Disinfection Alternatives 6-19 6.5.1 Alternative 1 – No Action 6-19 6.5.2 Alternative 2 – Upgraded Monitoring and Control 6-19 6.5.3 Alternative 3 – System Replacement 6-20 6.6 Evaluation of Biological and UV Disinfection Alternatives 6-20 6.6.1 Criteria and Relative Weight 6-20 6.6.2 Biological 6-22 6.6.3 UV Disinfection Alternatives 6-24 6.7 Summary of Recommended Improvements 6-25 Chapter 7 – Alternatives to Meet Facilities Goals: Biosolids 7-1 7.1 Introduction 7-1 7.2 Existing and Projected Biosolids Production 7-1 7.2.1 Biosolids Production - 2014 7-1 7.2.2 Biosolids Production - 2034 7-1 7.3 Existing Biosolids Management 7-2 7.4 Biosolids Unit Process Evaluation 7-2 7.4.1 WAS Pump Station 7-2 7.4.2 Aerated Solids Storage Lagoons 7-2 7.4.3 Biosolids Removal and Disposal 7-2 7.5 Biosolids Management Alternatives 7-3 7.5.1 Alternative 1 – No Action 7-4 7.5.2 Alternative 2 – Manage Un-Stabilized Biosolids 7-5 7.5.3 Alternative 3 – Manage Chemically Stabilized Biosolids 7-6 7.5.4 Alternative 4 – Manage Biologically Digested (Stabilized) Biosolids 7-8 7.5.5 Biosolids Management Alternatives Cost Summary 7-12 7.6 Class A Alternatives 7-12 7.6.1 Class A Alternative 1 – Mechanical Solar Air Drying 7-12 7.6.2 Class A Alternative 2 – Chemical Stabilization 7-15 7.6.3 Class A Alternative 3 – Thermal Drying 7-16 7.6.4 Class A Alternative 4 – Air Drying 7-18 7.6.5 Class A Alternative 5 – Composting 7-18 7.6.6 Class A and Base Management Alternative Planning Level Cost Opinion Summary 7-18 7.7 Biosolids Management Alternatives Evaluation 7-19 7.7.1 Criteria and Relative Weight 7-19 7.7.2 Biosolids Management Alternative Ranking 7-22 7.8 Summary of Recommended Improvements 7-23 Chapter 8 – SUMMARY OF RECOMMENDED IMPROVEMENTS AND CAPITAL IMPROVEMENT PLAN (cip)8-1 8.1 Selected Improvements 8-1 ---PAGE BREAK--- 8.2 Recommended Capital Improvement Plan (CIP) 8-5 8.3 Energy Efficiency Review 8-8 8.4 Reliability Considerations 8-8 8.4.1 Unit Process Reliability 8-8 8.4.2 Electrical Reliability 8-10 8.5 Estimated Staffing Needs 8-10 REFERENCES 8-12 ---PAGE BREAK--- Appendices Appendix 1-A – Checklist for Facility Plan Contents Appendix 2-A – National Wetlands Inventory Map Appendix 2-B – Farmland Classification Exhibit Appendix 2-C – FEMA Flood Insurance Rate Map Appendix 2-D – EZ1 Form – DOE Correspondence Appendix 2-E – Biological Assessment Appendix 4-A – NPDES Permit Appendix 4-B – NPDES Fact Sheet Appendix 4-C – AWC Toxics Tech Report Appendix 5-A – Process Calculations Appendix 5-B – WWTP Process Data Appendix 6-A – Process Calculations Appendix 6-B – UV Evaluation Appendix 6-C – Liquid Stream Cost Opinions Appendix 7-A – Biosolids Cost Opinions Appendix 8-A – ESI Energy Efficiency Review Figures Figure ES - 2 – Recommended Phasing 7 Figure 1-1 – WWTP Location and Service Area 1-1 Figure 1-2 – Facility Overview 1-3 Figure 1-3 – Upgrade History 1-4 Figure 2-1 – WWTP Study Boundary 2-4 Figure 3-1 – WWTP Influent Flow 3-3 Figure 3-2 – Influent BOD Loading 3-5 Figure 3-3 – Influent TSS Loading 3-7 Figure 5-1 – Facility Overview 5-2 Figure 5-2 – Upgrade History 5-3 Figure 5-3 – Historical Effluent BOD5 5-22 Figure 5-4 – Historical Effluent TSS 5-23 Figure 5-5 – Historical Effluent Ammonia 5-23 Figure 5-6 – Historical Effluent Fecal Coliform 5-24 Figure 5-7 – Existing Loading and Capacity Summary 5-28 Figure 6-1 – Intermediate Clarifier Overflow Rate 6-4 Figure 6-2 – Intermediate Clarifier Solids Loading Rate 6-4 Figure 6-3 – Hydraulic Profile at 2034 Flows 6-7 Figure 6-4 – Loading and Capacity Summary at Projected 2034 Conditions 6-11 Figure 7-1 – Solar Dryer (Courtesy of Huber) 7-14 Figure 7-2 – Bioset Demonstration Unit 7-15 Figure 7-3 – Thermal Dryer (Courtesy of Huber) 7-17 Figure 8-1 – Process Schematic with Recommended Improvements 8-3 ---PAGE BREAK--- Figure 8-2 – Site Plan with Recommended Improvements 8-4 Figure 8-3 – Recommended Phasing Plan 8-7 Tables Table ES-1 – Pairwise Analysis Results 3 Table ES-2 – Summary of Recommended CIP Projects 4 Table ES-3 – Recommended Phasing of Improvements 5 Table 1-1 – Document Outline 1-5 Table 2-1 – Climatological Data 2-2 Table 3-1 – Influent WWTP Flow Summary by Year 3-2 Table 3-2 – Wastewater Sources and Estimated Flow Contribution 3-4 Table 3-3 – Influent BOD Summary by Year 3-5 Table 3-4 – Influent TSS Summary by 3-6 Table 3-5 – Influent TKN Summary by Year 3-8 Table 3-6 – Existing Flows and Loads Summary 3-9 Table 3-7 – Projected Average Day Flows for 3-11 Table 3-8 – Projected Flow and Load Summary for Year 2034 3-12 Table 3-9 – Historical Effluent Average Temperatures 3-13 Table 4-1 – Design Criteria – 2008 NPDES Permit 4-4 Table 4-2 – Effluent Limits – 2008 NPDES Permit 4-5 Table 5-1 – Headworks Operating Conditions and Design Criteria 5-4 Table 5-2 – Influent Pump Station Operating Conditions and Design Criteria 5-6 Table 5-3 – HRT Cells Operating Conditions and Design Criteria 5-7 Table 5-4 – Existing Oxygen Demand and 5-8 Table 5-5 – Intermediate Clarification Operating Conditions and Design Criteria 5-11 Table 5-6 – RAS / WAS Operating Conditions and Design Criteria 5-12 Table 5-7 – Flash Mix and Flocculation Basin Operating Conditions and Design Criteria 5-14 Table 5-8 – Final Clarifier Operating Conditions and Design 5-15 Table 5-9 – UV Disinfection Operating Conditions and Design Criteria 5-17 Table 5-10 – Aerated Sludge Storage Lagoon Conditions and Design Criteria 5-19 Table 5-11 – Electrical Service Summary 5-21 Table 5-12 – Effluent Quality Summary and Historical Removal Averages) 5-22 Table 5-13 – Reliability Class II Requirements Compared to Existing Facility 5-25 Table 5-14 – Minimum Capacity of the Backup Power Source for Each Reliability Class 5-26 Table 5-15 – Summary of Existing Conditions 5-26 Table 6-1 – Projected 2034 Oxygen Demand and Supply with Existing Aerators 6-2 Table 6-2 – HRT Cell Temperature and Critical SRT for Nitrification 6-3 Table 6-3 – Summary of Conditions with No Action 6-8 Table 6-4 – Summary of General Facility Upgrades 6-12 Table 6-5 – New Concrete Treatment Basin Preliminary Design Criteria 6-17 Table 6-6 – Summary of Biological Treatment Alternatives 6-18 Table 6-7 – UV Disinfection Design Criteria 6-20 Table 6-8 – Evaluation Criteria 6-21 Table 6-9 – Pairwise Analysis Results 6-22 Table 6-10 – Biological Treatment Ranking 6-24 ---PAGE BREAK--- Table 6-11 – UV Disinfection Ranking 6-25 Table 6-12 – Summary of Recommended Liquid Stream Upgrades 6-26 Table 7-1 – Distinctive Components for Each Biosolids Alternative 7-3 Table 7-2 – Alternative 1 Present Value Cost Estimate (millions) 7-4 Table 7-3 – Alternative 1 Advantages and Disadvantages 7-4 Table 7-4 – Alternative 2 Advantages and Disadvantages 7-5 Table 7-5 – Design Criteria Associated with Dewatering Un-Stabilized WAS 7-6 Table 7-6 – Alternative 2 Present Value Cost Estimate (millions) 7-6 Table 7-7 – Lime Post Treatment Design Criteria, Un-Stabile WAS 7-7 Table 7-8 – Alternative 3 Present Value Cost Estimate 7-7 Table 7-9 – Alternative 3 Advantages and Disadvantages 7-7 Table 7-10 – Aerobic Digester Present Value Cost Estimate 7-9 Table 7-11 – Anaerobic Digester Present Value Cost Estimate 7-9 Table 7-12 – Dewatering Stabilized Biosolids Design Criteria 7-10 Table 7-13 – Alternative 4 Stabilized Biosolids Design Criteria 7-10 Table 7-14 – Alternative 4 Present Value Cost Estimate (millions) 7-11 Table 7-15 – Alternative 4 Advantages and Disadvantages 7-11 Table 7-16 – Biosolids Management Alternatives Cost Summary (in millions of 7-12 Table 7-17 – Solar Dryer Design Criteria 7-13 Table 7-18 – Class A Alt. Solar Dryer Present Value Cost (in millions of with and without Heat 7-13 Table 7-19 – Solar Dryer Advantages and Disadvantages 7-14 Table 7-20 – Chemical Treatment Present Value Cost (in millions of 7-16 Table 7-21 – Chemical Treatment Advantages and Disadvantages 7-16 Table 7-22 – Thermal Drying Present Value Cost (in millions of 7-17 Table 7-23– Thermal Drying Advantages and Disadvantages 7-17 Table 7-24 – Class A Biosolids Treatment Opinion Cost Summary (in millions of 7-19 Table 7-25 – Alternative Cost Summary (in millions of 7-19 Table 7-26 – Evaluation Criteria 7-21 Table 7-27 – Pairwise Analysis Results 7-22 Table 7-28– Biosolids Alternatives Ranking 7-23 Table 7-29 – Summary of Recommended Biosolids Management Upgrades 7-23 Table 8-1 – List of Recommended Improvements 8-2 Table 8-2 – Recommended Phasing of Improvements 8-6 Table 8-3 – Reliability Class II Requirements Compared to Proposed Facility 8-9 Table 8-4 – Minimum Capacity of the Backup Power Source for Each Reliability Class 8-10 Table 8-5 – Estimated Staffing Needs 8-11 ---PAGE BREAK--- CHAPTER 0 EXECUTIVE SUMMARY Because of operational issues and concerns about process capacities, the City of Kennewick (City) identified several potential upgrades to the Wastewater Treatment Plant (WWTP) within the last few years. Additionally, the City desired to complete a new Facility Plan that integrated the previous plans (1995 through 2007) while taking a comprehensive look at the entire facility and its needs over the next 20 years. The nature of these goals, in addition to requirements in WAC 173-240-030, requires that an engineering report be prepared and approved by the Washington State Department of Ecology (WDOE). The City therefore authorized J-U-B ENGINEERS, Inc. to undertake the WWTP Facilities Plan Update in 2013/2014. Major goals of the 2014 WWTP Facilities Plan Update are as follows: Incorporate information from previous studies performed in 1995, 2000, 2005, and 2007 Update flow and load projections for a planning period through 2034 Evaluate all major unit processes at the WWTP Develop alternatives to address critical needs at the WWTP Evaluate alternatives with City Staff and identify selected projects for implementation Prepare a phased capital improvement plan to prioritize projects and manage budgets Complete SERP permitting to qualify selected projects for funding The City of Kennewick WWTP operates under NPDES Waste Discharge Permit No. WA-004478-4. The permit was effective on December 1, 2008 and expired on November 30, 2013. The City has applied for renewal of the permit and has been following the terms and conditions of the existing permit in the interim. Based upon inquires made to the WDOE Staff, the new discharge permit is expected to be issued in 2015 and remain largely unchanged. Therefore, all analysis in this document is based upon the 2008 permit requirements. It should be noted that there are current rulemaking activities proposed by the Governor for human health criteria that are focusing on water quality standards for toxics (e.g. PCBs, arsenic, mercury,). The proposed schedule from the State is to have a final rule adopted after the 2015 legislative session; however, there is much controversy amongst various special interest groups. Because of the limited amount of existing data and uncertainty in the final water quality criteria, it is not currently possible to quantify what effect this rule might have on the City’s NPDES permit. Typically, it takes 15- 20 years to finalize a rule, gather data, establish criteria, and phase into existing permits. Given the amount of work necessary to implement the proposed rule, it is unlikely to affect the City during the current planning period. Therefore, our analysis was based on the 2008 permit and did not include any assumptions regarding potential long-term permit changes. ---PAGE BREAK--- This proposed toxics rulemaking is one the City should follow closely. While the permit conditions that will result from current rule-making efforts are far from clear, the evidence points toward more stringent standards. Involvement with the rule-making is critical to provide as much compliance flexibility as possible plus reasonable compliance schedules for any required upgrades. The City of Kennewick Wastewater Treatment Plant (WWTP) provides biological treatment for incoming domestic, commercial, and industrial waste. The WWTP is located in the northeast of the City of Kennewick near the bank of the Columbia River. The facility was originally constructed in 1952 and was subsequently upgraded in 1972, 1996, 2000, 2005, and 2007. This 67.6 acre facility is the only WWTP for the City – as such, the Service Area for the facility consists of all lands within the Urban Growth Area (UGA) Boundary. An aerial image of the facility, with major unit processes, is shown in Figure ES-1. The current City population is 76,410 (2013) with an estimated 10,500 people currently utilizing septic systems. The total population served is therefore approximately 66,000, and results in approximately 5.4 million gallons of wastewater per day being treated at the facility. The previous five years of influent flow and sampling data were analyzed to determine the existing baseline flows and loads for the WWTP. Flow and load projections were also developed consistent with the 2014 General Sewer Plan and the City’s Comprehensive Plan. The City has an excellent track record of meeting permit requirements – with no violations in recent history. In fact, in 2013 the City received its 7th consecutive “Outstanding Performance Award” from WDOE. However, our analysis identified a few unit processes in need of improvement, including: Influent Bypass – The existing emergency bypass around the influent screens is likely inoperable. A new bypass should be constructed that could be operated in the case of an emergency that required bypass around the influent screens. Improvements will address an existing operations and maintenance concern. Aeration Basins – There is currently not enough aeration capacity to meet the WDOE requirement for a minimum dissolved oxygen concentration of 0.5 mg/L during peak hour loading on an average day. Improvements will address ability to meet current and future oxygen demands. Final Clarifiers – The final clarifiers are 62 years old and surface deterioration is present. Solids pumping capability from the final clarifier is also compromised. The final clarifiers experience a large amount of algae growth – which affects the UV disinfection system and unnecessarily results in increased maintenance effort. Improvements will extend the life of the clarifiers and address existing operations and maintenance concerns. Ultraviolet (UV) Disinfection – The equipment has an antiquated control system and Staff are not able to optimize its operation or performance. Moreover, the manufacturer is no longer supporting the equipment which may make replacement parts impossible to get in coming years. There is also currently no backup power for this facility which can result in inadequately disinfected effluent being discharged to the Columbia River. Improvements will replace the equipment that is currently unsupported by the manufacturer and replace with equipment that can be optimized to reduce energy consumption. Solids Lagoons – Although the lagoons are an economical means of managing biosolids, unpredictable turnover events in the solids lagoons result in extremely foul odors that result in many citizen complaints. Improvements will eliminate the odor producing lagoons and adopt a more mechanized solids stabilization process where odors are localized and can be effectively treated. ---PAGE BREAK--- Several alternatives to address the noted deficiencies in aeration basins, UV disinfection, and solids lagoons were developed during multiple workshops and site visits with City Staff. To facilitate an objective comparison amongst the various alternatives, several evaluation criteria were identified that were deemed critical by City Staff. A pairwise analysis was then performed to compare the relative importance of one criterion to another; e.g. which is more important, Cost or Odor potential? The results of the pairwise comparison are shown in Table ES-1. Table ES-1 – Pairwise Analysis Results Criteria Definition Weight A) Present Worth Cost Planning level capital cost plus expected life-cycle cost of an alternative, both in 2014 dollars. The costs reported are approximate and for comparison purposes only. More refined cost estimates will be developed for the preferred alternatives. 8.3% B) Permit Compliance Ability to satisfy existing and projected permit requirements over the course of the study period. 16.7% C) Reliability Probability of adequate performance over the expected range of loading and operating conditions in the study period. Consideration is also given for number of similar facilities currently in operation. 11.3% D) Safety Degree to which operators are exposed to hazardous conditions that could result in injury. However, safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. 17.9% E) Ability to Expand Ability to expand and adapt a process for greater loading and/or to address changes in permit requirements. 10.1% F) Energy Efficiency Overall efficiency of the alternative, energy use, carbon footprint, and consumption of non-renewable resources. 7.1% G) Odor Potential Potential of an alternative to cause foul odors during operations through the course of a year. Significant foul odors negatively impact customer service and is considered to have a negative impact on economic development in the downtown area. 17.3% H) Ease of Operations Ease of operations and complexity of the process, including the need for specialized operators and process control / testing. 11.3% I) Ease of Disposal (Biosolids only) Ability to find suitable disposal sites for biosolids; also used to differentiate perceived quality or handling impacts of biosolids that attain the same 503b classification. 17.9% Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. A series of workshops were conducted with City Staff to evaluate the various alternatives and the pairwise comparison results were used to score and rank the alternatives. The resulting list of capital improvement projects identified are summarized in Table ES-2. Additional information regarding each specific project can be found in Chapters 6 and 7. The costs presented in Table ES-2 are planning level costs with a high level of variability that errs on the high side to assure that future rate changes can accommodate the inherent risk associated with planning level cost estimates. ---PAGE BREAK--- Table ES-2 – Summary of Recommended CIP Projects Item Description Purpose Approximate Capital Cost Preliminary Treatment Headworks Bypass: Construct a new gate in the intersection of Bruneau Avenue and Kingwood Street. Influent Pump Station: Add a 3-ton bridge crane and electric hoist at the Influent Pump Station; improve operator access to valve vault; modify wet well for grit trap prior to pumps. Address operational needs for emergency bypass conditions of the Headworks and normal operations of the Influent Pump Station. $430,000 Biological Treatment Grit Removal: Construction of a vortex or stacked tray grit removal system; grit pump and classifier; new building. Minimize grit accumulation at fine bubble diffusers and frequency of basin draining and cleaning. $3,590,000 Short-term Aeration Upgrade: Installation of one 100-hp aerator in each HRT Cell with accompanying electrical upgrades Provide sufficient oxygen transfer for the projected loads over the next eight to ten years. $310,000 New Concrete Aeration Basins with Diffused Aeration: Includes retrofitting the abandoned RAS pump building for blowers; two 3 MG concrete basins; fine bubble diffusers. Address oxygen deficiency projected over the 20-year planning period; improve operator process control and energy efficiency; improve safety. $18,290,000 Final Clarifiers Final Clarifiers 1 and 2: Rebuild walkway between clarifiers; rehabilitate degraded surface and weirs (approximately the top four feet); replace solids pump; construct Final Clarifier bypass line from Flash Mix Basin to UV system. Maintain existing infrastructure in a viable state; improve operations. $580,000 UV Disinfection System Replacement: New UV system; improve hydraulics, controls, and functionality. Improve system reliability; improve operations and energy efficiency; integrate system into WWTP SCADA. $2,300,000 Emergency Power: Add a 150 kW generator to the UV system for emergency power. Maintain adequate disinfection in the event of a utility service failure; limit chlorine use and associated dechlorination requirements. $230,000 Aerated Sludge Lagoons Lift Station: Construct a simplex lift station in the lagoon outlet manhole (northwest of Lagoon No. raise manhole rim; construct 6-in force main to HRT Inlet Structure; local controls and alarms. Short-term improvement to capture lower-quality effluent from the Aerated Sludge Lagoons and return it to the biological process. $190,000 Anaerobic Digester: Construct solids thickening, anaerobic digester, and solids dewatering processes. Produce dewatered Class B biosolids to allow abandonment of the aerated sludge lagoons $27,300,000 Class A Biosolids Enhancement Solar Dryer: Construct solar dryers. Further condition Class B biosolids to meet Class A criteria $10,400,000 Approximate capital cost in 2014 dollars; includes construction, contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. ---PAGE BREAK--- The improvements noted above were then reviewed to determine which were most critical for retaining adequate treatment capacity, maintaining reliable operation, and satisfying known permit conditions The projects were grouped into four phases that are spread out over the next 10 to 20 years. Table ES-3 lists the four phases and proposed timeframe for implementing each identified improvement, and Figure ES-2 illustrates the phasing on the site. Table ES-3 – Recommended Phasing of Improvements Item Description Approximate Capital Cost Phase 1 (2 Years) Phase 2 (2-5 Years) Phase 3 (5-10 Years) Phase 4 (10+ Years) Preliminary Treatment Headworks bypass and general upgrades to Influent Pump Station $0.4M • Biological Treatment Grit removal $3.6M • Short-term aeration upgrade $0.3M • New concrete aeration basins with fine bubble aeration $18.3M • Final Clarifiers Bypass Final Clarifiers; replace solids pumping; rehabilitation of Final Clarifiers 1 and 2 $0.6M • UV Disinfection Replace UV System $2.3M • 150 kW Generator for emergency power $0.2M • Biosolids Management Dredge solids from Aerated Sludge Lagoons $2.5M • Aerated Sludge Lagoon effluent lift station $0.2M • WAS thickening and anaerobic digestion $18.9M • Mechanical dewatering of digested solids $8.4M • Class A solar dryer $10.4M • TOTAL $63.6M $4.0M $27.3M $21.9M $10.4M Approximate capital cost in 2014 dollars; includes construction , contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. Biosolids dredging has already been budgeted by the City for 2017; therefore, the cost associated with dredging is not included in this phasing plan. ---PAGE BREAK--- Figure ES-1 – Facility Overview ---PAGE BREAK--- Figure ES - 2 – Recommended Phasing Plan ---PAGE BREAK--- Background Information CHAPTER 1 ---PAGE BREAK--- CHAPTER 1 – BACKGROUND INFORMATION The City of Kennewick Wastewater Treatment Plant (WWTP) provides biological treatment for incoming domestic, commercial, and industrial waste. The WWTP is located in the northeast of the City of Kennewick near the bank of the Columbia River. The WWTP operates under NPDES Waste Discharge Permit No. WA-004478-4. This facility is the only WWTP for the City – as such, the Service Area for the facility consists of all lands within the Urban Growth Area (UGA) Boundary. The location of the WWTP and UGA Boundary are shown in Figure 1-1. Figure 1-1 – WWTP Location and Service Area ---PAGE BREAK--- The facility currently includes the following major unit processes: Headworks Influent Parshall Flume Influent Pump Station High Rate Treatment (HRT) Cells Intermediate Clarification Intermediate Clarifier RAS / WAS Pump Station Flash Mix / Flocculation Final Clarification UV Disinfection Effluent Palmer Bowlus Flume Effluent Pump Station Aerated Sludge Lagoons An aerial of the facility identifying the location of the processes listed above, as well as other critical components, is included as Figure 1-2. The site consists of approximately 67.6 acres and is divided by the Burlington Northern Railroad line. Access to the east side of the facility, consisting primarily of biological treatment and biosolids storage lagoons, is through a 10-ft diameter tunnel directly east of the Influent Pump Station. The facility was originally constructed in 1952 and provided primary treatment with anaerobic digestion. A subsequent upgrade in 1972 transitioned the facility to secondary treatment and converted the primary clarifiers to final clarifiers. Improvements through the mid-1990s focused on minor upgrades and improvements to previously constructed components. In 1996, two high rate treatment (HRT) cells were constructed and the aerated lagoons were repurposed for solids storage and treatment. Additional upgrades in 1996 included influent screening, influent pumping, intermediate clarification, construction of flash mix / flocculation basins, expansion of the final clarifiers, and construction of a new administration building. Since 2000, the facility has undergone several improvements including: UV disinfection, replacement of influent screening, addition of second intermediate clarifier, and replacement of the RAS / WAS pumping system. The year of construction for currently active processes is summarized in Figure 1-3. ---PAGE BREAK--- Figure 1-2 – Facility Overview ---PAGE BREAK--- Figure 1-3 – Upgrade History ---PAGE BREAK--- Because of identified operational issues, concerns about process capacities, potential permit changes, and need to regularly update the City’s Facility Plan, the City of Kennewick authorized J-U-B ENGINEERS, Inc. to complete this Facility Plan in accordance with Washington Department of Ecology (WDOE) requirements. J-U-B ENGINEERS, Inc. is also concurrently working on an update to the City of Kennewick General Sewer Plan. The reader is referred to Chapter 2 of the General Sewer Plan for all population, demographics, land use, and planning information that was used in this analysis. Likewise, the General Sewer Plan refers the reader to this Facility Plan document for all information relating to the WWTP. These two planning documents are being submitted simultaneously to WDOE for review and approval. In order to qualify the identified WWTP improvements for WDOE funding, the State Environmental Review Process (SERP) was followed. The environmental review documents have been prepared in conjunction with the study. This Wastewater Treatment Plant Facility Plan document contains the chapters and appendices listed below. Table 1-1 – Document Outline Section Title Contents Chapter 1 Background Information Purpose, Scope, Organization, Planning Information 2 Existing Environment Summary of Environmental Issues and SERP Process 3 Flows and Loads Summary of Existing and Projected Flows and Loads to WWTP 4 Discharge Standards Summary of Current and Future Permit Requirements 5 Existing Facilities Evaluation Evaluation of Existing Facilities at Existing and Future Conditions 6 Alternatives – Liquid Stream Discussion of Various Alternatives for Liquid Stream Processes 7 Alternatives - Biosolids Discussion of Various Alternatives for Biosolids Management 8 Summary of Recommended Improvements and Capital Improvement Plans Cost Estimates and Prioritization Plan Appendix - 1-A Checklist for Facility Plan Contents Documenting compliance with WDOE and WAC 173-240-060 requirements 2-A National Wetlands Inventory Map Wetlands documentation for SERP Cross Cutter requirements 2-B Farmland Classification Exhibit Farmland documentation for SERP Cross Cutter requirements 2-C FEMA Flood Insurance Rate Map Floodplain documentation for SERP Cross Cutter requirements 2-D EZ1 Form – DOE Correspondence Historic Preservation documentation for SERP Cross Cutter requirements 2-E Biological Assessment Endangered Species Act documentation for SERP Cross Cutter requirements 4-A NPDES Permit The City’s most recent discharge permit for the WWTP 4-B NPDES Fact Sheet Most recent fact sheet that accompanied the previous discharge permit for the WWTP 4-C AWC Toxics Technical Report Evaluation of treatment technologies potentially capable of meeting the State of Washington’s revised effluent discharge limits associated with ---PAGE BREAK--- Section Title Contents revised human health water quality criteria. 5-A Process Calculations Preliminary mass balance at average day and maximum month conditions; oxygen demand and supply calculations 5-B WWTP Process Data April 2014 Facility process data and dissolved oxygen charts provided by the City for April 2014 6-A Process Calculations Process calculations related to liquid stream improvements 6-B UV Evaluations Technical memorandum evaluating the City’s existing UV disinfection system and alternatives for upgrading the system; 6-C Liquid Stream Cost Opinions Detailed opinions of probable costs for liquid stream improvements 7-A Biosolids Cost Opinions Detailed opinions of probable costs for biosolid improvements 8-A ESI Energy Efficiency Review Preliminary energy review and assessment of the proposed improvements This document was prepared in accordance with Washington Department of Ecology and Washington Administrative Code (WAC) 173-240-060 requirements. Appendix 1-A includes a summary of required facility plan contents from Orange Book Table G1-1 and the required contents for an engineering report listed in WAC 173-240-060 and further explained in Orange Book Table G1-2. The location of the required information is listed in these tables as an aid to the reader. Acknowledgements Many people were extremely helpful in providing documentation, information, and input throughout the course of this project. We wish, however, to especially thank the City of Kennewick’s Wastewater Utility staff who contributed to this report: Gary Deardorff, Pat Everham, Chris Espinoza, and Wade Bonds were instrumental in collecting data, presenting improvement ideas, evaluating alternatives, expressing system concerns, and giving timely, pointed feedback. This assistance is gratefully acknowledged. ---PAGE BREAK--- Existing Environment CHAPTER 2 ---PAGE BREAK--- CHAPTER 2 – EXISTING ENVIRONMENT For information regarding public health issues within the service area, the reader is directed to Chapter 2 of the 2014 General Sewer Plan Update. This includes information regarding: planning area, land use, water systems, unsewered areas, onsite sewer systems, and service area policies. In summary: The City’s Urban Growth Area (UGA) Boundary is the service area for the sewer system. Land uses for all areas within the UGA boundary have been established by the City Planning Department. The City owns and operates a Class A water system that provides potable water service to all areas within the UGA boundary. Irrigation districts also provide a separate source of non-potable water for irrigation to a majority of the service area. The General Sewer Plan identifies proposed extensions of sewer interceptors to serve all areas within the UGA that are currently unsewered. An estimated 10,500 people currently utilize onsite sewer systems. For planning purposes, it is assumed that approximately half of these will be connected to the public sewer system over the next 20 years. 2.2.1 Topography The topography of the Service Area slopes moderately from high elevations of 1200 feet in the southwest down to the normal pool elevation of the Columbia River, 340 feet, on its banks in Kennewick. Seasonal watercourses are oriented generally northerly as they drain toward the Columbia River. These drainage courses provide the only local instances of steep terrain and foster variation from the dominant shrub-steppe type native vegetation in the form of isolated stands of willow and cottonwood. A large percentage of the Wastewater Treatment Plant (WWTP) Facility is either developed, been graded or cleared, or lacks woody native vegetative assemblages. Undeveloped portions of the WWTP Facility generally contain upland bunch grasses and annual weeds. 2.2.2 Climate The climate of the area is semiarid, characterized by low annual precipitation and large inter-seasonal temperature variations. Strong winds from the west and southwest occur throughout the year and are responsible for localized soil movement and excessive evapotranspiration rates in summer. Annual precipitation seldom exceeds ten inches, with much of the total arriving with summer thunderstorms, which can cause flooding and severe erosion. The recent (2005 - 2013) climatological information for the City is summarized in Table 2-1. ---PAGE BREAK--- Table 2-1 – Climatological Data Year Average Temperature High Temperature Low Temperature Rainfall (in) 2005 55 102 10 7.4 2006 66 109 16 10.1 2007 65 105 10 5.3 2008 64 104 3 5.8 2009 65 105 5 6.2 2010 65 101 5 9.2 2011 64 97 14 5.0 2012 66 105 17 11.3 2013 68 108 13 7.3 2.2.3 Geology The geology of the Service Area relates to the long history of volcanic activity, which has influenced the Columbia Basin. At the surface is a layer of unconsolidated alluvial and glaciofluvial materials ranging in depth from 0 to 120 feet. The depth of this overburden generally does not exceed 30 feet within the Kennewick Sewer Service Area. The overburden rests on a thick series of basaltic strata known as the Columbia River basalts, each of which may consist of many distinct basalt flows. These basalts are interbedded with two major and many minor sedimentary strata. The uppermost basalt unit, the Saddle Mountain basalt, crops out in places where the overburden thins in the upper elevations of the Kennewick planning area. The Saddle Mountain basalt ranges in thickness from 125 to 625 feet, but it is typically about 250 feet thick. It may be interbedded with many sedimentary strata, some of which are up to 50 feet thick. The Saddle Mountain basalt is separated from the Wanapum basalt by the Mabton Interbed. The Mabton Interbed is composed of clay and siltstone and ranges in thickness from 10 to 75 feet, with a typical thickness of 45 feet. The Wanapum basalt ranges in thickness from 600 to 1200 feet, with a typical thickness of 800 feet. Interbedding sedimentary strata are insignificant in the Wanapum basalt. The Vantage sandstone interbed, averaging about 25 feet in thickness, separates the Wanapum basalt from the underlying Grande Ronde basalt. The Grande Ronde basalt has a typical thickness of 5,000 feet, but may range from 2,000 to 12,000 feet thick. The Grande Ronde basalt contains almost no interbedding sedimentary strata. Under the Grande Ronde basalt lies still more basalt groups, the Pre-Yakima and the Pre-Columbia River basalts. Locally significant hydrogeologic units occur in the Saddle Mountain and Wanapum basalts, in the Mabton Interbed, and in the overburden where its depth is sufficient. 2.2.4 Soils The soils in and around Kennewick are classified by the U.S. Department of Agriculture, Soil Conservation Service (SCS). Most of the Kennewick and Finley area soils are classified as being in either the Scooteney-Kennewick or the Finley-Burbank-Quincy associations. ---PAGE BREAK--- The Scooteney-Kennewick association is described as being gently sloping, very deep soils that are silt loam throughout. These soils are formed of old alluvium and lacustrine material and the precipitation zone ranges from 6 to 9 inches. The Finley-Burbank-Quincy association is similar to the Scooteney-Kennewick association with the main difference being a predominant sand content. These soils are generally described as being nearly level soils that are loamy sand to very fine sand and formed of old alluvium and windblown sand. The precipitation zones are also in the 6 to 9 inch range. Also in the Service Area are two groups (a silt loam and fine sandy loam) of soil which are both part of the Pasco Series. The Pasco Series is comprised of deep somewhat poorly drained, predominantly medium-textured soils on bottom lands along the Columbia River. This series of soils were formed from recent alluvium deposits and windblown sand in ponded areas. The soil areas are generally level to sloped (0 to 2 percent). Elevations throughout the areas of occurrence range from 350 to 600 feet. Pasco soils are characterized by stratified layers of very dark grayish-brown or very dark silt loam and/or fine sandy loam to a depth of 60 inches or more. In general, the surface areas are moderately to highly alkaline, and the lower layers mildly alkaline. In the silt loams, the permeability is typically moderate, the soil is somewhat poorly drained, the water holding capacity is high, and there is little to no erosion hazard. The City of Kennewick WWTP is located in the northeast region of the City of Kennewick near the southern bank of the Columbia River. The WWTP currently discharges approximately 5.4 million gallons per day (mgd) of effluent into the Columbia River. The WWTP operates under NPDES Waste Discharge Permit No. WA-004478-4, as detailed in Chapter 4. The WWTP Facility is situated on an approximate 67.6 acre property that is owned by the City of Kennewick. All planned improvements for the WWTP will occur within the 67.6 acre property. All environmental analyses herein are limited to the area of potential effects (APE) or study area boundary as shown in Figure 2-1. ---PAGE BREAK--- Figure 2-1 – WWTP Study Boundary 2.4.1 Flood Plains In order to assess the flooding potential associated with the WWTP Facility, the most recent Federal Emergency Management Agency (FEMA) flood insurance rate map was obtained and reviewed (see Appendix 2-C). Immediately north and adjacent to the WWTP there is a levee that isolates the WWTP from flooding that could otherwise occur when the Columbia River rises. The levee effectively contains the floodplains associated with the River. The Columbia River floodway within this region has been designated as a Zone A floodplain, which does not have a documented base flood elevation or flood hazard factor. All of the proposed project actions exist landward of the levee and are within a designated Zone C area, which is defined as having minimal flooding. According to City of Kennewick ordinance in place for Flood Damage Prevention (i.e. Chapter 18.66), a Flood-Prone Area Development Permit is required before construction or development begins within any area of special flood hazard. The City ordinance goes on to define a “Special Flood Hazard Area” as an area that is subject to a base or one hundred year flood. These areas are shown on FEMA flood insurance rate maps as Zones A, AO, A1-30, AE, A99, AH, VO, VI- 30, VE, or V. ---PAGE BREAK--- Because all of the proposed project actions are located outside of any “Special Flood Hazard Area”, a Flood-Prone Area Development Permit is not required. 2.4.2 Shorelines The Columbia River shoreline is located adjacent to the northern boundary of the WWTP. The River and the WWTP share approximately 2,000 linear feet of frontage. 2.4.3 Wetlands The National Wetlands Inventory (NWI) map identifies one wetland area (classified as PUBHx) within the WWTP boundary (see Appendix 2-A –National Wetland Inventory Map). However, the wetland identified by the NWI map, is in fact the sludge storage lagoon and clarifying pond at the WWTP. No evidence of wetland features (i.e. hydric soils, hydrophytic vegetation or wetland hydrology) exist within this area. Therefore, the original wetland characterization by the NWI is not applicable. 2.4.4 Prime or Unique Farmland The Farmland Classification (FC) map identifies three (HeA, PaA and PcA) areas rated as “farmland of statewide importance” (see Appendix 2-B – Farmland Classification Map). All ground within the project footprint has not been farmed since 1952 when the facility was built. In addition, the FC map classifies both sludge storage lagoons and clarifying pond as farmland of statewide importance. Based on the aforementioned qualities, the original farmland classification is discounted. 2.4.5 Archeological and Historical Sites The shorelines of the Columbia River in the project vicinity have been included in the Tri-Cities Archaeological District and is listed on the National Register. The District runs from approximately mile 330 to 340 and includes the majority of the Columbia River frontage in the City of Kennewick. In past surveys, presence of pre-contact human remains associated with pre-contact archaeological sites have been located in close proximity to the Kennewick WWTP. On August 12th, 2014 a Cultural Resource Report was completed by Transect Archaeology to document any significant archaeological sites and cultural resources associated with the 67.6 acre Area of Potential Affect (APE) associated with the site. During a site visit Transect Archaeology dug 86 shovel test pits within undisturbed areas of the APE, and conducted extensive pedestrian surveys as well as an underwater survey near the shore of the Columbia River. During these site investigations a pre-contact cobble spall flake isolate (isolate # 45BN01814) was found. An EZ1 form defining the APE for the proposed project actions has been submitted and approved by the Washington State Department of Ecology (WDOE) (Log No. 061614-09-ECY, see Appendix 2-D). The Cultural Resource Report completed by Transect Archaeology along with responses to previous comments made by the Nez Perce Tribe and Umatilla Indian Reservation have been submitted to the WDOE for review. The WDOE has distributed the report for a secondary review and comment period (see the WDOE Correspondence dated 9/17/2014, Appendix 2-D). If the WDOE has received no concerns at the end of the comment period, or if all parties contacted have expressed no concerns, a final determination letter of approval will be provided. ---PAGE BREAK--- The City of Kennewick has negotiated a memorandum of understanding with the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). All City construction projects that are undertaken on or near sites of potential archeological significance would contain a negotiated, mutually agreeable mitigation plan. These negotiations are on a case by case basis, in the event of discovery of significant archaeological artifact(s) during the course of construction. Based on findings from the Cultural Resource Report completed by Transect Archaeology, and consistent with the aforementioned MOU, archaeological monitoring of all ground disturbing activities outside of the existing previously disturbed WWTP fenced perimeter is recommended. 2.4.6 Wild and Scenic Rivers Act The Columbia River is not listed on the National Wild and Scenic Rivers System. In addition, the portion of the Columbia River in which the WWTP outfall is situated is slack water upstream of McNary Dam. 2.5.1 ESA Listed Species for the APE A biological assessment (BA) was developed as part of this WWTP Facilities Plan. The BA summarizes the potential impacts to species listed as endangered, threatened, proposed or candidate and, designated or proposed critical habitat under the Endangered Species Act (ESA). The BA presents the ESA status of relevant species, species specific habitat descriptions and a determination of effect for each. Essential Fish Habitats (EFH) as indicated in the Magnuson Stevens Fishery Conservation and Management Act (Magnuson Stevens Act) are also addressed in the BA. The BA concludes that the proposed (4-phased) project actions should not affect any listed ESA species, associated critical habitat, or EFH. Please see Appendix 2-E – Biological Assessment for the full report. The Biological Assessment is pending EPA approval. In order to qualify the identified WWTP improvements for WDOE funding, the State Environmental Review Process (SERP) was followed. This effort is limited to the APE as depicted in Figure 2-1. This included preparation of a SEPA Checklist, public notice, SERP Checklist, Federal Cross-Cutter Checklist, SERP Cover Sheet, Biological Assessment, and Cultural Resources Survey. The individual federal cross-cutter reports are included in the appendix. ---PAGE BREAK--- Flows and Loads CHAPTER 3 ---PAGE BREAK--- CHAPTER 3 – FLOWS AND LOADS The Kennewick WWTP receives wastewater from the following primary sources: residential, commercial entities, industrial entities, water treatment plant backwash, and infiltration. Influent flows for the Kennewick WWTP are recorded daily of the influent screening building using a 36-inch Parshall flume. Samples are also collected two to three times per week using a 24-hour composite sampler located immediately of the of Influent Screening and analyzed for BOD5 and TSS loading to the facility. data summaries were provided for the period January 2009 through December 2013 and were analyzed to characterize existing flows and loads to the facility on a calendar year basis. 3.2.1 Flows Initial discussions with the operations staff indicated a concern with the influent Parshall flume’s accuracy because it consistently read significantly lower than the effluent flume. These concerns led to recording the effluent flume daily value as the plant flow in lieu of the influent meter value until April 2008. Since May 1, 2008, separate influent and effluent values have been recorded and can be used to identify the potential degree of error in the influent flume and peak events that may otherwise be attenuated through the treatment facility. The accuracy of the influent flume was further questioned following the screening upgrade undertaken between 2009 and 2011. Prior to the upgrade, the influent was routed directly through the screens and the flume in a relatively linear orientation. With the new screening building, the flow is diverted perpendicularly to its original path into the new screening building and then through two 80°± bends in manholes. The final bend is approximately 30 ft upstream of the influent flume, which should provide sufficient distance to form uniform flow through the flume. However, waves in the flume are noticeable. Because of these concerns, the City installed a portable flow meter in November 2013 upstream of the influent flume to check the potential error of the influent flume. Observed flows in the portable meter from mid-November through mid- December ranged from -5 percent to +17 percent compared to the influent flume, with an average of +10 percent. The influent flow data were therefore adjusted by a factor of 1.10 and analyzed for the following conditions: Average Day Flow (ADF): The annual average flow rate at the facility over a 24-hour period. The ADF rate is used to estimate annual average pumping and chemical costs, solids production, and average organic loading rates. Maximum Month Flow (MMF): The flow corresponding to a peak month or continuous 30-day period in the year. This flow is typically used to design unit processes for permit compliance. Peak Day Flow (PDF): The flow corresponding to the peak day in the year. The PDF is primarily used to adequately size unit processes for peak hydraulic conditions. ---PAGE BREAK--- Peak Hourly Flow (PHF): The peak 1-hour flow rate occurring over the course of a day. PHF is utilized for the peak hydraulic design of pump stations, flow meters, influent screens, grit chambers, weirs, disinfection systems, and pipes and channels in the treatment plant. The historical flows and associated peaking factors for the adjusted influent are given in Table 3-1 and presented graphically in Figure 3-1. Also included is the “probable existing” condition, i.e. the value defined as typical for existing condition evaluations. Further observations on the data include the following: The influent exhibits a noticeable seasonal variation, with peak flows generally occurring in the summer months. As noted in Section 3.5 of the City’s 2014 General Sewer Plan these higher flows are the result infiltration generated by irrigation and other shallow water tables in portions of the City, and is considered non-excessive. There is an apparent decline in flows for the period analyzed. Potential reasons for this reduction include the following: a line leak at the golf course that was contributing water to the sewer system, ongoing water conservation measures, I/I removal projects, instrument errors in the influent Parshall flume. The observed peaking factors for maximum month and peak day are generally on the lower end of observed values for similar facilities. This is likely due to limited infiltration and proactive control of infiltration and inflow Peak hour flows were estimated based on data collected by the portable flow meter installed in November / December 2013, which recorded the influent flow rate every minute. The average flow during the period was 4.33 mgd and the peak hour flow was approximately 7.66 mgd, which corresponds to a peaking factor of 1.77. Since the data set is relatively limited, a peaking factor of 2.0 was used in this study. Table 3-1 – Influent WWTP Flow Summary by Year Item 2009 2010 2011 2012 2013 Probable Existing Average Day Flow (mgd) 5.88 5.32 5.27 5.38 4.80 5.35 Maximum Month Flow (mgd) 6.33 5.84 5.97 6.34 5.47 6.34 Peaking Factor 1.08 1.10 1.13 1.18 1.14 1.19 Peak Day Flow (mgd) 7.77 8.14 7.77 8.37 6.48 8.37 Peaking Factor 1.32 1.53 1.47 1.55 1.35 1.56 Peak Hour Flow (mgd) - - - - - 10.70 Peaking Factor - - - - - 2.00 The peaking factor for maximum month is based on the maximum observed value (6.34 mgd) divided by the average for the data set (5.35 mgd). The peaking factor for peak day is based on the maximum observed value (8.37 mgd) divided by the average for the data set (5.35 mgd). ---PAGE BREAK--- Figure 3-1 – WWTP Influent Flow A summary of wastewater sources and the estimated daily flows is included in Table 3-2. The flows are estimated based on a review of available water meter records during the winter months, industrial flow data, City-provided data for the water treatment plant backwash, and infiltration estimates from the 2006 Sewer Plan. 5.35 6.34 8.37 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Influent Flow (mgd) Date Influent Flow (Factored) Average Flow Max Month Peak Day 30-day Moving Average ---PAGE BREAK--- Table 3-2 – Wastewater Sources and Estimated Flow Contribution Category Average Flow (mgd) Percent of Total Residential 3.60 67% Commercial 0.78 15% Industrial 0.15 3% Other 0.12 2% Water Treatment Plant Backwash 0.40 7% Infiltration 0.30 6% TOTAL 5.35 “Other” refers to City-owned parks, green spaces, and related facilities. Infiltration varies from a peak of approximately 0.60 mgd during the summer months to nearly zero during the winter months. An average value of 0.30 mgd is included. 3.2.2 Biochemical Oxygen Demand (BOD) Because the influent flume has an apparent error, the influent BOD5 (five-day BOD) load was calculated based on the reported concentration and the adjusted influent flow. The loading characteristics of interest in further evaluations are as follows: Average Day Concentration and Loading: The average day concentration and load observed at the facility. The average day value is used to estimate annual organic loading rates. Maximum Month Loading: The expected loading for the peak month in the year. This factor is typically used to design unit processes for permit compliance. Peak Day Loading: The expected loading for the peak day in the year. The factor is used to size processes for peak events. The average day concentration and average day, maximum month, and peak day loading for each year is shown in Table 3-3; the data is also shown graphically in Figure 3-2. Also included is the “probable existing” condition, i.e. the value defined as typical for existing condition evaluations. General observations of the data are as follows: The data indicates a relatively consistent loading pattern throughout the year with observed maximum month peaking factors of 1.08 to 1.27. Observed peak day peaking factors have ranged from 1.43 to 2.01. This range of peaking factors is lower than typical values when compared against similar facilities (Metcalf and Eddy), but is considered reasonable for future projections. There is a slight downward trend for influent load, but this is primarily due to an apparent reduction in influent flows in 2013. The influent concentration has been consistent year-over-year, while showing a noticeable seasonal fluctuation due to increased infiltration in the summer. During the summer, the concentration generally drops to 200 to 250 mg/L. As flows in the fall and winter recede, the concentration trends towards 280 to 300 mg/L. The yearly average concentration is 253 mg/L, which is greater than typical medium-strength wastewater (Metcalf and Eddy). ---PAGE BREAK--- Table 3-3 – Influent BOD5 Summary by Year Item 2009 2010 2011 2012 2013 Probable Existing Average Day Concentration (mg/L) 251 265 266 237 253 255 Average Day Loading (ppd) 12,541 11,933 11,892 10,721 10,299 11,500 Maximum Month Loading (ppd) 15,895 14,249 12,883 12,532 11,891 15,900 Peaking Factor 1.27 1.19 1.08 1.17 1.15 1.38 Peak Day Loading (ppd) 18,627 17,062 17,020 15,431 18,284 18,630 Peaking Factor 1.49 1.43 1.43 1.44 1.78 1.62 The peaking factor for maximum month is based on the maximum observed value (15,900 ppd) divided by the average for the data set (11,500 ppd). The peaking factor for peak day is based on the maximum observed value (18,630 ppd) divided by the average for the data set (11,500 ppd). Figure 3-2 – Influent BOD5 Loading 11,500 15,900 18,630 0 5,000 10,000 15,000 20,000 25,000 30,000 0 50 100 150 200 250 300 350 400 450 500 Influent BOD5 (ppd) Influent BOD5 (mg/L) Date Influent BOD (mg/L) Influent BOD (ppd) Average BOD (ppd) Max Month BOD (ppd) Peak Day BOD (ppd) 30-day Moving Average BOD (mg/L) 30-day Moving Average BOD (ppd) ---PAGE BREAK--- BOD5 contributions from primary wastewater sources are estimated as shown in the list below. The values are based on typical literature values, general observations from other communities, and assumptions included in the 2006 Sewer Plan. Further, the values were adjusted to correspond approximately to the observed average day loading to the facility. Sampling of commercial and industrial sources is recommended to refine these values and the overall impact to the facility’s loading. Residential: 0.16 ppcd Commercial: 450 mg/L Industrial: 450 mg/L Other: assumed at 250 mg/L Water Treatment Plant Backwash: 22 mg/L Infiltration: no loading 3.2.3 Total Suspended Solids (TSS) Similar to the influent BOD5, influent TSS loading was calculated based on the reported concentration and the adjusted influent flow. Average day concentration and average day, maximum month, and peak day loading for each year is shown in Table 3-4. The data is also shown graphically in Figure 3-3. Also included is the “probable existing” condition, i.e. the value defined as typical for existing condition evaluations. General observations of the data are as follows: The data indicates a relatively consistent loading pattern throughout the year with observed maximum month peaking factors of 1.07 to 1.21. Observed peak day peaking factors have ranged from 1.35 to 1.80. This range of peaking factors is on the lower range of typical values when compared against similar facilities (Metcalf and Eddy), but is considered reasonable for future projections. The influent concentration has been consistent year-over-year with moderate seasonal fluctuations. The yearly average concentration is 290 mg/L, which is greater than typical medium-strength wastewater (Metcalf and Eddy). Table 3-4 – Influent TSS Summary by Year Item 2009 2010 2011 2012 2013 Probable Existing Average Day Concentration (mg/L) 281 295 298 271 293 290 Average Day Loading (ppd) 14,091 13,380 13,333 12,329 11,975 13,020 Maximum Month Loading (ppd) 15,993 14,984 14,299 13,691 14,542 16,000 Peaking Factor 1.13 1.12 1.07 1.11 1.21 1.23 Peak Day Loading (ppd) 22,133 22,005 19,117 16,622 16,727 22,140 Peaking Factor 1.57 1.64 1.43 1.35 1.40 1.70 The peaking factor for maximum month is based on the maximum observed value (16,000 ppd) divided by the average for the data set (13,020 ppd). The peaking factor for peak day is based on the maximum observed value (22,140 ppd) divided by the average for the data set (13,020 ppd). ---PAGE BREAK--- Figure 3-3 – Influent TSS Loading TSS contributions from primary wastewater sources are estimated as shown in the list below. The values are based on typical literature values, general observations from other communities, and assumptions included in the 2006 Sewer Plan. Further, the values were adjusted to correspond approximately to the observed average day loading to the facility. Sampling of commercial and industrial sources is recommended to refine these values and the overall impact to the facility’s loading. Residential: 0.20 ppcd Commercial: 200 mg/L Industrial: 200 mg/L Other: assumed at 200 mg/L Water Treatment Plant Backwash: 270 mg/L Infiltration: no loading 3.2.4 Total Kjeldahl Nitrogen (TKN) Sampling for influent TKN occurs on a quarterly basis in accordance with the City’s NPDES permit. One sample in 2010 and another in 2011 yielded concentrations less than 20 mg/L and appear to be outliers due to the relatively low ---PAGE BREAK--- values. Influent data excluding those samples is summarized in Table 3-5. Also included is the “probable existing” condition, i.e. the value defined as typical for existing condition evaluations. The observed average influent concentration is higher than a typical medium-strength wastewater (Metcalf and Eddy) but is consistent with the elevated influent BOD5 and TSS concentrations noted above. Typical literature values for maximum month and peak day conditions have been assumed since quarterly sampling does not provide statistically relevant peaking factors. Table 3-5 – Influent TKN Summary by Year Item 2009 2010 2011 2012 2013 Probable Existing Average Day Concentration (mg/L) 38 38 57 49 38 44 Average Day Loading (ppd) 1,859 1,530 2,536 2,216 1,534 1,940 Maximum Month Loading (ppd) - - - - - 2,520 Peaking Factor - - - - - 1.30 Peak Day Loading (ppd) - - - - - 4,260 Peaking Factor - - - - - 2.20 Typical literature values have been assumed since the available quarterly sampling will not provide statistically relevant peaking factors. TKN is assumed to represent all nitrogen in the wastewater stream with nitrate and nitrite concentrations being negligible. TKN contributions from primary wastewater sources are estimated as shown in the list below. The values are based on typical literature values (Metcalf and Eddy), general observations from other communities, and assumptions included in the 2006 Sewer Plan. Further, the values were adjusted to correspond approximately to the observed average day loading to the facility. Sampling of commercial and industrial sources is recommended to refine these values and the overall impact to the facility’s loading. Residential: 0.030 ppcd Commercial: 40 mg/L Industrial: 40 mg/L Other: assumed at 40 mg/L Water Treatment Plant Backwash: 1.6 mg/L Infiltration: no loading 3.2.5 Total Phosphorus (TP) Influent phosphorus is not regularly collected and analyzed at the facility. Typical literature values for influent total phosphorus are 6 to 11 mg/L for medium- to high-strength wastewater (Metcalf and Eddy). Since the observed influent BOD5, TSS, and TKN levels are generally higher than medium-strength wastewater, an influent value of 8 mg/L is assumed at the probable existing flow noted previously. Literature values for maximum month and peak day peaking factors are 1.3 and 1.8, respectively, and will be assumed in further analyses. ---PAGE BREAK--- 3.2.5 Summary of Current Flows and Loads The flow and load data presented above are summarized in Table 3-6. Table 3-6 – Existing Flows and Loads Summary Item Value Flow (mgd) Average Day 5.35 Maximum Month 6.34 Peaking Factor 1.19 Peak Day 8.37 Peaking Factor 1.56 Peak Hour 10.70 Peaking Factor 2.00 BOD5 (ppd) Average Day 11,500 Maximum Month 15,900 Peaking Factor 1.38 Peak Day 18,630 Peaking Factor 1.62 TSS (ppd) Average Day 13,020 Maximum Month 16,000 Peaking Factor 1.23 Peak Day 22,140 Peaking Factor 1.70 TKN (ppd) Average Day 1,940 Maximum Month 2,520 Peaking Factor 1.30 Peak Day 4,260 Peaking Factor 2.20 TP (ppd) Average Day 360 Maximum Month 460 Peaking Factor 1.30 Peak Day 640 Peaking Factor 1.80 The peaking factor is assumed to match typical literature values. No influent data is available for phosphorus; therefore, a value of 8 mg/L has been assumed at the probable existing average day flow. ---PAGE BREAK--- Growth projections for residential, commercial, industrial, and the water treatment plant backwash flows were discussed with the City to determine potential changes in flows and loads over the 20-year study period. The following growth assumptions were ultimately selected: Residential: o 1.41 percent per year, consistent with the 2011 City of Kennewick Comprehensive Plan and Benton County Comprehensive Plan. The growth is assumed to apply to the total population in the service area – 76,410 people in 2013 (State of Washington Office of Financial Management [OFM], 2014) – with all growth served by sewer. The total projected 2034 population is 102,529 people, representing an increase of 26,119 people. o For the residential population currently on septic systems – approximately 10,500 people (City of Kennewick, 2011) – it is assumed that 25 percent (2,625 people) will be sewered within the 20-year planning period. o The total sewered population in 2034 is estimated at 94,654 based on the following: 65,910 people currently on city sewer; growth of 26,119 people; and septic conversions representing another 2,625 people. Commercial: 3 percent per year Industrial: 1 percent per year Water treatment plant backwash: 1 percent per year I/I: no change from current levels The corresponding projected flows are summarized in Table 3-7. Loading to the facility is based on the projected average day flow, assumed loading by category discussed in previous sections, and observed peaking factors for flows and loads presented above. The resulting projected conditions for 2034 are summarized in Table 3-8 and will be used in subsequent evaluations of the facility over the study period. The City is also master planning its sewer collection system to provide sewer service to all residents currently on septic systems and to the City’s defined Urban Growth Area (UGA) – reference the 2014 General Sewer Plan. As part of the General Sewer Plan, the flow that will be generated upon complete buildout of the existing UGA boundary as well as the proposed UGA boundary expansion has been calculated. Based on this expanded service, average day flows are projected to be 10.5 mgd (General Sewer Plan Section 6.4.4). Applying a maximum month peaking factor of 1.19 to this value yields a projected maximum month flow of 12.5 mgd. In lieu of the flow calculated based upon OFM population projections for the 20-year study period (9.40 mgd), this UGA buildout flow (12.5 mgd) should be considered for long-term planning of the facility, including process selection, site layout and reserved space for expansion, and permitting. ---PAGE BREAK--- Table 3-7 – Projected Average Day Flows for 2034 Category Current Average Day Flow (mgd) Additional Flow (mgd) Total (mgd) Residential Sewered 3.60 1.59 5.19 Septic Systems to be Connected to Sewer - 0.16 0.16 Commercial 0.78 0.67 1.45 Industrial 0.15 0.04 0.19 Other 0.12 0.03 0.15 Water Treatment Plant Backwash 0.40 0.09 0.49 Infiltration 0.30 - 0.30 TOTAL 5.35 2.58 7.94 Projected population growth of 26,119 people at an average day flow of 61 gpcd.(the per capita water use developed in the City’s 2014 General Sewer Plan) Conversion of approximately 2,625 people from septic to sewer at an average day flow of 61 gpcd. (the per capita water use developed in the City’s 2014 General Sewer Plan) Infiltration varies from a peak of approximately 0.60 mgd during the summer months to nearly zero during the winter months. An average value of 0.30 mgd is included. ---PAGE BREAK--- Table 3-8 – Projected Flow and Load Summary for Year 2034 Item Value Flow (mgd) Average Day 7.94 Maximum Month 9.40 Peaking Factor 1.19 Peak Day 12.40 Peaking Factor 1.56 Peak Hour 15.90 Peaking Factor 2.00 BOD5 (ppd) Average Day 22,000 Maximum Month 30,400 Peaking Factor 1.38 Peak Day 35,700 Peaking Factor 1.62 TSS (ppd) Average Day 23,000 Maximum Month 28,300 Peaking Factor 1.23 Peak Day 39,100 Peaking Factor 1.70 TKN (ppd) Average Day 3,400 Maximum Month 4,400 Peaking Factor 1.30 Peak Day 7,500 Peaking Factor 2.20 TP (ppd) Average Day 520 Maximum Month 680 Peaking Factor 1.30 Peak Day 940 Peaking Factor 1.80 ---PAGE BREAK--- Influent temperature is necessary for some unit process design. Since influent data is not regularly collected and available, historical effluent wastewater temperature from 2009 through 2013 will be utilized. Effluent temperature is summarized in Table 3-9. The yearly average effluent temperature is 16.7° C (62.1° with a minimum 7-day temperature of 8.7° C (47.7° a minimum month temperature of 10.5° C (50.9° and a maximum month temperature of 23.8° C (78.8° Table 3-9 – Historical Effluent Temperatures Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Max Day 16.0 17.0 15.0 18.0 21.0 24.8 26.0 25.0 24.0 21.0 19.0 16.0 Average 11.7 12.0 13.2 14.9 17.4 19.6 22.1 22.5 21.1 18.1 15.4 12.1 . ---PAGE BREAK--- Discharge Standards CHAPTER 4 ---PAGE BREAK--- CHAPTER 4 – DISCHARGE STANDARDS The principal authority for the water pollution control programs is the Clean Water Act (33 U.S.C. 1251 et seq.). The aim of the act is to "restore and maintain the chemical, physical, and biological integrity of the nation’s waters." This act set forth the following national goals: • Eliminate the discharge of pollutants into navigable waters by 1985. • Set interim goals of water quality which will protect fish and wildlife and will provide for recreation by July 1, 1983. • Prohibit the discharge of pollutants in quantities that might adversely affect the environment. • Construct publicly owned waste treatment facilities with federal financial assistance. • Establish waste treatment management plans within each state. • Establish the technology necessary to eliminate the discharge of pollutants. • Develop and implement programs for the control of non-point sources of pollution to enable the goals of the act to be met. These goals were to be achieved by a legislative program which includes permits under the National Pollutant Discharge Elimination System (NPDES). Key provisions of the act include the development of such permit systems and effluent standards as well as state and local responsibilities. The Clean Water Act emphasizes that state governments are to use the minimum federal standards, guidelines, and goals, and establish individual pollution control programs and enforcement procedures. When the state has completed its programs for waste treatment management, its implementation plans for preserving or restoring water quality, and the Environmental Protection Agency (EPA) has approved those programs, the state assumes enforcement responsibilities. The Washington Department of Ecology (WDOE) has been delegated with these responsibilities by EPA. The State of Washington' s surface water quality standards are given in the Washington Administrative Code (WAC) Chapter 173-201A, the Water Quality Standards for Surface Waters of the State of Washington, and WAC Chapter 173-204, Sediment Management Standards. WAC 173-201A strives to establish surface water quality criteria which are consistent with public health and public enjoyment, and the propagation and protection of fish, shellfish, and wildlife, pursuant to the provisions of chapter 90.48 of the Revised Code of Washington (RCW). The surface water quality standards establish specific water quality criteria based on the Aquatic Life and Recreational Use designations. Use designations for the Columbia River (river mile 309.3 to 596.6), the reach in which Kennewick’s outfall is located, are defined in WAC 173-201A Table 602 as follows: • Aquatic Life Uses: Non-Core Salmon/Trout • Recreational Uses: Primary Contact • Water Supply Uses: Domestic Water, Industrial Water, Agricultural Water, and Stock Water • Miscellaneous Uses: Wildlife Habitat, Harvesting, Commerce/Navigation, Boating, and Aesthetics ---PAGE BREAK--- In accordance with the direction of EPA, WDOE has pursued compliance with surface quality standards based on a watershed management approach. The emphasis of watershed management is to monitor, analyze, and protect water quality on a geographic basis. The watershed management strategy was implemented as a means to: • Identify and address high priority water quality issues. • Tie NPDES permit conditions more closely to localized water quality conditions. • Improve coordination among state, tribal and local environmental programs. • Target activities to attain state water quality standards. In 1970, under WAC 173-500-040 and the Water Resources Act of 1971 (RCW 90.54), WDOE partitioned the state into 62 Water Resource Inventory Areas (WRIAs). These WRIAs are the administrative underpinning of WDOE’s business activities and provide the framework for the watershed approach which is embodied in the Section 303(d) process. The Columbia River at Kennewick is located between WRIA 31 (Rock/Glade) and WRIA 36 (Esquatzel Coulee). However, due to its size, the Columbia River Basin is managed as its own watershed area. In addition, in July 1993, WDOE designated 23 Water Quality Management Areas (WQMAs). The City of Kennewick is located within WQMA 31 (Horseheaven/Klickitat). These WQMAs are water quality management basins for which coordinated and integrated science, permitting and water pollution control, and prevention measures are implemented to meet State water quality standards. The WDOE program undertakes the following five activities in each WQMA over a five year, rotating cycle period: Year 1 Scope water quality. Year 2 Conduct water quality monitoring and special studies. Year 3 Analyze water quality and the effects of pollution. Year 4 Develop technical reports that record water quality, areas of concern, and strategies to respond to these concerns. Year 5 Issue wastewater discharge permits and implement other pollution prevention and pollution control actions that respond to priority water quality issues. 4.2.1 303(d) List The Federal Clean Water Act (Section 303(d)) and federal regulation 40 CFR Part 130.7 require states to develop a 303(d) list. The primary purpose of the 303(d) listing is to describe the health of rivers, coastal waters, estuaries and lakes. In Washington, WDOE submits this listing of “troubled waters" to EPA for approval and uses it to monitor water quality trends and establish priorities for protection. Water bodies must meet two criteria to be placed on the 303(d) list: • Current water quality does not meet the state water quality requirements. • Technology-based controls are not sufficient to achieve water quality requirements. Monitoring data to determine which water bodies should be identified on the 303(d) list are gathered from several sources, including WDOE's own monitoring, and project-specific monitoring conducted by resource agencies, tribes, and other sources. Monitoring information submitted to the WDOE is evaluated to ensure that the data was collected and analyzed using quality assurance/quality control methods and that data was tested by a state accredited laboratory. ---PAGE BREAK--- Water body protection involves the setting of Total Maximum Daily Load (TMDL) limits. The TMDL assignment process, as described in the Federal Clean Water Act, is used to establish allowable pollutant concentrations to be apportioned to both point and non-point sources of pollutants that may discharge to a water body while still supporting beneficial use and meeting water quality standards. are often referred to as Water Cleanup Plans. WDOE’s current listing process is much more comprehensive than the early 303(d) lists that were developed in 1996 and 1998. The current process assigns Water Quality Assessment Categories to water bodies ranging from Category 1 (clean waters) to Category 5 (polluted waters that require a TMDL). Since the categories are pollutant-specific, a single water body may be listed in multiple categories. Most of the Columbia River Mainstem fails to meet state and/or tribal Water Quality Standards for critical periods of time, mainly in the spring and summer months, for both water temperature and total dissolved gas. Therefore, this water body has been “303(d) listed" for these two pollutants. The status of the for these pollutants and the potential for future for other pollutants are discussed below. 4.2.2 Temperature TMDL Development of the temperature TMDL for the Columbia River from the Canadian border to its mouth at the Pacific Ocean was initiated by EPA in 2002 and was expected to be finalized by May 2003. However, due to public concerns regarding the EPA’s conclusions regarding the impacts of hydroelectric dams and other technical issues, the TMDL has been delayed indefinitely. According to conversations with WDOE staff, no schedule for completing the TMDL has been established. However, if this TMDL is finalized, it may have a significant impact on the City’s discharge, especially during the warmer months. 4.2.3 Dissolved Gas TMDL EPA approved WDOE’s submittal of the TDG TMDL for the Mid-Columbia River and Lake Roosevelt on July 27, 2004. The area covered by this TMDL includes the Columbia River Mainstem from the Canadian border to the Oregon/Washington border. Since the primary source of TDG pollution is hydroelectric dams, this TMDL is expected to have minimal impact on municipal wastewater discharges such as the City of Kennewick’s. 4.2.4 Future The WDOE Surface Water Quality Standards website includes Current Rule Activities with the recent update on ‘Human Health Criteria and Implementation Tools Rulemaking.’ This rulemaking is focusing on water quality standards for toxics. Ecology has committed to have a draft rule this fall and a final Rule adopted after the 2015 legislative session. This Rule could substantially reduce allowable concentrations of toxins in the effluent primarily due to an increase in fish consumption rates. Most toxins accumulate in the fatty portions of edible fish. For example, the current Washington WQS for Biphenyls (PCBs) is 170 pg/l. This concentration is difficult to consistently meet at a conventional wastewater treatment plant with advanced secondary treatment. There is not currently any data on Kennewick’s influent concentrations, but typical influent concentrations range from 1,000 – 10,000 pg/l. There is also limited to no data on the concentration of toxics in the Columbia River. If the new rule requires extensive treatment to remove toxics, it could trigger advanced oxidation processes after secondary treatment with filtration – which could double or triple the cost of treatment. ---PAGE BREAK--- A study titled ‘Treatment Technology Review and Assessment’ was prepared for the Association of Washington Cities by HDR Engineers on December 4, 2013. This study addresses the type of treatment facilities and costs associated with meeting the projected new rules for toxics. A copy of the key findings is presented in Appendix 4-C. If the new rules are adopted, must be prepared to allocate loading. WDOE does not appear to have immediate plans to develop these but this process could be completed in the next five years. After the TMDL is established, it typically takes two permit cycles to gather effluent data, update facilities plans, obtain necessary financing authority, design, and construct new treatment facilities to meet the TMDL allocated effluent limits for the wastewater treatment plants. Although the entire process could take 3 or more permit cycles before it is realized as an effluent limit, it would have dramatic effects on the City’s WWTP and would require a significant increase in the cost of treatment. This proposed toxics rulemaking is one the City should follow closely. Once the new rules are finalized, there are compliance strategies that the City should consider. For example, the Spokane River dischargers are developing source control programs in addition to membrane treatment at the end of the pipe. WDOE has been encouraging this form of pollution reduction which may help with permit compliance only if the dischargers that provide the source control get credit for the cleanup. The City of Kennewick WWTP operates under NPDES Waste Discharge Permit No. WA-004478-4. The permit was effective on December 1, 2008 and expired on November 30, 2013. The City has applied for renewal of the permit and has been following the terms and conditions of the existing permit in the interim. The City has an excellent track record of meeting permit requirements – with no violations in recent history. In fact, in 2013 the City received its 7th consecutive “Outstanding Performance Award” from WDOE. The permit requires the City to submit a plan and a schedule for continuing to maintain capacity whenever actual flow or load reaches 85% of any one of the design criteria for three consecutive months. The flows and loads for the permitted facility are based upon the following design criteria as listed in the permit: Table 4-1 – Design Criteria – 2008 NPDES Permit Parameter Design Criteria 85% of Design Average flow for maximum month 10.2 mgd 8.7 mgd BOD5 loading for maximum month 26,700 lbs/day 22,695 lbs/day TSS loading for average month 24,390 lbs/day 20,732 lbs/day The only effluent limitations in the permit relate to BOD5, TSS, fecal coliform, and pH. The existing effluent limits are presented in Table 4-2. ---PAGE BREAK--- Table 4-2 – Effluent Limits – 2008 NPDES Permit Parameter Average Maximum Average Weekly BOD5 30 mg/L, 2,552 lbs/day, 85% removal of influent BOD5 45 mg/L, 3,828 lbs/day TSS 30 mg/L, 2,552 lbs/day, 85% removal of influent BOD5 45 mg/L, 3,828 lbs/day Fecal Coliform Bacteria 200/100 mL 400/100 mL Parameter Daily pH 6.0 ≤ pH ≤ 9.0 Based upon inquires made to the WDOE Staff, the new discharge permit is expected to be issued in 2015 and remain largely unchanged. It should be noted that statewide trending for discharge permits includes various levels of water quality and source control testing beyond what existing permit holders have experienced in the past. For example, Walla Walla and College Place are now required to conduct PCB testing and develop toxic management control plans. The City should review the existing pretreatment program and source control programs with an eye towards reducing the compliance effort to meet future discharge limits for toxics. While the permit conditions that will result from current rule-making efforts are far from clear, the evidence points toward more stringent standards. Involvement with the rule- making is critical to provide as much compliance flexibility as possible plus reasonable compliance schedules for any required upgrades. As discussed in Chapter 3, the flow that will be generated upon complete buildout of the existing UGA boundary as well as the proposed UGA boundary expansion has been calculated. Based on this expanded service, average day flows are projected to be 10.5 mgd (General Sewer Plan Section 6.4.4). Applying a maximum month peaking factor of 1.19 to this value yields a projected maximum month flow of 12.5 mgd. In lieu of the flow calculated based upon OFM population projections for the 20-year study period (9.40 mgd), this UGA buildout flow (12.5 mgd) should be considered for permitting. . ---PAGE BREAK--- Existing Wastewater Treatment Facilities Evaluation CHAPTER 5 ---PAGE BREAK--- CHAPTER 5 – EXISTING WASTEWATER TREATMENT FACILITIES EVALUATION The City of Kennewick Wastewater Treatment Plant (WWTP) provides biological treatment for incoming domestic, commercial, and industrial waste. The facility currently includes the following major unit processes: Headworks Influent Parshall Flume Influent Pump Station High Rate Treatment (HRT) Cells Intermediate Clarification Intermediate Clarifier RAS / WAS Pump Station Flash Mix / Flocculation Final Clarification UV Disinfection Effluent Palmer Bowlus Flume Effluent Pump Station Aerated Sludge Lagoons An aerial of the facility identifying the location of the processes listed above, as well as other critical components, is included as Figure 5-1. The site consists of approximately 67.6 acres and is divided east/west by the Burlington Northern Railroad line. The Administration Building, Headworks, Influent Parshall Flume, Influent Pump station, Flash Mix and Flocculation, Final Clarifiers, and UV Disinfection are located on the west side of the facility. Biological treatment, intermediate clarification, and biosolids storage lagoons are located on the east side. Access between the sides is through a 10-ft diameter tunnel under the railroad northeast of the Influent Pump Station. The facility was originally constructed in 1952 and provided primary treatment with anaerobic digestion. A subsequent upgrade in 1972 transitioned the facility to secondary treatment using aerated lagoons and converted the primary clarifiers to final clarifiers. Improvements through the mid-1990s focused on minor upgrades and improvements to previously constructed components. In 1996, two high rate treatment (HRT) cells were constructed and the aerated lagoons were repurposed for solids storage and treatment. Additional upgrades in 1996 included influent screening, influent pumping, intermediate clarification, construction of a flash mix / flocculation basin, expansion of the final clarifiers, and construction of a new administration building. Since 2000, the facility has undergone several improvements to provide UV disinfection, replace influent screening, add a second intermediate clarifier, and replace the RAS / WAS pumping system. The year of construction for currently active processes is summarized in Figure 5-2. A general description of each process, observed deficiencies based on discussions with operations staff, and approximate capacity of unit processes are presented in the following sections. ---PAGE BREAK--- Figure 5-1 – Facility Overview ---PAGE BREAK--- Figure 5-2 – Upgrade History ---PAGE BREAK--- 5.2.1 Headworks (Influent Screening) Component Description and Operations The facility receives wastewater from an interceptor on Bruneau Avenue and another interceptor on Columbia Drive. The interceptors join on Kingwood Street and convey wastewater to the facility through a 36-in concrete sewer pipe west of the Headworks building. A bypass of the Headworks is available from the manhole located at the intersection of Bruneau Avenue and Kingwood Street; however, the facility’s Bypass Structure is approximately 200 feet from the manhole and located northeast of the Administration Building. This reach from the manhole to the Bypass Structure is currently boarded with plywood and sandbags, but solids have likely accumulated in the line and its capacity may be compromised. Additionally, the gate is old and would likely be submerged in the event the Headworks blinded, making emergency operation difficult. Bypassed influent is routed directly to the Influent Pump Station via a 30-in sewer. The Headworks was constructed in 2009 and has two mechanical screens, each with a design capacity of 20.3 mgd. Each screen is served by a dedicated washer / compactor to dewater screenings prior to disposal. Compacted solids are stored in a 6 cy dumpster, and operations staff note that four to five loads accumulate through the week (i.e. 24 to 30 cy of screenings per week). Operating conditions and design criteria associated with the Headworks are listed in Table 5-1. Based on the available data, the Headworks design criteria appear adequate for current conditions. Table 5-1 – Headworks Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference Type of Screen Perforated Plate - Screen Opening (mm) 6 2 - 6 Orange Book T3-3.1.1.A.2.c Number of Screens 2 (1 duty, 1 standby) - Peak Capacity, each (mgd) 20.3 - Number of Washer Compactors One dedicated to each screen - Operations staff indicate the Headworks is operating well, although the screens require frequent adjustment of the cleaning brushes to capture debris and prevent it from being conveyed to the side of the screen. Additionally, the invert of the screening channel is approximately 18 feet below the building slab, resulting in a deep and narrow channel that is difficult to clean. The channel is recessed 18 to 22 inches deep for a distance of approximately 12 feet upstream of the screen and 18 ft of the screen; this recessed area leads to solids accumulation in the channels. Observed Deficiencies The following deficiencies were noted during facility tours, discussions with operations staff, and the preceding assessment: The slide gate in the existing Bypass Structure is old and may not be operable during an emergency due to possible submergence. Additionally, the upstream portion of the bypass consists of plywood and sandbags, which is not a suitable long-term solution. The configuration of the screening channel results in solids accumulation that is difficult to access and remove. Further, the channel can only be drained with a portable pump. To remove solids, the operators use a vac truck in an upstream manhole. ---PAGE BREAK--- The cleaning brush on the screen requires frequent adjustment to prevent solids carryover to the backside of the screen. The roof hatches are too small for the screen and must therefore be removed as an entire assembly. Summary Performance: The screens operate well and have sufficient capacity for existing peak flows. Some carryover of solids has been observed if the cleaning brush is not adjusted. Reliability: A redundant screen and washer / compactor is available that can also process flows up to 20.3 mgd. Safety: No safety issues were identified during a site tour and discussions with the operators. 5.2.2 Influent Parshall Flume Influent flow is recorded by measuring depth with an ultrasonic transducer in a 36-in Parshall flume located of the Headworks and prior to the Influent Pump Station. The flume has a 36-in throat and a free flow capacity of 0.40 to 32.6 mgd, which covers the range of existing flows at the facility. The influent meter was originally constructed in 1996 in a vault approximately 16 feet below grade. The area is therefore designated a confined space and requires appropriate safety gear to inspect or maintain. As noted in Chapter 3, operations staff have questioned the accuracy of the influent flume, especially following the 2009 Headworks upgrade that diverted flow to the new structure and back into the existing flume inlet pipe. In early January 2014, a transducer specifically designed for operation in turbulent flow was installed and a noticeable increase (approximately +10 percent) in influent flow was observed, which corresponds well with the adjusted flows noted in Chapter 3. Through the spring of 2014, the influent flow has compared well with effluent flow. This issue is believed to have been satisfactorily addressed. 5.2.3 Influent Pump Station Component Description and Operations The Influent Pump Station is located of the Influent Parshall Flume and conveys wastewater to the HRT Cells. The pump station has two separate wet well chambers, each of which houses two submersible pumps capable of approximately 5,650 gpm each. Having two separate chambers allows the operators to isolate half of the lift station for grit and debris removal. According to operations staff, the wet well is cleaned approximately twice a year. The wet wells can be operated jointly by opening a slide gate on the common interior wall. The pump station’s valve vault is on a common wall with the wet well. Each set of pumps in a wet well chamber join into a single 24-in force main. The two 24-in force mains are routed to the HRT Inlet Structure, and are intertied immediately east of the pump station with isolation valves of the intertie to allow one of the force mains to be taken offline for maintenance. One of the force mains was constructed in the 1997 upgrades and is routed through the access tunnel under the railroad line. The other force main was likely constructed with the 1972 aerated lagoon project and is not believed to be encased under the railroad line. During the winter, operations staff cover the valve vault to minimize freezing potential of the process lines. Operating conditions and design criteria for the Influent Pump Station are listed in Table 5-2. ---PAGE BREAK--- Table 5-2 – Influent Pump Station Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Number of Wet Wells 2 - Pump Type Submersible - Quantity 3 Duty / 1 Standby (2 pumps in each wet well) - Horsepower (hp), each 100 - Capacity, each (gpm) 5,650 - Pump Station Firm Capacity (3 pumps in operation) (mgd) - Single 24-in Force Main through Tunnel 20.5 - Dual 24-in Force Mains 25.2 - Observed Deficiencies The following deficiencies were noted during facility tours, discussions with operations staff, and the preceding assessment: Hoists or lifting points are not available for the influent pumps and valves. To remove and reinstall the large items, the operators must rent a crane. The electrical connections for the pumps have shorted in the past, requiring new conductor from the MCC to the pump connection. Coarse grit accumulation results in periodic cleaning of the wet well. The valve vault is not covered, which exposes items to weathering. The valve vault could be classified as a confined space; the only access is by a ladder on the east side of the structure. The existing check valves do not seat properly and need to be rebuilt. Summary Performance: The pump station has performed adequately. The firm capacity with both force mains in operation is 25.2 mgd, which is sufficient for existing and projected flows through the planning period. If the older force main is not available, the firm capacity of the pump station is 20.5 mgd, and is still adequate for expected and projected flows through the planning period. Reliability: The pump station has a redundant pump and two force mains. Safety: The valve vault is likely classified a confined space, with limited access for operators, tools, and equipment. 5.2.4 Grit Removal The facility does not currently have a dedicated grit removal system. Coarse grit accumulates in the Influent Pump Station and is removed approximately twice a year. Fine grit is conveyed to the HRT Cells and results in significant accumulation over time as noted in Section 5.2.5. The fine grit conveyed by the influent pumps causes wear on the pumps and has resulted in replacing the pump impellers after ten to fifteen years of operation. 5.2.5 HRT Cells Component Description and Operations Screened wastewater is pumped from the Influent Lift Station to the High Rate Treatment (HRT) Inlet Structure centered west of the two HRT Cells. Originally constructed with the 1996 improvements, the Inlet Structure is configured to receive ---PAGE BREAK--- the two 24-inch diameter force mains at the bottom of the structure and dissipate energy vertically. A single 18-inch RAS line enters the division box from the east, and the solids are mixed with the screened influent hydraulically. Effluent from the division box is to the north and south through submerged slide gates and into 48-inch feed lines to each HRT Cell. The submerged gates do not appear to provide equal distribution to each HRT Cell based on the MLSS levels in the HRT Cells. Biological treatment is accomplished in the two HRT Cells constructed in 1996. Operating conditions and design criteria associated with the HRT Cells are listed in Table 5-3. As shown in the table, the HRT Cells operate within typical design values and have performed very well – see Section 5.4 for additional discussion. Table 5-3 – HRT Cells Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference HRT Cells Volume (MG), each 3.0 - Number in Operation 2 - Surface Area, each (sf) 32,500 - Basin Dimensions, top (ft x ft) 196 x 166 - Basin Dimensions, bottom (ft x ft) 106 x 76 - Side Slopes (H:V) 2:1 - Side Water Depth (ft) 22.5 ± - Hydraulic Residence Time (days) Existing Average Day 1.12 - Existing Maximum Month 0.95 0.25 - 1.0 M&E (2013) Existing Peak Day 0.72 Solids Residence Time, SRT (days) 8 - 13 5 - 15 3 - 15 Orange Book T3-3.1.1.A.3.a M&E (2013) MLSS Concentration (mg/L) 2,000 1,500 - 4,000 Orange Book T3-3.1.1.A.3.a M&E (2013) Percent Volatile Solids in 2013 81 - Observed Yield (volatile basis) in 2013 0.81 - Observed Yield (total solids basis) in 2013 0.93 1.0 - 1.2 Orange Book T3-3.1.1.A.3.d Food:Microorganism (F:M) 0.14 0.2 - 0.6 M&E (2013) Volumetric Loading (lb BOD5 / 1,000 ft3 / day) 14.3 20 - 100 M&E (2013) Aeration System Aerator Type Mechanical Aerators Operation Constant Speed; 100-hp units turn on at DO = 2.0 mg/l and off at DO = 4.0 mg/l HRT No. 1 Quantity of 100 hp Aerators (duty / standby) 1 / - - Quantity of 75 hp Aerators (duty / standby) 4 / - - HRT No. 2 Quantity of 100 hp Aerators (duty / standby) 1 / - - Quantity of 75 hp Aerators (duty / standby) 4 / - - Operating Horsepower in each Cell (hp) 400 - Mixing Energy (per cell) (hp / 1,000 ft3) 1.0 0.75 - 1.50 M&E (2013) Aeration is provided by four 75-hp and one 100-hp mechanical aerators in each HRT Cell. One spare mechanical aerator is available for each size aerator currently in operation. The four 75-hp mechanical aerators are run continuously, while the 100-hp mechanical aerators are operated in an on/off configuration based on dissolved oxygen readings in each ---PAGE BREAK--- basin. Residual DO is measured in the last third of each cell with a meter submerged approximately 5 feet below the surface. Currently, the 100-hp mechanical aerators shut off at a DO level of 4.0 mg/l and turn on at a DO level of 2.0 mg/l. Existing oxygen demand and supply is summarized in Table 5-4, assuming equal split of influent to the two HRT Cells, complete conversion of BOD5 and ammonia, and a MLSS concentration of 2,000 mg/l. Reference Appendix 5-A for accompanying calculations. As shown in the table and observed by operations staff, the existing aerators generally maintain adequate oxygen supply at existing average day conditions. However, the operations staff indicate that during the intraday peak (i.e. peak hour) loading conditions residual DO levels drop to 0.2 to 0.5 mg/l. Based on dissolved oxygen response curves obtained in early April 2014 (included in Appendix 5-B), the peak hour load factor is estimated at approximately 2:1, which generally matches the observed influent flow diurnal discussed in Chapter 3. In summary, the residual dissolved oxygen level is above 2.0 mg/l during average conditions but below the required value of 0.5 mg/l at peak hourly loading (T3-3.1.1.A.4.a). Therefore, the facility currently has sufficient oxygen transfer capacity at average day and maximum month conditions, but does not have adequate capacity during peak hour conditions. This is expected to worsen as loads to the facility increase through the planning period. Table 5-4 – Existing Oxygen Demand and Supply Condition Dissolved Oxygen Requirement (mg/l) Existing Oxygen Demand (ppd) Existing Oxygen Supply (ppd) Demand / Supply (percent) Average Day 2.0 20,600 29,000 71% Maximum Month 2.0 24,300 29,000 84% Peak Hour 0.5 39,800 37,200 107% Specified residual dissolved oxygen levels per Orange Book T3-3.1.1.A.4.a Estimated demand assuming complete conversion of BOD5 and ammonia, and a MLSS concentration of 2,000 mg/l Oxygen supply based on operating 75-hp and 100-hp aerator in each HRT cell during summer conditions Assuming a 2:1 peaking factor during maximum month loading conditions Process data from early April 2014 (Appendix 5-B) also highlight the likely flow split issues at the HRT Inlet Structure. The HRT Cells have observed differences in MLSS of up to 500 mg/l. This is indicative of different organic loading to the cells and/or biosolids return from the RAS pump system. The north cell has been operating at a higher MLSS since changes were made to the outlet weir of the HRT Cells and has a greater oxygen demand. Implementing a more effective flow split would aid in correcting some of the oxygen deprivation noted to date. The motor control center for the HRT Cells includes two spare starters and conductors that would permit installation of one additional 100-hp aerator in each cell, which would provide enough additional oxygen to satisfy current demands. However, the starters and conductors require moderate repair to enable operation. The HRT Cells also accumulate a significant amount of fine grit. A previous study concluded that grit accumulation was approximately 2 CY per day (HDR, 2007). During the 2009 project, the cells were removed from operation and drained, and the grit was removed by a contractor. Operations staff recall a total depth of 3 ft which represents approximately 7 percent of the cell volume. If left unchecked, the grit accumulation could reduce the effective volume of the treatment cells. ---PAGE BREAK--- During 2013, the average wasting rate from the HRT Cells was 131,000 gpd, which corresponded to 9,460 ppd of total solids and 7,690 ppd of volatile solids. The observed biosolids yield was 0.93 based on total solids, and 0.81 based on volatile solids. Observed Deficiencies The following deficiencies were noted during facility tours, discussions with operations staff, and the preceding assessment: Influent wastewater and RAS distribution in the Inlet Structure does not appear to be balanced, leading to higher oxygen demand and MLSS levels in the north HRT Cell. The original aeration system was designed for four 75-hp mechanical aerators, one 100-hp mechanical aerators, and the ability to add another 100-hp mechanical aerator in each HRT Cell in the future. However, electrical shorts have resulted in burned conductors, receptacles, and insulation in the spare 100-hp components that will require repair prior to being introduced into service. Redundant mechanical aerators are not available within the HRT Cells in the event one of the existing units is removed from service. However, spare mechanical aerators are located at the facility. The mechanical aerators require frequent maintenance and replacement. Operations staff estimate each aerator is rebuilt or replaced every five years. The mechanical aerators are constant speed units, and the only control the operators have is turning the 100-hp mechanical aerators on and off as DO levels fluctuate. During nighttime and early morning hours, DO levels approach 4 to 6 mg/l; however, midday loads result in DO levels of 0.2 to 0.5 mg/l at existing conditions. As the mechanical aerators move within the confines of the mooring cables, the power cords wear from dragging across the liner and the conductors can become exposed. No visible damage to the liners has been observed, however. Based on discussions with operations staff, mechanical aerator maintenance is a major safety concern. Launching the access boat is difficult and the potential for immersion, drowning, or physical harm is high while entering the cells. Also, aerator removal requires operator entry into the cells with an access boat and a crane rental. Grit accumulation results in lost treatment efficiency. Dredging is expected approximately every ten years. The HRT drain structure is not operable due to grit accumulation in the inlet pipes. Summary Performance: The HRT Cells are able to provide sufficient treatment for existing average day flows and loads. However, suppressed oxygen levels (0.2 to 0.5 mg/l) have been observed during peak intraday loads as normal variations in influent strength occur; this condition is expected to worsen as loads increase. Reliability: The biological process is reliable; however, insufficient redundancy is provided for the aeration system and oxygen supply is limited during peak diurnal loads. Safety: Accessing the aeration equipment poses an elevated risk of immersion, drowning, or physical harm to operations staff. 5.2.6 Intermediate Clarifiers Component Description and Operations The Intermediate Clarifiers are located of the HRT Cells. Discharge from the Intermediate Clarifiers can either be routed to the Flash Mix / Flocculation Basins (normal conditions) or the Aerated Sludge Lagoons. Because ---PAGE BREAK--- normal operation includes capturing biosolids in the Intermediate Clarifiers rather than final polishing in the Aerated Sludge Lagoons, the HRT Cells and Intermediate Clarifiers operate similarly to a conventional activated sludge facility. The Intermediate Clarifiers receive MLSS from the HRT Effluent Structure located east of HRT Cell No. 1, and flow is distributed proportional to the surface area of the clarifiers. Intermediate Clarifier No. 1 was originally constructed in 1996 and is 90-ft diameter. The clarifier mechanism is a spiral rake arm with sludge hopper near the center. In 2009, the rake mechanism was recoated, a peripheral walkway was added for safety, the launder was coated, and the outlet box was expanded to receive clarified effluent from the new Intermediate Clarifier. The launder coating in Intermediate Clarifier No. 1 failed several times, necessitating multiple repairs. A second Intermediate Clarifier was constructed in 2009 for improved solids capture and to reduce solids loading in the Final Clarifiers. Intermediate Clarifier No. 2 is 120-ft in diameter and has a suction header for solids removal. Operations staff note that tumbleweeds enter the HRT Cells and periodically plug the inlet holes in the suction header. The clarifier must then be removed from service for cleaning which frequently causes a plant upset. Similar to Intermediate Clarifier No. 1, the launder coating failed and was replaced. Operating conditions and design criteria associated with the HRT Cells are listed in Table 5-5. As shown in the table, the existing overflow and solids loading rates with both Intermediate Clarifiers in operation are below typical recommended ranges. Consequently, the Intermediate Clarifiers are able to capture most of the solids and routinely have effluent BOD5 and TSS concentrations less than 10 mg/l. However, if Intermediate Clarifier No. 2 is taken offline and only Intermediate Clarifier No. 1 is available, the overflow and solids loading rates are exceeded at existing average flows. Consequently, operations staff indicate the MLSS must be lowered to 1,000 mg/l to prevent significant solids carryover to the Final Clarifiers. If Intermediate Clarifier No. 1 is taken offline, Intermediate Clarifier No. 2 has sufficient capacity at existing average day and maximum month flows. Because the Intermediate Clarifiers are followed by Final Clarifiers, the capacity of the Intermediate Clarifiers is based on solids loading limits to ensure that adequate solids capture is achieved to maintain a desired MLSS concentration in the HRT Cells. Assuming a MLSS of 2,000 mg/l and RAS rate equal to the influent flow, the maximum month capacity with both Intermediate Clarifiers in operation is 15.0 mgd. If the Final Clarifiers are not available, the Intermediate Clarifiers would be hydraulically limited at 10.5 mgd. ---PAGE BREAK--- Table 5-5 – Intermediate Clarification Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference Intermediate Clarifier No. 1 Diameter, each (ft) 90 Surface Area (sf) 6,360 Side Water Depth (ft) 14 12 (Range 12 - 20) M&E (2013) Floor Slope (in / ft) 1.25 varies Percent of flow 36% Overflow Rate Existing Average Day Flow (gpd/sf) 300 400 - 800 M&E (2013) Existing Peak Day Flow (gpd/sf) 475 1,200 1,000 - 1,200 Orange Book T3-3.1.1.B.2.a M&E (2013) Solids Loading (pph/sf) Existing Average Day Flow 0.42 0.8 - 1.2 M&E (2013) Existing Peak Day Flow 0.66 2 M&E (2013) Intermediate Clarifier No. 2 Diameter, each (ft) 120 - Surface Area, each (sf) 11,310 - Side Water Depth (ft) 15 12 (Range 12 - 20) M&E (2013) Floor Slope (in / ft) none Percent of flow 64% Overflow Rate (gpd/sf) Existing Average Day Flow 300 400 - 800 M&E (2013) Existing Peak Day Flow 475 1,200 1,000 - 1,200 Orange Book T3-3.1.1.B.2.a M&E (2013) Solids Loading (pph/sf) Existing Average Day Flow 0.42 0.8 - 1.2 M&E (2013) Existing Peak Day Flow 0.66 2.0 M&E (2013) Assumes MLSS = 2,000 mg/l; QRAS equal to average day influent flow. Observed Deficiencies Intermediate Clarifier No. 2 experiences plugging problems when tumbleweeds enter the HRT Cells and are pulled into the suction arm inlet holes. The clarifier must be drained to clean the inlets. If Intermediate Clarifier No. 2 is taken off-line, Intermediate Clarifier No. 1 is overloaded and solids are carried over to the Final Clarifiers which are difficult to manage. One solution employed by the operations staff is to reduce the MLSS in the HRT Cells to bring Intermediate Clarifier No. 1 within a suitable loading range. However, this change in operation has historically resulted in process upsets. The work area around the drive on Intermediate Clarifier No. 1 is relatively small and makes maintenance more difficult. Summary Performance: Effluent quality is generally below 10 mg/l for BOD5 and TSS at current conditions. The Intermediate Clarifiers have a capacity of 15.0 mgd based on a solids capture limit (at a MLSS of 2,000 mg/l and RAS rate equal to the influent flow). If the Final Clarifiers are not available, the Intermediate Clarifiers would be hydraulically limited at 10.5 mgd. ---PAGE BREAK--- Reliability: The primary concern for reliability arises from plugged inlets to the suction arm in Intermediate Clarifier No. 2; when the clarifiers is removed from service, a plant upset is probable. Safety: Improvements in 2009 improved operator access to the periphery of the clarifiers. 5.2.7 Intermediate Clarifier RAS / WAS Pumping Component Description and Operations The facility’s current Intermediate Clarifier RAS / WAS Pump Station was constructed in 2009 with Intermediate Clarifier No. 2. The pump station includes flow meters on each of the Intermediate Clarifier underflow lines, which allows the RAS pumps to be operated proportionally to the clarifier area as well as incoming plant flows. Current valve settings isolate the two clarifier underflow lines. A spare RAS pump is available to serve either Intermediate Clarifier No. 1 or 2 and provide sufficient redundancy. The RAS rate is currently 30 percent of the influent, which resulted in an average underflow concentration of 9,360 mg/l in 2013. At maximum output and one pump in standby, the RAS pumps can return 165 percent of the existing maximum month flow. RAS is routed to the HRT Inlet Structure. Solids are wasted from the Intermediate Clarifier No. 2 underflow line using either of the two dedicated WAS pumps and discharged to the Aerated Sludge Lagoons. The average wasting rate in 2013 was 0.12 mgd, which corresponded to 9,460 ppd total solids and 7,690 ppd volatile solids (81 percent volatile). At the maximum discharge of 1.04 mgd and observed underflow concentrations, a single WAS pump can waste approximately 81,500 ppd total solids (66,000 ppd volatile solids). A summary of current operating conditions and design criteria for the Intermediate Clarifier RAS / WAS Pump Station is included in Table 5-6. The pump system has sufficient capacity based on a comparison to recommended design values. Table 5-6 – RAS / WAS Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference RAS Pumping Pump Type Centrifugal Intermediate Clarifier No. 1 Pump (Pump No. 1) Quantity 1 - Horsepower (hp) 20 - Capacity (gpm) 2,620 - Intermediate Clarifier No. 2 Pumps (Pump No. 2 and 3) Quantity 2 - Horsepower (hp) 40 - Capacity, each (gpm) 4,630 - Total RAS Rate Two pumps in operation (mgd) 10.4 - Capacity as a Percentage of average day flow, existing 195 25 - 100 Orange Book T3-3.1.1.A.3.c WAS Pumping Pump Type centrifugal - Quantity 2 - Horsepower (hp) 30 - Capacity, each (gpm) 720 25% of average day flow (930 gpm in 2014) Orange Book T3-3.1.1.A.4.e ---PAGE BREAK--- Observed Deficiencies Access to elevated valves is difficult. Summary Performance: RAS firm capacity is 165 percent of existing maximum month flows with adequate turndown; sufficient WAS capacity exists for existing conditions. Reliability: The pump station includes a standby pump for both the RAS and WAS lines. Safety: Access to valves for maintenance and replacement poses a safety risk to the operators; sufficient scaffolding and equipment must be employed to maintain safety. 5.2.8 Flash Mix / Flocculation Component Description and Operations The Flash Mix and Flocculation Basins receive effluent from the Intermediate Clarifiers and any discharge from the Aerated Sludge Lagoons. Design criteria are listed in Table 5-7 and are generally within recommended design values. Flash mixing and flocculation was added with the 1996 upgrades to bolster the Final Clarifier performance, especially as design flows and loads were reached. The process design assumed 20 to 50 mg/l of BOD5 and TSS would be discharged from the Intermediate Clarifiers and/or Aerated Sludge Lagoons, which would require chemical addition and flocculation prior to settling to satisfy NPDES permit requirements. This process was not initially necessary since flows and loads were low. Subsequent, construction of the second Intermediate Clarifier in 2009 effectively captured solids from the biological process making the process not necessary at this time. The operators currently route effluent through one train; however, a bypass channel of the entire process is also available. The peak flow capacity of the Flash Mix and Flocculation system is 18.3 mgd (J-U-B, 1995a and 1995b). ---PAGE BREAK--- Table 5-7 – Flash Mix and Flocculation Basin Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference Flash Mix Number of Basins 2 - Length, each (ft) 6.5 - Width, each (ft) 6.5 - Depth (ft) 6.5 - Volume per Basin (gal) 2,050 - Hydraulic Detention Time - single basin Existing avg day (seconds) 33 5 - 30 M&E (2013) Existing peak hour (seconds) 17 5 - 30 M&E (2013) Hydraulic Detention Time - two basins Existing avg day (seconds) 66 5 - 30 M&E (2013) Existing peak hour (seconds) 33 5 - 30 M&E (2013) Mixers Horsepower 10 - Velocity Gradient (1/sec) 2,000 500 - 1,500 M&E (2013) Turndown 5:1 - Flocculation Basins Number of Trains 2 Compartments per Train 3 Length, each (ft) 20 Width, each (ft) 20 Depth (ft) 13.5 Volume per Train (gal) 121,200 Hydraulic Detention Time - single train Existing avg day (minutes) 32.6 30 - 60 M&E (2013) Existing peak hour (minutes) 16.3 30 - 60 M&E (2013) Hydraulic Detention Time - two trains Existing avg day (minutes) 65.2 30 - 60 M&E (2013) Existing peak hour (minutes) 32.6 30 - 60 M&E (2013) 1st Stage Mixers Horsepower 1.5 - Velocity Gradient (1/sec) 71 - Turndown 5:1 2nd Stage Mixers Horsepower 1.0 - Velocity Gradient (1/sec) 51 - Turndown 5:1 3rd Stage Mixers Horsepower 0.5 - Velocity Gradient (1/sec) 25 - Turndown 5:1 ---PAGE BREAK--- Observed Deficiencies The existing chemical feed system has not been used since the original installation. General maintenance and some upgrades should be expected if the system is returned to operation. Summary Performance: N/A Reliability: The original design included bypass channels and a second train for operating during higher flows. Safety: No safety issues were identified during a site tour and discussions with the operators. However, the chemical storage area and feed equipment should be reviewed and updated as necessary to address changes in safety measures. 5.2.9 Final Clarifiers Component Description and Operations The Final Clarifiers are rectangular clarifiers with chains and flights, and are located of the Flash Mix / Flocculation Basins and prior to UV disinfection. The first two clarifiers were constructed in 1952 to operate as primary clarifiers but were converted to secondary clarifiers in the 1972 upgrade. Two additional clarifiers were added in 1972, and three more were constructed in 1996 bringing the total number of final clarifiers to seven. A summary of current operating conditions and design criteria for the Final Clarifiers is included in Table 5-8. As shown in the table, the Final Clarifiers are relatively shallow but operate within typical design values for the overflow rate and solids loading. Table 5-8 – Final Clarifier Operating Conditions and Design Criteria Item Actual / Observed Condition Typical Design Condition or Range Reference Number Available 7 - Length, each (ft) 100 - Width, each (ft) 28 - Average Side Water Depth (ft) 8 10 - 16 M&E (2013) Surface Area, each (sf) 2,800 - Overflow Rate Existing Average Day Flow (gpd/sf) 275 400 - 800 M&E (2013) Existing Peak Day Flow (gpd/sf) 550 1,200 1,000 - 1,200 Orange Book T3-3.1.1.B.2.a M&E (2013) Solids Loading (pph/sf) Existing Average Day Flow 0.01 0.8 - 1.2 M&E (2013) Existing Peak Day Flow 0.01 2.0 M&E (2013) All clarifiers in operation Assumes TSSinfluent = 50 mg/l; QRAS equal to approximately 33 percent of the average day influent flow As noted previously, the Intermediate Clarifiers capture most of the solids from the HRT Cells, which results in very little loading on the Final Clarifiers. The Final Clarifiers provide an additional settling step and redundancy in the event one of the Intermediate Clarifiers is off-line. However, there are several operational problems associated with the Final Clarifiers that limit their effectiveness: The Final Clarifiers cannot be bypassed and at least one basin must be in operation at any given time. Algae growth within the Final Clarifiers became so extensive that the horizontal flights in one clarifier were overloaded and broke. Operations staff have suggested covering the Final Clarifiers to limit algae growth. This, in turn, would reduce algae carryover to the UV system which results in additional maintenance in that process. ---PAGE BREAK--- The side water depth is shallower than typically used in secondary clarifiers. A lower solids loading rate should be considered if used as a redundant clarifier for the Intermediate Clarifiers. Additionally, use of the Flash Mix / Flocculation Basins should be considered to enhance settling. Solids removal is accomplished by a gravity manifold that returns solids to the upstream side of the Influent Pump Station of the Influent Parshall Flume). Each Final Clarifier has an isolation valve, but the operations staff cannot increase solids removal from one clarifier without shutting the isolation valves to the other clarifiers. A solids pump is available, but the operations staff indicate that it does not operate properly. When solids must be pumped from the Final Clarifiers, a portable trash pump is used. Since the clarifiers have little solids loading, the primary factor in determining capacity is the overflow rate. The maximum month capacity is 15.5 mgd with all seven clarifiers in operation; if only five are available, the maximum month capacity is 11.0 mgd. Observed Deficiencies The two clarifiers constructed in 1952 have surface deterioration in the concrete walls. The clarifiers are currently 62 years old and should be rehabilitated to retain use of the structure. Algae growth is problematic, increases operator labor, and has resulted in damage to the horizontal flights as well as increased maintenance at the UV facility. In 2013, three sets of flights were replaced because algae growth overloaded the mechanisms. The remaining flights are relatively old and should be considered for replacement in the coming years. A bypass channel is not available to bypass the Final Clarifiers when effluent quality from the Intermediate Clarifiers is satisfactory. Managing the solids inventory and return to the biological process is challenging. Additionally, the existing solids pump is not able to convey solids from the Final Clarifiers to the Influent Pump Station for return to the biological process. Operators currently use a portable trash pump. Summary Performance: The Final Clarifiers have minimal loading due to the performance of the Intermediate Clarifiers. Reliability: Adequate redundancy is available in the event one or more of the Final Clarifiers is inoperable. However, additional effort is required to maintain equipment in proper working order; i.e., rotating basins into service during the summer, removing algae, and managing solids inventories. Safety: Deteriorating structures are a safety concern. 5.2.10 UV Disinfection Component Description and Operations The UV system is immediately of the Final Clarifiers and provides disinfection of the effluent prior to discharge to the Columbia River. The existing system is a Trojan UV3000 and was constructed in 2000. It was one of the first generation of UV systems that Trojan manufactured in the mid-1990s. Between March 22 and April 4, 2014, an on-site review and assessment of the UV system was conducted. A copy of the technical memorandum summarizing the evaluation is contained in Appendix 6-B and discussed below. Observed operating conditions during the site visit are listed Table 5-9. ---PAGE BREAK--- Table 5-9 – UV Disinfection Operating Conditions and Design Criteria Item Actual / Observed Condition UV Transmittance (percent) 60 - 65 Dose (mJ/cm2) 10 - 15 Number of Channels 2 Number of Banks (per Channel) 2 Number of Modules (per Bank) 13 Number of Lamps Per Module 8 Total 416 Based on observations while on-site between March 22 and April 4, 2014 At current flows, the existing system satisfies the average and weekly limits of 200 fecal coliform forming units (CFU)/100ml and 400 CFU/100ml, respectively (see also Figure 5-6). The system is typically operated at 100-percent output since it has relatively limited controls to adjust UV dose. The dose model utilizes UV intensity and flow only, which was industry standard at the time. However, current dosing models employ UV transmittance, UV intensity, and flow with more accurate instruments, which provide a direct bearing on the actual dose provided. This, in turn, can provide real- time performance of the UV system, resulting in increased efficiency and potential energy savings. The system was also operating with bulbs that had a 50 percent reduction in output compared to a typical 10 to 15 percent reduction. The tested bulbs were from Livingston Micrographics and may not have the longevity that Trojan’s bulbs have historically shown. The system experiences relatively wide fluctuations in water depth that may compromise performance. Based on the on- site evaluation, the practical maximum flow for the system to limit water depth over the bulbs at no more than one inch is approximately 7.5 mgd. However, the practical limit for the existing system to maintain permit compliance (maximum week conditions) based on the collimated beam test is estimated to be 11.4 mgd, provided bulb output is maintained above 80 percent of the new-bulb output through replacement. The existing system is also poorly integrated within the facility’s SCADA system. Other than sensor intensity alarms and an overall system failure alarm (added fall of 2014), the SCADA system does not receive operating data from the UV system. This is a significant concern for operations staff since the first bank of lamps in an operating channel will fail periodically without cause, which could lead to insufficient dose if the second bank is not providing sufficient dose to satisfy the permit limits. The UV system is not currently supported by a generator. In the event a power outage occurs, operations staff must contact operators at the Water Treatment Plant and request that a chlorine feed line that is routed to the WWTP be activated for emergency disinfection of plant effluent. Alternatively, operations staff can store effluent in the Aerated Sludge Lagoons for short periods of time. Either approach requires operator response during emergency conditions and can result in inadequately disinfected effluent being discharged Perhaps most significant, operations staff were notified in March 2014 that Trojan would no longer be supporting the UV3000 system effective March 31, 2015. Basic consumables such as lamps, sleeves, ballasts, etc. are expected to ---PAGE BREAK--- have continued support through Trojan or another vendor. However, this product retirement has significant implications relative to control boards, power distribution systems, expandability with future flows, and controls. Given the functional problems observed to date, considerable changes to the UV system, including replacement, may be required to address risk of failure and capacity needs moving forward. Observed Deficiencies The system is typically operated at 100-percent output since it has relatively limited controls to adjust UV dose. The existing system is poorly integrated within the facility’s SCADA system. Operations staff have experienced limited vendor support for the system. Further, the vendor notified the City that they would no longer be supporting the system effective March 31, 2015. The practical maximum flow for the system to limit water depth over the bulbs at no more than one inch is approximately 7.5 mgd. However, the practical limit for the existing system to maintain permit compliance (maximum week conditions) based on the collimated beam test is estimated to be 11.4 mgd, provided bulb output is maintained above 80 percent of the new-bulb output through replacement. Algae from the Final Clarifiers can enter the channels and accumulate. Backup power is not provided for continuous operation in the event of a power failure. Summary Performance: The UV system has consistently operated below the average and maximum weekly limits in its discharge permit. The maximum week capacity of the system is 11.4 mgd, which is above existing peak flows. Reliability: The system experiences bank failures for unknown reasons. This is complicated by lack of integration with the plant-wide SCADA. Further, the vendor has notified the City that support will not be provided beyond March 31, 2015. Safety: No safety issues were identified during a site tour and discussions with the operators. 5.2.11 Effluent Palmer Bowlus Flume, Effluent Pump Station, and Outfall Disinfected effluent from the facility is discharged through a 36-in Palmer Bowlus flume and to the Effluent Pump Station located north of the main treatment plant. The Effluent Palmer Bowlus Flume has a rated capacity of approximately 24 mgd, and therefore has adequate capacity for existing flows. The Effluent Pump Station was constructed by the Army Corps of Engineers in conjunction with the flood levee to discharge effluent to the Columbia River. A gravity bypass is also available. During the 1997 upgrades, the pumps were replaced with three vertical turbine pumps. The total pump station capacity is 27.8 mgd, with a firm capacity of 19.3 mgd. Two pumps have constant speed drives, and one pump is driven by a VFD. No operational problems have been noted for the Effluent Pump Station. The facility’s Outfall extends approximately 270 ft into the Columbia River to a depth of 12 to 16 ft. The final 164 ft of the Outfall contains 4-in diameter vertical PVC risers spaced at approximately 6’-8” apart with three 3.14-in x 3.25-in ports on each riser serving as diffusers. An evaluation of the Outfall was conducted in 2010, and no issues were identified at the time. With maximum pool elevation in the Columbia River (357 ft), the Outfall should convey approximately 20.3 mgd. ---PAGE BREAK--- 5.2.12 Aerated Sludge Lagoons Component Description and Operations Solids are wasted from the biological process to the Aerated Sludge Lagoons located in the southeast quadrant of the facility. Operating conditions and general design criteria associated with the Aerated Sludge Lagoons are listed in Table 5-10. Table 5-10 – Aerated Sludge Storage Lagoon Conditions and Design Criteria Item Actual / Observed Condition Number of Storage Lagoons 2 Aerated Sludge Lagoon No. 1 (southern lagoon) Volume (Mgal) 42 Surface Area (acres) 9.2 Depth (ft) 12 - 14 Total Aeration (hp) 210 Aerated Sludge Lagoon No. 2 (northern lagoon) Volume (Mgal) 36 Surface Area (acres) 8.5 Depth (ft) 12 - 14 Total Aeration (hp) 235 In 2013, average solids wasting to the Aerated Sludge Lagoons was 9,460 ppd. Suspended solids are aerobically degraded, while settled solids likely undergo anaerobic digestion. Currently, operations staff waste to one of the two lagoons, while the other lagoon continues processing solids. Every six to eight years, one of the lagoons is hydraulically dredged and the solids are dewatered on-site by contract operators. The solids have historically satisfied Class B biosolids requirements and are therefore hauled off-site following dewatering. The last dredging project occurred in the fall of 2012 in Lagoon No. 1 (south lagoon). Project records indicate the total dry solids removed was 7,530 tons. Within the next three years, the City expects to dredge Lagoon No. 2. Aeration and mixing is provided using mechanical aerators as follows: Lagoon No. 1 has four 15-hp and two 75-hp mechanical aerators, for a total of 210 hp. Total oxygen provided is approximately 7,000 to 9,000 ppd during the summer. Lagoon No. 2 has nine 15-hp and four 25-hp mechanical aerators for a total of 235 hp. Total oxygen provided is approximately 8,000 to 10,000 ppd during the summer. Additionally, asphalt lining was installed several years ago to improve dredging procedures. As additional solids are wasted to the Aerated Sludge Lagoons, supernatant is discharged to the outlet line from the Intermediate Clarifiers and ultimately to the Flash Mix / Flocculation basins. Effluent quality has been observed to vary as discharge from the Aerated Sludge Lagoons occurs (reference Section 5.4) but not to a degree that would compromise effluent quality. Operations staff have indicated a desire to intercept the discharge and route it to the HRT Cells for additional treatment prior to discharge. This would improve overall effluent quality, but it would also result in an increase in oxygen demand since the Aerated Sludge Lagoon effluent likely has elevated ammonia levels. Sampling of the ---PAGE BREAK--- Aerated Sludge Lagoon effluent for BOD5, TSS, and ammonia is recommended to ascertain the potential impacts associated with returning this stream to the HRT Cells. Periodically, large masses of solids rise to the surface of the Lagoons and create extremely foul odors. Typically, these events have occurred in spring or fall and seem to correlate with typical lagoon turnover events; however, this does not occur consistently every spring and/or fall. When turnover does occur, extremely foul odors are present throughout the eastern portions of the City and numerous complaints are received. Additional aeration has been installed in an effort to maintain an oxygenated cap on the lagoon, but this has not been adequate to mitigate the odors during a lagoon turnover. Observed Deficiencies Odors are a significant concern during lagoon turnover in the spring and fall. Effluent from the lagoons is routed directly to the Flash Mix / Flocculation Basins and Final Clarifiers. Overall effluent quality from the facility is degraded as the solids inventory increases in the lagoons. The motor control center does not have capacity for aerator expansion. Summary Performance: The Aerated Sludge Lagoons are able to consistently achieve Class B biosolids under current operations. Reliability: Adequate stand-by units and a second Aerated Sludge Lagoon are available. Safety: Accessing the aeration equipment poses an elevated risk of immersion, drowning, or physical harm to operations staff. 5.2.13 Hydraulic Capacity The facility is currently operating within its previous hydraulic design values, and operations staff have not indicated any capacity issues. 5.3.1 Plant Water The plant currently uses City water at the administration building and for process water needs, with an average daily use of 0.18 mgd. The plant does not have facilities to allow treated effluent from the plant to be used for process water. 5.3.2 Supervisory Control and Data Acquisition (SCADA) The City has a dedicated automated control and telemetry specialist that provides in-house SCADA development for the WWTP, collection system lift stations, and the water system components. The SCADA provides data trending for influent flow, controls one 100-hp aerator in each HRT Cell based on DO levels in each basin, and identifies operating equipment and status (when available). One key limitation, however, is SCADA integration with the existing UV system is limited – reference to Section 5.2.10. ---PAGE BREAK--- 5.3.3 Standby Power / Power Distribution The wastewater treatment facility currently is fed from six separate utility transformers and electrical service points. The locations and service descriptions are listed in Table 5-11. The facility’s electrical gear is generally in good condition and remains serviceable. Expansion is limited in the Headworks and Influent Pump Station, and not available in the Aerated Sludge Lagoons. The Influent Pump Station and Headworks service is supplied with standby power via a 300KW/375KVA Generac diesel fueled generator. The generator is marginally sized to operate three influent pumps and the Headworks facility. No other source of standby power is available. Table 5-11 – Electrical Service Summary Service Area Meter Voltage Transformer Size (KVA) Influent Pump Station and Headworks Benton PUD meter No. 251630 480V/277 750KVA UV Benton PUD meter No. 251447 208Y/120 75KVA HRT and Intermediate Clarifier RAS/WAS Pumping Benton PUD meter No. 251633 480V/277 1500KVA Admin/Laboratory Benton PUD meter No. 251450 208Y/120 150KVA Aerated Sludge Lagoons Benton meter No. 250991 480V/277 500KVA Effluent Pump Station Benton meter No. 250881 240V/480 167KVA Also serves BNSF meter 250898 Observed Deficiencies Electrical service expansion in the Headworks and Influent Pump Station is limited. Electrical service expansion for the Aerated Sludge Lagoons is not possible. Standby power is not available for the HRT Cells nor the UV system. The facility has historically performed very well, with effluent BOD5 and TSS routinely below 10 mg/l and removal rates greater than 97 percent as shown in Table 5-12. Effluent BOD5, TSS, ammonia, fecal coliform levels are shown graphically in Figure 5-3, Figure 5-4, Figure 5-5, and Figure 5-6. As shown in the graphs, effluent quality in 2013 was better and less variable than in prior years. One potential reason for this is the dredging project performed in one of the Aerated Sludge Lagoons in the fall of 2012. Solids had been wasted to the lagoons for several years and had accumulated to relatively high levels. When the lagoons are approaching capacity for solids storage, continued wasting from the HRT Cells displaces contents that have higher levels of TSS and nutrients. Dredging occurred in September and October 2012 resulting in a short- term increase in effluent TSS and NH3. Through 2013, little to no solids discharge likely occurred because of dredging, and effluent quality improved. As loads increase to the facility, management of the solids return flow will become more critical. ---PAGE BREAK--- Table 5-12 – Effluent Quality Summary and Historical Removal Averages) Year BOD5 TSS NH3: Effluent Concentration (mg/l) Fecal Coliform (#/100ml) Concentration (mg/l) Percent Removal Concentration (mg/l) Percent Removal 2009 5.7 97.9 5.9 98.1 6.3 6.0 2010 5.5 98.0 7.2 97.6 7.7 10.8 2011 4.5 98.3 4.9 98.3 7.0 2.0 2012 5.4 97.7 9.1 96.4 9.6 3.4 2013 3.0 98.7 3.9 98.6 1.2 4.7 Effluent BOD5 permit limit is 30 mg/l and 85 percent removal of influent BOD5. Effluent TSS permit limit is 30 mg/l and 85 percent removal of influent TSS. The facility does not have an effluent ammonia limit. The average fecal coliform limit is 200 CFU/100ml. Figure 5-3 – Historical Effluent BOD5 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 5 10 15 20 25 30 35 40 45 50 Percent Removal Effluent BOD5 (mg/l) Date Effluent BOD (mg/L) Average BOD Limit (mg/l) BOD Percent Removal BOD Percent Removal Requirement 30-day Average Effluent BOD (mg/l) ---PAGE BREAK--- Figure 5-4 – Historical Effluent TSS Figure 5-5 – Historical Effluent Ammonia 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 5 10 15 20 25 30 35 40 45 50 Percent Removal Effluent TSS (mg/l) Date Effluent TSS (mg/l) Average TSS Limit (mg/l) TSS Percent Removal TSS Percent Removal Requirement 30-day Average Effluent TSS (mg/l) 0 5 10 15 20 25 30 35 40 45 50 Effluent NH3 (mg/l) Date Effluent NH3 (mg/L) 30-day Average Effluent NH3 (mg/l) ---PAGE BREAK--- Figure 5-6 – Historical Effluent Fecal Coliform 1 10 100 1000 Effluent Fecal Coliform (#/100ml) Date Effluent Fecal Coliform (#/100ml) Effluent Fecal Coliform 30-day Geometric Mean (#/100ml) 30-Day Fecal Coliform Limit (#/100ml) ---PAGE BREAK--- Based on the NPDES permit from DOE issued October 27, 2008, the Kennewick wastewater treatment plant is designated a Reliability Class II facility. Reliability Class II requirements are listed in Section G2-8.2 of the Orange Book and are summarized relative to the existing facility in Table 5-13. Table 5-13 – Reliability Class II Requirements Compared to Existing Facility Requirement Assessment of Existing Facility A. Mechanically Cleaned Bar Screens. A backup bar screen, designed for mechanical or manual cleaning, shall be provided. Facilities with only two bar screens shall have at least one bar screen designed to permit manual cleaning. A redundant screen capable of processing the peak hour flow is available. B. Pumps. A backup pump shall be provided for each set of pumps performing the same function. The capacity of the pumps shall be such that, with any one pump out of service, the remaining pumps will have the capacity to handle the peak flow. 1. Influent Pump Station: The peak hour flow can be satisfied with one pump out of service. 2. RAS Pumping: A redundant pump is available. 3. WAS Pumping: A redundant pump is available. C. Comminution Facility. If comminution of the total wastewater flow is provided, an overflow bypass with a manually-installed or mechanically-cleaned bar screen shall be provided. The hydraulic capacity of the comminutor overflow bypass should be sufficient to pass the peak flow with all comminution units out of service. N/A D. Primary Sedimentation Basins. The units shall be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the design basin flow. N/A E. Final Sedimentation Basins and Trickling Filters. The units shall be sufficient in number and size so that, with the largest-flow- capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the design basin flow. Both the Intermediate Clarifiers and Final Clarifiers serve this function. With one Intermediate Clarifier out of service, the facility can process the entire plant flow using the Final Clarifiers. F. Activated Sludge Process Components. 1. Aeration Basin. A backup basin will not be required; however, at least two equal-volume basins shall be provided. (For the purpose of this criterion, the two zones of a contact stabilization process are considered as only one basin.) The facility has two, equally-sized aeration basins. A backup basin is not provided. 2. Aeration Blowers or Mechanical Aerators. There shall be a sufficient number of blowers or mechanical aerators to enable the design oxygen transfer to be maintained with the largest- capacity-unit out of service. It is permissible for the backup unit to be an uninstalled unit, provided that the installed units can be easily removed and replaced. However, at least two units shall be installed. An uninstalled unit for each motor size is available in the event one of the mechanical aerators must be removed from service. However, the existing aerators cannot maintain a DO residual greater than 0.5 mg/l under peak hour conditions. 3. Air Diffusers. The air diffusion system for each aeration basin shall be designed so that the largest section of diffusers can be isolated without measurably impairing the oxygen transfer capability of the system. N/A ---PAGE BREAK--- Requirement Assessment of Existing Facility G. Disinfectant Contact Basins. The units shall be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the total design flow. The design basis for the UV system was 12.2 mgd. Current maximum month flow is 6.30 mgd, which is 52% of the design basis. Additionally, the facility must satisfy the Class II electrical reliability criteria in Section G2-8.3 of the Orange Book, summarized in Table 5-14. The standby electrical equipment only maintains the Headworks and Influent Pump Station; no other processes are sustained during a power outage. Consideration should be given to adding standby power for a portion of the biological system and all of the UV disinfection system. Table 5-14 – Minimum Capacity of the Backup Power Source for Each Reliability Class Reliability Class General Requirements I Sufficient to operate all vital components and critical lighting and ventilation during peak wastewater flow conditions. II The same as Reliability Class I, except that vital components used to support the secondary processes mechanical aerators or aeration basin air compressors) need not be operable to full levels of treatment, but shall be sufficient to maintain the biota. III Sufficient to operate the screening or comminution facilities, the main wastewater pumps, the primary sedimentation basins, the disinfection facility, and critical lighting and ventilation during peak wastewater A summary of each process is included in Table 5-15 based on the preceding discussion and current operations. Current loading and the estimated capacity of each component is shown in Figure 5-7. The capacity of the existing facility is estimated at 12.2 mgd, provided the spare aeration system components originally designed into the facility are installed. The assessment is based on typical literature values, design information contained in the facility’s O&M manual, discussions with vendors, and a planning level mass balance. Table 5-15 – Summary of Existing Conditions Item Observed Conditions Headworks Bypass Structure is old and may not be operable in an emergency Solids accumulation occurs in the screening channel; access to equipment is limited Influent Parshall Flume Historically, the influent flume has experienced turbulence that could affect influent flow measurement accuracy. This issue was resolved in 2014. Influent Pump Station Hoists and lifting points are not available for performing routine maintenance on pumps and valves. Coarse grit accumulation results in cleaning the wet well approximately twice a year. Access to the valve vault is limited. The existing check valves do not seat properly and need to be rebuilt. HRT Cells Influent wastewater and RAS distribution in the Inlet Structure does not appear to be balanced, leading to higher MLSS levels in the north HRT Cell and lower dissolved oxygen levels. Oxygen supply during daily peak loading conditions falls to 0.2 to 0.5 mg/l. Dissolved oxygen control is limited to turning on/off a 100-hp aerator in each cell. No redundant mechanical aerators within the basins; spares available on-site. ---PAGE BREAK--- Item Observed Conditions Spare electrical connections are not available within the basins. Safety concerns associated with entry into basins for aerator maintenance. Grit accumulation requires dredging approximately every 10 years. Intermediate Clarifiers Intermediate Clarifier No. 2 experiences plugging problems due to tumbleweeds entering the MLSS and suction arm. Intermediate Clarifier No. 1 has a limited work area around the clarifier drive. Intermediate Clarifier No. 1 cannot handle existing flows; process upsets occur when Intermediate Clarifier No. 2 is taken off-line. Intermediate Clarifier RAS/WAS Pump Station Access to valves for maintenance is difficult. Flash Mix / Flocculation The existing system has not been utilized since originally constructed. Final Clarifiers Final Clarifiers 1 and 2 were constructed in 1952 and have surface deterioration in the concrete walls. The clarifiers are currently 62 years old and should be rehabilitated to retain use of the structure. Without a bypass channel or cover, the Final Clarifiers experience significant algae growth when effluent quality from the Intermediate Clarifiers is sufficient for disinfection and discharge. Managing the solids inventory is difficult and may require isolating individual clarifiers while the others accumulate solids. Further, the solids pump does not operate reliability. UV Disinfection The system is typically operated at 100-percent output since it has relatively limited controls to adjust UV dose. The existing system is not satisfactorily integrated to the facility’s SCADA system due to UV system control panel limitations. Operations staff have experienced limited vendor support for the system. Further, the vendor notified the City that they would no longer be supporting the system effective March 31, 2015. The practical maximum flow for the system to limit water depth over the bulbs at no more than one inch is approximately 7.5 mgd. However, the practical limit for the existing system to maintain permit compliance (maximum week conditions) based on the collimated beam test is estimated to be 11.4 mgd, provided bulb output is maintained above 80 percent of the new-bulb output through replacement. Backup power is not provided for continuous operation in the event of a power failure. Effluent Palmer Bowlus Flume No issues identified. Effluent Pump Station and Outfall No issues identified. Aerated Sludge Lagoons Odors are a significant concern during lagoon turnover in the spring and fall. Effluent from the lagoons is routed directly to the Flash Mix / Flocculation Basins and Final Clarifiers. Overall effluent quality from the facility is degraded as the solids inventory increases in the lagoons. Hydraulic Capacity No issues identified. Ancillary Support Systems Electrical service expansion in the Headworks and Influent Pump Station is limited. Electrical service expansion for the Aerated Sludge Lagoons is not possible. Standby power is not available for the HRT Cells and the UV system, but should be considered for Class II reliability. ---PAGE BREAK--- Figure 5-7 – Existing Loading and Capacity Summary ---PAGE BREAK--- Alternatives to Meet Facility Goals: Liquid Stream CHAPTER 6 ---PAGE BREAK--- CHAPTER 6 – ALTERNATIVES TO MEET FACILITIES GOALS: LIQUID STREAM As noted in Chapter 5, processes within the Kennewick wastewater treatment plant have various operational and capacity issues at today’s flows and loads. Additionally, changes in hydraulic and organic loading will impose additional stresses on the facility and could affect the City’s ability to consistently achieve the required effluent quality. This chapter evaluates the expected treatment performance and operations with No Action and develops potential alternatives to sustain the facility through the 20-year planning period. The No Action alternative assumes the City continues to operate the facility diligently and fund necessary maintenance and replacement through the study period. However, no significant changes or improvements to the existing unit processes would be undertaken. Impacts to each unit process assuming adoption of the No Action Alternative is discussed in the following sections. 6.2.1 Headworks (Influent Screening) – No Action The influent screens have a firm capacity of 20.3 mgd and therefore have sufficient capacity for the projected peak hour flow of 15.9 mgd. Operational issues noted in Chapter 5 are not considered significant enough to warrant a large capital improvement project, with the exception of the influent bypass. However, in the event a bypass of the Headworks is necessary, it is uncertain if the plywood diversion in the manhole in the intersection of Bruneau Avenue and Kingwood Street could be removed safely and quickly enough to be useful. 6.2.2 Influent Parshall Flume – No Action The influent flume has sufficient capacity through the planning period. No significant changes from existing conditions are expected. 6.2.3 Influent Pump Station – No Action The firm capacity of the Influent Pump Station with three pumps in operation is 20.5 mgd with a single force main in operation and 25.2 mgd with both force mains in operation. Compared to the projected peak hour flow, the Influent Pump Station has adequate capacity through the planning period. Maintenance on the pumps, valves, and discharge piping is expected to increase as components continue aging, but a wholesale replacement of the items does not appear justified at this time. 6.2.4 HRT Cells – No Action The existing facility is not currently able to meet 2014 peak hour demand requirements. As loads increase to the facility, oxygen limitations with No Action will become more frequent, prolonged, and severe. Table 6-1 summarizes expected oxygen demand, with and without nitrification, compared to calculated oxygen supply with the existing aerators assuming all aerators are in operation. Reference Appendix 6-A for supporting oxygen demand and supply calculations. The existing aerators are only able to satisfy the projected BOD5 oxygen demand at average day and ---PAGE BREAK--- maximum month loads; when daily peaks are realized and as nitrification occurs, sufficient oxygen will not be available. Table 6-1 – Projected 2034 Oxygen Demand and Supply with Existing Aerators Condition Dissolved Oxygen Requirement (mg/l) Oxygen Demand without Nitrification (ppd) Oxygen Demand with Nitrification (ppd) Existing Oxygen Supply (ppd) Demand / Supply without Nitrification (percent) Demand / Supply with Nitrification (percent) Average Day 2.0 23,300 29,700 29,000 80% 102% Maximum Month 2.0 29,000 36,600 29,000 100% 126% Peak Hour 0.5 49,200 64,300 37,200 132% 173% Specified residual dissolved oxygen levels per Orange Book T3-3.1.1.A.4.a Estimated demand assuming complete conversion of BOD5 and a MLSS concentration of 2,000 mg/l Estimated demand assuming complete conversion of BOD5 and ammonia, and a MLSS concentration of 2,000 mg/l Oxygen supply based on operating 75-hp and 100-hp aerator in each HRT cell during summer conditions Assuming a 2:1 peaking factor during maximum month loading conditions It is conceivable that during oxygen deficit periods nitrate could be utilized as an electron acceptor and the facility could adopt a cyclic nitrification-denitrification process (cyclic NdN). The duration of the oxygen deficit would depend entirely on the incoming waste stream and not permit operator control of the process. Odors and process instability are likely outcomes. Controlling nitrification by reducing the solids residence time of the HRT Cells is also theoretically possible. As shown in Table 6-2, the HRT Cells would have to be operated at an SRT less than 2 days to avoid nitrification during the summer months If the facility could operate one HRT Cell at 1,750 mg/l MLSS, it is likely that nitrification could be avoided (reference Appendix 6-A for supporting calculations). However, the single HRT Cell would not have sufficient oxygen supply to support BOD conversion, and the food to microorganism ratio would increase to 0.63 (compared to a typical design range of 0.2 to 0.6). Undertaking this approach would likely result in an unstable process. ---PAGE BREAK--- Table 6-2 – HRT Cell Temperature and Critical SRT for Nitrification Month Average Effluent Temperature Critical SRT for Nitrification (days) January 11.7 5.9 February 12.0 5.7 March 13.2 5.1 April 14.9 4.3 May 17.4 3.4 June 19.6 2.7 July 22.1 2.1 August 22.5 2.0 September 21.1 2.3 October 18.1 3.1 November 15.4 4.1 December 12.1 5.6 Grit accumulation also presents a concern for the facility and is expected to increase proportionally to plant flow. Removal projects for grit that currently occur every ±10 years would likely need to occur every ±7 years. Given the increased loading and concerns with oxygen supply noted above, removing one of the HRT Cells from operation could severely impact facility operations and performance. 6.2.5 Intermediate Clarifiers – No Action The Intermediate Clarifiers have sufficient capacity for the increased flows and loads through the planning period. As shown in Figure 6-1 and Figure 6-2, the overflow rate and solids loading rate with two Intermediate Clarifiers in operation is within the typical operating range. If either Intermediate Clarifier is off-line, however, the remaining unit will not have sufficient capacity to handle projected conditions and the Final Clarifiers will be required to provide redundancy. Historically this has resulted in process upsets, which will require careful operator attention prior to taking the clarifier offline and during the period when it is out of service. Alternatively, flow could be routed to the Aerated Sludge Lagoons. ---PAGE BREAK--- 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061 0 100 200 300 400 500 600 700 [PHONE REDACTED] - 100 200 300 400 500 600 700 800 900 1,000 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 Overflow Rate (gal/sf/day) Plant Flow (mgd) Case 1: 90-ft Clarifier and 120-ft Clarifier Case 2: 90-ft Clarifier and 120-ft Clarifier Case 3: 90-ft Clarifier and 120-ft Clarifier Overflow Rate (low range), gal/sf/day Overflow Rate (high range), gal/sf/day Ex Average Day - 5.35 mgd Ex Max Month - 6.34 mgd 2034 Max Month - 9.50 mgd 2034 Average Day 8.02 mgd MLSS = 2,000 mg/L QRAS = 100% QInfluent Above Typical Range Typical Range Figure 6-1 – Intermediate Clarifier Overflow Rate Figure 6-2 – Intermediate Clarifier Solids Loading Rate 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 - 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 Solids Loading Rate (lb/sf/hr) Plant Flow (mgd) Case 1: 90-ft Clarifier and 120-ft Clarifier Case 2: 90-ft Clarifier and 120-ft Clarifier Case 3: 90-ft Clarifier and 120-ft Clarifier Solids Loading Rate (low range), lb/sf/hr Solids Loading Rate (high range), lb/sf/hr MLSS = 2,000 mg/L QRAS = 100% QInfluent Above Typical Range Typical Range Ex Average Day - 5.35 mgd Ex Max Month - 6.34 mgd 2034 Max Month - 9.50 mgd 2034 Average Day 8.02 mgd ---PAGE BREAK--- 6.2.6 Intermediate Clarifier RAS / WAS Pump Station – No Action The RAS pumps will be able to provide 130 percent return at the projected average day flows with one pump out of service (10.4 mgd firm capacity / 7.94 mgd average day flow). This is greater than the recommend operating range of 25 to 100 percent (Orange Book T3-3.1.1.A.3.c) and is therefore acceptable. The solids wasting rate is expected to increase to 0.27 mgd over the planning period, and each WAS pump is capable of 1.04 mgd with continuous operation. The recommended pumping rate is 25 percent of average day flow (Orange Book T3-3.1.1.A.4.e), and corresponds to 2.0 mgd at the projected 2034 conditions. However, one pump would have to operate only 16 minutes every hour and a redundant pump is available. WAS pumping is therefore considered acceptable through the planning period. 6.2.7 Flash Mix / Flocculation – No Action With the projected flows at the facility, this process will be within 85 percent of its design value. However, the process is not currently utilized at the facility and should not be considered for expansion or upgrades at this time. General maintenance and minor upgrades should be expected if the system is returned to operation. 6.2.8 Final Clarifiers – No Action Final Clarifiers No. 1 and 2 are currently 62 years old and have moderate surface deterioration. If not addressed, the surface deterioration will advance and the structures may become unusable. With the remaining five Final Clarifiers in operation, the hydraulic capacity is 11.0 mgd at sustained conditions which is sufficient to handle the projected maximum month flows. As noted in the Intermediate Clarifier discussion, the Final Clarifiers will be required to provide redundancy in the event either Intermediate Clarifier is taken off-line. This will result in additional solids loading on the Final Clarifiers and increased operator effort to maintain solids in the HRT Cells. As noted previously, solids removal from the Final Clarifiers is difficult since the solids pump does not operate properly. Operations will also remain difficult because the clarifiers cannot be bypassed and algae growth has been so extensive that the horizontal flights have broken. This increases operations and maintenance costs and also negatively affects UV system performance due to algae carryover to that process. 6.2.9 UV Disinfection – No Action As detailed in the UV evaluation completed by Carollo (Appendix 6-B) the UV system has adequate capacity for the projected flows, although flows greater than 7.5 mgd may result in reduced effectiveness due to short circuiting above the bulbs. Existing problems with UV bank failures, limited and antiquated controls, and limited SCADA integration will also worsen, especially since the vendor has discontinuing the UV system model and will not providing support after 2015. Not having support will likely result in limited availability for replacement parts and higher maintenance costs. Considerable changes to the UV system or replacement are therefore recommended to maintain suitable capacity and reduce the risk of failure. Additionally, emergency power should be considered to reduce the risk of non-disinfected effluent being discharged during a power outage. ---PAGE BREAK--- 6.2.10 Effluent Palmer Bowlus Flume, Effluent Pump Station, and Outfall – No Action The effluent Palmer Bowlus Flume, Effluent Pump Station, and Outfall have sufficient capacity through the planning period. No significant changes from existing conditions are expected. 6.2.11 Aerated Sludge Lagoons – No Action Reference Chapter 7 for an analysis of the Aerated Sludge Lagoons with No Action. Effluent quality from the Aerated Sludge Lagoons is poorer than the effluent from the Intermediate Clarifiers. This has resulted in higher BOD5 and TSS discharges, especially as the lagoons reach solids capacity. Additionally, the poorer quality effluent results in additional cleaning in the Final Clarifiers and UV system. As loads and wasting rates increase, the impact of discharge from the Aerated Sludge Lagoons is expected to worsen. 6.2.12 Hydraulic Capacity – No Action The hydraulic capacity of the facility was estimated based on available design and record drawing information and various water modeling tools. The facility was evaluated at the projected average day and peak hour flows. As shown in Figure 6-3, adequate freeboard (greater than 2 ft) remains at the peak day flows for most of the components. Limited freeboard was identified for the following components: Manhole A-1: 1.3 ft Flash Mix / Flocculation Basins: 1.5 ft Final Clarifiers: 1.4 ft UV Disinfection: 1.7 ft 6.2.13 Ancillary Support Facilities – No Action No significant changes from existing conditions are expected. ---PAGE BREAK--- Figure 6-3 – Hydraulic Profile at 2034 Flows ---PAGE BREAK--- 6.2.14 Summary of No Action Alternative A summary of the existing facility with No Action is included in Table 6-3 with recommended action moving forward. Projected loading with 2034 conditions compared to estimated capacity is included in Figure 6-4. Table 6-3 – Summary of Conditions with No Action Item Existing Conditions Projected Conditions in 2034 with No Action Recommended Action Headworks Bypass Structure is old and may not be operable in an emergency Solids accumulation occurs in the screening channel; access to equipment is limited The screens have sufficient capacity through the planning period. Improvements to the Bypass Structure should be considered. Influent Parshall Flume Historically, the influent flume has experienced turbulence that could affect influent flow measurement accuracy. This issue was resolved in 2014. The flume has sufficient capacity through the planning period. No significant changes from existing conditions are expected. No improvements appear warranted at this time. Influent Pump Station Hoists and lifting points are not available for performing routine maintenance on pumps and valves. Coarse grit accumulation results in cleaning the wet well approximately twice a year. Access to the valve vault is limited. The existing check valves do not seat properly and need to be rebuilt. The pump station has sufficient capacity through the planning period. Modifications to the lift station for pump and valve removal, as well as improved access and covering would help during routine maintenance. High Rate Treatment (HRT) Cells Influent wastewater and RAS distribution in the Inlet Structure does not appear to be balanced, leading to higher MLSS levels in the north HRT Cell and lower dissolved oxygen levels. Oxygen supply during daily peak loading conditions falls to 0.2 to 0.5 mg/l. Dissolved oxygen control is limited to turning on/off a 100-hp aerator in each cell. No redundant mechanical aerators within the basins; spares available on-site. Spare electrical connections are not available within the basins. Safety concerns associated with entry into basins for aerator maintenance. Grit accumulation requires dredging approximately every 10 years. The existing aeration system will barely satisfy projected average day loads; however, maximum month and peak hour loads will result in oxygen limitations. Odors and process instability are likely outcomes. Grit accumulation will increase with higher flows; dredging every ±7 years may be required. An aeration upgrade is recommended to maintain oxygenated MLSS at projected loading conditions. Improvements are recommended to improve operator safety if access to the basins is necessary. Grit removal is recommended to minimize accumulation in the HRT Cells. Additionally, removing a cell from operation with increased organic loading will likely cause process upsets. ---PAGE BREAK--- Item Existing Conditions Projected Conditions in 2034 with No Action Recommended Action Intermediate Clarifiers Intermediate Clarifier No. 2 experiences plugging problems due to tumbleweeds entering the MLSS and suction arm. Intermediate Clarifier No. 1 has a limited work area around the clarifier drive. Intermediate Clarifier No. 1 cannot handle existing flows; process upsets occur when Intermediate Clarifier No. 2 is taken off-line. With increased loading to the facility, removing one of the Intermediate Clarifiers from service will likely result in more significant process upsets and require more operator involvement in the process. Utilize the Final Clarifiers for redundancy; plant staff will have to plan and coordinate outages to minimize process upsets. Intermediate Clarifier RAS/WAS Pump Station Access to valves for maintenance is difficult. None identified beyond normal maintenance. No improvements appear warranted at this time. Flash Mix / Flocculation The existing system has not been utilized since originally constructed. This process will be within 85 percent of its design value at the end of the planning period. The process is not currently utilized at the facility and should not be considered for expansion or upgrades at this time. Final Clarifiers Final Clarifiers 1 and 2 were constructed in 1952 and have surface deterioration in the concrete walls. The clarifiers are currently 62 years old and should be rehabilitated to retain use of the structure. Without a bypass channel or cover, the Final Clarifiers experience significant algae growth when effluent quality from the Intermediate Clarifiers is sufficient for disinfection and discharge. Managing the solids inventory is difficult and may require isolating individual clarifiers while the others accumulate solids. Further, the solids pump does not operate reliability. Final Clarifiers No. 1 and 2 have reached their useful life and are not considered available without near- term rehabilitation. The Final Clarifiers will be within 85 percent of the design capacity. Since they are intended to provide redundancy for the Intermediate Clarifiers, no capacity upgrades appear warranted. A bypass channel should be considered to reduce algae growth and operations effort when Intermediate Clarifier effluent is suitable for disinfection and discharge. The solids return pump is not capable of reliable operation and should be replaced. This will improve operations when the Final Clarifiers are used for back-up to the Intermediate Clarifiers. Covering the Final Clarifiers may reduce algae growth and operations. UV Disinfection The system is typically operated at 100-percent output since it has relatively limited controls to adjust UV dose. The existing system is not satisfactorily integrated to the facility’s SCADA system due to UV system control panel limitations. Operations staff have experienced limited vendor support for the system. Further, the vendor notified the City that they would no longer be supporting the system effective March 31, 2015. The practical maximum flow for the system to limit water depth over the bulbs at no more than one inch is approximately 7.5 mgd. However, the practical limit for the existing system to maintain permit compliance (maximum week conditions) based on the collimated beam test is Replacement parts, including control boards, will have limited availability once the vendor discontinues support in 2015. Repairs and replacement parts may be costly and/or difficult to obtain. Flows greater than 7.5 mgd may result in lower dose effectiveness due to short circuiting above the bulbs. With a projected average day flow of 7.94 mgd, the system is expected to be compromised under normal operating conditions. Options for replacing the UV system should be considered due to limited availability of replacement parts and need for additional capacity. ---PAGE BREAK--- Item Existing Conditions Projected Conditions in 2034 with No Action Recommended Action estimated to be 11.4 mgd, provided bulb output is maintained above 80 percent of the new-bulb output through replacement. Backup power is not provided for continuous operation in the event of a power failure. . Chlorine disinfection can be implemented in an emergency, but consumes resources and can result in inadequately disinfected effluent being discharged. Effluent Palmer Bowlus Flume No issues identified. The flume has sufficient capacity through the planning period. No improvements appear warranted at this time. Effluent Pump Station and Outfall No issues identified. The pump station has sufficient capacity through the planning period. No improvements appear warranted at this time. Aerated Sludge Lagoons Odors are a significant concern during lagoon turnover in the spring and fall. Effluent from the lagoons is routed directly to the Flash Mix / Flocculation Basins and Final Clarifiers. Overall effluent quality from the facility is degraded as the solids inventory increases in the lagoons. Odors are expected to remain an issue. Increased loading can be accommodated with more frequent dredging (i.e. every six to eight years). Effluent quality is expected to be affected with a higher discharge rate of supernatant from the lagoons. See Chapter 7 for analysis and development of alternatives for solids management. A lift station to intercept effluent from the Aerated Sludge Lagoons is recommended to capture lower- quality effluent and route it back to the HRT Cells. Hydraulic Capacity No issues identified. Freeboard during projected peak hour flows will generally be greater than 2 ft for all components. Processes with limited freeboard do not appear to warrant an improvement. No changes appear warranted at this time. Ancillary Support Systems Electrical service expansion in the Headworks and Influent Pump Station is limited. Electrical service expansion for the Aerated Sludge Lagoons is not possible. Standby power is not available for the HRT Cells and the UV system, but should be considered for Class II reliability No significant changes expected. Electrical service modifications for biosolids management may be necessary, if improvements are made to that system. Standby power for the UV System is recommended. Standby power for the biological system should be considered in conjunction with potential alternatives to address oxygen deficiency. Reference Chapter 5 for a complete list of observed deficiencies. ---PAGE BREAK--- Figure 6-4 – Loading and Capacity Summary at Projected 2034 Conditions ---PAGE BREAK--- The deficiencies noted in Table 6-3 were reviewed with City staff over the course of several workshops to determine which upgrades were desired and the corresponding scope of such work. General facility upgrades are presented in Table 6-4 below, while biological treatment and UV disinfection alternatives are discussed in subsequent sections. Detailed cost opinions are included in Appendix 6-C. Table 6-4 – Summary of General Facility Upgrades Item Description Approximate Capital Cost Preliminary Treatment Headworks Bypass: Construct a new gate in the intersection of Bruneau Avenue and Kingwood Street. Influent Pump Station: Add a 3-ton bridge crane and electric hoist at the Influent Pump Station; improve operator access to valve vault; modify wet well for grit trap prior to pumps $430,000 Final Clarifiers Final Clarifiers 1 and 2: Rebuild walkway between clarifiers; rehabilitate degraded surface and weirs (approximately the top four feet); replace solids pump; construct Final Clarifier bypass line from Flash Mix Basin to UV system. $580,000 Final Clarifiers 1 through 7: Cover basins with aluminum plank to prevent algae growth (alternate covers include mesh or fabric, but were not considered at this time). Note: this improvement is not warranted if the Final Clarifier Bypass and Aerated Sludge Lagoon Lift Station are constructed. $1,350,000 UV Disinfection Emergency Power: Add a 150 kW generator to the UV system for emergency power. $230,000 Aerated Sludge Lagoons Lift Station: Construct a simplex lift station in the lagoon outlet manhole (northwest of Lagoon No. raise manhole rim; construct 6- in force main to HRT Inlet Structure; local controls and alarms. $190,000 Approximate capital cost in 2014 dollars; includes construction , contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. To address the HRT Cells’ insufficient oxygen supply (reference Table 6-1) and operational issues, the following alternatives were developed through workshops with the City and are discussed in subsequent sections: Alternative 1 – No Action Alternative 2 – Retain Existing HRT Cells and Add Mechanical Aeration Alternative 3 – Add a Third HRT Cell with Mechanical Aeration Alternative 4 – Retain Existing HRT Cells and Retrofit with Diffused Aeration Alternative 5 – New Concrete Aeration Basins with Fine Bubble Aeration ---PAGE BREAK--- 6.4.1 Alternative 1 – No Action As discussed in Section 6.2.4, a No Action approach to the HRT Cells is not viable due to insufficient oxygen supply. Current average day loading to the facility results in DO levels at or below 0.5 mg/l during peak hour loads, with conditions expected to worsen as loads increase to the facility. Additionally, the existing aerators pose an elevated safety risk related to entering the HRT Cell, accessing and maintaining the aerators in place, and during removal due to the narrow dike. This alternative is not considered viable; however, it is retained for subsequent ranking because it provides a baseline comparison to other alternatives. 6.4.2 Alternative 2 – Retain Existing HRT Cells and Add Mechanical Aeration Additional mechanical aerators could be added to the existing HRT Cells to increase oxygen supply. The following aeration is estimated to satisfy the projected 2034 oxygen demands listed in Table 6-1 (supporting calculations provided in Appendix 6-A): Maximum month conditions – 500 hp per HRT Cell; 1,000 hp total Peak hour oxygen demand – 700 hp per HRT Cell; 1,400 hp total This equates to an additional 300 hp installed per HRT Cell, which could be attained by using four 100-hp aerators and two 150-hp aerators per cell. This would constitute a significant electrical upgrade and necessitate improvements and expansion to the existing motor control center (MCC). Incorporation of VFDs to adjust aerator speed to match demand is recommended, as well as an improved boat launch to safely enter the HRT Cells. The primary benefits to this alternative are familiarity in operations and utilization of existing infrastructure. However, this alternative is not considered practical, in part, due to the amount of mechanical aeration required. Experience has shown a practical limit for the amount of mechanical aeration in a basin is 200 hp/MG without impacting oxygen transfer and mixing, and few lagoons are operated at that mixing level. With this alternative, 233 hp/MG would be required. The larger mixers also pose a potential problem to the existing HRT Cell liner. The recommended operating depth of the existing 75-hp mixers generally matches the side slopes of the HRTs, while the 100-hp mixers are suitable for the center of the HRTs where depth is greatest. Assuming the 100-hp aerators are located on the periphery of the HRTs, the aerators could potentially cause long-term wear on the liners. A similar situation exists for the 150-hp aerators. Safety concerns are amplified with this option due to the increased number of aerators. Furthermore, mechanical aerators are relatively inefficient compared to blowers and fine bubble systems. Operational flexibility is also a concern with this option. The HRT Cells must be removed from service and cleaned to remove accumulated grit approximately every ±10 years. With the increased loads, it is unlikely that a single cell would be able to satisfy oxygen demands while the other cell is taken offline. Utilization of the Aerated Sludge Lagoons would be required to process influent loads. During preliminary screening of alternatives with the City, Alternative 2 was not considered a viable long-term solution for the reasons noted above and therefore not carried forward for further evaluation. However, a hybrid of this option could be pursued as a short-term solution to the current oxygen limitations as part of an overall phasing plan. Each HRT Cell can accommodate one additional 100-hp aerator with minimal upgrades to the electrical system (reference Section 5.2.5). Implementing this short-term solution would potentially address ---PAGE BREAK--- existing oxygen deficiencies for the next eight to ten years, depending on how influent loading increases to the facility. 6.4.3 Alternative 3 – Add a Third HRT Cell with Mechanical Aeration Construction of an equally-sized, third HRT Cell (i.e. 3 MG) provides a way to distribute the minimum required 1,400 hp necessary for projected peak loads across three cells while addressing operational flexibility concerns if a cell is taken offline. The existing two HRT Cells would require an additional 75-hp aerator, and the new HRT Cell would be constructed with at five 75-hp and one 100-hp aerators (or a similar combination). The resulting mixing energy would be 158 hp/MG, which is below the practical limit of 200 hp/MG noted previously Similar to Alternative 2, this alternative would necessitate improvements and expansion to the existing motor control center (MCC), incorporation of VFDs to adjust aerator speed to match demand, and an improved boat launch to safely enter the HRT Cells. A new distribution box would also be required to evenly distribute influent and RAS to each of the three cells. The third cell could be constructed north of HRT Cell 1 without impacting other processes but would require a significant amount of fill. The size of the cell would effectively consume the remaining space on the north end of the site and limit future expansion opportunities or incorporation of other treatment processes (e.g. biological nutrient removal, primary clarification, filtration, chemical addition, etc.). Additional drawbacks include relatively high energy usage, with the projected energy cost over a 20-year period estimated at $5,000,000. As significant, this option would perpetuate the operator safety concerns associated with accessing and maintaining the mechanical aerators as previously discussed. The merits of this alternative were discussed during several workshops with the City, and although viable, Alternative 3 was not carried forward for further evaluation for the reasons noted above. 6.4.4 Alternative 4 – Retain Existing HRT Cells and Retrofit with Diffused Aeration Fine bubble aeration increases energy efficiency by more effectively supplying oxygen to the mixed liquor, and the depth of the existing HRT Cells (approximately 20 to 22 ft) is in the optimum range for diffused aeration. For example, the existing mechanical aerators have an estimated field transfer rate of 1.5 lb O2/hp-hr, while a typical blower and fine bubble diffuser system has an estimated field transfer rate of approximately 2.3 lb O2/hp-hr – approximately 53 percent more efficient. As a result, the following blower horsepower (active duty) is estimated to satisfy the projected 2034 oxygen demands listed In Table 6-1 (supporting calculations provided in Appendix 6-A): Maximum month conditions – 650 to 700 hp total Peak hour oxygen demand – 950 to 1,000 hp total The blowers could be constructed in the abandoned RAS building located near Intermediate Clarifier 1; expansion of the MCC would be required to accommodate the change to blowers. Nitrification is likely during summer months; therefore, aeration system sizing has included the demand due to ammonia oxidation. For purposes of this evaluation, it was assumed that all diffusers would be mounted to the floor of the existing HRT Cells, an area approximately 76 ft wide and 106 ft long (8,056 ft2). The existing lagoons would require cleaning to remove biosolids and grit, a sand base on top of the liner, and a new concrete floor for mounting the diffusers. A new ---PAGE BREAK--- liner would also be recommended during this work since the existing liner is approximately 20 years old. A critical component to diffuser systems is maintaining adequate spacing of the diffusers for cleaning and to prevent a reduction in oxygen transfer resulting for coalescing bubbles. Maintaining a ratio of floor area to diffuser area greater than 4.5 is typically suggested by manufacturers. An estimated floor to diffuser area ratio greater than 5 is expected to accommodate peak demands; therefore, diffuser spacing would be adequate if the existing HRT Cell floors are utilized. Accessing the diffusers for maintenance would be necessary, and a retractable staircase would likely be required. A significant concern with fine bubble aeration located on the floor of the HRT Cells, however, is the potential for incomplete mixing on the side slopes of the HRT Cells and possible short-circuiting in the cells which would compromise treatment performance. The sides of the HRT Cells are sloped at 2H:1V, creating a top surface that is approximately 166 ft wide by 196 ft long (32,536 ft2) and a basin surface that is nearly 4 times larger than the floor area where the diffusers would be mounted. It is possible that a rolling pattern would be induced on the side slopes, although this is not certain without a computation fluid dynamics (CFD) model or similar case studies to draw from. Mid-depth diffusers on the slopes may be required to provide mixing, but a separate blower system (or pressure regulating system) would be required because the diffusers would be at a lower pressure than those mounted on the basin floor. Additional side effects of incomplete diffuser coverage could include significant foam and scum buildup in the basins, with no positive means of removal. Alternatively, the existing mechanical aerators could be retained but this would result in significantly more labor and equipment maintenance, as well as a reduction in energy inefficiency. Grit removal would be required with this option to prevent material accumulation at the diffusers. Typical grit removal systems include vortex chambers, circular stacked trays, and rectangular aerated chambers. A specific process was not selected at this time. However, aerated grit chambers are generally considered less favorable due to higher energy usage and negative impacts to nutrient removal processes. Grit removal upstream of the Influent Pump Station is ideal, but adequate head is not available and only minor erosion of the pump impellers has been detected by the operators to date. Therefore grit removal would most likely be located immediately upstream of the HRT Cells and constructed against the exterior bank using import fill. A majority of the grit removal equipment would be located level with the top of the existing HRT Cell dike, with a grit classifier and accumulated grit container located at the lower road level. Plant staff would therefore be required to traverse a two-story building several times during the day for normal operations and maintenance. This alternative was determined to be viable during preliminary screening workshops with the City and therefore carried forward for further evaluation. The probable capital cost for this alternative is $7,810,000 to retrofit the HRT Cells and $3,590,000 for grit removal. The O&M cost for the 20-year planning period is expected to be approximately $4,500,000. Reference Appendix 6-C for detailed opinions of probable cost. 6.4.5 Alternative 5 – New Concrete Aeration Basins with Fine Bubble Aeration As noted in the preceding section, retrofitting the existing HRT Cells is problematic and may result in incomplete mixing, short-circuiting, difficultly in accessing the diffusers for maintenance, and potential impacts to treatment performance. New concrete basins were therefore evaluated in this alternative. Two equally sized basins would have a plug flow configuration to minimize short-circuiting and vertical walls to enable common wall construction and easier expansion in the future. Basin size for planning purposes was assumed to be 3 MG total. Although half the size of the existing HRT Cells, more efficient oxygen transfer is possible and the volume should be reduced to enable ---PAGE BREAK--- complete mixing with fine bubble diffusers. Grit removal will be required to prevent material accumulation in the basin. Blower requirements would be similar to Alternative 4; i.e. approximately 650 to 700 hp of active duty blowers for maximum month conditions and 950 to 1,000 hp of active duty blowers for peak hour condition. Nitrification will likely occur during the summer months. Since ammonia removal is not an expected permit condition, nitrification may be avoided in the winter by operating at lower MLSS concentrations or removing basins from service. Blower and diffuser system sizing is recommended to account for nitrification, although controls should be configured to match output with observed demand throughout the day. When nitrification does not occur, energy savings of 20 to 30 percent is possible. It is assumed that the abandoned RAS building will be retrofitted for the blowers. Preliminary design criteria for this alternative are included in Table 6-5. This alternative was determined to be viable during preliminary screening workshops with the City and therefore carried forward for further evaluation. The probable capital cost for this alternative is $17,120,000 and $3,590,000 for grit removal. The O&M cost for the 20-year planning period is expected to be approximately $4,500,000. Reference Appendix 6-C for detailed opinions of probable cost. 6.4.6 Summary of Biological Treatment Alternatives The biological treatment alternatives are summarized in Table 6-6 and evaluated in Section 6.6.2. ---PAGE BREAK--- Table 6-5 – New Concrete Treatment Basin Preliminary Design Criteria Item Projected Condition Typical Design Condition or Range Reference Treatment Basins Total Volume (MG) 3 - Number in Operation 2 - Length:Width >4 - Hydraulic Residence Time (days) Existing Average Day 0.56 - 2034 Average Day 0.38 0.25 - 1.0 M&E (2013) 2034 Maximum Month 0.32 0.25 - 1.0 M&E (2013) 2034 Peak Day 0.24 Solids Residence Time, SRT (days) 2 - 5 5 - 15 3 - 15 Orange Book T3-3.1.1.A.3.a M&E (2013) MLSS Concentration (mg/L) 2,000 1,500 - 4000 Orange Book T3-3.1.1.A.3.a M&E (2013) Percent Volatile Solids 80 - Observed Yield (volatile basis) 0.76 - Observed Yield (total solids basis) 0.93 1.0 - 1.2 Orange Book T3-3.1.1.A.3.d Food : Microorganism 2034 average day 0.37 0.2 - 0.6 M&E (2013) Volumetric Loading (lb BOD5 / 1,000 ft3 / day), 2034 average day 55 20 - 100 M&E (2013) Aeration System Blowers Low demand blower 100 to 200 hp High demand blowers 400 hp Standby Blowers High demand blower 400 hp Operation Variable speed to match oxygen demand Diffuser Type Fine bubble Dissolved Oxygen Levels Average day – 2.0 mg/l Maximum month – 2.0 mg/l Peak hour – 0.5 mg/l Orange Book T3-3.1.1.A.4.a Based on observed performance in 2013. ---PAGE BREAK--- Table 6-6 – Summary of Biological Treatment Alternatives Alternative 1: No Action Alternative 2: Retain Existing HRT Cells; Add Mechanical Aeration Alternative 3: Add a Third HRT with Mechanical Aeration Alternative 4: Retain Existing HRTs; Retrofit with Diffused Aeration Alternative 5: New Concrete Aeration Basins with Fine Bubble Aeration List of Upgrades None Utilize existing 3 MG basins Requires 1,400 hp± total in mechanical aeration; assumes complete nitrification Spare aerator(s) on bank required Replace MCC and electrical to existing aerators Provide variable speed control to match influent load Grit removal process not required Add boat launch Utilize existing 3 MG basins and construct an additional 3 MG basin Requires 1,400 hp± total in mechanical aeration; assumes complete nitrification Spare aerator(s) on bank required Replace MCC and electrical to existing aerators Provide variable speed control to match influent load Grit removal process not required Add boat launch Utilize existing basins: 3 MG basins Requires 1,000 hp of active duty blowers (approximately 1,400 hp for installed redundancy) and diffused aeration Complete nitrification Retrofit lagoons to support diffused aeration assemblies – concrete floor and anchors Reline existing HRT Cells since existing liner is approximately 20 years old Repurpose old RAS pump room for blowers Provide variable speed control to match influent load Grit removal is required Need safe access to diffusers Suitable drains on HRTs New basins: Two equally-sized basins with 3 MG total volume; expected SRT of 2 to 5 days; no redundant basins. Requires 1,000 hp of active duty blowers (approximately 1,400 hp for installed redundancy) and diffused aeration Seasonal nitrification depending on MLSS and number of basins in service Provide variable speed control to match influent load Grit removal is required Potential Options: Primary clarification to reduce BOD5 load by ±40%, with a corresponding reduction in oxygen demand Prevent nitrification year round Advantages No capital expenditure. Familiar, proven treatment approach Maximizes use of existing facilities Familiar, proven treatment approach Reduce oxygen demand on individual cells Increased flexibility with three basins Maximizes use of existing facilities Improved energy efficiency – 2034 average day operating load of 600 hp Improved safety and operations Similar process control and SRT Improved energy efficiency – 2034 average day operating load of 600 hp Easier to incorporate nutrient removal Improved safety and operations Smaller footprint which reserves space on the site for future process needs. Disadvantages Not a viable alternative Insufficient oxygen supply at 2034 loads Operator safety would remain an issue Grit removal required every 7 to 10 years Aerator replacement should be budgeted for every 5 years. A short-term upgrade is recommended to address existing oxygen limitations Not a practical alternative due to: Aeration limit: 200 hp/MG (600 hp per HRT), compared to 233 hp/MG with this alternative (700 hp per HRT) High energy usage compared to diffused aeration (i.e. comparatively inefficient) Operator safety would remain an issue Grit removal required every 7 to 10 years; however, process performance is not sustainable if a basin is removed from service. High energy usage compared to diffused aeration Operator safety would remain an issue The third HRT may consume space necessary for future process requirements beyond the current planning period (e.g. nutrient removal, primary clarification, filtration, chemical addition, etc.) Grit removal required every 7 to 10 years One basin must be removed from service for the retrofit New piping and diffusers would require modifications to the liner or thin-walled concrete lining. Limited access across basin (i.e. no walkways) Adequate mixing on side slopes may not be achieved, which could cause short-circuiting in the basins High Capital Cost different technology for the facility, but standard practice Does not allow for future digestion of solids Carried Forward for Evaluation? Yes (baseline comparison) No No Yes Yes ---PAGE BREAK--- The following alternatives were developed through workshops with the City and discussed in subsequent sections: Alternative 1 – No Action Alternative 2 – Upgraded Monitoring and Control Alternative 3 – System Replacement 6.5.1 Alternative 1 – No Action This alternative is not strictly a “No Action” approach as it includes minimal upgrades to the system to maintain functional operation; e.g. replacing lamps, hydraulic changes to maintain no more than 1 inch of water above the bulbs, and lamp replacement protocols to assure more reliable UV treatment as flows increase. Installation of wet sensors to monitor and extend lamp life is also included as a minor improvement. Existing performance is acceptable, but increased flows may result in higher effluent total coliform counts and potential permit violations. The probable capital cost for this alternative is $30,000. 6.5.2 Alternative 2 – Upgraded Monitoring and Control The existing system is controlled strictly on flow rate and does not account for water quality or lamp performance (age and fouling), which would improve efficiency and reliability. Current UV reactors rely on real-time measurements of flow rate, UV transmittance (UVT), and UV lamp intensity measurements to adjust the number of lamps in operation to meet a UV dose or effluent water quality goal. Upgraded monitoring and control would therefore include the following: Replace existing lamps Installation of wet sensors and online UVT meter in each channel to allow for more dose delivery confidence and monitoring of lamp output decay. Use of calibrated, reliable sensors in this way can result in an extension of lamp operational life to 18,000 hours before replacement, as well as more accurate determination of sleeve cleaning intervals. Upgrade the Programmable Logic Controller (PLC) and HMI, collectively referred to as the System Control Center (SCC), to provide continuous real-time dose monitoring of the system and better define alarm conditions and necessary responses. SCADA modifications to address the improved/added monitoring and control features These improvements will not allow the UV system to turn-down to meet varying demands except by turning entire banks on and off. Further, this alternative will not replace all the electronics that will become obsolete per the Trojan notice of equipment retirement (included in Appendix 6-B). In discussions with Trojan, the replacement of the electrical components and control boards of the UV3000 is not a feasible alternative as it would be more costly and result in a less reliable hybrid system compared to full replacement. The probable capital cost for this alternative is $390,000. ---PAGE BREAK--- 6.5.3 Alternative 3 – System Replacement System replacement was evaluated based on three likely manufacturers: Trojan, Xylem/Wedeco, and Calgon. New systems from any of these manufacturers would include several improvements that are now considered industry standard. These improvements include automatic lamp cleaning systems, ability to modulate power to a bank of lamps, online (and accurate) UV intensity sensors, and higher intensity lamps that result in a need for less equipment than the low pressure UV lamps in the UV3000 reactor. An online UVT meter is also recommended for accurate dose control, which can also reduce energy consumption. Design criteria for a new system are summarized in Table 6-7. A preliminary review of the Trojan 3000Plus, Xylem/Wedeco TAK55, and Calgon C3500 systems are included in Appendix 6-B, but no specific equipment selection is made. Each of the systems has advantages and disadvantages compared to the others, but all are expected to have improved efficiency and lower overall energy demand. The probable capital cost for this alternative is $2,300,000. Table 6-7 – UV Disinfection Design Criteria Item Design Criteria Design flow (peak hour) 15.9 mgd Number of channels 2 UV Transmittance (percent) 60 Dose (mJ/cm2) 20 Number of banks per channel 2 Remaining units shall have a design capacity of at least 50 percent of the total design flow (Orange Book G2-8.2) Using a T1 coliphage sizing model; equivalent to approximately 30 mJ/cm2 for an MS2 coliphage sizing model. 6.6.1 Criteria and Relative Weight During alternative development and screening workshops, evaluation criteria were established by the City to permit comparison and ranking of developed alternatives. The criteria utilized in the assessment and corresponding definitions are listed in Table 6-8. ---PAGE BREAK--- Table 6-8 – Evaluation Criteria Criteria Definition A) Present Worth Cost Planning level capital cost plus expected life-cycle cost of an alternative, both in 2014 dollars. The costs reported are approximate and for comparison purposes only. More refined cost estimates will be developed for the preferred alternatives. B) Permit Compliance Ability to satisfy existing and projected permit requirements over the course of the study period. C) Reliability Probability of adequate performance over the expected range of loading and operating conditions in the study period. Consideration is also given for number of similar facilities currently in operation. D) Safety Degree to which operators are exposed to hazardous conditions that could result in injury. However, safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. E) Ability to Expand Ability to expand and adapt a process for greater loading and/or to address changes in permit requirements. F) Energy Efficiency Overall efficiency of the alternative, energy use, carbon footprint, and consumption of non- renewable resources. G) Odor Potential Potential of an alternative to cause foul odors during operations through the course of a year. Significant foul odors negatively impact customer service and is considered to have a negative impact on economic development in the downtown area. H) Ease of Operations Ease of operations and complexity of the process, including the need for specialized operators and process control / testing. I) Ease of Disposal (Biosolids only) Ability to find suitable disposal sites for biosolids; also used to differentiate perceived quality or handling impacts of biosolids that attain the same 503b classification. Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. A pairwise analysis was then performed to compare the relative importance of one criterion to another; e.g. which is more important, Present Worth Cost or Permit Compliance? Relative importance was scored as follows: 5 – significantly more important 4 – more important 3 – equally important 2 – less important 1 – significantly less important The result of the pairwise analysis is shown in Table 6-9. Safety is a major concern for the City; however, it is imperative that safety concerns be addressed with all alternatives, even when considering a “No Action” approach. Safety measures and the costs must therefore be incorporated into the alternative. Safety can then effectively be scored in the Present Worth Cost and Ease of Operations criteria. ---PAGE BREAK--- Table 6-9 – Pairwise Analysis Results Criteria A) Present Worth Cost B) Permit Compliance C) Reliability D) Safety E) Ability to Expand F) Sustainability G) Odor Potential H) Ease of Operations Total Score Weight A) Present Worth Cost - 1 2 1 3 4 1 2 14 8.3% B) Permit Compliance 5 - 4 3 4 4 4 4 28 16.7% C) Reliability 4 2 - 2 3 4 1 3 19 11.3% D) Safety 5 3 4 - 5 5 4 4 30 17.9% E) Ability to Expand 3 2 3 1 - 4 1 3 17 10.1% F) Energy Efficiency 2 2 2 1 2 - 1 2 12 7.1% G) Odor Potential 5 2 5 2 5 5 - 5 29 17.3% H) Ease of Operations 4 2 3 2 3 4 1 - 19 11.3% Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. Alternatives may be compared by scoring each alternative in a category from 1 (least favorable) to 5 (most favorable). The raw score is then multiplied by the criterion’s weight to provide an overall score for the alternative. 6.6.2 Biological Alternatives Of the five alternatives developed for the biological system, only three were carried forward for detailed evaluation as noted in Section 6.4. The remaining three biological treatment alternatives were evaluated during a workshop with the City and ranked as shown in ---PAGE BREAK--- Table 6-10. Alternative 5 “New Concrete Aeration Basins with Diffused Aeration” is the preferred alternative despite the higher capital cost because it provides greater operational flexibility, reduces energy demand over the planning period by approximately 200 hp, allows the facility to transition to nutrient removal more easily, recaptures space at the facility due to a smaller footprint, permits easier expansion due to common wall construction and vertical walls (compared to earthen dikes), and has improved access and safety. ---PAGE BREAK--- Table 6-10 – Biological Treatment Ranking Criteria Alternative 1: No Action Alternative 4: Retrofit HRTs with Diffused Aeration System Alternative 5: New Concrete Aeration Basins with Diffused Aeration Weight A) Present Worth Cost 5.0 2.2 1.4 8.3% B) Permit Compliance 2 5 5 16.7% C) Reliability 1 3 5 11.3% D) Safety - - - 17.9% E) Ability to Expand 1 3 5 10.1% F) Energy Efficiency 1 4 3 7.1% G) Odor Potential 1 3 5 17.3% H) Ease of Operations 2 4 5 11.3% Weighted Score 1.43 2.92 3.81 Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. Therefore, no score was developed in the Safety category. 6.6.3 UV Disinfection Alternatives The three UV alternatives presented in Section 6.5 were evaluated with the City during a workshop to determine the preferred course of action. The results of the evaluation are shown in Table 6-11. Alternative 3 “System Replacement” was selected as the preferred alternative because it addresses critical deficiencies in the existing system’s controls, provides greater reliability, provides greater control for varying flows and UV demand (thereby reducing energy consumption), reduces potential hydraulic short-circuiting, and increases the UV system disinfection capacity. ---PAGE BREAK--- Table 6-11 – UV Disinfection Ranking Criteria Alternative 1: No Action Alternative 2: Upgraded Monitoring and Control Alternative 3: System Replacement Weight A) Present Worth Cost 5.0 4.5 1.0 8.3% B) Permit Compliance 1 5 5 16.7% C) Reliability 1 1 5 11.3% D) Safety - - - 17.9% E) Ability to Expand 1 1 5 10.1% F) Sustainability 1 3 5 7.1% G) Odor Potential N/A N/A N/A 17.3% H) Ease of Operations 2 3 5 11.3% Weighted Score 1.10 1.98 2.91 Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. Therefore, no score was developed in the Safety category. The list of potential general facility upgrades (Section 6.3) were reviewed with City during workshops in light of the selected biological and UV system recommendations (Section 6.6). The selected alternatives for the liquid stream unit processes are summarized in Table 6-12. ---PAGE BREAK--- Table 6-12 – Summary of Recommended Liquid Stream Upgrades Item Description Purpose Approximate Capital Cost Preliminary Treatment Headworks Bypass: Construct a new gate in the intersection of Bruneau Avenue and Kingwood Street. Influent Pump Station: Add a 3-ton bridge crane and electric hoist at the Influent Pump Station; improve operator access to valve vault; modify wet well for grit trap prior to pumps. Address operational needs for emergency bypass conditions of the Headworks and normal operations of the Influent Pump Station. $430,000 Biological Treatment Grit Removal: Construction of a vortex or stacked tray grit removal system; grit pump and classifier; new building. Minimize grit accumulation at fine bubble diffusers and frequency of basin draining and cleaning. $3,590,000 New Concrete Aeration Basins with Diffused Aeration: Includes retrofitting the abandoned RAS pump building for blowers; 3 MG concrete basins (2 At 1.5 MG/each); fine bubble diffusers. Address oxygen deficiency projected over the 20-year planning period; improve operator process control and energy efficiency; improve safety. $18,290,000 Final Clarifiers Final Clarifiers 1 and 2: Rebuild walkway between clarifiers; rehabilitate degraded surface and weirs (approximately the top four feet); replace solids pump; construct Final Clarifier bypass line from Flash Mix Basin to UV system. Maintain existing infrastructure in a viable state; improve operations. $580,000 Final Clarifiers 1 through 7: Cover basins with aluminum plank to prevent algae growth (alternate covers include mesh or fabric, but were not considered at this time). This improvement is not warranted if the Final Clarifier Bypass and Aerated Sludge Lagoon Lift Station are constructed. Therefore, this improvements is not carried forward. N/A UV Disinfection System Replacement: New UV system; improve hydraulics, controls, and functionality. Improve system reliability; improve operations and energy efficiency; integrate system into WWTP SCADA. $2,300,000 Emergency Power: Add a 150 kW generator to the UV system for emergency power. Maintain adequate disinfection in the event of a utility service failure. $230,000 Aerated Sludge Lagoons Lift Station: Construct a simplex lift station in the lagoon outlet manhole (northwest of Lagoon No. raise manhole rim; construct 6-in force main to HRT Inlet Structure; local controls and alarms. Capture lower-quality effluent from the Aerated Sludge Lagoons and return it to the biological process. $190,000 Approximate capital cost in 2014 dollars; includes construction , contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. ---PAGE BREAK--- Alternatives to Meet Facility Goals: Biosolids CHAPTER 7 ---PAGE BREAK--- CHAPTER 7 – ALTERNATIVES TO MEET FACILITIES GOALS: BIOSOLIDS As discussed in Chapters 5 and 6, The City of Kennewick’s wastewater treatment plant utilizes biological treatment processes to convert most of the incoming organic carbon-matter and nutrients into biological solids (biosolids) and carbon dioxide. To maintain an active biological population for effective treatment, a portion of the biosolids must be removed from the treatment process each day. To achieve this, biosolids are removed from the activated sludge treatment process by wasting after clarification (gravity settling). This portion of the solids that are routinely wasted is termed Waste Activated Sludge (WAS). WAS is currently pumped to one of two lagoons for additional stabilization via long term storage. Storing WAS in the lagoons is a cost effective way to stabilize waste sludge and reduce the mass of sludge that needs to be hauled off-site for beneficial use. However, long term biosolids storage has proven to have a high risk of odor potential when the lagoons turn over in the spring. Therefore, the City is investigating additional biosolids management alternatives. Existing biosolids management and potentially acceptable alternatives are discussed below. 7.2.1 Biosolids Production - 2014 The biosolids production ranged between 727 and 18,500 pounds per day (ppd) with an annual average production rate of 9,460 pound per day (total dry solids). The biosolids are about 81% volatile and 19% inert. The total biosolids production rate, on an annual average basis, is approximately 92% of the influent volatile BOD5 loading rate which is a relationship known as biosolids yield. This yield relationship will be used to project biosolids production to the end of the planning period based on the flows and loads generated in Chapter 3. The annual average waste activated sludge (WAS) concentration in 2013 was approximately 1% by weight, (9,360 mg/l) based on lab data from the City. Under average conditions, it would take 121,200 gallons of WAS to waste 9,460 pounds of biosolids per day; therefore, about 121,200 gallons per day of WAS are pumped to solids storage lagoons. 7.2.2 Biosolids Production - 2034 As noted in Chapter 3, the BOD5 load entering the plant is expected to increase to 22,000 pound per day which is expected to yield about 20,000 pounds of biosolids per day by the end of the planning period. The biosolids are expected to remain about 81% volatile on average. If the annual average waste activated sludge (WAS) concentration remained about 9,360 mg/l, it would take 256,000 gallons of WAS to waste 20,000 pounds of biosolids per day. Therefore, future facilities will need a hydraulic capacity greater than 256,000 gpd and a solids capacity greater than 20,000 pounds per day (10 dry tons per day – 3,650 dry tons per year). ---PAGE BREAK--- Biosolids are wasted from the activated sludge treatment process to one of two large lagoons where they are stored between 6 to 12 years depending on dredging schedule. The biosolids settle in the lagoon where they typically breakdown sufficiently to meet EPA Part 503 Class B requirements. The biosolids are periodically dredged from the lagoons. The last dredging project was in 2012 and removed approximately 7,530 tons (dry basis) of biosolids from the southern lagoon. Dredging methodology/approach may vary; however, in the 2012 project biosolids were pumped from the bottom of the lagoon by a floating dredge and pumped to a belt filter press dewatering process (mobile units set up by contractor) where the biosolids were dewatered and dumped into haul trucks. The biosolids were hauled to Natural Selection Farms for beneficial use. The filtrate from the dewatering units was pumped back into the lagoon. The north solids pond is scheduled to be dredged in the year 2017. Surface aerators (19 units for a total of 445 hp) were recently added to the solids storage lagoons to mitigate odors emitted when the lagoons turn over. However, the additional aeration was insufficient to prevent odors emanating from the lagoon in the spring of 2014. The City would like to evaluate biosolids management alternative that may be available to them to decrease risk of odors. Biosolids management alternative are discussed below. 7.4.1 WAS Pump Station See Section 5.2.7 for details regarding Component Description and Operations 7.4.2 Aerated Solids Storage Lagoons See Section 5.2.12 for details regarding Component Description and Operations 7.4.3 Biosolids Removal and Disposal The City does not own equipment to remove and manage biosolids after they enter the solids storage lagoons. As described above, the City contracts for services to remove and dispose of the biosolids as needed. The solids storage lagoons have enough capacity to serve throughout the planning period without significant modifications. Between now and the end of the planning period, three dredging projects would be necessary to remove and dispose of the accumulated biosolids. Observed Deficiencies Access to floating aerators increases risk to employee safety. Biosolids removal and disposal costs are subject to contract pricing and approved third party land application sites. Lagoon turnover events generate odor. Significant energy use Summary Sufficient capacity to serve throughout the planning period. Risk of odors Removal and disposal subject to market cost. ---PAGE BREAK--- There are four base methodologies available to the City to manage their biosolids and several sub-options within each alternative to achieve the end goal. Sub-options are discussed later. The base methodologies are: 1. No Action (Class B biosolids): Biosolids stabilization by long term lagoon storage with periodic dredging, dewatering and incorporation into cropland soils through contractor. 2. Manage Un-stabilized Biosolids (un-classified biosolids): Dewater WAS and haul un-classified biosolids off-site for additional treatment, by others, prior to beneficial use. Additional treatment may be digestion, drying, composting, or other EPA-approved methodology. 3. Manage Chemically stabilized Biosolids (Class B biosolids): Dewater WAS, add lime to stabilize the biosolids, and haul off-site for beneficial use, by others, as a crop land soil amendment. 4. Manage Biologically Digested (Stabilized) Biosolids (Class B biosolids): Thicken WAS, stabilize thickened biosolids via digestion, and dispose off-site for beneficial use, by others, as a crop land soil amendment. Each of these alternatives produces a biosolids product that could be additionally treated to meet Class A biosolids standards. Treating biosolids to Class A standards is not a regulatory requirement; however, the City wanted to evaluate the option to gain greater autonomy from outside fluctuations in the market and potentially utilize the biosolids within the community. Therefore, Class A biosolids treatment processes are included as an additive alternate in the evaluation. The major components for each alternative are listed in Table 7-1. Table 7-1 – Distinctive Components for Each Biosolids Alternative Alt 1 Alt 2 Alt 3 Alt 4 Major Components and/or Unit Processes No Action Un-Stabilized Biosolids Chemically Stabilized Biosolids Digestion Stabilized Biosolids Aeration X Dredging X Storage X X X Odor Control X X X Thickener X Dewater unstable biosolids X X Digestion X Dewater stabilized biosolids X Lime Treatment X Class A Process X X X Disposal at approved site X X X X There are several options within each alternative listed above. Sub-options are discussed below. ---PAGE BREAK--- 7.5.1 Alternative 1 – No Action The existing biosolids management methodology of long term storage of waste activated sludge in the lagoons has caused significant odors and concern for odors is the primary driver for an alternative management methodology. The No Action alternative odor potential will remain similar to historic levels. The existing biosolids management methodology could be employed throughout the planning period without significant modifications. Between now and the end of the planning period, three dredging projects would be necessary to remove and dispose of the accumulated biosolids (estimated in 2017, 2026, and 2032). The three dredging projects, similar in scope to the 2012 project have a present value cost of $5,800,000. The lagoons currently have 445 horsepower of surface aeration (19 units) consuming about $160,000 per year of power. The present value of the aerator power consumption is about $3,200,000. The present value of aerator replacement and other maintenance is about $1,100,000 and $500,000 respectively. The expected present value of Alternative 1 is $10.6 million dollars. The dredged material is removed and disposed of by contract; therefore, a Class A option for this alternative is not necessary. However, it should be noted that this option is subject to availability of adequate permitted farmland to accept Class B biosolids. Typically, contracted biosolids processors have crop rotations to accommodate large projects if planned in advance; however, there is limited certainty without long-term contractual obligations. The engineer’s opinion of probable cost, on a present value basis, for the No Action alternative is reported in Table 7-2. Table 7-2 – Alternative 1 Present Value Cost Estimate (millions) Component Contract Dredging $5.80 Power $3.20 Aerator Replacement $1.10 O & M $0.5 Total $10.60 The advantages and disadvantages of the current management strategy are listed in Table 7-3. Table 7-3 – Alternative 1 Advantages and Disadvantages Advantages Disadvantages Ability to waste 24 hours/day Aeration energy Low daily maintenance Odor generation Robust “wide spot” for emergency storage in the existing aerated sludge lagoons Contract dredging/removal/disposal Removal subject to market prices and availability of beneficial use sites Ability to control return flows Solubilize nitrogen to ammonia Evaporation of return flow Destroy 45-50% of biosolids Methane gas escapes (greenhouse gas impacts) ---PAGE BREAK--- 7.5.2 Alternative 2 – Manage Un-Stabilized Biosolids This alternative would remove the solids storage lagoons from service1 and add a mechanical dewatering step for daily processing of the WAS. Direct dewatering of the WAS will not result in Class B biosolids and will result in highly degradable solids that will become odorous very quickly. Because the biosolids are not stabilized on-site, they will have to be stabilized off-site prior to beneficial use. The WDOE2 has stated that they will not allow non-classified biosolids to be hauled off-site to a staging area for “air-drying” treatment to Class B requirements. Therefore, it was assumed the dewatered un-stabilized biosolids could be hauled to a licensed management entity (Natural Selection Farms, Madison Farms and/or the City of Richland’s compost operation) for additional treatment prior to beneficial use. This option is subject to increased risk depending on the availability of licensed beneficial use facilities and their continued willingness to receive the biosolids. The advantages and disadvantages of this alternative are listed in Table 7-4. Table 7-4 – Alternative 2 Advantages and Disadvantages Advantages Disadvantages Waste more often Return flows could impact the biological process Storage lagoons not needed (but retained for redundancy and emergency use) Manage biosolids daily No odors from lagoon Daily maintenance on equipment Less methane gas released No biosolids degradation (increase haul volume) Smaller overall footprint Requires daily haul and odor control Nutrients are not solubilized Off-site management of un- stabilized biosolids Typical WAS dewatering technology includes: screw press, belt filter press and centrifuge. Un-stabilized biosolids are typically more difficult to dewater than a stabilized biosolids. Therefore, the dewatering unit process equipment was de-rated to account for the required lower loading rates. Additional equipment is required to dewater un-stable WAS and reflected in the estimated cost. Belt Filter Press dewatering technology was used as the basis for performance and cost estimates for this master planning effort because the overall lifecycle cost between the technologies is not significant enough to effect the planning decisions. The state of the technology should be evaluated during the preliminary engineering phase. The WAS could be periodically wasted to a belt filter press mechanical dewatering unit process. For planning purposes, the BFP is expected to produce a biosolids with 18% solids content. At the end of planning period, four 2- meter BFP units will be required to dewater the un-stable biosolids. The design criteria for a typical belt filter press are listed in Table 7-5. ---PAGE BREAK--- Table 7-5 – Design Criteria Associated with Dewatering Un-Stabilized WAS Item Projected Condition Typical Design Condition/Range A Number of Units B Hydraulic Capacity 256,000 gpd 10,200 gph 4 Solids Capacity 20,000 pounds/day 800 lb/hr 4 Operation hours 7.5 hr/d – 7 day/week Wet Cake 18 % 15 – 20 % A De-rated Capacity 50% due to Un-Stabilized WAS being more difficult to dewater. B Redundancy and reliability provided by one of the existing solids storage lagoons and/or operating the units more hours The disposal fee for un-stabilized biosolids was assumed to be 50% more than for stabilized Class B Biosolids because of the extra effort needed by the contracted beneficial use facility to stabilize the biosolids. The estimated costs to manage un-stabilized biosolids are reported in Table 7-6. See Appendix for detailed cost estimates. Table 7-6 – Alternative 2 Present Value Cost Estimate (millions) Component Belt Press Dewatering Unit Process $13.00 O & M $5.20 Disposal $7.10 Total $25.30 7.5.3 Alternative 3 – Manage Chemically Stabilized Biosolids This alternative would remove the solids storage lagoons from service3 and add a mechanical dewatering step and lime addition for daily processing of the WAS. This alternative would dewater un-stabilized WAS and add lime to increase the pH to meet Class B requirements and reduce odor potential. Similar to Alternative 2, it was assumed the dewatered chemically stabilized biosolids could be disposed of by hauling to a licensed management entity (Natural Selection Farms, Madison Farms and/or the City of Richland’s compost operation) for beneficial use. The pH would need to be greater than 12 for at least 2 hours and, after that, greater than 11.5 for 22 hours. It is assumed these requirements can be met by monitoring the stock pile at the beneficial use site. Lime addition would require about 2,100 tons per year initially to achieve Class B and increase to 4,400 tons per year by the end of the planning period. Adding lime also increases the total solids disposal requirement and makes handling more difficult. As with Alternative 2, un-stabilized biosolids are typically more difficult to dewater and require lower loading rates than needed to dewater a stabilized biosolids. Therefore, additional equipment is required for this alternative compared to Alternative 4 which is reflected in the estimated cost. The dewatering technology evaluated for this alternative is the same as considered in Alternative 2 (belt filter press). This alternative includes a post-dewatering lime stabilization unit process (lime hopper with feeder and paddle mixer). ---PAGE BREAK--- For this alternatives it is assumed the hold time for elevated pH are met in the haul truck and by monitoring the stockpile at the beneficial use and/or compost facility. The design criteria for typical lime post treatment are listed in Table 7-7. Table 7-7 – Lime Post Treatment Design Criteria, Un-Stabile WAS Item Projected Condition Typical Design Condition/Range Number of Units Solids Capacity 20,000 pounds/day 3757 lb/hr 1 unit needed Assume 2 for reliability Operation hours 7.5 hr/d – 7 day/week The engineer’s opinion of probable cost, on a present value basis, for this Alternative is reported in Table 7-8. Table 7-8 – Alternative 3 Present Value Cost Estimate Component Belt Press Dewatering Unit Process $13.00 O & M $5.20 Disposal $4.70 Lime Post-Treatment $3.30 20-yr O & M and Production $1.50 Disposal Adder due to Lime wt. $0.80 Total $28.60 The advantages and disadvantages of managing chemically stabilized biosolids are listed in Table 7-9. Table 7-9 – Alternative 3 Advantages and Disadvantages Advantages Disadvantages Waste more often Return flow impacts Storage lagoons not needed (but retained for redundancy and emergency use) Manage biosolids daily No odors from lagoon Daily maintenance on equipment Less methane gas released No biosolids degradation (increased haul volume) Smaller overall footprint than existing Observe off-site stockpile for 24 hours Nutrients are not solubilized Multiple handling steps Product more desirable, due to high pH, for acid soil amendment Off-site management of partially stabilized biosolids ---PAGE BREAK--- 7.5.4 Alternative 4 – Manage Biologically Digested (Stabilized) Biosolids This alternative would remove the solids storage lagoons from service4 and add a mechanical dewatering step and digestion for daily processing of the WAS. The WAS could be stabilized by digestion which would produce Class B biosolids; thereby eliminating the need for lime addition required in Alternative 3 and managing un-stabilized biosolids needed in Alternative 2. In addition to stabilizing the biosolids, the digestion process consumes approximately 35% of the solids; thereby reducing the volume to dispose. It was assumed the dewatered stabilized biosolids could be disposed of by hauling to a licensed management entity (Natural Selection Farms, Madison Farms and/or the City of Richland’s compost operation) for beneficial use. For this alternative, it was assumed the WAS could be thickened prior to digestion to about 2.5% solids using a rotating drum thickener or a gravity belt thickener for about the same unit process cost. Digestion Unit Process Evaluation There are two main technologies to digest thickened biosolids: 1. Aerobic Digestion 2. Anaerobic Digestion The merits of aerobic and anaerobic digestion were discussed with City staff at a workshop. The technologies are evaluate below. Aerobic Digestion Sub-Evaluation The critical design criterion for aerobic digestion is a 60 day hydraulic detention time (HDT) based on the cool temperature of the wastewater in the winter. Aerobic digestion was considered a viable and cost effective option mainly due to the ability to convert part of the solids storage lagoon into a 60 day HDT aerobic digester with surface aeration; thereby, reducing the initial capital expense. However, the energy required for aerobic digestion has a high annual cost which negates the lower capital cost throughout the planning period. There are two significant uncertainties that reduce the viability of aerobic digestion: 4 For reliability and redundancy purposes, one lagoon should remain available for flow equalization, emergency storage and temporary sludge storage. 1. Aerobic digestion is an energy intensive unit process. Future energy prices are volatile and a disproportionate increase in electricity rates would negatively impact the viability of an energy intensive unit process. Additionally, the City has sustainability criteria which aerobic digestion negatively impacts. 2. The assumption that an existing lagoon could be partitioned and serve as a 6 million gallon aerobic digester adds risk to the option as the service life of the existing lagoons are unknown. Therefore, for cost estimating purposes, it was assume the lagoons could not server throughout the planning period and new tank volume would be needed. The engineer’s opinion of probable cost, on a present value basis, to construct an aerobic digestion process is reported in Table 7-10. ---PAGE BREAK--- Table 7-10 – Aerobic Digester Present Value Cost Estimate Component Capital $11.16 O & M $6.14 Total $17.30 Anaerobic Digestion Sub-Evaluation The critical design criterion for anaerobic digestion is a 20 day hydraulic detention time. Staff expressed a few concerns regarding the operation: 1. Odors associated with anaerobic sludge and digester gas 2. Managing flammable digester gas 3. Managing boilers and heat exchangers To address concerns, City staff toured facilities with anaerobic digestion and found the management and operation of the unit process to be reliable and issues associated with their concerns to be manageable. The engineer’s opinion of probable cost, on a present value basis, to construct an anaerobic digestion process is reported in Table 7-11. Table 7-11 – Anaerobic Digester Present Value Cost Estimate Component Capital $13.60 O & M $3.30 Total $16.90 ---PAGE BREAK--- Digestion Alternative Preferred Option Anaerobic digestion is the preferred digestion option because the life cycle cost is less given the uncertainties of retrofitting the existing lagoons and the high energy demand of aerobic digestion. Therefore, aerobic digestion was dropped from further evaluation. The dewatering technology evaluated for the digestion alternative is the same as that considered in Alternative 2 and 3. Because the biosolids are more stable, the biosolids are easier to reliably dewater and the dewatering units can consistently manage higher loads. The design criteria for a typical belt filter press dewatering stabilized biosolids are listed in Table 7-12. Table 7-12 – Dewatering Stabilized Biosolids Design Criteria Item Projected Condition Typical Design Condition/Range Number of Units Belt Filter Press Hydraulic Capacity 96,000 gpd 20,400 gph 2 Solids Capacity 13,000 pounds/day after digestion 2,857 lb/hr 2 Operation hours 7.5 hr/d – 7 day/week Additional design criterial for this alternative are listed in Table 7-13. Table 7-13 – Alternative 4 Stabilized Biosolids Design Criteria Item Projected Condition Typical Design Condition/Range Number of Units Thickening Hydraulic Flow, Gravity thickened WAS to 1% 240,000 gpd 125-200 gpm 2, redundancy provided by increased operating hours Solids Loading 20,000 pounds per day Operation hours 7.5 hr/d – 7 day/week Digestion Hydraulic Flow, Mechanically Thickened WAS to 2.5% 96,000 gpd Volatile Solids Loading 16,200 pounds per day 0.1-0.3 lb/ft3 (volume = 1.2 MG) Hydraulic Detention Time 15-20 d (volume = 1.9 MG) 2 at 1 MG each Mixing Power: 25-40 hp / MG 50 - 80 hp Dewatering Solids Capacity 13,000 pounds/day 2,857 lb/hr 1 needed, provide 2 for reliability Hydraulic Capacity 96,000 gpd 20,400 gph 1 needed, provide 2 for reliability Operation hours 7.5 hr/d – 7 day/week ---PAGE BREAK--- However, the primary savings is due to the 35% additional solids destruction which is reflected in the opinions of cost. The engineer’s opinion of probable cost, on a present value basis, for this option is reported in Table 7-14. Table 7-14 – Alternative 4 Present Value Cost Estimate (millions) Component Belt Press Dewatering Unit Process $8.40 O & M $4.20 Disposal $3.10 Thickening Unit Process $5.30 O & M $3.80 Anaerobic Digester $13.60 O & M $3.30 Total $41.70 The advantages and disadvantages of managing biologically stabilized biosolids are listed in Table 7-15. Table 7-15 – Alternative 4 Advantages and Disadvantages Advantages Disadvantages Storage lagoons not needed No odors from lagoon Manage biogas Methane gas is flared or beneficially used Additional processes to operated and maintain (e.g. thickeners, boilers, digester heating, etc.) Biosolids destruction by digestion Return flow impacts Class B product Manage biosolids daily Thicker biosolids Daily maintenance on equipment Product more acceptable to licensed biosolids management companies Expensive alternative ---PAGE BREAK--- 7.5.5 Biosolids Management Alternatives Cost Summary The estimated present worth of the life-cycle costs of the alternatives are summarized in Table 7-16. Table 7-16 – Biosolids Management Alternatives Cost Summary (in millions of Alt #1 No Action Alt #2 Un-Stabilized Biosolids Alt #3 Chemically Stabilized Biosolids Alt #4 Anaerobic Digestion Total $10.6 $25.3 $28.6 $41.8 Class B and un-classified biosolids can be treated to meet Class A requirements in a number of ways under the 503 regulations. Those options were reviewed in a workshop with the City and a short-list of acceptable options was developed. Those options are: Drying the biosolids to less than 10% moisture content. This can be done by: o Solar energy and fans to evaporate the water and move it away from the biosolids, or by o Adding external heat to evaporate the water, or a o Combination of solar energy and heat (radiant floor heating in solar drying greenhouses) Chemical treatment to increase the pH and temperature for a specific length of time. Aerobically composting classified or un-classified biosolids with a bulking agent to achieve time and temperature requirements. Class A alternatives are valid for all management alternatives; however, sludge chemically stabilized to meet Class B requirement is not needed prior to a Class A process. Therefore, Class A treatment is only considered for Alternatives 2 and 4. Meeting Class A requirements will provide with City with more flexibility over disposal options because they will not be subject to the price and availability of licensed beneficial use facilities and availability of land for Class B land application. Production of Class A biosolids will result in more certainty in future costs and more control for the City. Moreover, there is the opportunity to put the biosolids to beneficial use on City owned facilities such as parks and ball fields. 7.6.1 Class A Alternative 1 – Mechanical Solar Air Drying Class A biosolids requirements can be achieved by drying the biosolids to moisture content less than 10 percent (90% solids). Dewatered biosolids can be dried using solar energy in a greenhouse building with mechanical mixing and forced air movement. In this approach, the WAS is periodically (daily) wasted to a mechanical dewatering unit process (BFP) then conveyed to a Solar Drying unit process with a simple conveyor. The solar gain provides adequate heat most of the year to make a Class A biosolids by drying the biosolids to moisture content less than 10 percent. A solar dryer unit process receives biosolids at the front end of a long greenhouse type structure. The biosolids are spread over a 36 foot wide area and mixed/aerated with a traveling-bridge mixer. As the mixer moves along the length of the greenhouse, the biosolids are slowly moved from the front end of the building to the finished end of the building (about 380 feet away). As the biosolids move toward the finished end, the moisture is slowly removed by evaporation using solar energy5 and fans that move the moist air out of the greenhouse. A solar drying unit process is shown in Figure 7-1; note that several greenhouse solar dryers would be required based on the ---PAGE BREAK--- volume of solids and the moisture content of the material delivered to the solar dryer. Since solids content is significantly different between alternatives, associated sizing and cost changes with alternative and sub-options. The design criteria for solar dryer units are listed in Table 7-17. Table 7-17 – Solar Dryer Design Criteria Item Projected Condition Estimated Design Loading A Number of Units B Without Supplemental Heat Un-stabilized WAS 16,200 tonsC evaporated/yr 10.78 ft2 per Ton/yr 11 Stabilized Biosolids 10,500 tonsC evaporated/yr 10.78 ft2 per Ton/yr 7 With Supplemental Heat Un-stabilized WAS 16,200 tonsC evaporated/yr 7.54 ft2 per Ton/yr 8 Stabilized Biosolids 10,500 tonsC evaporated/yr 7.54 ft2 per Ton/yr 5 A Based on climate estimates at Kennewick, must be confirmed by vendor B Each solar dryer is 36 X 472 feet C Ton of water evaporated to achieve 90% solids The engineer’s opinion of probable costs to add solar drying unit processes after each of the scenarios presented above are reported in Table 7-18. Table 7-18 – Class A Alt. Solar Dryer Present Value Cost (in millions of with and without Heat Alt #2 Un-Stabilized Biosolids Alt #4 Anaerobic Digestion Unit Process BFP BFP Without Supplemental Heat # of Units 11 7 Capital $19.90 $12.70 O & M $9.20 $5.90 Disposal $0.70 $0.50 Total $29.80 $19.10 With Supplemental Heat # of Units 8 5 Capital $16.19 $10.38 O & M $7.24 $4.52 Disposal $0.70 $0.50 Total $24.12 $15.40 5 Supplemental heat (radiant floor) is an option which could cut the overall area by 27% and provide process reliability in winter months. To design this option, very accurate climatological data are required. ---PAGE BREAK--- At this point in the analysis, solar drying with supplemental heat is more cost effective. The assumption that supplemental heat will be included in the design will be carried forward. The actual performance of solar drying with supplemental heat can be evaluated as the greenhouses are phased in throughout the planning period. The advantages and disadvantages of producing Class A biosolids via solar dryer are listed in Table 7-19. Table 7-19 – Solar Dryer Advantages and Disadvantages Advantages Disadvantages Soil-like end product High capital investment Low operating cost Product must be kept dry Not as susceptible to future chemical and energy costs Single source equipment supplier Simple to operate Few Installations Conducive to arid climates Greenhouse maintenance/cleaning Diverse year-round land application Poor operation when cold and cloudy Disposal not subject to site-specific permitting Figure 7-1 – Solar Dryer (Courtesy of Huber) ---PAGE BREAK--- 7.6.2 Class A Alternative 2 – Chemical Stabilization This alternative utilizes a specific manufacture to represent the high pH/high temperature chemical treatment option. Other manufactures are available for consideration if this alternative is selected for preliminary design. The Bioset process is a chemical stabilization process that uses increased pH and increased temperature to achieve Class A biosolids. The WAS could be periodically wasted to a mechanical dewatering unit process (BFP) then conveyed to a chemical stabilization treatment unit where lime is mixed into the biosolids before being fed into the unit. The lime increases the pH and temperature of the mixture as it reacts with the water and organic content in the biosolids. The mixture is automatically moved with a progressive cavity pump through the treatment process. Additionally, the process produces ammonia which is used to kill pathogens in addition to the high temperature and pH. A demonstration chemical treatment unit (Bioset) unit is shown in Figure 7-2. The design criterion, as set by the manufacture, is 36 wet tons per day per unit. The expected loading (6 days per week) ranges from 38 to 77 wet tons per day depending on whether or not the biosolids are digested and how they are dewatered. Two Bioset units are required to manage the biosolids throughout the planning period. No redundant unit was assumed. Figure 7-2 – Bioset Demonstration Unit Two Bioset units are able to process the biosolids generated in all the alternatives mentioned above with different unit The length of the units does not significantly change the overall project cost. The disposal costs are different because Alternative #2 produces more material requiring disposal. An existing sludge lagoon may be required for redundancy under this option. ---PAGE BREAK--- The engineer’s opinion of probable costs to add a Class A Bioset Unit Process after each of the scenarios presented above are reported in Table 7-20. Table 7-20 – Chemical Treatment Present Value Cost (in millions of Alt #2 Un-Stabilized Biosolids Alt #4 Anaerobic Digestion Unit Process BFP BFP # of Units 2 2 Capital $9.70 $9.70 O & M $1.10 $1.10 Lime Cost $5.10 $3.30 Disposal $3.10 $2.00 Total $19.00 $16.20 The advantages and disadvantages of this alternative are listed in Table 7-21. Table 7-21 – Chemical Treatment Advantages and Disadvantages Advantages Disadvantages Some soils need high pH treatment Lime many not be attractive for some land application Relatively low capital cost Increase volume of product for disposal Low energy requirements Finished product with digested WAS is viscous (difficult to handle, transport, store and apply) Subject to uncontrollable lime cost 7.6.3 Class A Alternative 3 – Thermal Drying Class A biosolids requirements can be achieved by drying the biosolids to moisture content less than 10 percent (90% solids) using a thermal dryer. Thermal drying has a much smaller foot print than solar drying; however, the energy input is substantial. A thermal belt dryer is shown in Figure 7-3. One Thermal Drying unit can manage the biosolids loading from the alternatives but the annual operating cost varies depending on the pounds of biosolids received and the moisture content. For example, between the two extremes, a thermal dryer would have to evaporate 20,100 tons of water per year to dry straight WAS dewatered by a screw press and only 9,150 tons per year to dry digested sludge dewatered by a centrifuge. An existing sludge lagoon must be retained in order to provide a redundant treatment train. The engineer’s opinion of probable costs to add a Class A thermal drying Unit Process after each of the scenarios presented above are reported in Table 7-22. Power cost is a function of the mass of solids dewatered and moisture content and is specific to each option. Unit process installation cost and power cost for the various alternative sub- options are shown in Table 7-22. ---PAGE BREAK--- Table 7-22 – Thermal Drying Present Value Cost (in millions of Un-Stabilized Biosolids Anaerobic Digestion Unit Process BFP Cent Screw Press BFP Cent Capital $14.5 $14.5 O & M $3.2 $2.9 Disposal $0.7 $0.5 Total $18.4 $17.8 The advantages and disadvantages of this alternative are listed in Table 7-23. Table 7-23– Thermal Drying Advantages and Disadvantages Advantages Disadvantages Soil-like end product High energy consumption Simple to operate Final product must be kept dry Smaller foot print Subject to energy cost escalation Figure 7-3 – Thermal Dryer (Courtesy of Huber) ---PAGE BREAK--- 7.6.4 Class A Alternative 4 – Air Drying Class A biosolids requirements can be achieved by drying the biosolids to moisture content less than 10 percent (90% solids). Similar to the prior alternative, The WAS could be stabilized by digestion; however, in this option the digested biosolids would be air-dried in the repurposed solids storage lagoon to produce Class A biosolids. This option includes: WAS thickening prior to digestion to reduce the size of the digester, Aerobic or anaerobic digester, Air-drying on asphalt pad in repurposed solids storage lagoons Biosolids disposal. It is estimated that this alternative would require about 25 acres of exposed drying area and a substantial amount of equipment operation to move and mix the biosolids. The existing lagoons do not have sufficient bottom area to evaporate the expected biosolids production at the end of the planning period; therefore, this alternative was eliminated. 7.6.5 Class A Alternative 5 – Composting Disposing of Class B biosolids at Natural Selection Farms, as discussed above, technically produces a Class A biosolids through composting; albeit, out of the City’s control. The City could implement their own composting operations to gain independence from fluctuations in the open market while at the same time utilize green-waste generated within the City as a bulking agent and supplying the City’s parks with a valuable soil amendment. This option requires: On-site staging areas to hold biosolids prior to mixing with a bulking agent and windrowing Mixing area Windrowing area to pile the mixture while it composts with the bulking agent (30 day detention time) Curing area to stabilize the mixture after composting (30 day detention time) Out-of-specification product storage area Bulking agent recovery area Mixing equipment, monitoring equipment and other ancillary components Extensive record keeping Odor control Disposal by some beneficial use application Surface water and leachate storage and processing Process water system, utilities, operations building. At this time, the City does not have sufficient land to apply the Class A biosolids on if they developed a composting program nor does the City generate a sufficient volume of bulking agent (green waste from yards and parks); therefore, the City would have to buy bulking agent and attempt to sell or otherwise dispose of biosolids. Because the composting operation would not be self supporting with City resources a City owned composting alternative was dropped from further evaluation. If the economic drivers change when the Class A option is phased in, City owned composting should be evaluated. 7.6.6 Class A and Base Management Alternative Planning Level Cost Opinion Summary The cost for the Class A alternatives are summarized in Table 7-24 and the overall biosolids management alternatives cost are summarized in Table 7-25. ---PAGE BREAK--- Table 7-24 – Class A Biosolids Treatment Opinion Cost Summary (in millions of Un-Stabilized Anaerobic Digestion Unit Process BFP BFP Class A Adder Cost Solar Drying A $24.1 $15.4 Chemical Treatment $19.0 $16.2 Thermal Drying $18.4 $17.8 With Corresponding Base Treatment CostB Solar Drying A $42.4 $54.0 Chemical Treatment $37.3 $54.8 Thermal Drying $36.7 $56.4 A With Supplemental Heat B Does not include Base Treatment Disposal Cost (Class A has lower disposal cost) Table 7-25 – Alternative Cost Summary (in millions of Alt #1 No Action Alt #2 Un-Stabilized Biosolids Alt #3 Chemically Stabilized Biosolids Alt #4 Anaerobic Digestion Process BFP BFP BFP Class B $10.6 $25.3 $28.6 $41.7 Class A Solar Drying $42.4 $54.0 Chemical Treatment $37.30 0 $54.8 Thermal Drying $36.70 0 $56.4 7.7.1 Criteria and Relative Weight The base alternatives for dewatering, treatment and disposal were evaluated as well as options to treat the biosolids to Class A standards. After operators toured facilities with the different technologies, the preferred Class A adder sub-option was the solar dryer based on the quality of product, renewable energy input, and the disposal options. Class A biosolids disposal cost are expected to be either low or free with the expectation of providing some value as the product is used on City property or sold to landscapers or farmers. Most municipal biosolids qualify for ---PAGE BREAK--- “Exceptional Quality” designation when treated to Class A Standards with these methods. Therefore, disposal can be year round and limited only by the need to keep the biosolids dry prior to applying. At this time, the City recognizes that adding Class A treatment will be phased in at a future time and additional evaluation of options will be prudent. For now, the City will plan on Solar Drying biosolids in the future and set appropriate budgets and rates for their capital improvement plan. A workshop was held with City staff to establish the criteria for the evaluation of the base alternatives. The established evaluation criteria and their definitions are documented in Table 7-26. ---PAGE BREAK--- Table 7-26 – Evaluation Criteria Criteria Definition A) Present Worth Cost Planning level capital cost plus expected life-cycle cost of an alternative, both in 2014 dollars. The costs reported are approximate and for comparison purposes only. More refined cost estimates will be developed for the preferred alternatives. B) Permit Compliance Ability to satisfy existing and projected permit requirements over the course of the study period. C) Reliability Probability of adequate performance over the expected range of loading and operating conditions in the study period. Consideration is also given for number of similar facilities currently in operation. D) Safety Degree to which operators are exposed to hazardous conditions that could result in injury. However, safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. E) Ability to Expand Ability to expand and adapt a process for greater loading and/or to address changes in permit requirements. F) Energy Efficiency Overall efficiency of the alternative, energy use, carbon footprint, and consumption of non- renewable resources. G) Odor Potential Potential of an alternative to cause foul odors during operations through the course of a year. H) Ease of Operations Ease of operations and complexity of the process, including the need for specialized operators and process control / testing. I) Ease of Disposal (Biosolids only) Ability to find suitable disposal sites for biosolids; also used to differentiate perceived quality or handling impacts of biosolids that attain the same 503b classification. Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. A pairwise analysis was then performed to compare the relative importance of one criterion to another; e.g. which is more important, Present Worth Cost or Permit Compliance? Relative importance was scored as follows: 5 – significantly more important 4 – more important 3 – equally important 2 – less important 1 – significantly less important The result of the pairwise analysis is shown in Table 7-27. Safety is a major concern for the City; however, it is imperative that safety concerns be addressed with all alternatives, even when considering a “No Action” approach. Safety measures and the costs must therefore be incorporated into every alternative. Safety can then effectively be scored in the Present Worth Cost and Ease of Operations criteria. ---PAGE BREAK--- Table 7-27 – Pairwise Analysis Results Criteria A) Present Worth Cost B) Permit Compliance C) Reliability D) Safety E) Ability to Expand F) Sustainability G) Odor Potential H) Ease of Operations Total Score Weight A) Present Worth Cost - 1 2 1 3 4 1 2 14 8.3% B) Permit Compliance 5 - 4 3 4 4 4 4 28 16.7% C) Reliability 4 2 - 2 3 4 1 3 19 11.3% D) Ease of Disposal E) Ability to Expand 3 2 3 1 - 4 1 3 17 10.1% F) Energy Efficiency 2 2 2 1 2 - 1 2 12 7.1% G) Odor Potential 5 2 5 2 5 5 - 5 29 17.3% H) Ease of Operations 4 2 3 2 3 4 1 - 19 11.3% I) Ease of Disposal 5 3 4 - 5 5 4 4 30 17.9% Safety concerns must be addressed with all alternatives, even when considering a “No Action” approach. Different safety measures that may need to be employed are therefore included and scored in the Present Worth Cost and Ease of Operations criteria. Alternatives may be compared by scoring each alternative in a category from 1 (least favorable) to 5 (most favorable). The raw score is then multiplied by the criterion’s weight to provide an overall score for the alternative. 7.7.2 Biosolids Management Alternative Ranking A workshop was held with City staff to evaluate each biosolid management alternative from 1 to 5 based on the criteria. The evaluation score was multiplied by the weight from the pair-wise analysis for each criteria and summed for an overall score. The results of the alternative ranking are shown in Table 7-28. Based on the City’s ranking of the alternative, Alternative 4 (Anaerobic Digestion) is the preferred biosolids management methodology. Although the “No Action” Alternative 1 is ranked very close to using anaerobic digestion, the odor generation several times each year and during dredging makes it unacceptable. ---PAGE BREAK--- Table 7-28– Biosolids Alternatives Ranking Criteria Alternative 1: No Action Alternative 2: Mechanical Dewatering of Unstabilized Solids Alternative 3: Mechanical Dewatering with Lime Stabilization Alternative 4: Anaerobic Digestion and Dewatering Weight A) Present Worth Cost 5 3 2 1 8.3% B) Permit Compliance 5 2 5 5 16.7% C) Reliability 5 2 4 5 11.3% D) Safety - - - - 17.9% E) Ability to Expand 1 4 4 3 10.1% F) Sustainability 3 5 4 5 7.1% G) Odor Potential 1 1 2 4 17.3% H) Ease of Operations 5 4 2 4 11.3% I) Ease of Disposal 5 2 3 4 17.9% Weighted Score 3.76 2.55 3.25 4.00 The list of potential biosolids management facility upgrades were reviewed with City during workshops. The selected alternatives are summarized in Table 7-29. Table 7-29 – Summary of Recommended Biosolids Management Upgrades Item Description Purpose Approximate Capital Cost (millions) Thickening Two waste activated sludge thickeners to increase the solids content from 1% to 2.5% prior to digesting. Reduce the volume of the anaerobic digesters $5.3 Anaerobic Digestion Two, 1 million gallons anaerobic digesters with external sludge heaters, external mixers, biogas management and dual fuel boilers Stabilize biosolids on-site so Class B standards can be met and destroy biosolids through digestion $13.6 Dewatering Four, digested solids dewatering units to increase the solids content from 1.25% to 18% prior to additional treatment or disposal Reduce the volume and weight of the material needing additional treatment and/or transportation cost $8.4 Solar Drying Five solar drying greenhouses to condition Class B biosolids to Class A biosolids standards by increasing the solids content to at least 90% Create biosolids that are easy to beneficially use and manage $10.4 Approximate capital cost in 2014 dollars; includes construction, contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. Does not include O and M and disposal ---PAGE BREAK--- Summary of Recommended Improvements and Capital Improvement Plan (CIP) CHAPTER 8 ---PAGE BREAK--- CHAPTER 8 – SUMMARY OF RECOMMENDED IMPROVEMENTS AND CAPITAL IMPROVEMENT PLAN (CIP) Alternatives for addressing identified capacity and operational concerns are developed and evaluated in Chapters 6 and 7. The selected improvements are summarized in Table 8-1 and reflect an evaluation of monetary and non- monetary criteria as selected and ranked by the City and presented previously. Figure 8-1 and Figure 8-2 illustrate the changes to the process and likely siting for the improvements. An item added to the recommended improvements but not previously evaluated as a stand-alone improvement is a short-term aeration upgrade for the HRT Cells presented as Alternative 2 for the biological treatment system (see Section 6.4.2). The existing facility was constructed with one extra 100-hp drive for each cell, as well as conduits and conductors for a spare aerator. Plant staff had one extra 75-hp aerator available for each HRT Cell. In the winter of 2014/2015 the City completed minimal electrical repairs to the MCC, conductors, and plugs at the dike, and added one additional 75-hp aerator to each HRT Cell. This additional oxygen supply may help satisfy expected loads for the next eight to ten years, allowing the new basins to be phased in at a later time and address more pressing needs related to UV disinfection and biosolids management in the next several years. Primary clarification was also considered qualitatively during workshops with the City, especially with the proposed transition to anaerobic digestion and projected increases in influent loads, but was not included as a specific improvement project at this time. Incorporating a primary clarifier into the process would reduce influent BOD by approximately 40 percent and TSS by 60 percent, resulting in a substantial reduction in oxygen demand and more energy efficient treatment of the solids through anaerobic digestion. Additionally, incorporation of a primary clarifier may allow the new concrete aeration basin improvement project to be delayed thereby postponing capital outlays. The probable capital cost for a 100-ft diameter primary clarifier and primary solids pump station is on the order of $3 to $5M. However, this cost may be offset by reduced sizes of other processes at the facility, reduced energy demand, and the potential to use the primary clarifier for grit removal (by oversizing the process A detailed benefit/cost evaluation of primary clarification is therefore recommended during preliminary design of subsequent phases. The expected operation of the facility is such that the Final Clarifiers will serve as redundant units for the Intermediate Clarifiers. However, better performance and solids management has been achieved with the Intermediate Clarifiers. Therefore, space adjacent to the existing Intermediate Clarifiers should also be reserved to permit expansion of that process in the future, as shown in Figure 8-2. A specific project to expand the Intermediate Clarifiers is not included at this time. ---PAGE BREAK--- Table 8-1 – List of Recommended Improvements Item Description Approximate Capital Cost Preliminary Treatment Headworks bypass and general upgrades to Influent Pump Station $0.4M Biological Treatment Grit removal $3.6M Short-term aeration upgrade $0.3M New concrete aeration basins with fine bubble aeration $18.3M Final Clarifiers Bypass Final Clarifiers; replace solids pumping; rehabilitation of Final Clarifiers 1 and 2 $0.6M UV Disinfection Replace UV System $2.3M 150 kW Generator for emergency power $0.2M Biosolids Management Dredge solids from Aerated Sludge Lagoons $2.5M Aerated Sludge Lagoon effluent lift station $0.2M WAS thickening and anaerobic digestion $18.9 Mechanical dewatering of digested solids $8.4M Class A solar dryer $10.4M Approximate capital cost in 2014 dollars; includes construction , contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. A short-term aeration upgrade includes installation of two 100-hp mechanical aerators in each HRT Cell as presented in Alternative 2 for the biological treatment system (see Section 6.4.2) The City has previously budgeted for biosolids removal from the existing Aerated Sludge Lagoons in 2017. ---PAGE BREAK--- Figure 8-1 – Process Schematic with Recommended Improvements ---PAGE BREAK--- Figure 8-2 – Site Plan with Recommended Improvements ---PAGE BREAK--- The improvements noted above were reviewed with the City to determine which components were most critical for retaining adequate treatment capacity, maintaining reliable operation, and satisfying known permit conditions. A summary of each major process and phasing considerations are listed below. Preliminary Treatment: The influent bypass poses a hazard to operations in the event of emergency operation and has a relatively low cost. The Influent Pump Station improvement can also be put to use immediately for routine maintenance. These improvements are therefore recommended during the first phase of improvements. Biological Treatment: o Short-Term: An upgrade to the existing aeration system is necessary immediately to address deficient dissolved oxygen levels in the HRT Cells. Since the facility had the necessary components to enable an expansion (with minimal electrical work required); this improvement was implemented in the winter of 2014/2015. o Long-Term: The selected alternative of new concrete aeration basins with limited nitrification will likely be required within eight to ten years based on projected increases in loading and estimated capacity of the short-term aeration upgrade. Grit removal will be required with this upgrade. A detailed benefit/cost evaluation of incorporating primary clarification should also be considered. Final Clarifiers: Incorporating a bypass of the Final Clarifiers would improve operations and minimize solids buildup in the clarifiers and UV system. An upgrade to the solids pumping system is critical in the near-term in the event the Intermediate Clarifiers are taken offline. Rehabilitation is also recommended to prevent further degradation of the original two clarifiers. Given the cost of these improvements and impact to facility performance, this group of upgrades is recommended during the first phase of improvements. UV Disinfection: Without adequate vendor support, the potential for limited availability of replacement parts, and need for additional capacity, a UV upgrade is critical and should be programmed into the CIP as soon as possible. Emergency power is also recommended to minimize the potential for discharging non- disinfected effluent from the facility. Biosolids Management: o Short-Term: With incorporation of a bypass on the Final Clarifiers, a pump station on the effluent line from the Aerated Sludge Lagoons is necessary to intercept lower quality effluent and return it to the HRT Cells for treatment. o Long-Term: Minimizing odors and associated impacts on the facility’s neighbors is a critical goal of the City. Consequently, solids upgrades to incorporate thickening, anaerobic digestion, and mechanical dewatering should be completed as soon as practical. The City is currently planning another dredging project in 2017, which can be incorporated into these solids upgrades. Obtaining Class A biosolids is a longer-term objective for the City and can be programmed into subsequent phases. The recommended phasing plan based on the above considerations is included in Table 8-2. The capital costs are in 2014 dollars and do not include expected O&M. Prior to implementing projects, the estimated capital costs should be reviewed and revised accordingly to account for inflation, possible changes in facility needs or loading, and available funding sources. The phasing plan is also illustrated in Figure 8-3. Impacts to user rates are addressed in the City General Sewer Plan. ---PAGE BREAK--- Table 8-2 – Recommended Phasing of Improvements Item Description Approx. Capital Cost(a) Ph 1 (2 Yrs) Ph 2 (2-5 Yrs) Ph 3 (5-10 Yrs) Ph 4 (10+ Yrs) Major Equipment Equipment cost Expected Life (Yrs) Preliminary Treatment Headworks bypass and general upgrades to Influent Pump Station $0.4M • Isolation gate; bridge crane $50,000 20 Biological Treatment Grit removal $3.6M • Grit separator and classifier; HVAC $570,000 20 Short-term aeration upgrade $0.3M • Mechanical aerators $150,000 10 New concrete aeration basins with fine bubble aeration $18.3M • Gates, blowers; fine bubble aeration system; emergency generator $2,240,000 20 Final Clarifiers Bypass Final Clarifiers; replace solids pumping; rehabilitation of Final Clarifiers 1 & 2 $0.6M • Solids pump; actuated bypass $20,000 20 UV Disinfection Replace UV System $2.3M • UV equipment and controls $900,000 20 150 kW Generator for emergency power $0.2M • Generator $53,000 20 Biosolids Management Dredge solids from Aerated Sludge Lagoons $2.5M • N/A Aerated Sludge Lagoon effluent lift station $0.2M • Pump; control panel $30,000 20 WAS thickening and anaerobic digestion $18.9 • Thickeners; pumps; mixing systems; heating systems $1,925,000 20 Mechanical dewatering of digested solids $8.4M • Belt filter presses; conveyor system; pumps $2,067,000 20 Class A solar dryer $10.4M • Solar dryer; conveyors; green house components $5,000,000 20 TOTAL $63.6M $4.0M $27.3M $21.9M $10.4M Approximate capital cost in 2014 dollars; includes construction , contingency at 30 percent, local and state sales tax, engineering, and legal / administrative costs. Biosolids dredging has already been budgeted by the City for 2017; therefore, the cost associated with dredging is not included in this phasing plan. Equipment cost only; excludes taxes Equipment cost, contingency, and sales tax included; excludes ancillary work items that may be required upon replacement (e.g. mobilization, site work, yard pipping, electrical and controls, bonding, overhead and profit, design and construction.) ---PAGE BREAK--- Figure 8-3 – Recommended Phasing Plan ---PAGE BREAK--- An independent energy efficiency review was also completed on the selected improvements, and the facility as a whole, by Energy Smart Industrial (ESI). A copy of the evaluation is included in Appendix 8-A for reference. Many of the energy efficiency measures identified in the ESI evaluation have been presented previously in this study, while others will be specifically reviewed and implemented during design. The amount of incentives are currently 25 cents per kWh saved in the first year of operation and capped at 70 percent of the cost of the energy efficiency measures. Additionally, the incentives are paid following measurement and verification of implementing the energy efficiency measures. 8.4.1 Unit Process Reliability The facility with recommended improvements is reviewed in light of the Reliability Class II requirements listed in Section G2-8.2 of the Orange Book in Table 8-3. The proposed improvements were developed to address all reliability requirements. ---PAGE BREAK--- Table 8-3 – Reliability Class II Requirements Compared to Proposed Facility Requirement Assessment of Existing Facility A. Mechanically Cleaned Bar Screens. A backup bar screen, designed for mechanical or manual cleaning, shall be provided. Facilities with only two bar screens shall have at least one bar screen designed to permit manual cleaning. A redundant screen capable of processing the peak hour flow is available. B. Pumps. A backup pump shall be provided for each set of pumps performing the same function. The capacity of the pumps shall be such that, with any one pump out of service, the remaining pumps will have the capacity to handle the peak flow. Influent Pump Station: The peak hour flow can be satisfied with one pump out of service. RAS Pumping: A redundant pump is available. WAS Pumping: A redundant pump is available. C. Comminution Facility. If comminution of the total wastewater flow is provided, an overflow bypass with a manually-installed or mechanically-cleaned bar screen shall be provided. The hydraulic capacity of the comminutor overflow bypass should be sufficient to pass the peak flow with all comminution units out of service. N/A D. Primary Sedimentation Basins. The units shall be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the design basin flow. N/A E. Final Sedimentation Basins and Trickling Filters. The units shall be sufficient in number and size so that, with the largest- flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the design basin flow. Both the Intermediate Clarifiers and Final Clarifiers serve this function. With one Intermediate Clarifier out of service, the facility can process the entire plant flow using the Final Clarifiers. F. Activated Sludge Process Components. 4. Aeration Basin. A backup basin will not be required; however, at least two equal-volume basins shall be provided. (For the purpose of this criterion, the two zones of a contact stabilization process are considered as only one basin.) The facility will have two, equally-sized aeration basins. A backup basin is not provided. 5. Aeration Blowers or Mechanical Aerators. There shall be a sufficient number of blowers or mechanical aerators to enable the design oxygen transfer to be maintained with the largest-capacity-unit out of service. It is permissible for the backup unit to be an uninstalled unit, provided that the installed units can be easily removed and replaced. However, at least two units shall be installed. The proposed blower system will have a stand-by unit available equal to the largest capacity unit. 6. Air Diffusers. The air diffusion system for each aeration basin shall be designed so that the largest section of diffusers can be isolated without measurably impairing the oxygen transfer capability of the system. This provision will be incorporated in the design phase. G. Disinfectant Contact Basins. The units shall be sufficient in number and size so that, with the largest-flow-capacity unit out of service, the remaining units shall have a design flow capacity of at least 50 percent of the total design flow. The proposed UV system will be designed to satisfy this requirement ---PAGE BREAK--- 8.4.2 Electrical Reliability Class II electrical reliability criteria given in Section G2-8.3 of the Orange Book are included in Table 8-4. Existing standby power at the facility only serves the Headworks and Influent Pump Station. Additional standby power will be provided as follows: UV Disinfection Standby Power: The UV disinfection building will be provided with a new diesel engine stand-by generator in a weather protected, sound attenuated enclosure. The minimum size recommended for this application is 150KW and the service voltage would be 120/208V to match the existing service and new UV disinfection system requirements. There is adequate room adjacent to the UV Disinfection building to install the new generator and fuel system, which would be an in-base, double-walled tank system with full leak detection. Biological Treatment Stand-by Power: The biological treatment system will be provided with a new diesel engine stand-by generator in a weather protected, sound attenuated enclosure. The generator will be sized to accommodate the projected 2034 average day load of the aeration system, RAS/WAS pumping, intermediate clarification systems, process lighting, and other life safety elements. The minimum size recommended for this application is 800KW and the service voltage would be 480/277V to match the existing service and load requirements. There is adequate room adjacent to the abandoned RAS building to install the new generator and fuel system which would be an in-base, double-walled tank system with full leak detection. Table 8-4 – Minimum Capacity of the Backup Power Source for Each Reliability Class Reliability Class General Requirements I Sufficient to operate all vital components and critical lighting and ventilation during peak wastewater flow conditions. II The same as Reliability Class I, except that vital components used to support the secondary processes mechanical aerators or aeration basin air compressors) need not be operable to full levels of treatment, but shall be sufficient to maintain the biota. III Sufficient to operate the screening or comminution facilities, the main wastewater pumps, the primary sedimentation basins, the disinfection facility, and critical lighting and ventilation during peak wastewater Current staffing at the Kennewick facility consists of one crew leader (who manages the collection and WWTP), three plant operators, a pump specialist that is shared with the collections crew, and an automated control and telemetry specialist that is shared with the City’s water department. As flows and loads increase at the facility, and as improvements are undertaken, staffing levels are expected to increase. Table 8-5 identifies potential staffing needs at various points in the phasing plan based on EPA’s "Estimating Staffing for Municipal Wastewater Treatment Facilities" (1973). These estimates are intended to be guidelines only; specific staffing levels must be determined by the City and reviewed regularly to adequately operate and maintain the facility ---PAGE BREAK--- Table 8-5 – Estimated Staffing Needs Phase Additional Processes Total Estimated Employees Existing / Phase 1 N/A 5 (unchanged) Phase 2 Biosolids handling, including thickening, anaerobic digestion, and mechanical dewatering 8 Phase 3 Grit removal, fine bubble aeration; also includes increases in plant flow 10 Phase 4 Plant expansion to 20-year flow; addition of Class A biosolids process 12 Includes supervisory, administrative, clerical, laboratory, yard work, site maintenance, and unit process operations and maintenance. Assumes 1,500 working hours per employee after holidays, time off, training, etc. ---PAGE BREAK--- City of Kennewick; City of Kennewick Sewer System Plan; October 2006. City of Kennewick; Comprehensive Plan 2011: Horizons; 2011. HDR Engineering, Inc.; Wastewater Treatment Plant Facility Plan; November 2007. HDR; Treatment Technology Review and Assessment for Association of Washington Cities; December 2013. J-U-B ENGINEERS, Inc.; Biological Assessment for the City of Kennewick Wastewater Treatment Plant (WWTP) 2014 Facility Plan Update; September 2014. J-U-B ENGINEERS, Inc.; Design Engineering Report and Mass Diagrams: Wastewater Treatment Plant Expansion; August 1995. J-U-B ENGINEERS, Inc.; Wastewater Treatment Facilities Plan; May 1995. Metcalf & Eddy I AECOM; Wastewater Engineering: Treatment and Resource Recovery, Fifth Edition; 2013. NPDES Waste Discharge Permit No. WA-004478-4 Phone conversation with Ian Laseke, Sanjay Barik on 2-5-14. State of Washington Department of Ecology; Criteria for Sewage Works Design (Orange Book); August 2008. ---PAGE BREAK--- CHECKLIST FOR FACILITY PLAN CONTENTS APPENDIX 1-A ---PAGE BREAK--- Table G1-1. Requirements for Engineering Report and Facility Plan Element Requirements Location in Facility Plan Engineering Report Facility Plan Site Description, Problem Identification, and Map Well documented. Same as engineering report. Reference Chapter 1 for project background, WWTP site, and related general information. Description of Discharge Standards Well documented. Same as engineering report. Discharge standards for the WWTP are presented in Chapter 4. Background Information Existing Environment • Water, air, sensitive areas: • Flood plains • Shorelands • Wetlands • Endangered species/habitats • Public health Demographics and Land Use • Current population • Present wastewater treatment • AWT need evaluated • I/I studies • CSOs • Sanitary surveys for unsewered areas Existing Environment Same as engineering report, plus identification of: • Prime or unique farmland • Archaeological and historical sites • Any federally recognized “wild and scenic rivers” • Threatened species Demographics and Land Use Same as engineering report, plus specific determinations that I/I is not excessive (that is, not less expensive to remove it than treat it at plant). Existing Environment A review of environmental components is presented in Chapter 2 with additional details in Chapter 2 appendices. Demographics and Land Use Reference the City of Kennewick General Sewer Plan (2014), bound separately. Applicable population data is also presented in Chapter 3. Future Conditions Demographics and Land Use Projected population levels • Appropriateness of population date source, zoning changes • Future domestic and industrial flows, and flow reduction options • Future flows and coding • Reserved capacity • Future environment without project Same as engineering report, plus discussion of whether recreation and open space alternatives could be incorporated. Chapter 3 presents expected population growth, changes in domestic and industrial flows, and projected flows and loads Chapter 6 and 7 present a Do Nothing Alternative indicating conditions without a project. ---PAGE BREAK--- Element Requirements Location in Facility Plan Engineering Report Facility Plan Alternatives • List specific alternative categories, including no action • Collection system alternatives • Sludge management/use alternatives • Flow reduction • Costs • Environmental impacts • Public acceptability • Rank order • Recommended alternative Same as engineering report, plus description of innovative and alternative technologies [that is, those saving energy and nonconventional treatment (land application, etc.)]. Reference the City of Kennewick General Sewer Plan (2014) for collection system related issues. Chapter 6 presents potential liquid stream alternatives, analysis and evaluation, and selection of a preferred alternative. Chapter 7 presents biosolids management alternatives, analysis and evaluation, and selection of a preferred alternative. Final Recommended Alternative • Site layout • Flow diagram • Sizing • Environmental impacts • Design life • Sludge management • Ability to expand • O&M/staffing needs • Design parameters • Feasibility of implementation Same as engineering report. Details related to the selected alternative are included in Chapter 8. Financial Analysis • Costs • User charges • Financial capability • Capital financing plan • Implementation plan Same as engineering report. The financial analysis for the selected WWTP alternative is presented in the City of Kennewick General Sewer Plan (2014). Project costs for the selected alternative are presented in Chapter 8. ---PAGE BREAK--- Other • Water quality management plan conformance • SEPA approval • List required permits Same as engineering report, plus state- approved SERP compliance, including: • Environmental issues analysis • Documentation that the project is identified in a sewer general plan • Capital improvement plan • Documentation of adequate public involvement process Chapter 2 presents environmental elements with additional details in Chapter 2 appendices. Chapter 8 presents the recommended Capital Improvement Plan (CIP). The City of Kennewick General Sewer Plan (2014) Chapter 7 (bound separately) also summarizes the CIP. ---PAGE BREAK--- Table G1-2. Explanation of Engineering Report Requirements (Rev. 11/2007) Text from WAC 173-240-060 Explanation Location in Facility Plan 060(1) Planning Requirements The engineering report for a domestic wastewater facility shall include each appropriate (as determined by Ecology) item required in WAC 173-240-050 for general sewer plans unless an up-to-date general sewer plan is on file with Ecology. Normally, an engineering report is not required for sewer line extensions or pump stations. See WAC 173-240-020(13) and 173-240-030(5). The facility plan described in 40 CFR 35 is an “engineering report.” The report must comply with an up-to-date general sewer plan (WAC 173- 240-050) that is on file with Ecology. The community must certify that its general sewer plan adequately addresses the current conditions and service area. If Ecology does not have an adequate, up-to-date, existing general sewer plan, it will identify those portions of Section 050 that include in the engineering report. Where no up-to-date general sewer plan exists, the entity may expand the engineering report to meet the requirements for a general sewer plan, including local approval requirements in Chapters 35.63, 36.70, 36.94, and 56.08 RCW. Ecology does not normally require an engineering report for sewer line extensions or pump stations that conform with an Ecology- approved general sewer plan, where Ecology does not provide financial assistance. Reference City of Kennewick General Sewer Plan (2014), bound separately. 060(2) Sufficiently Complete The engineering report shall be sufficiently complete so that plans and specifications can be developed from it without substantial changes. “Sufficiently complete” as used in the regulations is defined to mean the report must contain sufficient design information to allow an engineer not involved in writing the report to produce construction drawings for the facility as envisioned by the report writer without any need for process change or more than minor unit-sizing modifications. “Substantial change” means a change in the selected treatment process, facility size, design criteria, performance standards, or environmental impacts, or an increase in total project cost. A substantial change requires an amendment to the approved engineering report. “Adequate detail” means that the report includes suitable attention to the individual elements and components that make up the whole proposed project. A description of each alternative is presented in Chapters 6 and 7 with applicable design criteria. Detailed opinions of probable cost are included in appendices corresponding to each chapter. A preliminary process schematic, site plan, and phasing plan is provided in Chapter 8. 060(3) Minimum Information Required The engineering report shall include the following information, together with any other relevant data as requested by Ecology: ---PAGE BREAK--- The name, address, and telephone number of the owner of the proposed facilities, and their authorized representative. The report must include the name, address, and telephone number of the owner and the owner's representative. The named person or position must have the authority to sign contracts relating to this project. Examples of the owner's representative include the mayor, chair of the city council sewer committee, city manager, public works director, etc. Additionally, the entity may identify a specific project contact person other than the legal representative. The owner of the proposed facilities is the City of Kennewick. The appropriate contact is: Gary Deardorff, Utility Services Manager City of Kennewick (509)585-4301 [EMAIL REDACTED] P.O. Box 6108 Kennewick, WA 99336 A project description including a location map and a map of the present and proposed service area. The project description includes the where, what, and why of the report and documentation of the need for the proposed project. Include a location map of the project area, along with a map showing the current and proposed sewer service area. Scale the map(s) so that at least one map shows the complete, current, and proposed service areas along with the relationship of this service area to adjacent service areas. One map must show the existing collection system changes and the proposed locations of land applications of wastewater. Include a current zoning map for the service area to support the population and waste load projection process. The service area for the WWTP is shown in Figure 1-1. Details pertinent to the collection system are included in the City of Kennewick General Sewer Plan (2014), bound separately. A statement of the present and expected future quantity and quality of wastewater, including any industrial wastes which may be present or expected in the sewer system. This includes an analysis of the current waste load (flow, BOD, TSS, etc.) received by the treatment plant, its sources (the percentages of domestic, commercial, and industrial dischargers), the characteristics of industrial discharges/pretreatment, the current I/I flows, CSOs as defined in Chapter 173-245 WAC, diurnal flow and loading variations, and seasonal load and flow variations. Include at least one full year of CURRENT wastewater flow and loading data to justify appropriate design parameters for the new system (more than one year of data is preferable). Data must include sufficient detail to demonstrate the degree of flow and loading variability expected. Wastewater characterization must also identify any constituents that may have a detrimental impact on any proposed unit process chemicals toxic to microbes, constituents that may interfere with disinfection, high variability in peak flows and loading). Proponents must ensure that laboratory data were obtained from an Ecology- accredited laboratory. Proponents must obtain flow data from meters that have a documented history of proper calibration. Include the location of influent and effluent sampling, the type of samples taken, and the locations of treatment process return streams. To demonstrate that the data is truly representative of current conditions, RCW 90.48.495 requires the entity consider water conservation measures in sewer plans. Include a discussion of water conservation measures considered or under way and their anticipated impact on public sewer service. Estimate the future (normally 20 years from the date of the report) waste load and sources of wastewater including the above items. Base the estimates on the present (or known future) zoning pattern, council of government’s population forecasts, historical population trends, existing industrial users, and anticipated future industrial wastewater sources. Available waste load (flow, BOD, TSS, etc.) for the previous five years is presented in Chapter 3. Projected conditions through the 20-year planning period are also included in Chapter 3. ---PAGE BREAK--- The degree of treatment required based upon applicable permits and regulations, the receiving water, the amount and strength of wastewater to be treated, and other influencing factors. Include a copy of the current discharge permit and any compliance orders in the engineering report. For new discharges, include a draft permit. Use the evaluation results of Sections 3(e), and to estimate the degree of treatment needed in lieu of the existence of a current permit or a draft permit prepared by Ecology. At a minimum, the engineering report must contain an evaluation of the WWTP discharge compliance with water quality criteria (Chapter 173-201A WAC). For municipal this means an analysis of ammonia and chlorine that may indicate the need for nitrification or dechlorination. If the receiving water is listed on the 303(d) list as impaired, the analysis must include the parameters identified in the impairment listing. Design values must align with waste load allocations established in a TMDL, if available. Additionally, the report must evaluate the effects of industrial discharges to the collection system on the final effluent, including the potential for toxic materials to pass through the treatment facility to the final effluent or sludge. The engineering report must determine if the discharge from a proposed system will cause a measurable change in existing water quality measured at the boundary of the chronic mixing zone if one has been authorized. A measurable change is any one of the following: 1) Temperature increase 0.3 C. or greater. 2) Dissolved oxygen decrease of 0.2 mg/L or greater. 3) Bacteria count increase of 2 cfu or greater. 4) pH change of 0.1 units or greater. 5) Turbidity increase of 0.5 NTU or greater or. 6) Any detectable increase in the concentration of a toxic pollutant or radioactive substance. The proponent must consult with regional Ecology staff to determine the level of analysis needed to comply with the Antidegradation provisions of WAC 173-201A-300 to 330. The City of Kennewick currently has authorization to discharge to the Columbia River through a Washington Department of Ecology NPDES permit. Water quality requirements of the receiving water are summarized in Chapter 4 based on the previous NPDES permit and accompanying Fact Sheet. The facility is assessed in Chapter 5 based on satisfying the currently known discharge requirements. Alternatives in Chapters 6 and 7 are developed to address known water quality requirements during the planning period. ---PAGE BREAK--- A description of the receiving water, applicable water quality standards, and how water quality standards will be met at the boundary of any applicable dilution zone. (173-201A-10Q WAC) Give the name, location (river mile, latitude/longitude, waterway segment number, township/range, etc.), and water quality classification of the proposed receiving water. Summarize any existing receiving water data (monitoring stations reporting to STORET, CRMS, USGS reports, NOAA reports, FERC license reports, data collected for this report, etc.). Include data collected for this report in an appendix to the report. For fresh water streams and rivers, determine and provide the 7Q10 (seven- day, ten-year recurrence low flow) flow in the report. This is the flow used for calculating mixing zone sizing in streams and rivers. For salt water and estuaries, determine and provide current velocity, appropriate salinity, density, and temperature profile conditions in the report. This information is then used to design and evaluate the size and shape of allowable mixing zones. Evaluate toxic chemicals in the effluent (toxic pollutant scan may be required). This includes an evaluation of the effects of toxic chemicals on migratory fish barrier to fish migration). Evaluate the applicable numerical Water Quality Criteria (EPA) and determine which criteria are limiting for this discharge (see Ecology’s “Permit Writer’s Manual”). The NPDES permit may contain requirements for whole effluent toxicity testing and limits (WET rule, Chapter 173-205 WAC). Identification of the various chemicals that may be present in the discharge and the species present in the receiving water may affect the need or frequency of biomonitoring WET testing. In salt water, evaluate not only the effects of chemical discharges, but also the impacts of bacterial discharges on shellfish beds (certification or decertification). Refer to the criteria and information in the DOH documents “Special Sewage Works Design Consideration for Protection of Waters Used for Shellfish Harvest,” “Water Supplies or Other Areas of Special Public Health Concern,” and “Shellfish and Domestic Wastewater Discharge Outfall Projects,” Oct. 1995 (interagency permit streamline). For groundwater discharges, address the minimum requirements of the hydrogeologic study. These requirements are listed in E3-4 and are fully described in the “Implementation Guidance for Ground Water Quality Standards” (Ecology, 1996; Revised October 2005). The City of Kennewick currently has authorization to discharge to the Columbia River through a Washington Department of Ecology NPDES permit – reference Chapter 4 and accompanying appendices. ---PAGE BREAK--- The type of treatment process proposed, based upon the character of the wastewater to be handled, the method of disposal, the degree of treatment required, and a discussion of the alternatives evaluated and the reasons they are unacceptable. Consider at least one of each of the following wastewater treatment categories and options: fixed growth processes, suspended growth processes, land treatment processes, lagoons, innovative treatment processes, nonstructural alternatives (operational changes), and no action. The report must include the no action alternative. Rank the alternatives considered (with their reasons) according to their ability to meet the receiving water quality standards, costs, and other objectives of the engineering report. From this group of ranked alternatives, select for further development and evaluation a top group of three to five distinct, final alternatives that meet the report's objectives. Further evaluation includes environmental impact, applicability to available site(s), cost effectiveness (capital cost and present worth cost), ease of operation, and other criteria deemed important by the community. Base costs on EPA cost curves, CAPDET analysis, or any other cost estimating method acceptable to Ecology. A final alternate recommended for implementation should rank first in this further evaluation. The selection of the recommended alternate includes a discussion of why the other alternates were not selected. If the selected alternative is not the lowest cost effective alternative, provide discussion to support the decision to not choose the cost effective alternative. If the proponent will seek Ecology funding from the Centennial Clean Water Fund and/or the Sate Revolving Fund, project eligibility may be limited if the least cost alternative is not selected. Consult with regional Ecology staff in advance to identify how alternative selection may impact project eligibility. Evaluation of a No Action alternative for the liquid stream components is included in Chapter 6.2. Alternatives to satisfy water quality objectives and identified deficiencies are included in subsequent sections of Chapter 6. The alternatives were limited to no action, nonstructural alternatives, and alternative suspected growth processes. Other alternatives were not deemed practical during preliminary screening workshops. Ranking of alternatives is presented in Chapter 6. Evaluation of a No Action alternative for the solids stream components is included in Chapter 7.2. Alternative for biosolids treatment and disposal are included in subsequent sections of Chapter 7. The basic design data and sizing calculations of each unit of the treatment works. Expected efficiencies of each unit, the entire plant, and character of effluent anticipated. Provide basic design data and sizing calculations for all of the final alternates as part of the ranking process. Use the data to estimate construction and operation and maintenance costs for cost comparisons as required in 3(p) below. The detailed sizing calculations and design criteria used for sizing the selected alternative treatment systems must agree with the appropriate chapters of this manual or other authoritative reference. Thoroughly justify any deviation from the design criteria in this manual. Section 3(c) above provides the basic hydraulic and pollutant loading data to be used for sizing the treatment systems. Describe the age, capacities, and adequacy of all existing treatment units used in the upgraded facilities. Pertinent design criteria for alternatives are presented in Chapter 6 (liquid Stream) and Chapter 7 (solids stream). ---PAGE BREAK--- Discussion of the various sites available and the advantages and disadvantages of the site(s) recommended. The proximity of residences or developed areas to any treatment works. The relationship of a 25-year and 100-year flood to the treatment plant site and the various plant units. This is part of the alternative evaluation process through When evaluating multiple potential treatment plant sites, assess their topography, flood potential, impacts to existing wetlands, soils suitability for construction, zoning, and proximity to residential areas. Do not limit flood analysis to determining whether or not a site is included within a flood plain mapped on a FEMA Flood Insurance Rate Map (FIRM). Evaluate the flooding potential of any drainage way passing through or near the site for site flooding potential. Show the existence of wetlands on a proposed site on the site map. Mapping the extent of wetlands may require the use of a wetlands specialist. Compare wall and floor elevations to potential 100-yr flood elevations to ensure that basins are not over-topped or buildings flooded if major flooding occurs. Consider using a continuous hydrologic and hydraulic model with long term (20+ years) precipitation record to model the development and its contributing drainage area to evaluate the hydraulic capacity of the conveyance system and flooding potential. During the planning stage, conduct adequate soils analyses at the final alternate sites to understand the ability of the soils to structurally support the proposed structures or provide the wastewater treatment required. That is, perform enough soils analyses to ensure that during design or construction a “changed site condition” clause does not need to be invoked because the soils are unable to perform as required). The existing treatment plant site will be utilized for any expansion or changes to the process. A flow diagram showing general layout of the various units, the location of the effluent discharge, and a hydraulic profile of the system that is the subject of the engineering report and any hydraulically related portions. Proponent must present flow diagrams for each of the final alternates considered. Reports must include a schematic flow diagram showing all wastewater liquid and solids flow paths. Include proposed sampling locations as well as a scaled site layout (with the site topography) that shows how proposed treatment units fit on the land available. Develop hydraulic profile(s) in detail for the selected alternate. Include the hydraulic profile for at least the high plant flow and high receiving water flow/elevation and low plant flow conditions. Include hydraulic profiles for other critical flow conditions if necessary to justify unique design elements or operating conditions. A process schematic for the selected alternative is included in Figure 8-1, and preliminary site map is included in Figure 8-2. The selected alternative must be incorporated into the facility’s existing hydraulic profile; therefore, the hydraulic profile provided in Figure 6-3 is consider applicable at this stage. It is anticipated that hydraulic profiles will be developed during preliminary design. ---PAGE BREAK--- A discussion of infiltration and inflow problems, overflows and bypasses, and proposed corrections and controls. Evaluate the existing treatment plant flows showing the degree of I/I in the collection system. The analysis must include a review of the age and characteristics of the existing sewerage system, flow monitoring in the system and location of sewer lines with high I/I. A complete evaluation of I/I in a system requires at least one year of testing to establish the baseline flows and conditions for further evaluations. Refer to section C1-7 for further guidance on conducting I/I investigations. Identify discharge locations for sanitary sewer overflows (SSOs) and combined sewer overflows (CSOs) on a map and discuss their current frequency and impacts on receiving water. Include any recommendations of how to eliminate SSOs and minimize CSOs and their effect on the receiving water. Ecology will not approve plans that will result in an increase of the frequency or impact of SSO and/or CSO discharges. Chapter 173-245 WAC requires municipalities to submit a CSO reduction plan if their sewer system contains any CSOs. The final project recommendation must include plans for I/I reduction, SSO elimination, and incorporate recommendations presented in a CSO control plan that conform to Chapter 173-245 WAC. An I/I evaluation of the collection system is included in the City of Kennewick General Sewer Plan (2014),bound separately. A discussion of any special provisions for treating industrial wastes, including any pretreatment requirements for significant industrial sources. Identify any industrial wastes that require special handling by the treatment plant and discuss proposed methods for handling those wastes. Reference appropriate treatability studies for existing industrial wastewaters to identify the potential to interfere with proposed treatment plant unit processes. Identify the extent of industrial pretreatment needed to ensure stable plant operation and water quality protection. Reference the City of Kennewick General Sewer Plan (2014),bound separately. The City of Kennewick does not have any known industrial users with discharges that are expected to affect plant performance. Detailed outfall analysis or other disposal method selected. See 3(e) above. The outfall location and diffuser design, whether existing or proposed, must ensure effluent discharge will meet applicable water quality standards presented in Chapter 173-201A WAC. The report must include a detailed outfall analysis to justify that water quality standards will be met at the point of discharge or at the boundaries of acute and chronic mixing zones as defined by 173-201A-400 WAC. The analysis must be consistent with Ecology’s “Guidance for Conducting Mixing Zone Analyses” (Publication 97- e12) and EPA’s “Technical Support Document for Water Quality-based Toxics Control”. Ecology encourages the use of computer dilution models, such as PLUMES or CORMIX, that are calibrated to actual conditions in the field to develop the outfall analysis. The analysis must include all critical flow and loading situations expected for the facility. For river discharges the low flow must represent the 7Q10 flow or other regulated low flow. Marine discharges must use mean lower low water elevation and seasonal conditions that result in the greatest stratification in the water column. Ecology considers the outfall and diffuser a basic unit of the treatment system and proponents must include them in the data for 3(g) above. For land application of wastewater, see below. The facility’s existing outfall, as well as previous reports and evaluations, is summarized in Chapter 5.2.11. ---PAGE BREAK--- A discussion of the method of final sludge disposal and any alternatives considered. Include a residual solids management plan that evaluates the expected solids quantities and quality, and the potential disposal or beneficial use options (including regional biosolids disposal and utilization options). The management plan includes evaluating sludge treatment options at the plant and relating these treatment options to the sludge disposal or biosolids utilization options considered. The proponent must ensure compliance with applicable laws and regulations (40 CFR 503 and 258), Ecology’s Minimal Functional Standards and local permits. Guidance on the content of a residual solids management plan is available in Chapter S of this manual and from Ecology’s Regional Biosolids Coordinator. Determine solids mass balance for the treatment plant as an important part of the process of developing and comparing both the sludge treatment and wastewater treatment alternatives. Present a ranking of the various residual solids handling alternatives considered and identify the preferred alternative and actions necessary for implementation. Also present the reasons for not selecting the other alternatives. Part of the alternatives analysis referred to in 3(f) and above includes the selection of a residual solids treatment and disposal process. Evaluation of a No Action alternative for the solids stream components is included in Chapter 7.2. Alternative for biosolids treatment and disposal are included in subsequent sections of Chapter 7. Provision for future needs. The proponent must discuss the future wastewater needs of the community with an emphasis on identifying potential alternatives to accommodate for future growth. The discussion should include the potential to expand an existing treatment plant on a given site, construction a new plant on an alternate site (including locations to construct a new facility), and the ability to extend the sewerage system. Identify the population, industrial, and commercial growth expectations of the service area. Growth expectations should consider high, medium, and low growth profiles. The time frame for this evaluation may range from five years for a phased project to 20 years for complete build out of the service area. Ecology recommends that proponents include 20 years of treatment capacity in each project. The facility plan was completed with a 20-year study period. Expansion needs for the facility are estimated and presented in Chapter 8. Staffing and testing requirements for the facilities. The comparison of alternatives must discuss the potential staffing needs of each final treatment alternative, including staffing levels and specialization needs of each. EPA’s document “Estimating Staffing for Municipal Wastewater Facilities” provides an acceptable estimating tool for this purpose. Evaluate the facility during the design phase facility classification under Chapter 173-230 WAC. The staffing plan must include at least one operator matching the facility classification as the operator in responsible charge. Describe the selected alternative in adequate detail to evaluate the facility classification. Existing staffing levels are compared to estimated staffing needs for the selected alternative in Chapter 8. ---PAGE BREAK--- An estimate of the costs and expenses of the proposed facilities and the method of assessing costs and expenses. The total amount shall include both capital costs and also operation and maintenance costs for the life of the project, and shall be presented in terms of total annual cost and present worth. The cost estimate must be the engineer's best opinion of probable final costs based on an intermixed estimate of quantities and costs. Proponents interested in obtaining construction financial assistance from Ecology must provide a project financing (user charge) evaluation. The financing evaluation must include the potential Ecology grant or loan funding in addition to an analysis that does not include any Ecology grant or loan funding. Also include a present worth analysis of O&M costs for each of the final alternates as part of the ranking process. Detailed cost opinions are presented in Chapter 6 and 7 appendices and summarized in Chapter 8. Project financing is presented in the City of Kennewick General Sewer Plan (2014), bound separately. A statement regarding compliance with any applicable state or local water quality management plan or any such plan adopted pursuant to the federal Water Pollution Control Act as amended. Identify any applicable water quality management plan connected to the proposed project and discuss how the project is connected to that plan. Refer to Chapter 3 for a discussion on applicable water quality plans. A statement regarding compliance with SEPA and NEPA, if applicable. Prepare an environmental report that identifies the potential environmental impacts of the project. Include a copy of the completed SEPA checklist along with the appropriate adopted SEPA determination (Determination of Non- significance, mitigation plan, Environmental Impact Statement, etc.) in the engineering report. The action taken that requires SEPA is the adoption of the engineering report and its recommended project. For federally funded projects, excluding SRF Loans, append a NEPA environmental assessment or reference to an applicable FEIS and final NEPA action in the engineering report. The local government must make final SEPA declaration prior to approval of the engineering report. If the project anticipates Ecology SRF or Centennial Grant funding, the proponent must also complete the SERP process. This process is in addition to the SEPA process, but can be replaced by NEPA. See G1-2.6 for more information about SERP. Reference Chapter 2 for a discussion on potential environmental impacts of the project. A SEPA checklist has been prepared and submitted to the City as lead agency. The status of the SEPA is currently: in review. The public notice requirements for SERP are scheduled for a December 16, 2014 City Council meeting where the Facilities Plan will be presented to Council. Cross Cutter documentation is provided in the Appendix as described in Chapter 2. 060(4) Land Application Discharges ---PAGE BREAK--- The engineering report for projects utilizing land application, including seepage lagoons, irrigation, and subsurface disposal, shall include information on the following together with appropriate parts of subsection C(3) of this table, as determined by Ecology: Soils and their permeability. Geohydrologic evaluation of such factors as: Depth to ground and ground water movement during different times of the year. (ii.) Water balance analysis of the proposed discharge area. (iii.) Overall effects of the proposed facility upon the ground water in conjunction with any other land application facilities that may be present. Availability of public sewers. Reserve areas for additional subsurface disposal. Section refers to the availability of public sewers connected to a conventional treatment facility. One criterion (especially for grant/loan considerations) used to compare conveyance and treatment at a WWTP versus treatment on-site is a 20-year present worth calculations. If the present worth to convey wastewater to a larger, conventional facility is equal or lower than treatment in an approved on-site wastewater treatment facility, then the entity should select conveyance and treatment. If an approved on- site treatment process costs less (present worth basis), site soils can provide drainage, and the entity has addressed other environmental and local concerns, the proponent should select the on-site treatment. The selection process is related to long-term reliability of the treatment and disposal process. Section requires adequate area for 100% replacement of the drain field if the entity selects subsurface disposal (see DOH’s ”Design Standards for Large On-Site Sewage Systems”). See Chapter E3 for determining the ground water quality criteria for land application process. NOTE: WAC 173-240-035 restricts the use of subsurface wastewater disposal systems if other methods are available. Satisfying the above requirements will satisfy the reasonability test (WAC 173-240-035). Not applicable. ---PAGE BREAK--- NATIONAL WETLANDS INVENTORY MAP APPENDIX 2-A ---PAGE BREAK--- Kennewick WWTF Jul 25, 2014 This map is for general reference only. The US Fish and Wildlife Service is not responsible for the accuracy or currentness of the base data shown on this map. All wetlands related data should be used in accordance with the layer metadata found on the Wetlands Mapper web site. User Remarks: Kennewick, WA ---PAGE BREAK--- FARMLAND CLASSIFICATION EXHIBIT APPENDIX 2-B ---PAGE BREAK--- Farmland Classification—Benton County Area, Washington (City of Kennewick WWTP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2014 Page 1 of 4 5119000 5119100 5119200 5119300 5119400 5119500 5119600 5119700 5119800 5119900 5120000 5120100 5119000 5119100 5119200 5119300 5119400 5119500 5119600 5119700 5119800 5119900 5120000 337800 337900 338000 338100 338200 338300 338400 338500 338600 337700 337800 337900 338000 338100 338200 338300 338400 338500 46° 12' 54'' N 119° 6' 14'' W 46° 12' 54'' N 119° 5' 33'' W 46° 12' 16'' N 119° 6' 14'' W 46° 12' 16'' N 119° 5' 33'' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 [PHONE REDACTED] 1500 Feet 0 50 100 200 300 Meters Map Scale: 1:5,710 if printed on A portrait (8.5" x 11") sheet. ---PAGE BREAK--- MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons Not prime farmland All areas are prime farmland Prime farmland if drained Prime farmland if protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated and drained Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season Prime farmland if subsoiled, completely removing the root inhibiting soil layer Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance Farmland of local importance Farmland of unique importance Not rated or not available Soil Rating Lines Not prime farmland All areas are prime farmland Prime farmland if drained Prime farmland if protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated and drained Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season Prime farmland if subsoiled, completely removing the root inhibiting soil layer Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance Farmland of local importance Farmland of unique importance Not rated or not available Soil Rating Points Not prime farmland All areas are prime farmland Prime farmland if drained Prime farmland if protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated Prime farmland if drained and either protected from flooding or not frequently flooded during the growing season Prime farmland if irrigated and drained Prime farmland if irrigated and either protected from flooding or not frequently flooded during the growing season Prime farmland if subsoiled, completely removing the root inhibiting soil layer Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Prime farmland if irrigated and reclaimed of excess salts and sodium Farmland of statewide importance Farmland of local importance Farmland of unique importance Not rated or not available Water Features Farmland Classification—Benton County Area, Washington (City of Kennewick WWTP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2014 Page 2 of 4 ---PAGE BREAK--- MAP INFORMATION Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:20,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Benton County Area, Washington Survey Area Data: Version 9, Dec 9, 2013 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 6, 2010—Oct 17, 2010 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Farmland Classification—Benton County Area, Washington (City of Kennewick WWTP) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2014 Page 3 of 4 ---PAGE BREAK--- Farmland Classification Farmland Classification— Summary by Map Unit — Benton County Area, Washington (WA605) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI BbA Burbank loamy fine sand, 0 to 2 percent slopes Not prime farmland 0.6 0.9% HeA Hezel loamy fine sand, 0 to 2 percent slopes Farmland of statewide importance 19.7 27.8% PaA Pasco fine sandy loam, 0 to 2 percent slopes Farmland of statewide importance 24.7 34.8% PcA Pasco silt loam, 0 to 2 percent slopes Farmland of statewide importance 24.8 35.0% W Water Not prime farmland 1.1 1.6% Totals for Area of Interest 70.9 100.0% Description Farmland classification identifies map units as prime farmland, farmland of statewide importance, farmland of local importance, or unique farmland. It identifies the location and extent of the soils that are best suited to food, feed, fiber, forage, and oilseed crops. NRCS policy and procedures on prime and unique farmlands are published in the "Federal Register," Vol. 43, No. 21, January 31, 1978. Rating Options Aggregation Method: No Aggregation Necessary Tie-break Rule: Lower Farmland Classification—Benton County Area, Washington City of Kennewick WWTP Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 7/11/2014 Page 4 of 4 ---PAGE BREAK--- FEMA FLOOD INSURANCE RATE MAP APPENDIX 2-C ---PAGE BREAK--- ---PAGE BREAK--- EZ1 FORM DOE CORRESPONDENCE APPENDIX 2-D ---PAGE BREAK--- PROJECT REVIEW SHEET – EZ1 HISTORIC & CULTURAL RESOURCES REVIEW PROPERTY / CLIENT NAME: City of Kennewick FUNDING AGENCY: City of Kennewick Project Applicant: Contact Person: Vince Barthels (Authorized Agent with J-U-B Engineers) Address: 422 W. Riverside, Suite 304 City, State: Spokane, WA Zip: 99201 County: Spokane Phone/ FAX: (509) 458-3727 E-Mail: [EMAIL REDACTED] Funding Agency: Organization: Washington State Department of Ecology, Ian Laseke, P.E. Address: 15 W. Yakima Ave City, State: Yakima, WA Zip: 98902 Phone: (509) 457-7108 PLEASE DESCRIBE THE PROPOSED WORK AND DETAIL ALL GROUND DISTURBING ACTIVITIES AND PROVIDE PHOTOS OF AREAS OF WORK. Provide a detailed description of the proposed project: The City of Kennewick is currently in the process of updating their Wastewater Treatment Plant (WWTP) Facilities Plan. In doing so, the City identified several areas of improvement which include: influent piping, pumping, biological treatment, solids management, final clarifiers, and UV disinfection. The aforementioned projects are described in the 2014 WWTP Facilities Plan and will address concerns regarding capacity and condition of existing equipment. With regard to the potential projects outlined in the updated Facilities Plan, a 67.6-acre proposed Area of Potential Effects (APE) had been established (see Cultural Resources Map). Any foreseeable projects (within the next 20 years) at the WWTP should be contained in the proposed APE. Describe the existing project site conditions: The WWTP provides biological treatment for incoming domestic, commercial, and industrial waste. The facility was originally constructed in 1952 and provided primary treatment with anaerobic digestion. A subsequent upgrade in 1972 transitioned the facility to secondary treatment and converted the primary clarifiers to final clarifiers. Improvements through the mid-1990s focused on minor upgrades and improvements to previously constructed components. In 1995, two high rate treatment (HRT) cells were constructed and the aeration lagoons were repurposed for solids storage and treatment. Additional upgrades in 1995 included influent screening, influent pumping, intermediate clarification, construction of a flash mix / flocculation basin, expansion of the final clarifiers, and construction of a new administration building. Since 2000, the facility has undergone several additional improvements to provide UV disinfection, replace influent screening equipment / system, add a second intermediate clarifier, and to replace the return activated sludge (RAS) / waste activated sludge (WAS) pumping system. This facility currently includes the following major process / components: headworks, influent parshall flume, influent pump station, HRT cells, intermediate clarification, intermediate clarifier RAS / WAS pump station, flash mix / flocculation, final clarification, UV disinfection, effluent palmer bowlus flume, effluent pump station and aerated sludge lagoons. PLEASE DESCRIBE THE TYPE OF WORK TO BE COMPLETED (Be as detailed as possible to avoid having to provide additional information) ---PAGE BREAK--- Describe the proposed ground disturbing activities: Generally speaking, ground disturbing activities will include: grading/reshaping within the APE and digging new ditches for utility piping. It should be noted that the design phase for these projects have not started. Check if building(s) will be altered or demolished. If so please complete a DAHP Determination of Eligibility “EZ2” form for each building effected by the proposed project. ---PAGE BREAK--- Project Location Township: 8 N Range: 30 E Section: 5 and 6 Address: 416 N. Kingwood St. City: Kennewick County: Benton Mail this form to: Department of Archaeology and Historic Preservation or E-mail to: Robert Whitlam, Ph.D. 1063 S. Capitol Way, Suite 106 State Archaeologist, DAHP P.O. Box 48343 (360) 586-3080 Olympia, WA 98504-8343 [EMAIL REDACTED] ( W i t h i n 3 0 d a y s D A H P w i l l m a i l t h e i r o p i n i o n b a c k t o y o u . ) Please be aware that this form may only initiate consultation. For some projects, DAHP may require additional information to complete our review such as plans, specifications, and photographs. An historic property inventory form may need to be completed by a qualified preservation professional. SEE ATTACHED CULTURAL RESOUCES MAP PLEASE ATTACH A COPY OF THE RELEVANT PORTION OF A 7.5 SERIES USGS QUAD MAP AND OUTLINE THE PROJECT INPACT AREA. USGS Quad maps are available on-line at http://maptech.mytopo.com/onlinemaps/index.cfm ---PAGE BREAK--- %7.674#.4'5174%'/#2 2.16' .#5672' >>521-#0'>27$.+%>241,'%65>Ä'08+41)42241,015>ÄÄ-'00'9+%-9962>%#&>5*''6>%7.674#.4'5174%'/#2 400 0 800 SCALE IN FEET CHEMICAL DR. 3RD AVE. NUTMEG ST. OAK ST. COLUMBIA DR. KINGWOOD ST. ---PAGE BREAK--- ---PAGE BREAK--- BIOLOGICAL ASSESSMENT APPENDIX 2-E ---PAGE BREAK--- Biological Assessment for the City of Kennewick Wastewater Treatment Plant (WWTP) 2014 Facility Plan Update [Benton County, Washington] September 2014 Prepared for: Gary Deardorff, Utility Services Manager City of Kennewick 1010 E. Chemical Drive Kennewick, WA 99336 (509) 585-4289 Prepared by: Vincent Barthels, Biologist J-U-B ENGINEERS, Inc. 422 W. Riverside Avenue, Suite 304 Spokane, WA 99201 [EMAIL REDACTED] (509) 458-3727 (Office) (509) 951-9564 (Cell) (509) 458-3762 (Fax) ---PAGE BREAK--- ---PAGE BREAK--- Table of Contents Introduction 1 Description of the Project Actions 1 Planned Best Management Practices (BMPs) 4 Environmental Baseline 4 Biological Resources 5 Summary of Determination of Effects 10 Conclusion 10 References 11 Attachments 1. Vicinity Map 2. WWTP Improvement Phasing Exhibit 3. Action Area Exhibit 4. IPaC Species List [dated 9/15/2014] 5. NMFS EFH Report [dated 9/17/2014] ---PAGE BREAK--- 1 Introduction The City of Kennewick is located in Benton County, approximately 20 miles north of the Washington /Oregon border. The City limits are bordered on the north by the Columbia River. The City operates a wastewater treatment plant (WWTP), providing treatment for domestic, commercial and industrial wastewater. The WWTP is contained within a 67.6-acre property boundary and includes the following major components: headworks, influent parshall flume, influent pump station, high rate treatment (HRT) cells, intermediate clarification (IC), IC returned activated sludge (RAS) / waste activated sludge (WAS) pump station, flash mix/flocculation, final clarification, ultraviolet (UV) disinfection, effluent palmer bowlus flume, effluent pump station and aerated sludge lagoons. This WWTP currently discharges into the Columbia River under a National Pollutant Discharge Elimination System (NPDES) permit. According to the 2010 U.S. Census Bureau, the projected population growth for the City of Kennewick (WA) is +1.0% annually (USCB 2010). The City is currently in the process of updating their Facilities Plan based upon this population projection. Improvements to the operations, maintenance and replacement (OM&R) portions of the WWTP would enable the facility to handle capacity increases correlated with the presumed population growth. The Facilities Plan Update functions as a twenty year outlook for planning and operations at the WWTP. This biological assessment (BA) was prepared to analyze the effects of the proposed construction activities described within the City of Kennewick’s WWTP Facilities Plan Update on candidate, proposed, threatened, or endangered species and critical habitats listed under the Endangered Species Act (ESA). This BA also evaluates the presence of Essential Fish Habitat (EFH) as indicated by the Magnuson Stevens Fishery Conservation and Management Act (Magnuson Stevens Act). Description of the Project Actions Project Location The physical address of the WWTP is 416 N. Kingwood St., Kennewick, Washington. The WWTP is situated within Sections 5 and 6 of Township 8 North and Range 30 East. The Kennewick WWTP is bordered by the Columbia River to the north, Kingwood St. to the west, a vacant lot owned by the Port of Kennewick to the east and 3rd Ave. to the south (see the Vicinity Map, Attachment The vacant lot located immediately east of the WWTP is planned to be used for the project actions and will be included in the area evaluated for this analysis. Proposed Actions Because of ongoing OM&R needs, the City of Kennewick plans to upgrade several components of their WWTP. The proposed WWTP upgrades have been divided into four individual phases. The attached WWTP Improvement Phasing Exhibit (Attachment 2) illustrates the location and sequencing/timing of the itemized improvements. ---PAGE BREAK--- 2 Phase 1 includes the replacement of the current UV system as well as several minor improvements to existing facilities to address operational concerns. These improvements include the following additions: Emergency bypass: Replacement of the existing gate structure, which serves as emergency bypass around influent screens in case of screen failure. Influent Pump Station: Construction of a crane and hoist to improve operator access to valve vault. Aeration Upgrades: Addition of two new surface aerators to increase aeration capability to meet existing peak hour demands. Sludge Lagoon Effluent Lift Station: Construction of a pump station to pump supernatant from solids storage lagoons back through the treatment process for additional treatment. UV System: Replacement of the existing UV disinfection system that is antiquated and no longer supported by the manufacturer. Phase 2 consists of improvements to the biosolids management process at the WWTP. Currently, biosolids are stored in two ponds and are periodically dredged, dewatered, and hauled offsite for land application disposal. There are many strong and unpleasant odors associated with the solids ponds; therefore, Phase 2 would institute a new way of handling the solids that would reduce the potential odor. Phase 2 would include implementation of equipment to thicken and anaerobically digest the waste solids to make them more stable and less odorous. In addition, dewatering equipment would be installed to dewater the digested solids to meet Class B requirements. The dewatered materials would be stockpiled for periodic removal and land application disposal. Phase 2 improvements would be constructed in the vacant lot to the immediate east of the existing WWTP. The existing northern solids pond would be repurposed for stockpiling the dewatered Class B biosolids. Phase 3 consists of upgrades to the biological treatment components of the WWTP. Currently, biological treatment occurs in lined ponds with surface aerators. Future loading to the WWTP as the population grows would require additional aeration capacity. Because no additional aerators can feasibly be added to the existing ponds, Phase 3 would involve abandoning the current aerated ponds and constructing new concrete basins with diffused air technology. The switch to diffused air would require the addition of a grit removal step in order to prevent grit buildup on the submerged diffusers. The diffused air technology is more energy efficient than surface aerators; therefore, the upgrades would make the WWTP more energy efficient and would also address safety concerns associated with working near surface aerators. Phase 3 upgrades would occur within the existing footprint of the northern solids storage pond. Phase 4 consists of constructing solar dryers that are capable of further treatment of the Class B waste solids into a Class A product that could be beneficially used throughout the community. The solar dryers are essentially large greenhouses that take advantage of the areas arid climate and abundance of sunshine to turn the Class B solids into Class A solids that are safe for public contact. The end product would be soil-like in consistency and could be used in creating compost, top dressing for parks, and many other beneficial uses. The Phase 4 upgrades ---PAGE BREAK--- 3 would be constructed to the east of the Phase 2 upgrades (see the WWTP Improvement Phasing Exhibit, Attachment None of the proposed actions would measurably alter the quantity or quality of ongoing effluent discharge. The City has an excellent record of meeting the requirements of the existing NPDES discharge permit with no violations in recent history. These proposed improvements will allow the WWTP to continue to meet the requirements of the existing NPDES discharge permit. Defined Project Footprint and Action Area The “project footprint” is defined as the immediate area involved in the project action. The project footprint has been defined as the 66.7 acre WWTP property minus the section of property that extends into the Columbia River and contains the WWTP outfall (see the Action Area Exhibit, Attachment The project’s “action area” includes all areas to be affected directly or indirectly by the project action. Therefore, the action area includes the project footprint and all areas surrounding the project footprint where construction activities could affect the environment, directly, indirectly, or through interrelated or interdependent actions. The action area was defined by determining the area in which the subject project-related impacts may occur. Because the temporary construction related noise impacts have been determined to be the farthest reaching project effects, the project’s action area is defined as: the limits of physical disturbance (including staging areas) plus a horizontal buffer equivalent to terrestrial noise impacts. The Endangered Species Act (ESA) considerations presented herein are focused on the defined action area described in this section. The most prevalent construction noise source is equipment powered by internal combustion engines (usually diesel). Noise from equipment likely to be used on this project (loaders, excavators, graders, vibratory rollers and miscellaneous trucks) will peak at about 89 decibels (dBA) when measured from a distance of 15 meters [50 feet] (WSDOT 2013). To reduce the impact of construction noise, most construction activities will be confined to the period least disturbing to adjacent and nearby residents, between 7:00 a.m. and 7:00 p.m. on weekdays. Mitigation of potential project construction noise impacts shall incorporate low-cost, easy-to- implement measures into project plans and specifications (e.g. equipment muffler requirements and/or work-hour limits). Because the project area is currently exposed to high levels of noise from consistent heavy truck, city and railroad traffic (associated with the Burlington Northern Railroad and SR-397), the ambient or background noise for the entire project action area is keyed into the traffic related noise. This correlates to a background sound of approximately 86 dBA. To define the horizontal extent of the project related temporary construction noise effects, Table 1 (an attenuation table) was developed. Table 1 (located on page 6) shows temporary construction noise levels should reach background or ambient sound levels at a distance of 100 feet from the edge of the project footprint. Based on this information the project action area has been defined as the project footprint plus a 100 foot radius (see the Action Area Exhibit, Attachment The defined action area encompasses approximately 87.0 acres and is situated entirely above the ordinary high water mark (OHWM) of the Columbia River. All ESA listed species that have the potential to occur within this defined action area will be analyzed in this report. ---PAGE BREAK--- 4 Table 1: Noise attenuation table for the defined project footprint. Distance from Roadway (feet) Construction Noise (-7.5 dBA)* Background Sound – Traffic Noise (-4.5 dBA)* 50 89 86 100 81.5 81.5 200 74 77 400 66.5 72.5 800 59 68 Note: = The project action area is characterized as having “soft site” conditions. Planned Best Management Practices (BMPs) The following subsection prescribes best management practices (BMPs) that will be incorporated into the project actions. BMPs are used to minimize short-term and direct construction impacts. It should be noted that the following BMPs are guidelines and should vary based upon the scope and nature of each individual project phase. 1. All work would be completed during daylight hours and within the defined project footprint. 2. Temporary Erosion and Sediment Control (TESC) structures would be in place during construction. Implementation of the TESC structures would be consistent with the developed Construction Stormwater Pollution Prevention Plan 3. The contractor(s) would have a spill prevention, control and countermeasures (SPCC) plan developed, approved and in place prior to any construction activities. Emergency spill equipment would be onsite at all times. 4. Fueling of general construction equipment (e.g. pickup trucks, dump trucks, etc.) would be fueled offsite at a commercial facility. The fueling of excavation equipment (e.g. backhoes, excavators, etc.) would be fueled within the project footprint at a preapproved location. Drip pans and absorbent cloths would be used during all fueling activities to reduce the potential of any contaminants leaving the site. 5. Disturbed barren areas would by hydro-seeded upon the completion of construction activities. Environmental Baseline The proposed action area is contained within the Columbia Plateau – Pleistocene Lake Basin, within the Rock-Glade Watershed (EPA 2010). The Columbia River flows westerly and intercepts many smaller rivers/tributaries before draining into the Pacific Ocean. The Columbia River contains suitable habitat, migration routes and spawning/rearing grounds for many varieties of aquatic species. ---PAGE BREAK--- 5 The action area is mostly developed except for intermittent patches of upland bunch grasses and annual weeds scattered in undeveloped portions. This property currently houses the existing City of Kennewick WWTP. Soils within the project area are comprised of: Pasco fine sandy loam (0-2% slopes); Pasco fine silt loam (0-2% slopes); and, Hezel loamy fine sand (0-2% slopes) (USDA/NRCS 2014). Hot dry summers and moderate winters are common for the project vicinity. The average annual precipitation is 7.7 inches and the average annual snowfall is 8.1 inches (NOAA 2000). Biological Resources ESA Consultation The U.S. Fish and Wildlife Service (USFWS) regulates threatened and endangered species, and designated critical habitat, which are afforded protection under the ESA. The USFWS manages these species through their Information, Planning, and Conservation (IPaC) database system. On September 15th, 2014, a project specific species listing was obtained from the IPaC system for the project action area. A total of seven potentially occurring species were included on the IPaC listing (see Attachment However, only five species warrant protection under the ESA, because “candidate” species are not afforded protection. No designated critical habitats were identified within the project action area according to the IPaC listing. Table 2 summarizes the information obtained from the IPaC listing. Table 2: Summary of IPaC ESA species listing for the action area (dated 9/15/2014). Species Listing Status Designated Critical Habitat within the Action Area Bull trout (Salvelinus confluentus) Threatened No Gray wolf (Canis lupus) Endangered No Greater sage-grouse (Centrocercus urophasianus) Candidate No Northern wormwood (Artemisia campestris var. wormskioldii) Candidate No rabbit (Brachylagus idahoensis) Endangered No Umtanum Desert buckwheat (Erogonum codium) Threatened No Ute ladies’-tresses (Spiranthes diluvialis) Threatened No NMFS Consultation The National Marine Fisheries Service (NMFS) is the lead federal agency responsible for the stewardship of marine resources and associated habitats. Based on the project location (i.e. in close proximity of the Columbia River) the NMFS EFH for the project vicinity was reviewed. On September 17th, 2014, the NMFS EFH mapping website was accessed to determine the presence/absence of EFH near the project action area. Chinook salmon and Coho salmon EFH ---PAGE BREAK--- 6 was determined to exist immediately north of the action area (see Appendix 5 – NMFS EFH Report). Table 3 summarizes the information obtained from the NMFS mapping website. Table 3 – Summary of NMFS listed species and EFH in the vicinity of the action area. Species EFH Life stages known to occur in the Columbia River Chinook salmon Yes All Coho salmon kisutch) Yes All Species Descriptions, Habitat Requirements and Effects Determinations The following sections include descriptions of individual species, habitat requirements and a determination of effect for each species listed in Tables 2 and 3. Species listed as “candidate” are not afforded protection under the ESA Section 7. In the event that a “candidate” species becomes a listed species (threatened or endangered) prior to or during construction, a provisional effects determination has been provided within this BA. Bull trout Bull trout are salmonids that are members of the char family. They have grayish to dark green sides with white to pinkish spots. The fish is recognized by the white margins on its pectoral, ventral, and anal fins (Eddy and Underhill 1978). The dorsal fin also lacks the spots that cover the back and sides of the body. Bull trout spawn in the fall in streams with cold, unpolluted water, clean gravel and cobble substrate, and gentle stream slopes (USFWS 1998). Bull trout eggs require a long incubation period, hatching in late winter or early spring. Some may live near areas where they were hatched; however, others migrate from streams to lakes or reservoirs a few weeks after emerging from the gravel. Bull trout habitat consists mainly of oligotrophic lakes and deep pools of pristine cold fluvial habitats in mountainous regions, mainly 45 to 55 degrees Fahrenheit (Sternberg 1996). The proposed project actions do not include any work below the OHWM of the Columbia River. Neither the amount of effluent discharge nor the effluent quality are anticipated to measurably change as a result of the proposed actions. Furthermore, all work associated with the proposed actions will be conducted landward of a levee that contains the Columbia River floodplain. Due to the scope and nature of the anticipated OM&R work, the proposed project actions have been determined to have “no effect” on bull trout. Gray Wolf Wolves have evolved to avoid people due to many centuries of wolf hunting (Maas 1997). The gray wolf requires vast forests and mountain foothills for hunting, usually far from humans (Maas 1997). They show little preference for special habitats as long as there is food available. Wolves generally travel in packs of up to 25 animals. The dominant male (the alpha male) and dominant female (the alpha female) make all the decisions for the group, including when and where they hunt (Maas 1997). A single territory for a pack can range between 100 to 600 square miles. On a single hunt they may travel over 50 miles in pursuit of food. ---PAGE BREAK--- 7 The project vicinity is surrounded by urban and industrial areas. The action area contains existing buildings and active facility operations. There are no forests or suitable hunting grounds within the project vicinity. Because no suitable habitat conditions exist within the action area, coupled with a low likelihood of species occurrence, a “no effect” determination has been applied to the gray wolf. Greater Sage-Grouse The greater sage-grouse is a federally listed “candidate” species. As the name implies, greater sage-grouse are found only in areas where sagebrush is abundant (Colorado Division of Wildlife 2009). The largest of all grouse, the greater sage-grouse is up to 30 inches long, 2 feet tall, and weighs from 2 to 7 pounds (USFWS 2010). Male greater sage-grouse have a white breast ruff, mottled gray-brown overall, a black belly, black throat and bib, and long stiff spike like tail feathers. Females have a mottled gray-brown overall, a black belly, a white throat, and lack the yellow eye comb seen in the males. Diet consists of evergreen leaves, plain sagebrush shoots, blossoms, leaves, pods, buds, and insects (Alsop 2001). Dependent on sagebrush for food and cover, required habitat consists of relatively open flats or rolling sagebrush hills at elevations ranging from 4,000 to 9,000 feet above sea level (Colorado Division of Wildlife 2009, USFWS 2010). Land clearing and overgrazing by livestock are documented threats to this species’ habitat. Generally speaking, the project action area lacks rolling hills dominated by sagebrush. The action area sits at approximately 350 feet 25 feet) above sea level, which is well below the typical range of the greater sage-grouse. Furthermore, the proposed project activities would be contained within a pre-disturbed setting. The proposed project actions “will not jeopardize the continued existence of” the greater sage-grouse based upon the lack of suitable habitat. Northern wormwood Northern wormwood is a perennial plant commonly known as Pacific sagebrush. Generally a low-growing plant, 15-30 cm, the northern wormwood has a taproot and basal leave crowded into rosettes. Stems and leaves of this plant are covered with silky hairs. This plant is the only variety of Artemisia that flowers in April and May. The flowers are yellow and arranged in relatively large heads. This species is restricted to exposed basalt, cobbly-sandy terraces, and sand habitat along the banks of the Columbia River. There are only two known populations that exist, one in Klickitat County, Washington and one in Grant County, Washington (USFWS 2014). Currently, the action area contains a pre-disturbed setting and generally lacks native vegetative communities. The action area lacks the preferred soils of the Northern wormwood (i.e. exposed basalt and cobbly-sandy terraces). This project is located well outside of both Klickitat County and Grant County, where the only known populations of Northern wormwood exist. Due to the proposed project location, the lack of suitable habitat, and the minimal likelihood of species occurrence, the proposed actions “will not jeopardize the continued existence of” Northern wormwood. rabbit The smallest rabbit species in North America, the rabbit measures 9.2-11.6 inches in length, weighs a slight 0.88-1.02 pounds, and is able to fit in the palm of a hand. rabbits ---PAGE BREAK--- 8 are generally limited to areas on deep soils with tall, dense sagebrush that they use for cover and food (Green and Flinders 1980). The rabbit is the only native leporid that digs burrows. Washington populations were historically found in sagebrush habitat in Benton, Adams, Grant, Lincoln and Douglas counties. Washington’s extant rabbit population totals fewer than 50 individuals and occurs on Sagebrush Flat in central Douglas County (Warren 2001). The closest known population of rabbits live within Sagebrush Flat in central Douglas County, located approximately 130 miles north of the project action area. The action area also lacks dense sagebrush, which is a habitat requirement for the rabbit. A “no effect” determination has been applied to the rabbit based upon the lack of known occurrence and lack of suitable habitat conditions. Umtanum Desert Buckwheat Umtanum Desert buckwheat is a low, mat-forming woody perennial with leaves covered with dense white hairs and yellow flowers. This plant species may live to be over 100 years old. The only known population of this species occurs along one ridgeline, on flat gently sloping mircosites, near the top of the steep, north-facing basalt cliffs overlooking the Columbia River. Wildfires are a particular threat to the Umtanum Desert buckwheat because they are very heat sensitive (U.S. Federal Register 2011). The action area lacks the preferred habitat conditions (e.g. basalt cliffs), that the Umtanum Desert buckwheat requires for growth and survival. Furthermore, the only known population of this species does not exist within or near the action area. A “no effect” determination has been applied to Umtanum Desert buckwheat based upon the aforementioned rationale. Ute ladies’-tresses Ute ladies’-tresses is a member of the orchid family. It was first described in 1984 and was federally listed as “threatened” by the USFWS under the ESA in January, 1992 (USFWS, 1995). Populations have been found in Utah, Colorado, Wyoming, Montana, Nevada, Idaho, and Washington. The elevation ranges in which populations have been found vary from 750 to 7,000 feet, with most populations above 4,000 feet. It is found in wetlands and riparian areas, including spring habitats, mesic meadows, river meanders and floodplains. They require open habitats, and populations decline if trees and shrubs invade the habitat. They are not tolerant of permanent standing water, and do not compete well with aggressive species such as reed canary grass (Phalaris arundinacea). The survey time for the species, as identified by the USFWS (1995), is mid-August through mid-September. There are no riparian areas, springs, meadows or floodplains within the defined action area. The project action area also sits well below the most common elevation range where Ute ladies- tresses are documented to occur. No known Ute ladies-tresses have been observed within the project footprint. Based on low likelihood of occurrence and lack of suitable habitat conditions, a “no effect” determination is warranted for Ute ladies-tresses. ---PAGE BREAK--- 9 Chinook salmon Also known as King salmon, adult Chinook salmon are the largest Pacific salmon species, often exceeding 40 pounds (NOAA 2014). They feed on aquatic and terrestrial insects when young, and primarily on other fish when adults. Chinook spawn on both sides of the Cascade Range, with some fish traveling hundreds of miles upstream before they reach their spawning grounds. Due to their size, chinook tend to spawn in the main stem of streams, where water flow is high (WDFW 2014). Chinook salmon is an important food source for Pacific Northwest wildlife including orca whales, bears, seals, larger birds of prey and humans. Over fishing, loss of habitat and dams all pose a threat to the longevity of this species (NWF 2014). The proposed project actions do not include any work below the OHWM of the Columbia River. Neither the amount of effluent discharge nor the effluent quality are anticipated to measurably change as a result of the proposed actions. Furthermore, all work associated with the proposed actions will be conducted landward of a levee that contains the Columbia River floodplain. Due to the scope and nature of the anticipated OM&R work, the proposed project actions have been determined to have “no effect” on Chinook salmon and its associated EFH. Coho salmon Coho salmon have a dark metallic blue or greenish backs with silver sides and a light belly. Spawning fish in inland rivers are dark with reddish coloration on their sides. The average adult male weighs 8 pounds and is 2 feet in length (NOAA 2014). Coho salmon habitat ranges from Northern Japan to Siberia and from California to Alaska, with the majority of spawning in Alaska, Washington and Oregon 1996). They prefer shallower water, smaller gravel and lower stream velocities, compared to other salmonids, when spawning. The proposed project actions do not include any work below the OHWM of the Columbia River. Neither the amount of effluent discharge nor the effluent quality are anticipated to measurably change as a result of the proposed actions. Furthermore, all work associated with the proposed actions will be conducted landward of a levee that contains the Columbia River floodplain. Due to the scope and nature of the anticipated OM&R work, the proposed project actions have been determined to have “no effect” on Coho salmon and its associated EFH. ---PAGE BREAK--- ---PAGE BREAK--- 11 References Alsop, F. 2001. Birds of North America (Western Region). DK Publishing, Inc. New York, New York. Colorado Division of Wildlife. 2009. Species Profile: Greater Sage-Grouse. Colorado Department of Natural Resources. Accessed 12/2/2010 at http://wildlife.state.co.us/WildlifeSpecies/Profiles/Birds/GreaterSageGrouse.htm Eddy, S. and J.C. Underhill. 1978. How to Know Fresh Water Fishes. Brown Company Publishers, USA. Environmental Protection Agency. 2010. Ecoregions of Washington (Map). [Online]. Accessed 6/12/14 at http://www.epa.gov/wed/pages/ecoregions/wa_eco.htm Green, J.S. and J.T. Flinders. 1980. Brachylagus idahoensis. Mammalian species. 125: 1-4. Maas, D. 1997. North American Game Animals. Cowles Creative Publishing, Minnetonka, Minnesota. National Wildlife Foundation (NWF). 2014. Wildlife Library: Chinook Salmon. [Online]. Accessed 04/11/2014 at http://www.nwf.org/wildlife/wildlife-library/amphibians-reptiles- and-fish/chinook-salmon.aspx National Oceanic and Atmospheric Administration (NOAA). 2000. Climatography of the United States No. 20 1971-2000, Kennewick, WA. [Online]. Accessed 6/16/14 at http://cdo.ncdc.noaa.gov/climatenormals/clim20/wa/454154.pdf NOAA. 2014. Coho Salmon kisutch). [Online]. Accessed 04/11/2014 at http://www.nmfs.noaa.gov/pr/species/fish/cohosalmon.htm Pacific States Marine Fisheries Commission 1996. Coho Salmon. [Online]. Accessed 04/11/2014 at Sternberg, D. 1996. Freshwater Game Fish of North America. Cy DeCosse, Inc. Minnetonka, Minnesota. U.S. Census Bureau (USCB). 2010. United Census 2010 [On-line]. Accessed on 8/14/14 at http://www.census.gov/2010census/. U.S. Department of Agriculture, Natural Resources Conservation Service (USDA/NRCS) Web Soil Survey. Accessed http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx on 6-3-14. U.S. Fish and Wildlife Service (USFWS). 1998. Bull trout facts (Salvelinus confluentus) [On- line]. Accessed 2/15/06 at http://www.fws.gov/pacific//news/bulltrout/bultrt2.pdf. USFWS. Endangered Species: Greater Sage-Grouse. Accessed 12/2/2010 at http://www.fws.gov/mountain-prairie/species/birds/sagegrouse/ USFWS. 1995. Ute ladies’-tresses (Spiranthes diluvialis) Draft Recovery Plan. U.S. Fish and Wildlife Service, Denver, Colorado. ---PAGE BREAK--- 12 USFWS. 2014. Species Fact Sheet Northern wormwood (Artemisia borealis var. wormskioldii). [Online]. Accessed 6/9/14 at http://www.fws.gov/wafwo/species/Fact%20sheets/NWormwoodfinal.pdf. U.S. Federal Register. 2011. Endangered Species Program: Umtanum Desert buckwheat. Accessed 04/10/2014 at AX72/endangered-and-threatened-wildlife-and-plants-listing-and-critical-habitat-designation- for-the-umtan Warren, C. 2001. Emergency rule to list the Columbia Basin distinct population segment of the rabbit (Brachylagus idahoensis) as endangered. November 30, 2001. Federal Register, Vol. 66, No. 231:pp 59734-59749. Washington Department of Fish & Wildlife (WDFW). 2014. Recreational Salmon Fishing: Chinook (King) Salmon [Online]. Accessed 04/11/2014 at http://wdfw.wa.gov/fishing/salmon/chinook.html Washington State Department of Transportation (WSDOT). 2013. Biological Assessment Preparation for Transportation Projects Advanced Training Manual Version 2013. Olympia, WA. ---PAGE BREAK--- PROJECT LOCATION Copyright 2009 MyTopo 7' 00.00" W 7' 00.00" W 119° 06' 00.00" W 119° 06' 00.00" W 119° 05' 00.00" W 119° 05' 00.00" W 119° 04' 00.00" W 119° 04' 00.00" W 119° 03' 00.00 119° 03' 00.00 046° 14' 00.00" N 046° 14' 00.00" N 046° 13' 00.00" N 046° 13' 00.00" N 046° 12' 00.00" N 046° 12' 00.00" N 046° 11' 00.00" N 046° 11' 00.00" N 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 FEET 1 inch = 3,000 ft. HORIZONTAL DATUM:NAD27 CITY OF KENNEWICK WWTF FACILITY PLAN UPDATE VICINITY MAP MAP: PASCO NE SE SW NW N E S W ---PAGE BREAK--- ---PAGE BREAK--- Item Description 1 Headworks 2 Influent Bypass 3 Influent Parshall Flume 4 Influent Pump Station 5 HRT Inlet Structure 6 HRT Lagoons No. 1 and 2 7 HRT Splitter Box 8 HRT Effluent Structure 9 Intermediate Clarifier No. 1 10 Intermediate Clarifier No. 2 11 ICE 1 Outlet Box 12 Flash Mix / Floc Basins No. 1 and 2 Item Description 13 Final Clarifiers No. 1 - 7 14 UV Disinfection 15 Effluent Palmer Bowlus Flume 16 Effluent Pump Station 17 Gravity Bypass 18 Sludge Storage Lagoon Inlet Structure 19 Aerated Sludge Lagoon No. 1 20 Aerated Sludge Lagoon No. 2 21 IC RAS / WAS Pump Station 22 Secondary Sludge Pump Station 23 Outfall to Columbia River 24 Administration Building Source: Google 1 2 3 5 6 7 8 10 9 12 4 13 14 16 15 17 18 19 20 21 22 24 23 11 25 26b 33 27 28 30 Item Description 25 Grit Removal and Inlet Distribution Box 26a Near-Term Aeration Upgrade 26b New Aeration Basins and Expansion Area 27 WAS Thickening 28 Anaerobic Digestion 29 Dewatering 30 Class A Solar Dryer 31 Aerated Sludge Lagoon Lift Station 32 Primary Clarification 33 Additional Intermediate Clarifiers 29 32 31 Phase 1 (2 Years) Phase 2 (2-5 Years) Phase 3 (5-10 Years) Phase 4 (10+ Years) Potential Future Process / Component No Scheduled Upgrades Property Line (approximate) # # # # # # 26a WWTP IMPROVEMENT PHASING EXHIBIT ---PAGE BREAK--- ---PAGE BREAK--- 400 0 800 SCALE IN FEET CHEMICAL DR. 3RD AVE. LEGEND KINGWOOD ST. NUTMEG ST. OAK ST. BURLINGTON NORTHERN RAILROAD ---PAGE BREAK--- ---PAGE BREAK--- United States Department of the Interior FISH AND WILDLIFE SERVICE Washington Fish and Wildlife Office 510 DESMOND DRIVE SE, SUITE 102 LACEY, WA 98503 PHONE: (360)753-9440 FAX: (360)753-9405 URL: www.fws.gov/wafwo/ Consultation Tracking Number: 01EWFW00-2014-SLI-0760 September 15, 2014 Project Name: City of Kennewick WWTP Facility Plan Update Subject: List of threatened and endangered species that may occur in your proposed project location, and/or may be affected by your proposed project. To Whom It May Concern: The enclosed species list identifies threatened, endangered, and proposed species, designated and proposed critical habitat, and candidate species that may occur within the boundary of your proposed project and/or may be affected by your proposed project. The species list fulfills the requirements of the U.S. Fish and Wildlife Service (Service) under section 7(c) of the Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 et seq.). New information based on updated surveys, changes in the abundance and distribution of species, changed habitat conditions, or other factors could change this list. The species list is currently compiled at the county level. Additional information is available from the Washington Department of Fish and Wildlife, Priority Habitats and Species website: or at our office website: http://wdfw.wa.gov/mapping/phs/ . Please note that under 50 CFR 402.12(e) of the http://www.fws.gov/wafwo/species_new.html regulations implementing section 7 of the Act, the accuracy of this species list should be verified after 90 days. This verification can be completed formally or informally as desired. The Service recommends that verification be completed by visiting the ECOS-IPaC website at regular intervals during project planning and implementation for updates to species lists and information. An updated list may be requested through the ECOS-IPaC system by completing the same process used to receive the enclosed list. The purpose of the Act is to provide a means whereby threatened and endangered species and the ecosystems upon which they depend may be conserved. Under sections 7(a)(1) and 7(a)(2) of the Act and its implementing regulations (50 CFR 402 et seq.), Federal agencies are required to utilize their authorities to carry out programs for the conservation of threatened and endangered species and to determine whether projects may affect threatened and endangered species and/or designated critical habitat. ---PAGE BREAK--- A Biological Assessment is required for construction projects (or other undertakings having similar physical impacts) that are major Federal actions significantly affecting the quality of the human environment as defined in the National Environmental Policy Act (42 U.S.C. 4332(2) For projects other than major construction activities, the Service suggests that a biological evaluation similar to a Biological Assessment be prepared to determine whether or not the project may affect listed or proposed species and/or designated or proposed critical habitat. Recommended contents of a Biological Assessment are described at 50 CFR 402.12. If a Federal agency determines, based on the Biological Assessment or biological evaluation, that listed species and/or designated critical habitat may be affected by the proposed project, the agency is required to consult with the Service pursuant to 50 CFR 402. In addition, the Service recommends that candidate species, proposed species, and proposed critical habitat be addressed within the consultation. More information on the regulations and procedures for section 7 consultation, including the role of permit or license applicants, can be found in the "Endangered Species Consultation Handbook" at: http://www.fws.gov/endangered/esa-library/pdf/TOC-GLOS.PDF Please be aware that bald and golden eagles are protected under the Bald and Golden Eagle Protection Act (16 U.S.C. 668 et seq.). You may visit our website at information on disturbance or take of the species and http://www.fws.gov/pacific/eagle/for information on how to get a permit and what current guidelines and regulations are. Some projects affecting these species may require development of an eagle conservation plan: ( Additionally, wind energy projects http://www.fws.gov/windenergy/eagle_guidance.html should follow the wind energy guidelines ( ) for minimizing http://www.fws.gov/windenergy/ impacts to migratory birds and bats. Also be aware that all marine mammals are protected under the Marine Mammal Protection Act (MMPA). The MMPA prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas. The importation of marine mammals and marine mammal products into the U.S. is also prohibited. More information can be found on the MMPA website: . http://www.nmfs.noaa.gov/pr/laws/mmpa/ We appreciate your concern for threatened and endangered species. The Service encourages Federal agencies to include conservation of threatened and endangered species into their project planning to further the purposes of the Act. Please include the Consultation Tracking Number in the header of this letter with any request for consultation or correspondence about your project that you submit to our office. Related website: National Marine Fisheries Service: http://www.nwr.noaa.gov/protected_species/species_list/species_lists.html Attachment 2 ---PAGE BREAK--- http://ecos.fws.gov/ipac, 09/15/2014 10:48 AM 1 Official Species List Provided by: Washington Fish and Wildlife Office 510 DESMOND DRIVE SE, SUITE 102 LACEY, WA 98503 (360) 753-9440 http://www.fws.gov/wafwo/ Consultation Tracking Number: 01EWFW00-2014-SLI-0760 Project Type: Transportation Project Description: Biological Assessment for the City of Kennewick 2014 Facility Plan Update United States Department of Interior Fish and Wildlife Service Project name: City of Kennewick WWTP Facility Plan Update ---PAGE BREAK--- http://ecos.fws.gov/ipac, 09/15/2014 10:48 AM 2 Project Location Map: Project Coordinates: MULTIPOLYGON (((-[PHONE REDACTED] 46.2147757, -[PHONE REDACTED] 46.2137363, -[PHONE REDACTED] 46.2122218, -[PHONE REDACTED] 46.2107666, -[PHONE REDACTED] 46.2096678, - [PHONE REDACTED] 46.2043515, -[PHONE REDACTED] 46.2044109, -[PHONE REDACTED] 46.2063415, -[PHONE REDACTED] 46.2094332, -[PHONE REDACTED] 46.2128187, -[PHONE REDACTED] 46.2127563, -[PHONE REDACTED] 46.2147757))) Project Counties: Benton, WA United States Department of Interior Fish and Wildlife Service Project name: City of Kennewick WWTP Facility Plan Update ---PAGE BREAK--- http://ecos.fws.gov/ipac, 09/15/2014 10:48 AM 3 Endangered Species Act Species List There are a total of 7 threatened, endangered, or candidate species on your species list. Species on this list should be considered in an effects analysis for your project and could include species that exist in another geographic area. For example, certain fish may appear on the species list because a project could affect species. Critical habitats listed under the Has Critical Habitat column may or may not lie within your project area. See the Critical habitats within your project area section further below for critical habitat that lies within your project. Please contact the designated FWS office if you have questions. Birds Status Has Critical Habitat Condition(s) Greater sage-grouse (Centrocercus urophasianus) Population: Columbia basin DPS Candidate Fishes Bull Trout (Salvelinus confluentus) Population: U.S.A., conterminous, lower 48 states Threatened Final designated Flowering Plants Northern Wormwood (Artemisia campestris var. wormskioldii) Candidate Umtanum Desert buckwheat (Eriogonum codium) Threatened Final designated Ute ladies'-tresses (Spiranthes diluvialis) Threatened Mammals Gray wolf (Canis lupus) Population: U.S.A.: All of AL, AR, CA, CO, CT, DE, FL, GA, KS, KY, LA, MA, MD, ME, Endangered United States Department of Interior Fish and Wildlife Service Project name: City of Kennewick WWTP Facility Plan Update ---PAGE BREAK--- http://ecos.fws.gov/ipac, 09/15/2014 10:48 AM 4 MO, MS, NC, NE, NH, NJ, NV, NY, OK, PA, RI, SC, TN, VA, VT and WV; those portions of AZ, NM, and TX not included in an experimental population; and portions of IA, IN, IL, ND, OH, OR, SD, UT, and WA. Mexico. Rabbit (Brachylagus idahoensis) Population: Columbia Basin DPS Endangered United States Department of Interior Fish and Wildlife Service Project name: City of Kennewick WWTP Facility Plan Update ---PAGE BREAK--- http://ecos.fws.gov/ipac, 09/15/2014 10:48 AM 5 Critical habitats that lie within your project area There are no critical habitats within your project area. United States Department of Interior Fish and Wildlife Service Project name: City of Kennewick WWTP Facility Plan Update ---PAGE BREAK--- ---PAGE BREAK--- NPDES PERMIT APPENDIX 4-A ---PAGE BREAK--- Page 1 of 1 Permit No.: WA-004478-4 Issuance Date: October 27, 2008 Effective Date: December 1, 2008 Expiration Date: November 30, 2013 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM WASTE DISCHARGE PERMIT NO. WA-004478-4 State of Washington DEPARTMENT OF ECOLOGY Yakima, Washington 98902 In compliance with the provisions of The State of Washington Water Pollution Control Law Chapter 90.48 Revised Code of Washington and The Federal Water Pollution Control Act (The Clean Water Act) Title 33 United States Code, Section 1342 et seq. CITY OF KENNEWICK PUBLICLY-OWNED TREATMENT WORKS PO BOX 6108 KENNEWICK, WA 99336-0108 Plant Location: 416 North Kingwood Street, Kennewick, WA Receiving Water: Columbia River (Lake Wallula) Water Body I.D. No.: 1189897461506 Discharge Location: Latitude: 46° 12' 47" N Longitude: 119° 05' 58" W Plant Type: High-rate aerated lagoons with return activated sludge, clarification, and UV Disinfection is authorized to discharge in accordance with the special and general conditions that follow. Robert F. Barwin Acting Section Manager Central Regional Office Washington State Department of Ecology ---PAGE BREAK--- Page 2 of 2 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 TABLE OF CONTENTS Page SUMMARY OF PERMIT REPORT SUBMITTALS 5 SPECIAL CONDITIONS 6 S1. DISCHARGE LIMITATIONS 6 A. Effluent Limitations 6 B. Mixing Zone Descriptions 7 B1. Chronic Mixing Zone 7 B2. Acute Mixing Zone 7 S2. MONITORING REQUIREMENTS 8 A. Monitoring Schedule 8 B. Sampling and Analytical Procedures 11 C. Flow Measurement 11 D. Laboratory Accreditation 11 S3. REPORTING AND RECORDING REQUIREMENTS 11 A. 11 B. Records Retention 12 C. Recording of Results 12 D. Additional Monitoring by the Permittee 13 E. Notice of Noncompliance Reporting 13 1. Immediate Noncompliance Notification 13 2. Twenty four hour Noncompliance Notification 13 3. Report Within Five Days 14 4. Waiver of Written Reports 14 5. Report Submittal 14 F. Other Noncompliance Reporting 14 G. Maintaining a Copy of This Permit 15 S4. FACILITY LOADING 15 A. Design Criteria 15 B. Plans for Maintaining Adequate Capacity 15 C. Duty to Mitigate 16 D. Notification of New or Altered Sources 16 E. Infiltration and Inflow Evaluation 16 S5. OPERATION AND MAINTENANCE 17 A. Certified Operator 17 ---PAGE BREAK--- Page 3 of 3 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 B. O & M Program 17 C. Short-term Reduction 18 D. Electrical Power Failure 18 E. Prevent Connection of Inflow 18 F. Bypass Procedures 18 G. Operations and Maintenance Manual 20 S6. PRETREATMENT 21 A. General Requirements 21 B. Wastewater Discharge Permit Required 21 C. Identification and Reporting of Existing, New, and Proposed Industrial Users 21 D. Industrial User Survey 21 E. Duty to Enforce Discharge Prohibitions 22 S7. RESIDUAL SOLIDS 23 S8. APPLICATION FOR PERMIT RENEWAL 23 S9. EFFLUENT MIXING STUDY FOR HUMAN HEALTH CARCINOGENS AND SEDIMENT DEPOSITION STUDY 23 A. Effluent Mixing Study For Human Health Carcinogens 23 B. Sediment Deposition 24 S10. WHOLE EFFLUENT TOXICITY TESTING 25 A. Acute Toxicity Tests 25 A1. Testing Requirements 25 A2. Sampling and Reporting Requirements 25 B. Chronic Toxicity Tests 26 B1. Testing Requirements 26 B2. Sampling and Reporting Requirements 27 S11. OUTFALL EVALUATION 28 GENERAL CONDITIONS 29 G1. SIGNATORY 29 G2. RIGHT OF INSPECTION AND ENTRY 30 G3. PERMIT 31 G4. REPORTING PLANNED 32 G5. PLAN REVIEW REQUIRED 32 ---PAGE BREAK--- Page 4 of 4 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 G6. COMPLIANCE WITH OTHER LAWS AND STATUTES 32 G7. TRANSFER OF THIS PERMIT 32 G8. REDUCED PRODUCTION FOR COMPLIANCE 33 G9. REMOVED SUBSTANCES 33 G10. DUTY TO PROVIDE INFORMATION 33 G11. OTHER REQUIREMENTS OF 40 CFR 34 G12. ADDITIONAL MONITORING 34 G13. PAYMENT OF FEES 34 G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS 34 G15. UPSET 34 G16. PROPERTY RIGHTS 35 G17. DUTY TO COMPLY 35 G18. TOXIC 35 G19. PENALTIES FOR TAMPERING 35 G20. REPORTING ANTICIPATED NON-COMPLIANCE 36 G21. REPORTING OTHER INFORMATION 36 G22. COMPLIANCE SCHEDULES 36 G23. CONTRACT REVIEW 36 ---PAGE BREAK--- Page 5 of 5 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 SUMMARY OF PERMIT REPORT SUBMITTALS Refer to the Special and General Conditions of this permit for additional submittal requirements. Permit Section Submittal Frequency First Submittal Date S3.A. Discharge Monitoring Report January 1, 2009 S3.E. Noncompliance Notification As necessary S4.B. Plans for Maintaining Adequate Capacity As necessary S4.D. Notification of New or Altered Sources As necessary S4.E. Infiltration and Inflow Evaluation 1/permit cycle November 30, 2012 S5.G. Operations and Maintenance Manual Update As necessary S6.D. Industrial User Survey 1/permit cycle November 30, 2012 S8. Application for permit renewal 1/permit cycle November 30, 2012 S9.A. Effluent Mixing Study for Human Health Carcinogens 1/permit cycle October 15, 2011 S9.B. Sediment Deposition Study 1/permit cycle October 15, 2011 S10.A2.10 Acute Toxicity Effluent Test Results with Permit Renewal Application 2/permit cycle February 2012 and August 2012 Submittal due November 30, 2012 S10.B2.10 Chronic Toxicity Effluent Test Results with Permit Renewal Application 2/permit cycle February 2012 and August 2012 Submittal due November 30, 2012 S11. Outfall Evaluation 1/permit cycle October 15, 2011 G1. Signatory Authorization as necessary G4. Reporting Planned Changes As necessary G5. Plan Review Required As necessary G20. Reporting Anticipated Non- compliance As necessary G21. Reporting Other Information As necessary G23. Contract Review As necessary ---PAGE BREAK--- Page 6 of 6 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 SPECIAL CONDITIONS In this permit the word “must” denotes an action that is mandatory and is equivalent to the word “shall” used in previous permits. S1. DISCHARGE LIMITATIONS A. Effluent Limitations All discharges and activities authorized by this permit must comply with the terms and conditions of this permit. The discharge of any of the following pollutants more frequently than, or at a level in excess of, that identified and authorized by this permit constitutes a violation of the terms and conditions of this permit. Beginning on December 1, 2008 and lasting through November 30, 2013, the permittee may discharge treated municipal wastewater to the Columbia River at the permitted location subject to compliance with the following limitations: EFFLUENT LIMITATIONS a: OUTFALL # 1 Parameter b Average Maximum Average Weekly Biochemical Oxygen Demand (5 day) 30 mg/L, 2,552 lbs/day 85% removal of influent BOD 45 mg/L, 3,828 lbs/day Total Suspended Solids 30 mg/L, 2,552 lbs/day 85% removal of influent TSS 45 mg/L, 3,828 lbs/day Fecal Coliform Bacteria 200 /100 mL 400 /100 mL pH c Daily minimum is equal to or greater than 6.0 and the daily maximum is less than or equal to 9.0. a The average and weekly effluent limitations equal the arithmetic mean of the samples taken. The average and weekly limitations for fecal coliform bacteria are equal to the geometric mean of the samples taken. b For pollutants with limitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. This does not apply to pH. c Indicates the range of permitted values. The permittee must report the instantaneous maximum and minimum pH Do not average pH values. ---PAGE BREAK--- Page 7 of 7 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 B. Mixing Zone Descriptions The following paragraph defines the maximum boundaries or flow-volume restriction of the mixing zones: B1. Chronic Mixing Zone WAC 173-201A-400(7)(a)(i) specifies mixing zones must not extend from the discharge ports for a distance greater than 300 feet plus the depth of water over the discharge ports at low flow. The mixing zone extends 310 feet and 100 feet upstream from the diffuser. Chronic aquatic life criteria and human health criteria must be met at the edge of the chronic zone. B2. Acute Mixing Zone WAC 173-201A-400(8)(a) specifies that acute criteria may be exceeded within 10% of the distance established for the chronic zone as measured independently from the discharge ports. The acute mixing zone extends 31 feet both up and from the diffuser. Acute aquatic life criteria must be met at the edge of the acute zone. Available Dilution (dilution factor) Acute Aquatic Life Criteria 37.2 Chronic Aquatic Life Criteria 103 Human Health Criteria - Carcinogen Not available Human Health Criteria - Non-carcinogen 103 ---PAGE BREAK--- Page 8 of 8 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 S2. MONITORING REQUIREMENTS A. Monitoring Schedule The permittee must monitor in accordance with the following schedule: Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Wastewater Influent Flow mgd Headworks Continuous a Measurement “ BOD5 mg/L “ 3/week b 24-Hour Composite “ BOD5 lbs/day “ 3/week Calculation c “ TSS mg/L “ 3/week 24-Hour Composite “ TSS lbs/day “ 3/week Calculation “ Total Kjeldahl Nitrogen mg/L N “ 1/quarter d Grab e “ Nitrate plus Nitrite N mg/L N “ 1/quarter Grab “ Total Nitrogen lbs/day 1/quarter Calculation Wastewater Effluent Flow mgd UV Building Continuous Measurement “ BOD5 mg/L “ 3/week 24-Hour Composite “ BOD5 lbs/day 3/week Calculation “ BOD5 % removal f 1/month g Calculation “ TSS mg/L “ 3/week 24-Hour Composite “ TSS lbs/day 3/week Calculation “ TSS % removal 1/month Calculation Wastewater Effluent pH Standard Units UV Building 3/week Grab “ Temperature h °C River Levee Lift Station Continuous Measurement “ Fecal Coliform Bacteria Colonies/ 100 mL UV Building 3/week Grab “ Total Ammonia mg/L “ 3/week Grab ---PAGE BREAK--- Page 9 of 9 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type “ Dissolved Oxygen mg/L “ 3/week Grab “ Total Kjeldahl Nitrogen mg/L N “ 1/quarter Grab “ Nitrate plus Nitrite N mg/L N “ 1/quarter Grab “ Total Nitrogen lbs/day “ 1/quarter Calculation Sludge As specified in Permit Condition S7 and the General Biosolids Permit Sediment As specified in Permit Conditions S9 and S11. Reapplication Monitoring Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type Wastewater Effluent Total Residual Chlorine mg/L UV Building 1/year i Grab “ Oil and Grease mg/L “ 1/year Grab “ Phosphorus (Total) mg/L P “ 1/year Grab “ Total Dissolved Solids mg/L “ 1/year Grab “ Total Hardness mg/L “ 1/year Grab “ Alkalinity mg/L “ 1/year Grab “ EPA Priority Pollutants - metals, cyanide and phenols. 1M-15M µg/L “ 1/year during 2010, 2011, & 2012 Grab Wastewater Effluent EPA Priority Pollutants – Volatile Organic Compounds. 1V – 31V µg/L UV Building 1/year during 2010, 2011, & 2012 Grab “ EPA Priority Pollutants – Acid- extractable compounds 1A – 11A µg/L “ 1/year during 2010, 2011, & 2012 Grab ---PAGE BREAK--- Page 10 of 10 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 Category Parameter Units Sample Point Minimum Sampling Frequency Sample Type “ EPA Priority Pollutants – Base- neutral compounds 1B – 46B µg/L “ 1/year during 2010, 2011, & 2012 Grab Wastewater Effluent Benzo(GHI)Perylene (Semi-volatile Organic Compound; SVOC), µg/L µg/L “ 1/year during 2012 Grab “ Phthalate (SVOC), µg/L µg/L “ 1/year during 2012 Grab “ Dibenzo(A,H) Anthracene (SVOC), µg/L µg/L “ 1/year during 2012 Grab “ Indeno(1,2,3-CD) Pyrene (SVOC), µg/L µg/L “ 1/year during 2012 Grab “ Whole effluent toxicity testing Testing using two species as specified in Permit Condition S10. Footnotes: a. Continuous means uninterrupted except for brief of time for calibration, for power failure, or for equipment repair or maintenance. The permittee must sample six times per day when continuous monitoring is not possible. b. "3/week" means three times during each calendar week and on a rotational basis throughout the days of the week, except weekends and holidays. c. "Calculation" means figured concurrently with the respective sample, using the following formula: Concentration (in mg/L) X Flow (in MGD) X Conversion Factor (8.34) = lbs/day. d. “1/quarter” means quarterly sampling and analysis during alternate months. e. “Grab" means an individual sample collected over a fifteen (15) minute, or less, period. f. Percent removal of BOD and TSS must be calculated with the following algorithm (concentrations in mg/L): (Average Influent Concentration - Average Effluent Concentration)/Average Influent Concentration g. "1/Month" means once every calendar month during alternate weeks. h. For temperature, the permittees must report the highest value each day. The monitoring system must record values every thirty minutes or less. Chart recorders may be used, with the peak temperature reported as read from the chart. Exclude any false readings caused during probe maintenance. Keep a record of each day's chart or temperature readings. i. “1/year” means once each year during alternate quarters. ---PAGE BREAK--- Page 11 of 11 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 B. Sampling and Analytical Procedures Samples and measurements taken to meet the requirements of this permit must be representative of the volume and nature of the monitored parameters. The permittee must conduct representative sampling of any unusual discharge or discharge condition, including bypasses, upsets and maintenance-related conditions that may affect effluent quality. Sampling and analytical methods used to meet the monitoring requirements specified in this permit must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 CFR Part 136. C. Flow Measurement The permittee must select and use appropriate flow measurement devices and methods consistent with accepted scientific practices. The permittee must install, calibrate, and maintain the flow devices. This work is necessary to ensure that the accuracy of the measurements are consistent with the accepted industry standard and the manufacturers recommendation for that type of device. The permittee must perform calibration at the frequency recommended by the manufacturer. The permittee must maintain calibration records for at least three years. D. Laboratory Accreditation The permittee must ensure that all monitoring data required by Ecology is prepared by a laboratory registered or accredited under the provisions of Chapter 173-50 WAC, Accreditation of Environmental Laboratories. Flow, temperature, settleable solids, conductivity, pH, and internal process control parameters are exempt from this requirement. Conductivity and pH must be accredited if the laboratory must otherwise be registered or accredited. Ecology exempts crops, soils, and hazardous waste data from this requirement pending accreditation of laboratories for analysis of these media. S3. REPORTING AND RECORDING REQUIREMENTS The permittee must monitor and report in accordance with the following conditions. Falsification of information submitted to Ecology is a violation of the terms and conditions of this permit. A. Reporting The first monitoring period begins on December 1, 2008. The permittee must submit monitoring results each month. The permittee must summarize, report, and submit ---PAGE BREAK--- Page 12 of 12 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 monitoring data obtained during each monitoring period on a Discharge Monitoring Report (DMR) form provided, or otherwise approved, by Ecology. The permittee must ensure that DMR forms are postmarked or received by Ecology no later than the 15th day of the month following the completed monitoring period, unless otherwise specified in this permit. The permittee must submit priority pollutant analysis data no later than forty-five (45) days following the monitoring period. Unless otherwise specified, the permittee must submit all toxicity test data within sixty (60) days after the sample date. The permittee must send report(s) to: Water Quality Data Coordinator Department of Ecology Central Regional Office 15 West Yakima Avenue, Suite 200 Yakima, Washington 98902 All laboratory reports providing data for organic and metal parameters must include the following information: sampling date, sample location, date of analysis, parameter name, CAS number, analytical method/number, method detection limit (MDL), laboratory practical quantitation limit (PQL), reporting units, and concentration detected. Analytical results from samples sent to a contract laboratory must include information on the chain of custody, the analytical method, QA/QC results, and documentation of accreditation for the parameter. The permittee must submit DMR forms whether or not the facility was discharging. If there was no discharge during a given monitoring period, the permittee must submit the form as required with the words "no discharge" entered in place of the monitoring results. B. Records Retention The permittee must retain records of all monitoring information for a minimum of three years. Such information must include all calibration and maintenance records and all original recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit. During the course of any unresolved litigation regarding the discharge of pollutants by the permittee or when requested by Ecology, the permittee must extend this period of retention. C. Recording of Results For each measurement or sample taken, the permittee must record the following information: ---PAGE BREAK--- Page 13 of 13 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 the date, exact place, method, and time of sampling or measurement; the individual who performed the sampling or measurement; the dates the analyses were performed; the individual who performed the analyses; the analytical techniques or methods used; and the results of all analyses. D. Additional Monitoring by the Permittee If the permittee monitors any pollutant more frequently than required by Condition S2 of this permit, then the permittee must include the results of such monitoring in the calculation and reporting of the data submitted in the permittee's DMR. E. Notice of Noncompliance Reporting The permittee must take the following action upon violation of any permit condition: Immediately take action to stop, contain, and cleanup unauthorized discharges or otherwise stop the noncompliance and correct the problem and, if applicable, immediately repeat sampling and analysis. The results of any repeat sampling must be submitted to Ecology within 30 days of sampling. 1. Immediate Noncompliance Notification Any failure of the disinfection system, any collection system overflows, or any plant bypass discharging to a waterbody used as a source of drinking water must be reported immediately to the Department of Ecology and the Department of Health, Drinking Water Program. The Department of Health’s Drinking Water Program number is (360) 521-0323 (business hours) or (360) 481-4901 (after business hours). 2. Twenty four hour Noncompliance Notification The permittee must report the following occurrences of noncompliance by telephone, to Ecology at [PHONE REDACTED], within 24 hours from the time the permittee becomes aware of any of the following circumstances: a. any noncompliance that may endanger health or the environment, unless previously reported under subpart 1. above, b. any unanticipated bypass that exceeds any effluent limitation in the permit (See Part S4.B, “Bypass Procedures”); c. any upset that exceeds any effluent limitation in the permit (See G15, “Upset”); d. any violation of a maximum daily or instantaneous maximum discharge ---PAGE BREAK--- Page 14 of 14 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 limitation for any of the pollutants in Section S1.A. of this permit; or e. any overflow prior to the treatment works, whether or not such overflow endangers health or the environment or exceeds any effluent limitation in the permit. 3. Report Within Five Days The permittee must also provide a written submission within five days of the time that the permittee becomes aware of any event required to be reported under subparts 1 or 2, above. The written submission must contain: a. a description of the noncompliance and its cause; b. the period of noncompliance, including exact dates and times; c. the estimated time noncompliance is expected to continue if it has not been corrected; d. steps taken or planned to reduce, eliminate, and prevent recurrence of the noncompliance; and e. if the non compliance involves an overflow prior to the treatment works, an estimate of the quantity (in gallons) of untreated overflow. 4. Waiver of Written Reports Ecology may waive the written report required in subpart 3 above on a case-by- case basis upon request if a timely oral report has been received. 5. Report Submittal Reports must be submitted to the address in S3. “REPORTING AND RECORDKEEPING REQUIREMENTS”. F. Other Noncompliance Reporting The permittee must report all instances of noncompliance, not required to be reported immediately or within 24 hours, at the time that monitoring reports for S3.A ("Reporting") are submitted. The reports must contain the information listed in paragraph S3.E above. Compliance with these requirements does not relieve the permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply. The spill of oil or hazardous materials must be reported in accordance with the instructions obtained at the following website: http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm ---PAGE BREAK--- Page 15 of 15 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 G. Maintaining a Copy of This Permit The permittee must keep a copy of this permit at the facility and make it available upon request to Department of Ecology inspectors. S4. FACILITY LOADING A. Design Criteria The flows or waste loads for the permitted facility must not exceed the following design criteria: • Average flow for the maximum month: 10.2 mgd • BOD5 loading for maximum month: 26,700 lbs/day • TSS loading for average month: 24,390 lbs/day B. Plans for Maintaining Adequate Capacity The permittee must submit a plan and a schedule for continuing to maintain capacity to Ecology when: 1. The actual flow or waste load reaches 85 percent of any one of the design criteria in S4.A for three consecutive months; or 2. The projected increase would reach design capacity within five years, whichever occurs first. 3. The plan and schedule for continuing to maintain capacity must be sufficient to achieve the effluent limitations and other conditions of this permit. This plan must identify any of the following actions or any other actions necessary to meet the objective of maintaining capacity. a. Analysis of the present design including the introduction of any process modifications that would establish the ability of the existing facility to achieve the effluent limits and other requirements of this permit at specific levels in excess of the existing design criteria specified in S4.A above. b. Reduction or elimination of excessive infiltration and inflow of uncontaminated ground and surface water into the sewer system. c. Limitation on future sewer extensions or connections or additional waste loads. d. Modification or expansion of facilities necessary to accommodate increased flow or waste load. e. Reduction of industrial or commercial flows or waste loads to allow for increasing sanitary flow or waste load. ---PAGE BREAK--- Page 16 of 16 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 4. Engineering documents associated with the plan must meet the requirements of WAC 173-240-060, "Engineering Report," and be approved by Ecology prior to any construction. 5. If the permittee intends to apply for State or Federal funding for the design or construction of a facility project, the plan must also meet the requirements of an engineering report or “Facility Plan” as described in 40 CFR 35.2030. The plan must specify any contracts, ordinances, methods for financing, or other arrangements necessary to achieve this objective. C. Duty to Mitigate The permittee must take all reasonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely affecting human health or the environment. D. Notification of New or Altered Sources 1. The permittee must submit written notice to Ecology whenever any new discharge or a substantial change in volume or character of an existing discharge into the POTW is proposed which: a. would interfere with the operation of, or exceed the design capacity of, any portion of the POTW; b. is not part of an approved general sewer plan or approved plans and specifications; or c. would be subject to pretreatment standards under 40 CFR Part 403 and Section 307(b) of the Clean Water Act. 2. This notice must include an evaluation of the POTW's ability to adequately transport and treat the added flow and/or waste load, the quality and volume of effluent to be discharged to the POTW, and the anticipated impact on the permittee’s effluent [40 CFR 122.42(b)]. E. Infiltration and Inflow Evaluation 1. The permittee must conduct an updated infiltration and inflow evaluation and submit it with the application for permit renewal. Refer to the U.S. EPA publication, I/I Analysis and Project Certification, available as Publication No. 97-03 at: Publications Office, Department of Ecology, PO Box 47600, Olympia, WA, 98504- 7600 or at http://www.ecy.wa.gov/programs/wq/permits/guidance.html. The ---PAGE BREAK--- Page 17 of 17 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 permittee may use plant monitoring records to assess measurable infiltration and inflow. 2. The permittee must prepare a report which summarizes any measurable infiltration and inflow. If infiltration and inflow have increased by more than 15 percent from that found in the previous report based on equivalent rainfall, the report must contain a plan and a schedule for: • locating the sources of infiltration and inflow; and • correcting the problem. S5. OPERATION AND MAINTENANCE The permittee must at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) that are installed to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance also includes keeping a daily operation logbook (paper or electronic), adequate laboratory controls and appropriate quality assurance procedures. This provision of the permit requires the permittee to operate back-up or auxiliary facilities or similar systems only when the operation is necessary to achieve compliance with the conditions of this permit. A. Certified Operator This permitted facility must be operated by an operator certified by the state of Washington by the state of Washington for at least a Class III plant. This operator must be in responsible charge of the day-to-day operation of the wastewater treatment plant. An operator certified for at least a Class II plant must be in charge during all regularly scheduled shifts. B. O & M Program 1. The permittee must institute an adequate operation and maintenance program for the entire sewage system. 2. The permittee must keep maintenance records on all major electrical and mechanical components of the treatment plant, as well as the sewage system and pumping stations. Such records must clearly specify the frequency and type of maintenance recommended by the manufacturer and must show the frequency and type of maintenance performed. 3. The permittee must make maintenance records available for inspection at all times. ---PAGE BREAK--- Page 18 of 18 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 C. Short-term Reduction If a permittee contemplates a reduction in the level of treatment that would cause a violation of permit discharge limitations on a short-term basis for any reason, and such reduction cannot be avoided, the permittee must: 1. Give written notification to Ecology, if possible, 30 days prior to such activities, 2. The notice must detail the reasons for, length of time of, and the potential effects of the reduced level of treatment. 3. This notification does not relieve the permittee of its obligations under this permit. D. Electrical Power Failure The permittee must ensure that adequate safeguards prevent the discharge of untreated wastes or wastes not treated in accordance with the requirements of this permit during electrical power failure at the treatment plant and/or sewage lift stations. Adequate safeguards include but are not limited to: alternate power sources, standby generator(s), or retention of inadequately treated wastes. For Reliability Class II - The permittee must maintain Reliability Class II (EPA 430/9- 74-001) at the wastewater treatment plant. Reliability Class II requires a backup power source sufficient to operate all vital components and critical lighting and ventilation during peak wastewater flow conditions. Vital components used to support the secondary processes mechanical aerators or aeration basin air compressors) need not be operable to full levels of treatment, but must be sufficient to maintain the biota. E. Prevent Connection of Inflow The permittee must strictly enforce its sewer ordinances and not allow the connection of inflow (roof drains, foundation drains, etc.) to the sanitary sewer system. F. Bypass Procedures Bypass is the intentional diversion of waste streams from any portion of a treatment facility. This permit prohibits bypass. Ecology may take enforcement action against a permittee for bypass unless one of the following circumstances 2, or 3) is applicable. 1. Bypass is for essential maintenance without the potential to cause violation of permit limits or conditions. This permit authorizes a bypass if it allows for essential maintenance and does not have the potential to cause violations of limitations or other conditions of this permit, or adversely impact public health as determined by Ecology prior to the ---PAGE BREAK--- Page 19 of 19 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 bypass. The permittee must submit prior notice, if possible, at least ten (10) days before the date of the bypass. 2. Bypass is unavoidable, unanticipated and results in noncompliance with the conditions of this permit. This permit authorizes such a bypass only if: b. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage. “Severe property damage” means substantial physical damage to property, damage to the treatment facilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. c. No feasible alternatives to the bypass exist, such as: • the use of auxiliary treatment facilities, • retention of untreated wastes, • stopping production, • maintenance during normal periods of equipment downtime, but not if adequate backup equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass • or transport of untreated wastes to another treatment facility. d. The permittee has properly notified Ecology of the bypass as required in condition S3.E of this permit. 3. If bypass is anticipated and has the potential to result in noncompliance of this permit. a. The permittee must notify Ecology at least thirty (30) days before the planned date of bypass. The notice must contain: i. a description of the bypass and its cause; ii. an analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing; iii. a cost-effectiveness analysis of alternatives including comparative resource damage assessment; iv. the minimum and maximum duration of bypass under each alternative; v. a recommendation as to the preferred alternative for conducting the bypass; vi. the projected date of bypass initiation; vii. a statement of compliance with SEPA; ---PAGE BREAK--- Page 20 of 20 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 viii. a request for modification of water quality standards as provided for in WAC 173-201A-410, if an exceedance of any water quality standard is anticipated; and ix. details of the steps taken or planned to reduce, eliminate, and prevent recurrence of the bypass. b. For probable construction bypasses, the permittee must notify Ecology of the need to bypass as early in the planning process as possible. The permittee must consider the analysis required above during preparation of the engineering report or facilities plan and plans and specifications and must include these to the extent practical. In cases where the permittee determines the probable need to bypass early, the permittee must continue to analyze conditions up to and including the construction period in an effort to minimize or eliminate the bypass. c. Ecology will consider the following prior to issuing an administrative order for this type of bypass: i. If the bypass is necessary to perform construction or maintenance-related activities essential to meet the requirements of this permit. ii. If feasible alternatives to bypass exist, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production, maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility. iii. If the permittee planned and scheduled the bypass to minimize adverse effects on the public and the environment. After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve or deny the request. The public will be given an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Ecology will approve of a request to bypass by issuing an administrative order under RCW 90.48.120. G. Operations and Maintenance Manual The permittee must keep the approved Operations and Maintenance Manual available at the treatment plant and all operators must follow the instructions and procedures of this manual. Whenever the permittee makes substantial changes or updates to the O&M Manual the permittee must submit the changes to Ecology for review and approval. ---PAGE BREAK--- Page 21 of 21 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 S6. PRETREATMENT A. General Requirements The permittee must work with Ecology to ensure that all commercial and industrial users of the publicly owned treatment works (POTW) comply with the pretreatment regulations in 40 CFR Part 403 and any additional regulations that may be promulgated under Section 307(b) (pretreatment) and 308 (reporting) of the Federal Clean Water Act. B. Wastewater Discharge Permit Required The permittee must not allow any significant industrial users (SIUs) to discharge wastewater to the permittee's sewer system until such user has received a wastewater discharge permit from Ecology in accordance with Chapter 90.48 RCW and Chapter 173-216 WAC. C. Identification and Reporting of Existing, New, and Proposed Industrial Users 1. The permittee must take continuous, routine measures to identify all existing, new, and proposed SIUs and potential significant industrial users (PSIUs) discharging or proposing to discharge to the permittee's sewer system (see Appendix B of the Fact Sheet for definitions). 2. Within 30 days of becoming aware of an unpermitted existing, new, or proposed industrial user who may be an SIU, the permittee must notify such user by registered mail that, if classified as an SIU, they must apply to Ecology and obtain a State Waste Discharge Permit. The permittee must send a copy of this notification letter to Ecology within this same 30-day period. 3. The permittee must also notify all Potential SIUs (PSIUs), as they are identified, that if their classification should change to an SIU, they must apply to Ecology for a State Waste Discharge Permit within 30 days of such change. D. Industrial User Survey The permittee must update the Industrial User Survey listing of all SIUs and PSIUs discharging to the POTW. The permittee must submit the survey to Ecology with the application for permit renewal. At a minimum, the permittee must develop the list of SIUs and PSIUs by means of a telephone book search, a water utility billing records search, and a physical reconnaissance of the service area. Information on PSIUs must include at a minimum: the business name, telephone number, address, description of the industrial process(es), and the known wastewater volumes and characteristics. ---PAGE BREAK--- Page 22 of 22 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 E. Duty to Enforce Discharge Prohibitions 1. Under 40 CFR 403.5(a), the permittee must not authorize or knowingly allow the discharge of any pollutants into its POTW which cause pass through or interference, or which otherwise violate general or specific discharge prohibitions contained in 40 CFR Part 403.5 or WAC-173-216-060. 2. The permittee must not authorize or knowingly allow the introduction of any of the following into their treatment works: a. Pollutants which create a fire or explosion hazard in the POTW (including, but not limited to waste streams with a closed cup flashpoint of less than 140 degrees Fahrenheit or 60 degrees Centigrade using the test methods specified in 40 CFR 261.21). b. Pollutants which will cause corrosive structural damage to the POTW, but in no case discharges with pH lower than 5.0, or greater than 11.0 standard units, unless the works are specifically designed to accommodate such discharges. c. Solid or viscous pollutants in amounts that could cause obstruction to the flow in sewers or otherwise interfere with the operation of the POTW. d. Any pollutant, including oxygen demanding pollutants, (BOD, etc.) released in a discharge at a flow rate and/or pollutant concentration which will cause interference with the POTW. e. Petroleum oil, nonbiodegradable cutting oil, or products of mineral origin in amounts that will cause interference or pass through. f. Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity which may cause acute worker health and safety problems. g. Heat in amounts that will inhibit biological activity in the POTW resulting in interference but in no case heat in such quantities such that the temperature at the POTW headworks exceeds 40 degrees Centigrade (104 degrees Fahrenheit) unless Ecology, upon request of the permittee, approves, in writing, alternate temperature limits. h. Any trucked or hauled pollutants, except at discharge points designated by the permittee. i. Wastewaters prohibited to be discharged to the POTW by the Dangerous Waste Regulations (Chapter 173-303 WAC), unless authorized under the Domestic Sewage Exclusion (WAC 173-303-071). 3. This permit prohibits all of the following from discharge to the POTW unless approved in writing by Ecology under extraordinary circumstances (such as a lack of direct discharge alternatives due to combined sewer service or the need to augment sewage flows due to septic conditions): ---PAGE BREAK--- Page 23 of 23 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 a. Noncontact cooling water in significant volumes. b. Stormwater, and other direct inflow sources. c. Wastewaters significantly affecting system hydraulic loading, which do not require treatment, or would not be afforded a significant degree of treatment by the system. 4. The permittee must notify Ecology if any industrial user violates the prohibitions listed in this section. S7. RESIDUAL SOLIDS Residual solids include screenings, grit, scum, primary sludge, waste activated sludge, and other solid waste. The permittee must store and handle all residual solids in a manner that prevents their entry into state ground or surface waters. The permittee must not discharge leachate from residual solids to state surface or ground waters. S8. APPLICATION FOR PERMIT RENEWAL The permittee must submit an application for renewal of this permit by November 30, 2012. S9. EFFLUENT MIXING STUDY FOR HUMAN HEALTH CARCINOGENS AND SEDIMENT DEPOSITION STUDY A. Effluent Mixing Study For Human Health Carcinogens The permittee must determine the degree of effluent and receiving water mixing which occurs within the chronic mixing zone during the harmonic mean flow. The permittee must use the Guidance for Conducting Mixing Zone Analyses (Ecology, 1996) to establish the harmonic mean condition scenarios. The permittee must submit the results of the harmonic mean flow dilution factor estimate to Ecology for approval no later than October 15, 2011. 1. Protocols The permittee must determine the dilution ratio using protocols outlined in the following references, approved modifications thereof, or by another method approved by Ecology: ---PAGE BREAK--- Page 24 of 24 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 -Akar, P.J. and G.H. Jirka, Cormix2: An Expert System for Hydrodynamic Mixing Zone Analysis of Conventional and Toxic Multiport Diffuser Discharges, USEPA Environmental Research Laboratory, Athens, GA, Draft, July 1990. -Baumgartner, D.J., W.E. Frick, P.J.W. Roberts, and C.A. Bodeen, Dilution Models for Effluent Discharges, USEPA, Pacific Ecosystems Branch, Newport, OR, 1993. -Doneker, R.L. and G.H. Jirka, Cormix1: An Expert System for Hydrodynamic Mixing Zone Analysis of Conventional and Toxic Submerged Single Port Discharges, USEPA, Environmental Research Laboratory, Athens, GA, EPA/600- 3-90/012, 1990. -Ecology, Permit Writer’s Manual, Water Quality Program, Department of Ecology, Olympia WA 98504, July, 1994, including most current addenda. -Ecology, Guidance for Conducting Mixing Zone Analyses, Permit Writer’s Manual, (Appendix 6.1), Water Quality Program, Department of Ecology, Olympia WA 98504, October 1996. -Kilpatrick, F.A., and E.D. Cobb, Measurement of Discharge Using Tracers, Chapter A16, Techniques of Water-Resources Investigations of the USGS, Book 3, Application of Hydraulics, USGS, U.S. Department of the Interior, Reston, VA 1985. -Wilson, J.F., E.D. Cobb, and F.A. Kilpatrick, Fluorometric Procedures for Dye Tracing, Chapter A12. Techniques of Water-Resources Investigations of the USGS, Book 3, Application of Hydraulics, USGS, U.S. Department of the Interior, Reston, VA 1986. B. Sediment Deposition Study The permittee must evaluate the potential for sediment deposition of the outfall by using information collected during the outfall evaluation and river flow conditions in the vicinity of the outfall. The results must be submitted by October 15, 2011. ---PAGE BREAK--- Page 25 of 25 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 S10. WHOLE EFFLUENT TOXICITY TESTING A. Acute Toxicity Tests A1. Testing Requirements The permittee must: • Conduct acute toxicity testing on final effluent during February 2012 and August 2012. • Submit the results to Ecology with the permit renewal application. • Conduct acute toxicity testing on a series of at least five concentrations of effluent, including 100% effluent, and a control. • Use each of the following species and protocols for each acute toxicity test: 1. Fathead minnow, Pimephales promelas (96-hour static-renewal test, method: EPA-821-R-02-012). 2. Daphnid, Ceriodaphnia dubia, Daphnia pulex, or Daphnia magna (48- hour static test, method: EPA-821-R-02-012). A2. Sampling and Reporting Requirements 1. The permittee must submit all reports for toxicity testing in accordance with the most recent version of Department of Ecology Publication # WQ- R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must contain bench sheets and reference toxicant results for test methods. If the lab provides the toxicity test data in electronic format for entry into Ecology’s database, then the permittee must send the data to Ecology along with the test report, bench sheets, and reference toxicant results. 2. The permittee must collect grab samples for toxicity testing. The permittee must cool the samples to 0 - 6 degrees Celsius during collection and send them to the lab immediately upon completion. The lab must begin the toxicity testing as soon as possible but no later than 36 hours after sampling was completed. 3. The laboratory must conduct water quality measurements on all samples and test solutions for toxicity testing, as specified in the most recent version of Department of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. ---PAGE BREAK--- Page 26 of 26 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 4. All toxicity tests must meet quality assurance criteria and test conditions specified in the most recent versions of the EPA methods listed in subsection C of the Department of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. If Ecology determines any test results to be invalid or anomalous, the permittee must repeat the testing with freshly collected effluent. 5. The laboratory must use control water and dilution water meeting the requirements of the EPA methods listed in subsection A. or pristine natural water of sufficient quality for good control performance. 6. The permittee must conduct whole effluent toxicity tests on an unmodified sample of final effluent. 7. The permittee may choose to conduct a full dilution series test during compliance testing in order to determine dose response. In this case, the series must have a minimum of five effluent concentrations and a control. The series of concentrations must include the acute critical effluent concentration (ACEC). The ACEC equals 2.7 % effluent. 8. All whole effluent toxicity tests, effluent screening tests, and rapid screening tests that involve hypothesis testing must comply with the acute statistical power standard of 29% as defined in WAC 173-205-020. If the test does not meet the power standard, the permittee must repeat the test on a fresh sample with an increased number of replicates to increase the power. 9. Reports of individual characterization or compliance test results must be submitted to Ecology within 60 days after each sample date. 10. The Acute Toxicity Summary Report must be submitted to Ecology by November 30, 2012. B. Chronic Toxicity Tests B1. Testing Requirements The permittee must: • Conduct chronic toxicity testing on final effluent during February 2012 and August 2012. • Submit the results to Ecology with the permit renewal application. ---PAGE BREAK--- Page 27 of 27 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 • Conduct chronic toxicity testing on a series of at least five concentrations of effluent and a control. This series of dilutions must include the acute critical effluent concentration (ACEC). The ACEC equals 2.7 % effluent. • Compare the ACEC to the control using hypothesis testing at the 0.05 level of significance as described in Appendix H, EPA/600/4-89/001. • Perform chronic toxicity tests with all of the following species and the most recent version of the following protocols: Freshwater Chronic Test Species Method Fathead minnow Pimephales promelas EPA-821-R-02-013 Water flea Ceriodaphnia dubia EPA-821-R-02-013 B2. Sampling and Reporting Requirements 1. The permittee must submit all reports for toxicity testing in accordance with the most recent version of Department of Ecology Publication # WQ- R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. Reports must contain bench sheets and reference toxicant results for test methods. If the lab provides the toxicity test data in electronic format for entry into Ecology’s database, then the permittee must send the data to Ecology along with the test report, bench sheets, and reference toxicant results. 2. The permittee must collect grab samples for toxicity testing. The permittee must cool the samples to 0 - 6 degrees Celsius during collection and send them to the lab immediately upon completion. The lab must begin the toxicity testing as soon as possible but no later than 36 hours after sampling was completed. 3. The laboratory must conduct water quality measurements on all samples and test solutions for toxicity testing, as specified in the most recent version of Department of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. 4. All toxicity tests must meet quality assurance criteria and test conditions specified in the most recent versions of the EPA methods listed in subsection C of the Department of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria. If Ecology determines any test results to be invalid or anomalous, the permittee must repeat the testing with freshly collected effluent. ---PAGE BREAK--- Page 28 of 28 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 5. The laboratory must use control water and dilution water meeting the requirements of the EPA methods listed in subsection C. or pristine natural water of sufficient quality for good control performance. 6. The permittee must conduct whole effluent toxicity tests on an unmodified sample of final effluent. 7. The permittee may choose to conduct a full dilution series test during compliance testing in order to determine dose response. In this case, the series must have a minimum of five effluent concentrations and a control. The series of concentrations must include the CCEC and the ACEC. The CCEC and the ACEC may either substitute for the effluent concentrations that are closest to them in the dilution series or be extra effluent concentrations. The CCEC equals 1.0 % effluent. The ACEC equals 2.7 % effluent. 8. All whole effluent toxicity tests that involve hypothesis testing must comply with the chronic statistical power standard of 39% as defined in WAC 173-205-020. If the test does not meet the power standard, the permittee must repeat the test on a fresh sample with an increased number of replicates to increase the power. 9. Reports of individual characterization or compliance test results must be submitted to Ecology within 60 days after each sample date. 10. The Chronic Toxicity Summary Report must be submitted to Ecology by November 30, 2012. S11. OUTFALL EVALUATION The permittee must inspect the submerged portion of the outfall line and diffuser to document its integrity and continued function. If conditions allow for a video or photographic verification, the permittee must include such verification in the report. The permittee must collect any additional information at the outfall required to determine the potential for sediment deposition (Permit Condition S9). The permittee must submit the inspection report to Ecology by October 15, 2011. ---PAGE BREAK--- Page 29 of 29 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 GENERAL CONDITIONS G1. SIGNATORY REQUIREMENTS A All applications, reports, or information submitted to Ecology must be signed and certified. In the case of corporations, by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision making functions for the corporation, or (ii) the manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessary systems are established or actions taken to gather complete and accurate information for permit application requirements; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. In the case of a partnership, by a general partner. In the case of sole proprietorship, by the proprietor. In the case of a municipal, state, or other public facility, by either a principal executive officer or ranking elected official. Applications for permits for domestic wastewater facilities that are either owned or operated by, or under contract to, a public entity shall be submitted by the public entity. B. All reports required by this permit and other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if: 1. The authorization is made in writing by a person described above and submitted to Ecology. 2. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility, such as the position of plant manager, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters. (A duly ---PAGE BREAK--- Page 30 of 30 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 authorized representative may thus be either a named individual or any individual occupying a named position.) C. Changes to authorization. If an authorization under paragraph B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph B.2 above must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative. D. Certification. Any person signing a document under this section must make the following certification: I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. G2. RIGHT OF INSPECTION AND ENTRY The permittee must allow an authorized representative of Ecology, upon the presentation of credentials and such other documents as may be required by law: A. To enter upon the premises where a discharge is located or where any records must be kept under the terms and conditions of this permit. B. To have access to and copy, at reasonable times and at reasonable cost, any records required to be kept under the terms and conditions of this permit. C. To inspect, at reasonable times, any facilities, equipment (including monitoring and control equipment), practices, methods, or operations regulated or required under this permit. D. To sample or monitor, at reasonable times, any substances or parameters at any location for purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act. ---PAGE BREAK--- Page 31 of 31 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 G3. PERMIT ACTIONS This permit may be modified, revoked and reissued, or terminated either at the request of any interested person (including the permittee) or upon Ecology’s initiative. However, the permit may only be modified, revoked and reissued, or terminated for the reasons specified in 40 CFR 122.62, 40 CFR 122.64 or WAC 173-220-150 according to the procedures of 40 CFR 124.5. A. The following are causes for terminating this permit during its term, or for denying a permit renewal application: 1. Violation of any permit term or condition. 2. Obtaining a permit by misrepresentation or failure to disclose all relevant facts. 3. A material change in quantity or type of waste disposal. 4. A determination that the permitted activity endangers human health or the environment, or contributes to water quality standards violations and can only be regulated to acceptable levels by permit modification or termination. 5. A change in any condition that requires either a temporary or permanent reduction, or elimination of any discharge or sludge use or disposal practice controlled by the permit. 6. Nonpayment of fees assessed pursuant to RCW 90.48.465. 7. Failure or refusal of the permittee to allow entry as required in RCW 90.48.090. B. The following are causes for modification but not revocation and reissuance except when the permittee requests or agrees: 1. A material change in the condition of the waters of the state. 2. New information not available at the time of permit issuance that would have justified the application of different permit conditions. 3. Material and substantial alterations or additions to the permitted facility or activities which occurred after this permit issuance. 4. Promulgation of new or amended standards or regulations having a direct bearing upon permit conditions, or requiring permit revision. 5. The permittee has requested a modification based on other rationale meeting the criteria of 40 CFR part 122.62. 6. Ecology has determined that good cause exists for modification of a compliance schedule, and the modification will not violate statutory deadlines. 7. Incorporation of an approved local pretreatment program into a municipality’s permit. C. The following are causes for modification or alternatively revocation and reissuance: ---PAGE BREAK--- Page 32 of 32 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 1. When cause exists for termination for reasons listed in A1 through A7 of this section, and Ecology determines that modification or revocation and reissuance is appropriate. 2. When Ecology has received notification of a proposed transfer of the permit. A permit may also be modified to reflect a transfer after the effective date of an automatic transfer (General Condition G8) but will not be revoked and reissued after the effective date of the transfer except upon the request of the new permittee. G4. REPORTING PLANNED CHANGES The permittee must, as soon as possible, but no later than sixty (60) days prior to the proposed changes, give notice to Ecology of planned physical alterations or additions to the permitted facility, production increases, or process modification which will result in: 1) the permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b); 2) a significant change in the nature or an increase in quantity of pollutants discharged; or 3) a significant change in the permittee’s sludge use or disposal practices. Following such notice, and the submittal of a new application or supplement to the existing application, along with required engineering plans and reports, this permit may be modified, or revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is effective, any new or increased discharge in excess of permit limits or not specifically authorized by this permit constitutes a violation. G5. PLAN REVIEW REQUIRED Prior to constructing or modifying any wastewater control facilities, an engineering report and detailed plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173-240 WAC. Engineering reports, plans, and specifications must be submitted at least one hundred eighty (180) days prior to the planned start of construction unless a shorter time is approved by Ecology. Facilities must be constructed and operated in accordance with the approved plans. G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in this permit must be construed as excusing the permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations. G7. TRANSFER OF THIS PERMIT In the event of any change in control or ownership of facilities from which the authorized discharge emanate, the permittee must notify the succeeding owner or controller of the existence of this permit by letter, a copy of which must be forwarded to Ecology. ---PAGE BREAK--- Page 33 of 33 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 A. Transfers by Modification Except as provided in paragraph below, this permit may be transferred by the permittee to a new owner or operator only if this permit has been modified or revoked and reissued under 40 CFR 122.62(b)(2), or a minor modification made under 40 CFR 122.63(d), to identify the new permittee and incorporate such other requirements as may be necessary under the Clean Water Act. B. Automatic Transfers This permit may be automatically transferred to a new permittee if: 1. The permittee notifies Ecology at least 30 days in advance of the proposed transfer date. 2. The notice includes a written agreement between the existing and new permittees containing a specific date transfer of permit responsibility, coverage, and liability between them. 3. Ecology does not notify the existing permittee and the proposed new permittee of its intent to modify or revoke and reissue this permit. A modification under this subparagraph may also be minor modification under 40 CFR 122.63. If this notice is not received, the transfer is effective on the date specified in the written agreement. G8. REDUCED PRODUCTION FOR COMPLIANCE The permittee, in order to maintain compliance with its permit, must control production and/or all discharges upon reduction, loss, failure, or bypass of the treatment facility until the facility is restored or an alternative method of treatment is provided. This requirement applies in the situation where, among other things, the primary source of power of the treatment facility is reduced, lost, or fails. G9. REMOVED SUBSTANCES Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of wastewaters must not be resuspended or reintroduced to the final effluent stream for discharge to state waters. G10. DUTY TO PROVIDE INFORMATION The permittee must submit to Ecology, within a reasonable time, all information which Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The ---PAGE BREAK--- Page 34 of 34 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 permittee must also submit to Ecology upon request, copies of records required to be kept by this permit. G11. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by reference. G12. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification. G13. PAYMENT OF FEES The permittee must submit payment of fees associated with this permit as assessed by Ecology. G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is deemed guilty of a crime, and upon conviction thereof must be punished by a fine of up to ten thousand dollars ($10,000) and costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a willful violation occurs may be deemed a separate and additional violation. Any person who violates the terms and conditions of a waste discharge permit will incur, in addition to any other penalty as provided by law, a civil penalty in the amount of up to ten thousand dollars ($10,000) for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing violation, every day's continuance is deemed to be a separate and distinct violation. G15. UPSET Definition – “Upset” means an exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation. ---PAGE BREAK--- Page 35 of 35 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 An upset constitutes an affirmative defense to an action brought for noncompliance with such technology-based permit effluent limitations if the requirements of the following paragraph are met. A permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed, contemporaneous operating logs, or other relevant evidence that: 1) an upset occurred and that the permittee can identify the cause(s) of the upset; 2) the permitted facility was being properly operated at the time of the upset; 3) the permittee submitted notice of the upset as required in condition S3.E; and 4) the permittee complied with any remedial measures required under S4.C of this permit. In any enforcement action the permittee seeking to establish the occurrence of an upset has the burden of proof. G16. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege. G17. DUTY TO COMPLY The permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application. G18. TOXIC POLLUTANTS The permittee must comply with effluent standards or prohibitions established under Section 307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that establish those standards or prohibitions, even if this permit has not yet been modified to incorporate the requirement. G19. PENALTIES FOR TAMPERING The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit must, upon conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for not more than two years per violation, or by both. If a conviction of a person is for a violation committed after a first conviction of such person under this Condition, punishment must be a fine of not more than $20,000 per day of violation, or by imprisonment of not more than four years, or by both. ---PAGE BREAK--- Page 36 of 36 Permit No.: WA-004478-4 Expiration Date: November 30, 2013 G20. REPORTING ANTICIPATED NON-COMPLIANCE The permittee must give advance notice to Ecology by submission of a new application or supplement thereto at least one hundred and eighty (180) days prior to commencement of such discharges, of any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility or activity which may result in noncompliance with permit limits or conditions. Any maintenance of facilities, which might necessitate unavoidable interruption of operation and degradation of effluent quality, must be scheduled during non-critical water quality periods and carried out in a manner approved by Ecology. G21. REPORTING OTHER INFORMATION Where the permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application, or in any report to Ecology, such facts or information must be submitted G22. COMPLIANCE SCHEDULES Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule of this permit must be submitted no later than fourteen (14) days following each schedule date. G23. CONTRACT REVIEW The permittee must submit to Ecology any proposed contract for the operation of any wastewater treatment facility covered by this permit. The review is to ensure consistency with chapters 90.46 and 90.48 RCW. In the event that Ecology does not comment within a thirty-day period, the permittee may assume consistency and proceed with the contract. ---PAGE BREAK--- NPDES FACT SHEET APPENDIX 4-B ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK PUBLICLY-OWNED TREATMENT WORKS AUGUST 15, 2008 PURPOSE OF THIS FACT SHEET This fact sheet explains and documents the decisions Ecology made in drafting the proposed National Pollutant Discharge Elimination System (NPDES) permit for the City of Kennewick Publicly-Owned Treatment Works. This fact sheet complies with Section 173-220-060 of the Washington Administrative Code (WAC), which requires Ecology to prepare a draft permit and accompanying fact sheet for public evaluation before issuing an NPDES permit. Ecology makes the draft permit and fact sheet available for public review and comment at least thirty (30) days before we issue the final permit. Copies of the fact sheet and draft permit for the City of Kennewick Publicly-Owned Treatment Works, NPDES Permit No. WA-004478-4, are available for public review and comment from September 10, 2008 until October 10, 2008. For more details on preparing and filing comments about these documents, please see Appendix A - Public Involvement. The City of Kennewick reviewed the draft permit and fact sheet for factual accuracy. Ecology corrected any errors or omissions regarding the facility’s location, history, discharges, or receiving water. After the public comment period closes, Ecology will summarize substantive comments and provide responses to them. Ecology will include the summary and responses to comments in this Fact Sheet as Appendix D - Response to Comments. SUMMARY The City of Kennewick Publicly-Owned Treatment Works is a unique design. The facility has large high-rate aeration lagoons with activated sludge. This results in low variability in effluent pollutant concentrations. The proposed permit includes limits for Biochemical Oxygen Demand, Total Suspended Solids, Fecal Coliform Bacteria, and pH. The previous permit also included limits for Total Residual Chlorine and Ammonia, but an analysis using EPA methods did not show a reasonable potential to exceed water quality standards. Additional requirements include an outfall evaluation, the estimation of dilution factors for human health carcinogen pollutants, and a determination of the potential for sediment deposition from the effluent. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 2 of 2 TABLE OF CONTENTS Page PURPOSE OF THIS FACT SHEET SUMMARY INTRODUCTION BACKGROUND INFORMATION GENERAL FACILITY INFORMATION FACILITY DESCRIPTION Collection System Status Treatment Processes Discharge Outfall Residual PERMIT STATUS SUMMARY OF COMPLIANCE WITH PREVIOUS PERMIT ISSUED WASTEWATER CHARACTERIZATION SEPA COMPLIANCE PROPOSED PERMIT LIMITS DESIGN CRITERIA TECHNOLOGY-BASED EFFLUENT LIMITS SURFACE WATER QUALITY-BASED EFFLUENT LIMITS Numerical Criteria for the Protection of Aquatic Life and Recreation Numerical Criteria for the Protection of Human Health Narrative Criteria Antidegradation Mixing Zones DESCRIPTION OF THE RECEIVING WATER DESIGNATED USES AND SURFACE WATER QUALITY CRITERIA EVALUATION OF SURFACE WATER QUALITY-BASED EFFLUENT LIMITS FOR NUMERIC CRITERIA Chronic Mixing Zone Acute Mixing Zone BOD5 Temperature pH Fecal Coliform Bacteria Toxic Pollutants Chlorine and Cyanide ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 3 of 3 Arsenic, Copper, Nickel & Zinc (Aquatic Life Standards) Human Health Arsenic, Benzo(GHI)Perylene, Phthalate, Dibenzo(A,H) Anthracene, Indeno(1,2,3-CD) Pyrene (Human Health Standards) Whole Effluent Toxicity Sediment Quality Ground Water Quality Limits COMPARISON OF EFFLUENT LIMITS WITH THE PREVIOUS PERMIT ISSUED ON SEPTEMBER 18, 2003 MONITORING REQUIREMENTS LAB ACCREDITATION OTHER PERMIT CONDITIONS REPORTING AND RECORDKEEPING PREVENTION OF FACILITY OVERLOADING OPERATION AND MAINTENANCE (O&M) PRETREATMENT Federal and State Pretreatment Program Requirements Requirements for Routine Identification and Reporting of Industrial Users Requirements for Performing an Industrial User Survey Duty to Enforce Discharge Prohibitions Support by Ecology for Developing Partial Pretreatment Program by a POTW RESIDUAL SOLIDS HANDLING EFFLUENT MIXING STUDY FOR HUMAN HEALTH CARCINOGENS OUTFALL EVALUATION GENERAL CONDITIONS PERMIT ISSUANCE PROCEDURES PERMIT MODIFICATIONS PROPOSED PERMIT ISSUANCE REFERENCES FOR TEXT AND APPENDIX A--PUBLIC INVOLVEMENT INFORMATION APPENDIX B--GLOSSARY APPENDIX C—DATA AND TECHNICAL CALCULATIONS APPENDIX D--RESPONSE TO COMMENTS ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 4 of 4 INTRODUCTION The Federal Clean Water Act (FCWA, 1972, and later amendments in 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United States. One mechanism for achieving the goals of the Clean Water Act is the National Pollutant Discharge Elimination System (NPDES), administered by the federal Environmental Protection Agency (EPA). The EPA authorized the State of Washington to manage the NPDES permit program in our state. Our state legislature accepted the delegation and assigned the power and duty for conducting NPDES permitting and enforcement to Ecology. The legislature defined Ecology's authority and obligations for the wastewater discharge permit program in 90.48 RCW (Revised Code of Washington). The following regulations apply to municipal NPDES permits: • Procedures Ecology follows for issuing NPDES permits (chapter 173-220 WAC) • Technical criteria for discharges from municipal wastewater treatment facilities (chapter 173-221 WAC) • Water quality criteria for surface waters (chapter 173-201A WAC) and for ground waters (chapter 173-200 WAC) • Sediment management standards (chapter 173-204 WAC). These rules require any treatment facility operator to obtain an NPDES permit before discharging wastewater to state waters. They also define the basis for limits on each discharge and for other requirements imposed by the permit. Under the NPDES permit program Ecology must prepare a draft permit and accompanying fact sheet, and make it available for public review. Ecology must also publish an announcement (public notice) telling people where they can read the draft permit, and where to send their comments on the draft permit, during a period of thirty days (WAC 173-220-050). (See Appendix A--Public Involvement for more detail about the Public Notice and Comment procedures). After the Public Comment Period ends, Ecology may make changes to the draft NPDES permit. Ecology will summarize the responses to comments and any changes to the permit in Appendix D. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 5 of 5 BACKGROUND INFORMATION BACKGROUND INFORMATION TABLE 1. GENERAL FACILITY INFORMATION TABLE 1. GENERAL FACILITY INFORMATION Applicant: Applicant: City of Kennewick City of Kennewick Facility Name and Address: City of Kennewick Publicly-Owned Treatment Works 416 North Kingwood Street, Kennewick, WA Type of Treatment: High-rate aeration lagoons with activated sludge and UV Disinfection Discharge Location: Columbia River, River Mile 328, Lake Wallula Latitude: 46º 12' 47" N Longitude: 119º 05' 58" W Water Body ID Number: 1189897461506, Lake Wallula Figure 1. Map showing the facility location (arrow). FACILITY DESCRIPTION The City of Kennewick Publicly-Owned Treatment Works (POTW) discharges to the Columbia River at river mile 328.0. A river levee prevents flooding of the area. The POTW site is 45 acres. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 6 of 6 History Primary treatment of waste has been conducted at the POTW site since 1952. During 1972, the plant was upgraded to provide secondary waste treatment with aerated ponds. The city has added numerous improvements since that time. A major expansion was constructed in 1996. Since the expansion, improvements added include: • A vacuum truck waste disposal facility and pump station (1999) • An ultraviolet (UV) disinfection facility (2000) • Lagoon reconstruction and equipment replacement (2001) The Kennewick POTW has been identified as an EPA major facility. During 1996, Ecology prepared a Memorandum of Agreement with the City of Kennewick for delegation of certain engineering review and approval authority as part of a two-year pilot project. An amendment to the agreement was prepared in April 1998 and the agreement has been extended until further notice. Collection System Status The collection system dates to 1952, but most pipes have been installed in the past 30 years (City of Kennewick 2003). The collection system serves a residential population of about 50,400. The system consists of about 247 miles of gravity pipe and 15 lift stations. The majority of pipes are 10-inches or smaller. About 13,000 acres are available for residential housing within the urban growth boundary. The urban growth area has about 2,300 acres available for industrial and commercial use. Infiltration and inflow (I&I) to the collection system is present, but not excessive (City of Kennewick 2006). During the irrigation season, the amount of inflow and infiltration (I&I) ranges from 0.2 to 0.6 mgd. Two irrigation systems provide untreated river water to large portion of Kennewick, but are not able to service the higher elevation areas. Treatment Processes The current treatment process consists of the following: • Influent screening and pumping • Two high rate aerated lagoons (6 million gallons total) • One intermediate clarifier • Two aerated sludge lagoons (80 million gallons total) • Two flocculation basins ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 7 of 7 • Seven final clarifiers • UV Disinfection • Effluent flow and sampling The high-rate aeration lagoons receive screened influent and return activated sludge. Flow from the aeration lagoons is piped to intermediate and final clarifiers and flocculation basins, as needed. Two larger aerated sludge lagoons treat waste sludge. The effluent is disinfected with UV prior to discharge. To reduce odor and improve system reliability and efficiency, improvements to the POTW are planned for the initial phase of construction in 2009. The planned improvements include: • New headworks including fine screens and screenings washer compactor systems to wash and dewater grit from the screenings • High Rate Treatment (HRT) effluent flow split structures • Additional intermediate clarifier and upgrade of the existing one • New RAS/WAS pump station • Replacement of the existing aerators in the high-rate treatment cells with fine bubble diffusers and remodel an existing building to serve as the blower building • Install a new standby generator Biosolids management options were discussed in the Sewer System Plan (City of Kennewick 2006), but there are no plans for solids handling improvements at this time. Two Significant Industrial Users (SIUs) discharge to the POTW: Baker Produce (produce washing and packing) and Titanium Sports (wheel chair and bicycle frames). These facilities have not had an impact on the POTW. Six potential significant industrial users (PSIUs) also discharge to the POTW. The PSIUs include a part-time cannery, Perfection Latex Paints (cleanup water), decant water from street sweeping and vactor waste, waste transfer station wash down, J. Lieb Foods (water bottling), and the Kennewick Water Treatment facility (filter backwash). The backwash flow is about 0.4 mgd during peak water use (City of Kennewick 2006). The POTW has not reported any problems with the industrial users. Commercial dischargers include restaurants (over 125), taverns, grocery stores, car washes, auto repair shops, auto body and paint shops, metal fabricators and machine shops, dry cleaners, health care facilities, and veterinary offices. The classification level of the POTW is Class 3. The POTW has four certified operators: one class 4, one class 3, and two class 2 operators. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 8 of 8 The POTW is staffed Monday through Friday from 7 a.m. to 3:30 p.m. The facility is also staffed on weekends from 7 to 9 a.m. for plant process control parameter checks. Discharge Outfall The treated and disinfected effluent flows into the Columbia River through a submerged multi- port diffuser. The outfall is located on a shallow shelf in the river at a depth that varies from about 12 to 16 feet deep (JUB Engineers 1997). Residual Solids Waste sludge is currently allowed to build up in two lined sludge storage lagoons until a biosolids removal project is conducted. Biosolids removal (about 8,000 tons) may occur in 2011 in accordance with the General Permit for Biosolids Management. Options for improving biosolids handling were presented in the Kennewick Sewer Plan (2006), but there are no plans for implementation at this time. Odor problems result from spring turnover in the sludge lagoons. The current grit removal and screening setup at the headworks is not effective. The planned headworks improvements (fine screens, mechanical bar screens, and vortex grit removal systems to wash and dewater grit from the screenings) will remove a larger amount of grit, but it will be in a compacted form. The grit will automatically fill a dumpster for transfer to a local landfill. PERMIT STATUS Ecology issued the previous permit for this facility on September 18, 2003. The previous permit placed effluent limits on Biochemical Oxygen Demand, Total Suspended Solids, Fecal Coliform Bacteria, pH, Total Residual Chlorine, and Ammonia. The Kennewick POTW submitted an application for permit renewal on November 2, 2007. Ecology accepted it as complete on November 13, 2007. SUMMARY OF COMPLIANCE WITH PREVIOUS PERMIT ISSUED Ecology staff last conducted a non-sampling compliance inspection on June 20, 2008. During the history of the NPDES permit issued on September 18, 2003, the Kennewick POTW has remained substantially in compliance with the effluent limits and conditions of the permit. Ecology’s assessment of compliance is based on our review of the facility’s Discharge Monitoring Reports (DMRs) and on inspections conducted by Ecology. In order to reduce odors from the sludge lagoon during spring turnover, the POTW staff sent effluent from the intermediate clarifier to the sludge lagoons. This resulted in violations for maximum daily ammonia concentrations during April 2005 and May 2006. There were no ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 9 of 9 violations during 2007. The Kennewick POTW received an Ecology “Outstanding Treatment Plant” award for 2007. WASTEWATER CHARACTERIZATION The concentration of pollutants in the discharge was reported in the NPDES application and in discharge monitoring reports. The effluent is characterized as follows: Table 2: Wastewater Characterization (January 2005 to March 2008) from the Kennewick POTW reports. Parameter Average Concentration Maximum Concentration Effluent Flow, mgd 5.63 6.99 (daily) Biochemical Oxygen Demand 5-day (BOD5), mg/L 4.9 19 (weekly average) BOD5, lbs/day 221 923 (weekly average) Total Suspended Solids (TSS), mg/L 7.6 29 (weekly average) TSS, lbs/day 354 1,300 (weekly average) Fecal Coliform Bacteria, geometric mean 4.3 107 (weekly) pH, standard units, range 6.9 to 8.1 Ammonia, mg/L 3.9 46.7 (daily) Temperature, ºC 15.6 24.0 (daily) Influent BOD5 , mg/L 268 390 BOD5, lbs/day 12,480 18,080 TSS, mg/L 294 359 TSS, lbs/day 13,790 17,160 Total Kjeldahl Nitrogen (TKN; Ammonia and Organic Nitrogen), mg/L 43 94 TKN, lbs/day 2,050 4,170 Bioassays or Whole effluent Toxicity (WET) tests are conducted to determine if toxicity results from unknown pollutants or combinations of pollutants in the wastewater. Ecology reviewed the Kennewick POTW WET tests for November 2002, June 2002, September 2006, and June 2007. Except for anomalous results (where tests with low concentrations of effluent showed effects, but higher concentrations did not), there were no statistically significant reduction in survival or growth at any effluent concentration when compared to control tests. Additional WET tests will be required with the next permit application to determine if there has been a change in toxicity of the effluent. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 10 of 10 Table 3. Pollutant parameters not reported on the Kennewick POTW reports for the period October 2006 through September 2007 (from the 2007 Permit Application). Parameter Average Concentration Maximum Concentration Total Residual Chlorine, mg/L 0.122 0.18 Dissolved Oxygen, mg/L 8.2 13.5 Nitrate/Nitrite Nitrogen, mg/L 18.4 24 Oil and Grease, mg/L <0.1 <0.1 Total Phosphorus, mg/L 4.0 5.3 Total Dissolved Solids, mg/L 540 660 Table 4. Priority pollutants measured in two effluent samples collected for the November 2007 Permit Application. Parameter Average Concentration Maximum Concentration Arsenic, µg/L 1.8 2.0 Copper, µg/L 18.8 19 Nickel, µg/L <2 1.8 Zinc, µg/L 68.8 73 Cyanide, µg/L <17 25.2 Toluene (Volatile Organic Compound), µg/L <0.5 0.5 Benzo(GHI)Perylene (Semi- volatile Organic Compound; SVOC), µg/L <0.385 0.616 Phthalate (SVOC), µg/L 4.179 7.78 Dibenzo(A,H) Anthracene (SVOC), µg/L <0.38 0.661 Indeno(1,2,3-CD) Pyrene (SVOC), µg/L <0.385 0.67 Hardness (as CaCO3), mg/L 150 160 SEPA COMPLIANCE The City of Kennewick issued a Determination of Non-Significance for the planned improvements to the Kennewick POTW January 10, 2008. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 11 of 11 PROPOSED PERMIT LIMITS Federal and State regulations require that effluent limits in an NPDES permit must be either technology- or water quality-based. • Technology-based limits are based upon the treatment methods available to treat specific pollutants. Technology-based limits are set by the EPA and published as a regulation, or Ecology develops the limit on a case-by-case basis (40 CFR 125.3, and chapter 173-220 WAC). • Water quality-based limits are calculated so that the effluent will comply with the Surface Water Quality Standards (chapter 173-201A WAC), Ground Water Standards (chapter 173-200 WAC), Sediment Quality Standards (chapter 173-204 WAC) or the National Toxics Rule (40 CFR 131.36). • Ecology must apply the most stringent of these limits to each parameter of concern. These limits are described below. The limits in this permit reflect information received in the application. Ecology evaluated the permit application and determined the limits needed to comply with the rules adopted by the State of Washington. Ecology does not develop effluent limits for all reported pollutants. Some pollutants are not treatable at the concentrations reported, are not controllable at the source, are not listed in regulation, or do not have a reasonable potential to cause a water quality violation. Nor does Ecology usually develop limits for pollutants that were not reported in the permit application but that may be present in the discharge. The permit does not authorize discharge of the non-reported pollutants. If significant changes occur in any constituent of the effluent discharge, the Kennewick POTW is required to notify Ecology (40 CFR 122.42(a)). The Kennewick POTW may be in violation of the permit until the permit is modified to reflect additional discharge of pollutants. DESIGN CRITERIA Under WAC 173-220-150 flows and waste loadings must not exceed approved design criteria. Ecology approved design criteria for the POTW were obtained from the most recent facility plan (HDR 2007). ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 12 of 12 Table 5: City of Kennewick POTW Design Criteria (HDR 2007). Parameter Design Criteria Average Flow, mgd 9.3 Maximum Flow, mgd 10.2 Peak Hourly Flow, mgd 20.3 Average BOD5 influent loading, lbs/day 24,500 Maximum BOD5 influent loading, lbs/day 26,700 Average TSS influent loading, lbs/day 24,390 TECHNOLOGY-BASED EFFLUENT LIMITS Federal and state regulations define technology-based effluent limits for municipal wastewater treatment plants. These effluent limits are given in 40 CFR Part 133 (federal) and in chapter 173-221 WAC (state). These regulations are performance standards that constitute all known, available, and reasonable methods of prevention, control, and treatment (AKART) for municipal wastewater. Chapter 173-221 WAC lists the technology-based limits for pH, fecal coliform, BOD5, and TSS (Table Table 6. Technology-based Limits. Parameter Limit pH: shall be within the range of 6 to 9 standard units. Fecal Coliform Bacteria Geometric Mean = 200 organisms/100 mL Weekly Geometric Mean = 400 organisms/100 mL BOD5 (concentration) Average Limit is the most stringent of the following: - 30 mg/L - may not exceed fifteen percent (15%) of the average influent concentration Average Weekly Limit = 45 mg/L TSS (concentration) Average Limit is the most stringent of the following: - 30 mg/L - may not exceed fifteen percent (15%) of the average influent concentration Average Weekly Limit = 45 mg/L ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 13 of 13 The technology-based mass limits are based on WAC 173-220-130(3)(b) and 173-221- 030(11)(b). effluent mass loadings (lbs/day) = maximum design flow (10.2 mgd) x Concentration limit (30 mg/L) x 8.34 (conversion factor) = mass limit 2,552 lbs/ day. The maximum weekly average effluent mass loading = 1.5 x loading = 3,828 lbs/day. SURFACE WATER QUALITY-BASED EFFLUENT LIMITS The Washington State Surface Water Quality Standards (chapter 173-201A WAC) are designed to protect existing water quality and preserve the beneficial uses of Washington's surface waters. Waste discharge permits must include conditions that ensure the discharge will meet the surface water quality standards (WAC 173-201A-510). Water quality-based effluent limits may be based on an individual waste load allocation or on a waste load allocation developed during a basin wide total maximum daily load study (TMDL). Numerical Criteria for the Protection of Aquatic Life and Recreation Numerical water quality criteria are listed in the water quality standards for surface waters (chapter 173-201A WAC). They specify the maximum levels of pollutants allowed in receiving water to protect aquatic life and recreation in and on the water. Ecology uses numerical criteria along with chemical and physical data for the wastewater and receiving water to derive the effluent limits in the discharge permit. When surface water quality-based limits are more stringent or potentially more stringent than technology-based limits, the discharge must meet the water quality-based limits. Numerical Criteria for the Protection of Human Health The U.S. EPA has published 91 numeric water quality criteria for the protection of human health that are applicable to dischargers in Washington State (EPA 1992). These criteria are designed to protect humans from exposure to pollutants linked to cancer and other diseases, based on consuming fish and shellfish and drinking contaminated surface waters. The Water Quality Standards also include radionuclide criteria to protect humans from the effects of radioactive substances. Narrative Criteria Narrative water quality criteria (WAC 173-201A) limit concentrations of toxic, radioactive, or deleterious material. Levels are set below those which have the potential to adversely affect characteristic water uses, cause acute or chronic toxicity to biota, impair aesthetic values, or ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 14 of 14 adversely affect human health. Narrative criteria protect the specific beneficial uses of all fresh and marine surface waters in the state of Washington. Antidegradation The purpose of Washington's Antidegradation Policy (WAC 173-201A-300 to 330; 2006) is to: • Restore and maintain the highest possible quality of the surface waters of Washington. • Describe situations under which water quality may be lowered from its current condition. • Apply to human activities that are likely to have an impact on the water quality of surface water. • Ensure that all human activities likely to contribute to a lowering of water quality, at a minimum, apply all known, available, and reasonable methods of prevention, control, and treatment (AKART). • Apply three Tiers of protection (described below) for surface waters of the state. Tier I ensures existing and designated uses are maintained and protected and applies to all waters and all sources of pollutions. Tier II ensures that waters of a higher quality than the criteria assigned are not degraded unless such lowering of water quality is necessary and in the overriding public interest. Tier II applies only to a specific list of polluting activities. Tier III prevents the degradation of waters formally listed as "outstanding resource waters," and applies to all sources of pollution. A facility must prepare a Tier II analysis when all three of the following conditions are met: • The facility is planning a new or expanded action. • Ecology regulates or authorizes the action. • The action has the potential to cause measurable degradation to existing water quality at the edge of a chronic mixing zone. Ecology’s analysis described in this section of the fact sheet demonstrates that the proposed permit will protect existing and designated uses of the receiving water. Proposed improvements at the POTW are to improve plant reliability and redundancy. The improvements will not increase the amount of overall flow or pollutant load discharged to the Columbia River. The improvements are likely to reduce pollutants, reduce maintenance costs, and improve equipment reliability. Therefore a Tier II analysis is not required. Existing and designated uses must be maintained and protected. No degradation may be allowed that would interfere with, or become injurious to, existing or designated uses, except as provided for in chapter 173-201A WAC. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 15 of 15 Mixing Zones A mixing zone is the defined area in the receiving water surrounding the discharge port(s), where wastewater mixes with receiving water. Within mixing zones the pollutant concentrations may exceed water quality numeric standards, so long as the diluting wastewater doesn’t interfere with designated uses of the receiving water body recreation, water supply, and aquatic life and wildlife habitat, etc.) The pollutant concentrations outside of the mixing zones must meet water quality numeric standards. State and federal rules allow mixing zones because the concentrations and effects of most pollutants diminish rapidly after discharge, due to dilution. Ecology defines mixing zone sizes to limit the amount of time any exposure to the end-of-pipe discharge could harm water quality, plants, or fish. The state’s water quality standards allow Ecology to authorize mixing zones for the facility’s permitted wastewater discharges only if those discharges already receive all known, available, and reasonable methods of prevention, control and treatment (AKART). Mixing zones typically require compliance with water quality criteria within 200 to 300 feet from the point of discharge; and use no more than 25% of the available width of the water body for dilution. We use modeling to estimate the amount of mixing within the mixing zone. Through modeling we determine the potential for violating the water quality standards at the edge of the mixing zone and derive any necessary effluent limits. Steady-state models are the most frequently used tools for conducting mixing zone analyses. Ecology chooses values for each effluent and for receiving water variables that correspond to the time period when the most critical condition is likely to occur (see Ecology’s Permit Writer’s Manual). Each critical condition parameter, by itself, has a low probability of occurrence and the resulting dilution factor is conservative. The term “reasonable worst-case” applies to these values. The mixing zone analysis produces a numerical value called a dilution factor (DF). A dilution factor represents the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. For example, a dilution factor of 10 means the effluent is 10% and the receiving water is 90% of the total volume of water at the boundary of the mixing zone. We use dilution factors with the water quality criteria to calculate reasonable potentials and effluent limits. Water quality standards include both aquatic life-based criteria and human health-based criteria. The former are applied at both the acute and chronic mixing zone boundaries; the latter are applied only at the chronic boundary. The concentration of pollutants at the boundaries of any of these mixing zones may not exceed the numerical criteria for that zone. Each aquatic life acute criterion is based on the assumption that organisms are not exposed to that concentration for more than one hour and more often than one exposure in three years. Each aquatic life chronic criterion is based on the assumption that organisms are not exposed to that concentration for more than four consecutive days and more often than once in three years. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 16 of 16 The two types of human health-based water quality criteria distinguish between those pollutants linked to non-cancer effects (non-carcinogenic) and those linked to cancer effects (carcinogenic). The human health-based water quality criteria incorporate several exposure and risk assumptions. These assumptions include: • A 70-year lifetime of daily exposures. • An ingestion rate for fish or shellfish measured in kg/day. • An ingestion rate of two liters/day for drinking water • A one-in-one-million cancer risk for carcinogenic chemicals. This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone around the point of discharge (WAC 173-201A-400). The water quality standards impose certain conditions before allowing the discharger a mixing zone: 1. Ecology must specify both the allowed size and location in a permit. The proposed permit specifies the size and location of the allowed mixing zone. 2. The facility must fully apply “all known available and reasonable methods of prevention, control and treatment” (AKART) to its discharge. Ecology has determined that the treatment provided at the Kennewick POTW meets the requirements of AKART (see “Technology based Limits”). 3. Ecology must consider critical discharge conditions. Surface water quality-based limits are derived for the water body’s critical condition (the receiving water and waste discharge condition with the highest potential for adverse impact on the aquatic biota, human health, and existing or designated water body uses). The critical discharge condition is often pollutant-specific or water body-specific. Critical discharge conditions are those conditions that result in reduced dilution or increased effect of the pollutant. Factors affecting dilution include the depth of water, the density stratification in the water column, the currents and the rate of discharge. Density stratification is determined by the salinity and temperature of the receiving water. Temperatures are warmer in the surface waters in summer. Therefore, density stratification is generally greatest during the summer months. Density stratification affects how far up in the water column a freshwater plume may rise. The rate of mixing is greatest when an effluent is rising. The effluent stops rising when the mixed effluent is the same density as the surrounding water. After the effluent stops rising, the rate of mixing is much more gradual. Water depth can affect dilution when a plume might rise to the surface when there is little or ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 17 of 17 no stratification. Ecology’s Permit Writer’s Manual describes additional guidance on criteria/design conditions for determining dilution factors. The manual can be obtained from Ecology’s website at: http://www.ecy.wa.gov/biblio/92109.html. During 1997, a mixing zone study was conducted for the Kennewick POTW discharge from a diffuser constructed in 1972 (JUB Engineers 1997). The Cormix 2 model was used to determine dilution factors for several different effluent flows. The seven day average low river flow with a recurrence interval of ten years (7Q10) was used for modeling chronic dilution factors and the low daily average river flow with a recurrence interval of ten years (1Q10) was used for acute dilution factors. The thirty day low river flow with a recurrence interval of five years (30Q5) now used by Ecology for human health analysis was not modeled, but the difference from the 7Q10 is not significant in the Columbia River because of the size of the river (the depth does not vary significantly with minor flow differences and the depth is important for dilution factors). Ecology used the dilution factors associated with the maximum design criteria (10.2 mgd) for this permit. Ecology uses the harmonic mean flow to determine reasonable potential to exceed human health carcinogen criteria. Information on the depth of the diffuser at the harmonic mean flow is not available. The following critical conditions were used to model the discharge (JUB Engineers 1997): • 7Q10 flow: 54,000 cfs. • 1Q10: 40,000cfs. • Discharge depth of 10.5 feet at the 7Q10 period. • River Velocity (7Q10) of 0.656 feet per second. • Manning Roughness coefficient 0.035. • Channel width of 0.7 mile (3,700 feet). • Maximum average effluent flow of 10.2 mgd for chronic and human health non- carcinogen. • Effluent temperature of 25 degrees C. The following flows, used to make human health determinations, were included in the previous permit: • 30Q5 flow 61,100 cfs. • Harmonic mean flow: 97,800 cfs. The dilution factor that corresponds to the harmonic mean flow has not been calculated. The proposed permit requires the city to estimate dilution factors for the harmonic mean because ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 18 of 18 those factors are used for human health carcinogens. A few carcinogens have been measured in the effluent. 4. Supporting information must clearly indicate the mixing zone would not: • Have a reasonable potential to cause the loss of sensitive or important habitat, • Substantially interfere with the existing or characteristic uses, • Result in damage to the ecosystem, or • Adversely affect public health. Ecology established Washington State water quality criteria for toxic chemicals using EPA criteria. EPA developed the criteria using toxicity tests with numerous organisms, and set the criteria to generally protect 95% of the species tested and to fully protect all commercially and recreationally important species. EPA sets acute criteria for toxic chemicals assuming organisms are exposed to the pollutant at the criteria concentration for one hour. They set chronic standards assuming organisms are exposed to the pollutant at the criteria concentration for 4 days. Dilution modeling under critical conditions generally shows that both acute and chronic criteria concentrations are reached within minutes of being discharged. The discharge plume does not impact drifting and non-strong swimming organisms because they cannot stay in the plume close to the outfall long enough to be affected. Strong swimming fish could maintain a position within the plume, but they can also avoid the discharge by swimming away. Mixing zones generally do not affect benthic organisms (bottom dwellers) because the buoyant plume rises in the water column. Ecology has additionally determined that the effluent will not exceed 33 degrees C for more than 2 seconds after discharge. Ecology evaluates the cumulative toxicity of an effluent by testing the discharge with whole effluent toxicity (WET) testing. Ecology reviewed the above information, the specific information on the characteristics of the discharge, the receiving water characteristics and the discharge location. Based on this review we conclude that the discharge does not have a reasonable potential to cause the loss of sensitive or important habitat, substantially interfere with existing or characteristics uses, result in damage to the ecosystem or adversely affect public health. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 19 of 19 5. The discharge/receiving water mixture must not exceed water quality criteria outside the boundary of a mixing zone. Ecology conducted a reasonable potential analysis, using procedures established by the EPA and by Ecology, for each pollutant. We concluded the discharge/receiving water mixture will not violate water quality criteria outside the boundary of the mixing zone. 6. The size of the mixing zone and the concentrations of the pollutants must be minimized. At any given time, the effluent plume uses only a portion of the acute and chronic mixing zone, which minimizes the volume of water involved in mixing. The plume rises through the water column as it mixes therefore much of the receiving water volume at lower depths in the mixing zone is not mixed with discharge. Similarly, because the discharge may stop rising at some depth due to density stratification, waters above that depth will not mix with the discharge. Ecology determined it is impractical to specify in the permit the actual, much more limited volume in which the dilution occurs as the plume rises and moves with the current. Ecology minimizes the size of mixing zones by requiring dischargers to install diffusers when they are appropriate to the discharge and the specific receiving waterbody. When a diffuser is installed the discharge is more completely mixed with the receiving water in a shorter time. Ecology also minimizes the size of the mixing zone (in the form of the dilution factor) using design criteria with a low probability of occurrence. For example, Ecology uses the expected 95th percentile pollutant concentration, the 90th percentile background concentration, the centerline dilution factor and the lowest flow occurring once in every 10 years to perform the reasonable potential analysis. Because of the above reasons, Ecology has effectively minimized the size of the mixing zone authorized in the proposed permit. 7. Maximum size of mixing zone. The authorized mixing zone does not exceed the maximum size restriction. 8. Acute Mixing Zone. • The discharge/receiving water mixture must comply with acute criteria as near to the point of discharge as practicably attainable ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 20 of 20 Ecology determined the acute criteria will be met at 10% of the chronic mixing zone at the ten year low flow. • The pollutant concentration, duration and frequency of exposure to the discharge, will not create a barrier to migration or translocation of indigenous organisms to a degree that has the potential to cause damage to the ecosystem. As described above the toxicity of any pollutant depends upon the exposure, the pollutant concentration and the time the organism is exposed to that concentration. Authorizing a limited acute mixing zone for this discharge assures that it will not create a barrier to migration. The effluent from this discharge will rise as it enters the receiving water, assuring that the rising effluent will not cause translocation of indigenous organisms near the point of discharge (below the rising effluent). • Comply with size restrictions. The mixing zone authorized for this discharge complies with the size restrictions published in chapter 173-201A WAC. 9. Overlap of Mixing Zones. This mixing zone does not overlap another mixing zone. DESCRIPTION OF THE RECEIVING WATER The Kennewick POTW discharges to the Columbia River. Other point source outfalls include the Pasco POTW on the other side of the Columbia and Richland POTW upstream. Neither of these facilities is close enough to have overlapping mixing zones. Nearby non-point sources of pollutants include storm drains at the Port of Kennewick. The EPA is conducting a Columbia/Snake River Temperature TMDL study. The large Columbia River dams have increased river temperatures by 13 percent (EPA 2002). The areas impounded by the dams are not cooled as are the free-flowing areas. The Kennewick POTW may receive a temperature wasteload allocation as a result of the TMDL study. The EPA is the lead agency for the temperature TMDL. Most of the Columbia River is considered impaired for temperature (EPA 2002). A location upstream of the POTW has been listed on Ecology’s 303 list of impaired waters for temperature. A river segment immediately upstream of the POTW has been identified as “Category 2” for pH (insufficient data for listing). The ambient background data used for this permit (Table 7) are from the nearest Ecology long- term sampling station at the I-82 bridge over the Columbia located near Umatilla, Oregon ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 21 of 21 (Ecology 2008). Ecology did not collect temperature data by continuous monitoring, therefore the daily maximum temperatures are not equal to the highest annual 1-Day Maximum (1-DMax). Table 7. Ambient Background Data (Ecology 2008). Parameter Value used Temperature, Maximum, degrees C 22.4 Maximum temperature (ºC) during October 21 to December 15. 13.4 pH (high), standard units 8.4 (upper 90th percentile) Dissolved Oxygen, mg/L 8.84 mg/L (lower 10th percentile) Total Ammonia, mg/L 0.034 mg/L (upper 90th percentile) Turbidity, NTU 5.2 (90th percentile) Hardness, mg/L as CaCO3 60.3 (average) Alkalinity, mg/L as CaCO3 53.4 (average) Chromium, µg/L 0.500 (upper 90th percentile) Copper, µg/L 1.180 (upper 90th percentile) Lead, µg/L 0.306 (upper 90th percentile) Nickel, µg/L 0.875 (upper 90th percentile) Zinc, µg/L 5.266 (upper 90th percentile) DESIGNATED USES AND SURFACE WATER QUALITY CRITERIA Applicable designated uses and surface water quality criteria are defined in chapter 173-201A WAC. In addition, the US EPA set human health criteria for toxic pollutants (EPA 1992). Criteria applicable to this facility’s discharge are summarized below in Table 8. Aquatic Life Uses are designated based on the presence of, or the intent to provide protection for, the key uses. All indigenous fish and non-fish aquatic species must be protected in waters of the state in addition to the key species. The Aquatic Life Uses for this receiving water are identified in Table 8. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 22 of 22 Table 8. Aquatic Life Uses & Associated Criteria Salmonid Spawning, Rearing, And Migration Temperature Criteria – Highest 7DAD MAX Special Condition 20°C (68°F); When natural conditions exceed a 1-DMax of 20ºC, no temperature increase will be allowed which will raise the receiving water temperature greater than 0.3ºC due to any single source or 1.1ºC due to all activities combined. Dissolved Oxygen Criteria – Lowest 1 Day Minimum 8.0 mg/L; Special Condition: dissolved oxygen shall exceed 90 percent of saturation Turbidity Criteria • 5 NTU over background when the background is 50 NTU or less; or • A 10 percent increase in turbidity when the background turbidity is more than 50 NTU pH Criteria pH shall be within the range of 6.5 to 8.5 with a human-caused variation within the above range of less than 0.5 units The recreational uses are extraordinary primary contact recreation, primary contact recreation, and secondary contact recreation. The recreational uses for this receiving water are identified in Table 9. Table 9. Recreational Uses & Associated Criteria Recreational use Criteria Primary Contact Recreation Fecal coliform organism levels must not exceed a geometric mean value of 100 colonies /100 mL, with not more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 200 colonies /100 mL The water supply uses are domestic, agricultural, industrial, and stock watering. The miscellaneous fresh water uses are wildlife habitat, harvesting, commerce and navigation, boating, and aesthetics. A wide diversity of native and introduced fish species use the Columbia River habitat near Kennewick. Introduced Largemouth Bass, Catfish, Panfish, Crappie, and Walleye are popular recreational fishing species in the area. Two fish ladders are available for migrating salmonids at McNary dam. Salmon species migrating through Lake Wallula include steelhead, spring Chinook salmon, fall Chinook salmon, and Coho salmon. The Upper Columbia River Spring-run Chinook salmon environmentally significant unit (ESU) is endangered. The Columbia River near Kennewick is within the Mid-Columbia Spring-run Chinook salmon ESU (not listed at this time) and the Middle Columbia Steelhead ESU (listed as threatened). A ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 23 of 23 “healthy” stock of fall Chinook salmon called Hanford Reach Fall Chinook spawn in a 45-mile section of the mainstem of the Columbia River from Kennewick to Priest Rapids (WDFW 2008). Although this stock is native, the majority of juveniles result from hatchery production at the Priest Rapids Hatchery. The 273-acre Two Rivers County Park is located three river miles of the Kennewick POTW. The park includes a 20-acre lagoon and extensive wetlands. The mouth of the Snake River is located on the other side of the Columbia across from the park. EVALUATION OF SURFACE WATER QUALITY-BASED EFFLUENT LIMITS FOR NUMERIC CRITERIA Pollutants in an effluent may affect the aquatic environment near the point of discharge (near field) or at a considerable distance from the point of discharge (far field). Toxic pollutants, for example, are near-field pollutants; their adverse effects diminish rapidly with mixing in the receiving water. Conversely, a pollutant such as biological oxygen demand (BOD) is a far-field pollutant whose adverse effect occurs away from the discharge even after dilution has occurred. Thus, the method of calculating surface water quality-based effluent limits varies with the point at which the pollutant has its maximum effect. With technology-based controls (AKART), predicted pollutant concentrations in the discharge exceed water quality criteria. Ecology therefore authorizes a mixing zone in accordance with the geometric configuration, flow restriction, and other restrictions imposed on mixing zones by chapter 173-201A WAC. The diffuser at Outfall 001 is 164 feet long with a diameter of 30 inches (JUB Engineers 1997). The diffuser has a total of 25, 4-inch diameter ports. The distance between ports is 6-feet and 8- inches. The diffuser depth is 10.5 feet at the 7Q10 flow. Chronic Mixing Zone WAC 173-201A-400(7)(a) specifies that mixing zones must not extend in a direction from the discharge ports for a distance greater than 300 feet plus the depth of water over the discharge ports or extend upstream for a distance of over 100 feet, not utilize greater than 25% of the flow, and not occupy greater than 25% of the width of the water body. The horizontal distance of the chronic mixing zone is 310 feet. The mixing zone extends from the river bottom to the top of the water surface. Acute Mixing Zone WAC 173-201A-400(8)(a) specifies that in rivers and streams a zone where acute toxics criteria may be exceeded must not extend beyond 10% of the distance towards the upstream and ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 24 of 24 boundaries of the chronic zone, not use greater than 2.5% of the flow and not occupy greater than 25% of the width of the water body. The acute mixing zone for Outfall 001 extends 31 feet in any spatial direction from any discharge port. The dilution factor is based on this distance. Consultants to the City of Kennewick determined the dilution factors that occur within these zones at the critical condition using Cormix 2 (JUB Engineers 1997). The dilution factors are listed in Table 10. Table 10. Dilution Factors (DF) Criteria Acute Chronic Aquatic Life 37.2 103.0 Human Health, Carcinogen Not available Human Health, Non- carcinogen 103.0 Ecology determined the impacts of dissolved oxygen deficiency, temperature, pH, fecal coliform, chlorine, ammonia, metals, and other toxics as described below, using the dilution factors in the above table. The derivation of surface water quality-based limits also takes into account the variability of pollutant concentrations in both the effluent and the receiving water. BOD5 Modeling predicted no violation of the surface water quality standards for biochemical oxygen demand (BOD) under critical conditions (JUB Engineers 1997). Therefore, the proposed permit contains the technology-based effluent limitation for BOD5. The impact of BOD on the receiving water was modeled using Cormix 2, at critical condition and with the technology-based effluent limitation for BOD5 described under "Technology-Based Effluent Limits" above. During the previous permit period, data required to determine immediate dissolved oxygen impacts were collected by the POTW, but were not required to be reported to Ecology. Dissolved oxygen data will be reported by the POTW and analyzed by Ecology during the period of the proposed permit. Temperature The new state temperature standards include multiple criteria, each with different durations of exposure and points of application. Ecology evaluates each criterion independently to determine ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 25 of 25 reasonable potential and permit limits. For this permitted discharge, there was not sufficient information on temperature of the effluent or the receiving water to determine compliance with the new water quality criteria for temperature. The permit requires the permittee to continuously monitor effluent temperature and report the maximum daily results to Ecology. The permit will not require monitoring of the receiving water because the temperature is not predicted to exceed the allowable 0.3 degrees centigrade increase at the edge of the mixing zone and sampling in the Columbia River requires expensive equipment and specialized expertise. The Columbia and Snake River temperature TMDL is in progress and a temperature wasteload allocation for the facility may be developed as part of that process (EPA 2002). pH Both the effluent and receiving water pH measurements are within the water quality limits for pH (6.5 to 8.5). Therefore, Ecology predicts no violation of the pH criteria under critical conditions. The proposed permit includes technology-based effluent limits for pH. Fecal Coliform Bacteria Ecology modeled the numbers of fecal coliform bacteria by simple mixing analysis using the technology-based limit of 400 organisms per 100 ml and a dilution factor of 103. During the past three years, the maximum weekly bacteria count was 107. Under critical conditions, modeling predicts no violation of the water quality criterion for fecal coliform. Therefore, the proposed permit includes the technology-based effluent limitation for fecal coliform bacteria. Toxic Pollutants Federal regulations (40 CFR 122.44) require Ecology to place limits in NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for those chemicals to exceed the surface water quality criteria. Ecology does not exempt facilities with technology-based effluent limits from meeting the surface water quality standards. The following toxic pollutants are present in the discharge: chlorine, ammonia, copper, nickel, zinc, cyanide. Ecology conducted a reasonable potential analysis (Appendix C) to determine whether effluent limits for these pollutants would be required in this permit, using procedures given in EPA, 1991. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 26 of 26 Ammonia Ammonia's toxicity depends on that portion which is available in the unionized form. The amount of unionized ammonia depends on the temperature and pH in the receiving water. To evaluate ammonia toxicity, Ecology used the available receiving water information from the long-term sampling station at Umatilla (Table 7) and Ecology spreadsheet tools (Appendix The log-normalized effluent ammonia data from January 2005 to March 2008 were analyzed using the SPSS statistical program and the frequency-percentile method (Appendix The following are the percentile results for ammonia: Percentile Ammonia Concentration, mg/L 90th 8.8 95th 12.6 99th 23.7 Calculations using all applicable data show no reasonable potential for this discharge to cause a violation of the water quality criterion for ammonia. An ammonia limit is not required. Chlorine and Cyanide No valid ambient background data were available for total residual chlorine and cyanide. Ecology found no reasonable potential to exceed the water quality criteria using zero for background. The Kennewick POTW disinfects with ultraviolet light. Total residual chlorine is predicted to be well below water quality standards within the acute mixing zone. Therefore a limit for chlorine is not required. A cyanide limit is also not required because there is no reasonable potential to exceed water quality standards. Arsenic, Copper, Nickel & Zinc (Aquatic Life Standards) Valid ambient background data were available for arsenic, copper, nickel and zinc. Calculations using all applicable data show no reasonable potential for this discharge to cause a violation of water quality standards for aquatic life and limits are not required. Human Health Washington’s water quality standards include 91 numeric human health-based criteria that Ecology must consider when writing NPDES permits. These criteria were established in 1992 ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 27 of 27 by the US EPA in its National Toxics Rule (40 CFR 131.36). The National Toxics Rule allows states to use mixing zones to evaluate whether discharges comply with human health criteria. Ecology determined the effluent may contain chemicals of concern for human health, based on data indicating regulated chemicals occur in the discharge. However, the chemicals in the discharge have not been identified as contaminants of concern in fish. Ecology requires additional information to evaluate the discharge's potential to violate the water quality standards as required by 40 CFR 122.44(d). The proposed permit will require a study to determine the dilution factor at the harmonic mean flow. Arsenic, Benzo(GHI)Perylene, Phthalate, Dibenzo(A,H) Anthracene, Indeno(1,2,3-CD) Pyrene (Human Health Standards) Arsenic, Benzo(GHI)Perylene, Phthalate, Dibenzo(A,H) Anthracene, and Indeno(1,2,3-CD) Pyrene were measured in the effluent at low concentrations and are carcinogens. Phthalate is a plasticizer. Arsenic was formerly used in fertilizers and can be found in groundwater that is in contact with soils and rocks that contain arsenic. The other compounds are products of incomplete combustion. The proposed permit requires the POTW to determine dilution factors for the harmonic mean flow (used to determine compliance with human health standards for carcinogens) will be estimated in accordance with the proposed permit so that Ecology can evaluate carcinogens compliance with human health standards. Whole Effluent Toxicity The water quality standards for surface waters forbid discharge of effluent that causes toxic effects in the receiving waters. Many toxic pollutants cannot be measured by commonly available detection methods. However, laboratory tests can measure toxicity directly, by exposing living organisms to the wastewater and measuring their responses. These tests measure the aggregate toxicity of the whole effluent, so this approach is called whole effluent toxicity (WET) testing. Some WET tests measure acute toxicity and other WET tests measure chronic toxicity. • Acute toxicity tests measure mortality as the significant response to the toxicity of the effluent. Dischargers who monitor their wastewater with acute toxicity tests find early indications of any potential lethal effect of the effluent on organisms in the receiving water. • Chronic toxicity tests measure various sublethal toxic responses such as retarded growth or reduced reproduction. Chronic toxicity tests often involve either a complete life cycle test on an organism with an extremely short life cycle, or a partial life cycle test during a critical stage of a test organism's life. Some chronic toxicity tests also measure organism survival. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 28 of 28 Ecology-accredited WET testing laboratories use the proper WET testing protocols, fulfill the data requirements, and submit results in the correct reporting format. Accredited laboratory staff know about WET testing and how to calculate an NOEC, LC50, EC50, IC25, etc. Ecology gives all accredited labs the most recent version of Ecology Publication # WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria (http://www.ecy.wa.gov/biblio/9580.html), which is referenced in the permit. Ecology recommends that the Kennewick POTW send a copy of the acute or chronic toxicity sections(s) of its NPDES permit to the laboratory. WET testing conducted during effluent characterization showed no reasonable potential for effluent discharges to cause receiving water acute or chronic toxicity. The proposed permit will not impose an acute WET limit. The Kennewick POTW must retest the effluent before submitting an application for permit renewal. In addition, • If this facility makes process or material changes which, in Ecology's opinion, increase the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit modification, or in the permit renewal) require the facility to conduct additional effluent characterization. • If WET testing conducted for submittal with a permit application fails to meet the performance standards in WAC 173-205-020, Ecology will assume that effluent toxicity has increased. The Kennewick POTW may demonstrate to Ecology that effluent toxicity has not increased, by performing additional WET testing after the process or material changes have been made. Sediment Quality The aquatic sediment standards (chapter 173-204 WAC) protect aquatic biota and human health. Under these standards Ecology may require a facility to evaluate the potential for its discharge to cause a violation of sediment standards (WAC 173-204-400). The proposed permit includes Permit Conditions S9 and S11, which require the Kennewick POTW to provide additional information on the characteristics of the Columbia River in the vicinity of the outfall and determine if it is likely to have sediment deposited from the effluent discharge. Ground Water Quality Limits The Ground Water Quality Standards, (chapter 173-200 WAC), protect beneficial uses of ground water. Permits issued by Ecology must not allow violations of those standards (WAC 173-200- 100). ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 29 of 29 The Kennewick POTW does not discharge wastewater to the ground. No permit limits are required to protect ground water. COMPARISON OF EFFLUENT LIMITS WITH THE PREVIOUS PERMIT ISSUED ON SEPTEMBER 18, 2003 Ecology made the following changes to the proposed permit limits: • Adjusted the pounds per day for the updated maximum design flow. • Removed the total recoverable chlorine limit because the POTW no longer uses chlorine for disinfection and there is no reasonable potential to exceed water quality standards. • Removed the ammonia limits because they had been previously included in error and there is no reasonable potential to exceed water quality standards. Table 11. Comparison of Effluent Limits with the Previous Permit. Previous Effluent Limits Proposed Effluent Limits: Parameter Basis of Limit Average Maximum Average Weekly Average Maximum Daily Biochemical Oxygen Demand (5-day) Technology 30 mg/L; 3,052 lbs/day; 85% removal 45 mg/L; 4,579 lbs/day 30 mg/L; 2,552 lbs/day; 85% removal 45 mg/L; 3,828 lbs/day Total Suspended Solids Technology 30 mg/L; 3,052 lbs/day; 85% removal 45 mg/L; 4,579 lbs/day 30 mg/L; 2,552 lbs/day; 85% removal 45 mg/L; 3,828 lbs/day Fecal Coliform Bacteria Technology 200 400 200 400 pH, standard units Technology 6 to 9 6 to 9 Total Residual Chlorine Water Quality 0.20 mg/L 0.50 mg/L None None Ammonia Water Quality 27.3 mg/L 43.0 mg/L None None ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 30 of 30 MONITORING REQUIREMENTS Ecology requires monitoring, recording, and reporting (WAC 173-220-210 and 40 CFR 122.41) to verify that the treatment process is functioning correctly and that the discharge complies with the permit’s effluent limits. The monitoring schedule is detailed in the proposed permit under Condition S2. Specified monitoring frequencies take into account the quantity and variability of the discharge, the treatment method, past compliance, significance of pollutants, and cost of monitoring. The frequency of BOD testing was increased for the proposed permit because of the plant flow quantity. Monitoring of sludge quantity and quality is necessary to determine the appropriate uses of the sludge. Sludge monitoring is required by the current state and local solid waste management program and also by EPA under 40 CFR 503. LAB ACCREDITATION Ecology requires that all monitoring data (with the exception of certain parameters) must be prepared by a laboratory registered or accredited under the provisions of chapter 173-50 WAC, Accreditation of Environmental Laboratories. Ecology accredited the laboratory at this facility for Ammonia, Biochemical Oxygen Demand (BOD/CBOD), Total Residual Chlorine, Dissolved Oxygen, pH, Total Suspended Solids, and Fecal Coliform Bacteria counts. OTHER PERMIT CONDITIONS REPORTING AND RECORDKEEPING Ecology based permit condition S3 on its authority to specify any appropriate reporting and recordkeeping requirements to prevent and control waste discharges (WAC 173-220-210). PREVENTION OF FACILITY OVERLOADING Overloading of the treatment plant is a violation of the terms and conditions of the permit. To prevent this from occurring, RCW 90.48.110 and WAC 173-220-150 require the permittee to take the actions detailed in proposed permit requirement S4 to plan expansions or modifications before existing capacity is reached and to report and correct conditions that could result in new or increased discharges of pollutants. Condition S4 restricts the amount of flow. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 31 of 31 OPERATION AND MAINTENANCE (O&M) The proposed permit contains condition S5 as authorized under RCW 90.48.110, WAC 173-220- 150, Chapter 173-230 WAC, and WAC 173-240-080. It is included to ensure proper operation and regular maintenance of equipment and to ensure that adequate safeguards are taken so that constructed facilities are used to their optimum potential in terms of pollutant capture and treatment. PRETREATMENT Federal and State Pretreatment Program Requirements Under the terms of the addendum to the “Memorandum of Understanding between Washington Department of Ecology and the United States Environmental Protection Agency, Region 10” (1986), the Department of Ecology (Department) has been delegated authority to administer the Pretreatment Program. Under this delegation of authority, Ecology issues wastewater discharge permits for significant industrial users discharging to POTWs which have not been delegated authority to issue their own wastewater discharge permits. The requirements for a Pretreatment Program are contained in Title 40, part 403 of the Code of Federal Regulations. Under the requirements of the Pretreatment Program (40 CFR 403.8(f)(1)(iii)), Ecology is required to approve, condition, or deny new discharges or a significant increase in the discharge for existing significant industrial users (SIUs) ( 40 CFR 403.8 Ecology is responsible for issuing State Waste Discharge Permits to industrial users of the sewer system. Industrial dischargers must obtain these permits from Ecology before the POTW accepts the discharge (WAC 173-216-110(5)). Industries discharging wastewater that is similar in character to domestic wastewater are not required to obtain a permit. Requirements for Routine Identification and Reporting of Industrial Users The NPDES permit requires non-delegated POTWs to take “continuous, routine measures to identify all existing, new, and proposed SIUs and potential significant industrial users (PSIUs)” discharging to their sewer systems. Examples of such routine measures include regular review of business tax licenses, water billing records and existing connection authorization records. System maintenance personnel can also identify and report new industrial dischargers in the course of performing their jobs. Local newspapers, telephone directories, and word-of-mouth can also be important sources of information regarding new or existing discharges. The POTW must notify an industrial discharger, in writing, of their responsibility to apply for a state waste discharge permit and send a copy of the written notification to Ecology. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 32 of 32 Requirements for Performing an Industrial User Survey This POTW has the potential to serve significant industrial or commercial users and is required to perform an Industrial User Survey. The goal of this survey is to develop a list of SIUs and PSIUs. Of equal importance, the survey should provide sufficient information about industries which discharge to the POTW to determine whether they require state waste discharge permits or other regulatory controls. An Industrial User Survey helps to prevent interference with treatment processes at the POTW and to protect water quality. The Industrial User Survey can also help maintain sludge quality, so that sludge can be a useful biosolids product rather than an expensive waste problem. An Industrial User Survey is a rigorous method for identifying existing, new, and proposed significant industrial users and potential significant industrial users. Duty to Enforce Discharge Prohibitions This provision prohibits the POTW from authorizing or permitting an industrial discharger to discharge certain types of waste into the sanitary sewer. • The first portion of the provision prohibits acceptance of pollutants which cause pass through or interference. Definitions of pass through and interference are in Appendix B of the fact sheet. • The second portion of this provision prohibits the POTW from accepting certain specific types of wastes, namely those which are explosive, flammable, excessively acidic, basic, otherwise corrosive, or obstructive to the system. In addition, wastes with excessive BOD, petroleum based oils, or substances which result in toxic gases are prohibited. The regulatory basis for these prohibitions is 40 CFR Part 403, with the exception of the pH provisions which are based on WAC 173-216-060. • The third portion of this provision prohibits certain types of discharges unless the POTW receives prior authorization from Ecology. These discharges include cooling water in significant volumes, stormwater and other direct inflow sources, and wastewaters significantly affecting system hydraulic loading, which do not require treatment. Support by Ecology for Developing Partial Pretreatment Program by a POTW Ecology commits to providing technical and legal assistance to the Kennewick POTW in fulfilling these joint obligations. In particular, Ecology will assist with developing an adequate sewer use ordinance, notification procedures, enforcement guidelines, and developing local limits and inspection procedures. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 33 of 33 RESIDUAL SOLIDS HANDLING To prevent water quality problems, the permittee is required in permit condition S7 to store and handle all residual solids (grit, screenings, scum, sludge, and other solid waste) in accordance with the requirements of RCW 90.48.080 and State Water Quality Standards. The final use and disposal of sewage sludge from this facility is regulated by US EPA under 40 CFR 503, and by Ecology under Chapter 70.95J RCW, Chapter 173-308 WAC “Biosolids Management”, and Chapter 173-350 WAC “Solid Waste Handling Standards”. The disposal of other solid waste is under the jurisdiction of the Benton County Health Department. EFFLUENT MIXING STUDY FOR HUMAN HEALTH CARCINOGENS Consultants to the Kennewick POTW previously estimated the amount of mixing of the discharge with receiving water, and the potential for the mixture to violate the water quality standards for the protection of aquatic life at the edge of the mixing zone (chapter 173-201A WAC). The proposed permit requires the Kennewick POTW to determine the mixing zone dilution for human health carcinogen conditions at the harmonic mean flow (Permit Condition S9). OUTFALL EVALUATION The proposed permit requires the City of Kennewick to conduct an outfall inspection and submit a report detailing the findings of that inspection (Permit Condition S11). The inspection must evaluate the physical condition of the discharge pipe and diffusers, and evaluate the extent of sediment accumulations in the vicinity of the outfall. GENERAL CONDITIONS Ecology bases the standardized General Conditions on state and federal law and regulations. They are included in all individual municipal NPDES permits issued by Ecology. PERMIT ISSUANCE PROCEDURES PERMIT MODIFICATIONS Ecology may modify this permit to impose numerical limits, if necessary to comply with water quality standards for surface waters, with sediment quality standards, or with water quality standards for ground waters, based on new information from sources such as inspections, effluent monitoring, outfall studies, and effluent mixing studies. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 34 of 34 Ecology may also modify this permit to comply with new or amended state or federal regulations. PROPOSED PERMIT ISSUANCE This proposed permit meets all statutory requirements for Ecology to authorize a wastewater discharge. The permit includes limits and conditions to protect human health and aquatic life, and the beneficial uses of waters of the State of Washington. Ecology proposes to issue this permit for a term of five years. REFERENCES FOR TEXT AND APPENDICES JUB 1997. City of Kennewick Effluent Mixing Zone Study. Prepared by: J-U-B Engineers, Inc., Kennewick, WA. HDR 2007. City of Kennewick Wastewater Treatment Plant Facility Plan Final, November 2007. Prepared by: HDR Engineering, Inc., Pasco, WA. HDR 2005. City of Kennewick Wastewater Facility Project: Modifications to the May 1995 Facility Plan, March 2005. Prepared by: HDR Engineering, Inc., Pasco, WA. Environmental Protection Agency (EPA) 2002. Columbia/Snake Rivers Temperature TMDL: Preliminary Draft September 2002. Available at: http://yosemite.epa.gov/r10/water.nsf/2fb9887c3bbafaaf88256b5800609bf0/9d61ce85bb bd93ba88256c3300601055!OpenDocument 1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992. 1991. Technical Support Document for Water Quality-based Toxics Control. EPA/505/2- 90-001. 1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling. USEPA Office of Water, Washington, D.C. 1985. Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water. EPA/600/6-85/002a. 1983. Water Quality Standards Handbook. USEPA Office of Water, Washington, D.C. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 35 of 35 Tsivoglou, E.C., and J.R. Wallace. 1972. Characterization of Stream Reaeration Capacity. EPA-R3-72-012. (Cited in EPA 1985 op.cit.) Washington State Department of Ecology. 2008. Umatilla Long Term Station access at :http://www.ecy.wa.gov/apps/watersheds/riv/station.asp?theyear=&tab=notes&scrolly=0 &sta=31A070 2006. Permit Writer’s Manual. Publication Number 92-109 (http://www.ecy.wa.gov/biblio/92109.html) Laws and Regulations( http://www.ecy.wa.gov/laws-rules/index.html ) Permit and Wastewater Related Information (http://www.ecy.wa.gov/programs/wq/wastewater/index.html Washington State Department of Fish and Wildlife (WDFW) 2008. SalmonScape mapping for the Endangered Species fish distribution and status. Accessed 8 July. http://wdfw.wa.gov/mapping/salmonscape/index.html Water Pollution Control Federation. 1976. Chlorination of Wastewater. Wright, R.M., and A.J. McDonnell. 1979. In-stream Deoxygenation Rate Prediction. Journal Environmental Engineering Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.) ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 36 of 36 APPENDIX A--PUBLIC INVOLVEMENT INFORMATION Ecology proposes to reissue a permit to the City of Kennewick POTW. The permit includes wastewater discharge limits and other conditions. This fact sheet describes the facility and Ecology’s reasons for requiring permit conditions. Ecology placed a Public Notice of Application on June 21, 2007 in the Tri City Herald to inform the public about the submitted application and to invite comment on the reissuance of this permit. Ecology will place a Public Notice of Draft on September 10, 2008 in the Tri-City Herald to inform the public and to invite comment on the proposed draft National Pollutant Discharge Elimination System permit and fact sheet. The Notice – • tells where copies of the draft Permit and Fact Sheet are available for public evaluation (a local public library, the closest Regional or Field Office, posted on our website.). • offers to provide the documents in an alternate format to accommodate special needs. • asks people to tell us how well the proposed permit would protect the receiving water. • invites people to suggest fairer conditions, limits, and requirements for the permit. • invites comments on Ecology’s determination of compliance with antidegradation rules. • urges people to submit their comments, in writing, before the end of the Comment Period • tells how to request a public hearing of comments about the proposed NPDES Permit. • explains the next step(s) in the permitting process. NOTICE: ANNOUNCEMENT OF AVAILABILITY OF DRAFT PERMIT PERMIT NO.: WA-004478-4 APPLICANT: CITY OF KENNEWICK PO BOX 6108 KENNEWICK, WA 99336 has applied for renewal of National Pollutant Discharge Elimination System (NPDES) Permit No. WA-004478-4 in accordance with the provisions of Chapter 90.48 Revised Code of Washington (RCW), Chapter 173-220 Washington Administrative Code (WAC), and the Federal Clean Water Act. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 37 of 37 Following evaluation of the application and other available information, a draft permit has been developed which would allow the discharge of treated municipal wastewater to a maximum of 10.2 million gallons per day to the Columbia River (Lake Wallula) from its facility located at 416 N. Kingwood St. in Kennewick. All discharges to be in compliance with the Department of Ecology's Water Quality Standards for a permit to be issued. A tentative determination has been made to reissue this permit based on the effluent limitations and special permit conditions that will prevent and control pollution. A final determination will not be made until all timely comments received in response to this notice have been evaluated. PUBLIC COMMENT AND INFORMATION The draft permit and fact sheet may be viewed at the Department of Ecology (Department) website: http://www.ecy.wa.gov/programs/wq/permits/central_permits.html. The application, fact sheet, proposed permit, and other related documents are also available at the Department’s Central Regional Office for inspection and copying between the hours of 8:00 a.m. and 5:00 p.m., weekdays. To obtain a copy or to arrange to view copies at the Central Regional Office, please call Cindy Huwe at 509/457-7105, e-mail [EMAIL REDACTED], or write to the address below. Interested persons are invited to submit written comments regarding the proposed permit. All comments must be submitted by October 10, 2008 (within 30 days of the final date of publication of this notice) to be considered for the final determination. Comments should be sent to: Department of Ecology, Central Regional Office, 15 West Yakima Avenue, Suite 200, Yakima, WA 98902, Attention: Cindy Huwe. E-mail comments should be sent to Cindy Huwe at [EMAIL REDACTED]. Any interested party may request a public hearing on the proposed permit within 30 days of the publication date of this notice. The request for a hearing shall state the interest of the party and the reasons why a hearing is necessary. The request should be sent to the above address. The Department will hold a hearing if it determines that there is significant public interest. If a hearing is to be held, public notice will be published at least 30 days in advance of the hearing date. Any party responding to this notice with comments will be mailed a copy of a hearing public notice. Please bring this public notice to the attention of persons who you know would be interested in this matter. The Department is an equal opportunity agency. If you have a special accommodation needs, please contact Cindy Huwe at 509/457-7105 or TTY (for the speech and hearing impaired) at 1-[PHONE REDACTED]. Publication date of this Notice is September 10, 2008. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 38 of 38 Ecology has published a document entitled Frequently Asked Questions about Effective Public Commenting which is available on our website at http://www.ecy.wa.gov/biblio/0307023.html. You may obtain further information from Ecology by telephone, 509/575-2490 or by writing to the address listed below. Water Quality Permit Coordinator Department of Ecology Central Regional Office 15 West Yakima Avenue, Suite 200 Yakima, WA 98902 The primary author of this permit and fact sheet is Jean Hays. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 39 of 39 APPENDIX B--GLOSSARY Acute Toxicity--The lethal effect of a compound on an organism that occurs in a short period of time, usually 48 to 96 hours. AKART-- An acronym for “all known, available, and reasonable methods of prevention, control and treatment”. Ambient Water Quality--The existing environmental condition of the water in a receiving water body. Ammonia--Ammonia is produced by the breakdown of nitrogenous materials in wastewater. Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contributes to eutrophication. It also increases the amount of chlorine needed to disinfect wastewater. Average Discharge Limitation --The average of the measured values obtained over a calendar month's time. Best Management Practices (BMPs)--Schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the State. BMPs include treatment systems, operating procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. BMPs may be further categorized as operational, source control, erosion and sediment control, and treatment BMPs. BOD5--Determining the Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of organic material present in an effluent that is utilized by bacteria. The BOD5 is used in modeling to measure the reduction of dissolved oxygen in receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen levels makes organisms less competitive and less able to sustain their species in the aquatic environment. Although BOD is not a specific compound, it is defined as a conventional pollutant under the federal Clean Water Act. Bypass--The intentional diversion of waste streams from any portion of a treatment facility. Chlorine--Chlorine is used to disinfect wastewaters of pathogens harmful to human health. It is also extremely toxic to aquatic life. Chronic Toxicity--The effect of a compound on an organism over a relatively long time, often 1/10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction or growth rates, or other parameters to measure the toxic effects of a compound or combination of compounds. Clean Water Act (CWA)--The Federal Water Pollution Control Act enacted by Public Law 92- 500, as amended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 40 of 40 Compliance Inspection - Without Sampling--A site visit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes and regulations. Compliance Inspection - With Sampling--A site visit to accomplish the purpose of a Compliance Inspection - Without Sampling and as a minimum, sampling and analysis for all parameters with limits in the permit to ascertain compliance with those limits; and, for municipal facilities, sampling of influent to ascertain compliance with the 85 percent removal requirement. Additional sampling may be conducted. Composite Sample--A mixture of grab samples collected at the same sampling point at different times, formed either by continuous sampling or by mixing discrete samples. May be "time- composite"(collected at constant time intervals) or "flow-proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected by increasing the volume of each aliquot as the flow increased while maintaining a constant time interval between the aliquots. Construction Activity--Clearing, grading, excavation and any other activity which disturbs the surface of the land. Such activities may include road building, construction of residential houses, office buildings, or industrial buildings, and demolition activity. Continuous Monitoring –Uninterrupted, unless otherwise noted in the permit. Critical Condition--The time during which the combination of receiving water and waste discharge conditions have the highest potential for causing toxicity in the receiving water environment. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is reduced. Dilution Factor (DF)--A measure of the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction e.g., a dilution factor of 10 means the effluent comprises 10% by volume and the receiving water 90%. Engineering Report--A document which thoroughly examines the engineering and administrative aspects of a particular domestic or industrial wastewater facility. The report must contain the appropriate information required in WAC 173-240-060 or 173-240-130. Fecal Coliform Bacteria--Fecal coliform bacteria are used as indicators of pathogenic bacteria in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform bacteria in a water body can indicate the recent release of untreated wastewater and/or the presence of animal feces. Grab Sample--A single sample or measurement taken at a specific time or over as short a period of time as is feasible. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 41 of 41 Industrial Wastewater--Water or liquid-carried waste from industrial or commercial processes, as distinct from domestic wastewater. These wastes may result from any process or activity of industry, manufacture, trade or business, from the development of any natural resource, or from animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also, leachate from solid waste facilities. Major Facility--A facility discharging to surface water with an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact. Maximum Daily Discharge Limitation--The highest allowable daily discharge of a pollutant measured during a calendar day or any 24-hour period that reasonably represents the calendar day for purposes of sampling. The daily discharge is calculated as the average measurement of the pollutant over the day. Method Detection Level (MDL)--The minimum concentration of a substance that can be measured and reported with 99% confidence that the pollutant concentration is above zero and is determined from analysis of a sample in a given matrix containing the pollutant. Minor Facility--A facility discharging to surface water with an EPA rating score of < 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact. Mixing Zone--An area that surrounds an effluent discharge within which water quality criteria may be exceeded. The area of the authorized mixing zone is specified in a facility's permit and follows procedures outlined in state regulations (chapter 173-201A WAC). National Pollutant Discharge Elimination System (NPDES)--The NPDES (Section 402 of the Clean Water Act) is the Federal wastewater permitting system for discharges to navigable waters of the United States. Many states, including the State of Washington, have been delegated the authority to issue these permits. NPDES permits issued by Washington State permit writers are joint NPDES/State permits issued under both State and Federal laws. pH--The pH of a liquid measures its acidity or alkalinity. A pH of 7 is defined as neutral, and large variations above or below this value are considered harmful to most aquatic life. Quantitation Level A calculated value five times the MDL (method detection level). Responsible Corporate Officer-- A president, secretary, treasurer, or vice-president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation, or the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 dollars), if authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22). Technology-based Effluent Limit--A permit limit that is based on the ability of a treatment method to reduce the pollutant. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 42 of 42 Total Suspended Solids (TSS)--Total suspended solids is the particulate material in an effluent. Large quantities of TSS discharged to receiving waters may result in solids accumulation. Apart from any toxic effects attributable to substances leached out by water, suspended solids may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills and respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen out light and can promote and maintain the development of noxious conditions through oxygen depletion. State Waters--Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington. Stormwater--That portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water drainage system into a defined surface water body, or a constructed infiltration facility. Upset--An exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limits because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, lack of preventative maintenance, or careless or improper operation. Water Quality-based Effluent Limit--A limit on the concentration of an effluent parameter that is intended to prevent the concentration of that parameter from exceeding its water quality criterion after it is discharged into receiving waters. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 43 of 43 APPENDIX C—DATA AND TECHNICAL CALCULATIONS Several of the Excel® spreadsheet tools used to evaluate a discharger’s ability to meet Washington State water quality standards can be found on Ecology’s homepage at http://www.ecy.wa.gov. ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 44 of 44 DATA ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 45 of 45 BOD, 5-DABOD, 5-DABOD, 5-DABOD, 5-DABOD, 5-DACOLIFORMCOLIFORMFLOW, IN FLOW, IN C AVG AVG AVG AVW AVW GEM GM7 AVG MAX PERCENT LBS/DAY MG/L LBS/DAY MG/L #/100 ML #/100 ML MGD MGD Value Value Value Value Value Value Value Value Value KENNEWICK POTW WA0044784D DMR EFFLUENT ***Corrected from Ecology database or DMRs as necessary*** 1 1-Jan-05 99 209 5 267 10 3 6 5.463 6.037 1-Feb-05 97 311 7 502 19 3 9 5.423 5.961 1-Mar-05 97 447 10 823 17 8 61 5.491 6.041 1-Apr-05 98 226 5 376 8 5 44 5.679 6.404 1-May-05 98 232 5 370 8 4 24 5.843 6.552 1-Jun-05 99 181 4 249 5 7 31 6.088 6.506 1-Jul-05 99 180 3 187 4 10 46 6.199 6.581 1-Aug-05 99 124 2 210 4 4 20 6.411 6.94 1-Sep-05 99 110 2.1 127 3 3 5 6.155 6.68 1-Oct-05 99 142 3.1 283 4 4 9 5.951 6.667 1-Nov-05 99 102 2.3 138 4 4 21 5.544 5.883 1-Dec-05 98 222 4.6 359 8 4 19 5.64 6.986 1-Jan-06 99 158 3.6 217 5 3 6 5.537 6.86 1-Feb-06 98 261 6.1 345 8 3 11 5.179 5.615 1-Mar-06 97 382 9 532 12 2 7 5.253 5.924 1-Apr-06 98 261 6 459 10 3 107 5.409 6.461 1-May-06 97 421 8.9 923 19 4 22 5.534 6.394 1-Jun-06 98 267 6 285 6 6 22 5.646 6.117 1-Jul-06 98 190 4 329 7 4 46 5.6 6.133 1-Aug-06 99 108 2 126 3 5 24 5.713 6.093 1-Sep-06 99 69 1.4 97 2 2 2 5.792 6.032 1-Oct-06 99 74 2 93 2 2 7 5.462 6.099 1-Nov-06 99 87 2 152 4 4 15 5.266 5.678 1-Dec-06 99 118 3 150 4 3 10 5.34 5.974 1-Jan-07 98 208 5 282 7 3 9 5.265 6.188 1-Feb-07 97 320 7 437 10 4 10 5.179 5.86 1-Mar-07 96 494 11 548 13 4 13 5.328 5.745 1-Apr-07 98 243 6 437 10 6 28 5.427 6.459 1-May-07 98 278 6 365 8 2 10 5.622 5.956 1-Jun-07 98 235 5 287 6 6 51 5.778 6.292 1-Jul-07 99 127 3 201 4 2 4 5.948 6.373 1-Aug-07 99 126 3 178 4 4 10 6.077 6.223 1-Sep-07 99 93 2 99 2 2 4 5.884 6.141 1-Oct-07 99 118 2 125 3 3 16 5.799 6.06 1-Nov-07 99 114 2 142 3 4 38 5.633 5.907 1-Dec-07 99 122 3 138 3 6 23 5.514 6.155 1-Jan-08 98 209 5 425 9 8 50 5.441 5.788 1-Feb-08 97 459 10 550 12 7 30 5.492 6.543 1-Mar-08 96 589 13 684 15 6 9 5.622 6.134 average 98.231 220.949 4.874 320.436 7.308 4.282 22.538 5.631 6.216 max 99.000 589.000 13.000 923.000 19.000 10.000 107.000 6.411 6.986 min 96.000 69.000 1.400 93.000 2.000 2.000 2.000 5.179 5.615 ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 46 of 46 CONDUIT OAMMONIA AMMONIA AMMONIAAMMONIA PH PH TSS TSS TSS TSS TSS TEMPERA TEMPERAT AVG AVG MAX MAX MAX MIN AVG AVG AVG AVW AVW AVG MAX LBS/DAY MG/L LBS/DAY MG/L S.U. S.U. PERCENT LBS/DAY MG/L LBS/DAY MG/L °C °C Value Value Value Value Value Value Value Value Value Value Value Value Value KENNEWICK POTW WA0044784D DMR EFFLUENT ***Corrected from Ecology database or DMRs as necessary*** 1 1-Jan-05 115 2.3 337 6.7 8 7 97.46 370 8 468 10 11 13 1-Feb-05 423 9 1430 31 7.9 7.4 96 625 13 682 19 10 13 1-Mar-05 440 9 740 16 7.7 7.4 96.46 572 12 790 17 13 15 1-Apr-05 537 10.7 2494 46.7 7.6 7.3 98 322 7 394 8 15 18 1-May-05 353 7.1 956 17.5 7.5 7.2 96.5 424 9 539 10 18 20 1-Jun-05 177 3.5 244 5 7.4 7 98 203 4 265 5 19 20 1-Jul-05 122 2.4 148 2.9 7.4 7 98 216 4 328 6 22 23 1-Aug-05 117 2 202 4 7.4 7.1 99 181 3 251 5 22 23 1-Sep-05 236 5 310 6 7.4 7 99 104 2 138 3 19.9 22 1-Oct-05 204 4 809 15 7.5 7 99 152 3 168 4 18.1 20 1-Nov-05 185 4 250 5.3 7.7 7.3 99 119 3 139 4 14 16 1-Dec-05 211 4 746 13 7.9 7.4 98 274 6 408 8 9.9 13 1-Jan-06 158 3 1133 20 8 7.4 98 224 6 300 6 12 14 1-Feb-06 466 11 943 21 7.9 7.2 98 219 5 275 6 8 13 1-Mar-06 346 7.8 387 9 7.8 7.4 98 305 7 487 11 10 13 1-Apr-06 132 2.9 480 9 7.6 7.3 98 311 7 464 10 14 17 1-May-06 216 5 2123 45 7.6 7 96 591 13 1255 26 17 22 1-Jun-06 148 3.1 259 5 7.2 6.9 97 480 10 509 11 20 22 1-Jul-06 101 2.2 179 4 7.5 7.1 98 235 5 372 8 22 24 1-Aug-06 29 0.6 59 1 7.6 7 99 147 3 248 5 21 23 1-Sep-06 8 0.2 30 1 7.5 7.2 99 81 2 111 2 20 22 1-Oct-06 24 5.8 275 6 7.7 7.3 99 93 2 138 3 17 20 1-Nov-06 0 0.1 0 0.1 7.7 7.3 99 110 3 217 5 14 19 1-Dec-06 3 0.3 24 1 7.7 7.3 98 193 4 239 5 11 14 1-Jan-07 152 6.1 868 20 8 7.3 97 352 8 684 15 9 13 1-Feb-07 248 0.7 494 11 8 7.4 95 808 14 705 16 8 10 1-Mar-07 265 6 445 10 7.8 7.5 93 957 22 1300 29 11 14 1-Apr-07 107 2.5 412 10 7.7 7.1 97 472 11 1040 24 15 17 1-May-07 204 4.3 343 7 7.5 6.9 95 480 10 811 17 18 20 1-Jun-07 225 4.7 411 9 7.6 7.1 96 521 11 602 16 20 22 1-Jul-07 72 1.5 132 3 7.5 7.1 99 205 4 274 5 22 23 1-Aug-07 33 1 72 1 7.6 7 99 181 4 306 6 22 23 1-Sep-07 16 1 33 1 7.6 7.1 99 93 2 98 2 21 23 1-Oct-07 18 1 75 4 7.4 7 99 174 4 265 5 18 21 1-Nov-07 15 1 21 1 7.7 7 99 166 4 204 4 16 16 1-Dec-07 36 1 58 1 7.6 7.2 98 222 5 242 5 14 16 1-Jan-08 53 1.35 146 3.2 7.6 7.1 98 306 7 813 8.5 13 16 1-Feb-08 453 9.5 1168 24 8.1 7.3 92 1085 23 1195 23 11 17 1-Mar-08 333 7.1 400 8.3 7.9 7.5 91 1239 27 1270 27 12 15 average 179.000 3.942 503.487 10.377 7.662 7.182 97.395 354.154 7.615 487.026 10.244 15.587 18.077 max 537.000 11.000 2494.000 46.700 8.100 7.500 99.000 1239.000 27.000 1300.000 29.000 22.000 24.000 min 0.000 0.100 0.000 0.100 7.200 6.900 91.000 81.000 2.000 98.000 2.000 8.000 10.000 ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 47 of 47 Ammonia Statistics Log-normalized statistics lnammonia N Valid 503 Missing 0 Percentiles 90 2.1744 95 2.5352 99 3.1654 Freshwater un-ionized ammonia criteria based on Chapter 173-201A WAC Amended November 20, 2006 1. Temperature (deg 22.4 2. pH: 8.40 3. Is salmonid habitat an existing or designated use? Yes 4. Are non-salmonid early life stages present or absent? Present 1. Unionized ammonia NH3 criteria (mgNH3/L) Acute: 0.334 Chronic: 0.042 2. Total ammonia nitrogen criteria (mgN/L): Acute: 2.593 Chronic: 0.329 OUTPUT INPUT ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 48 of 48 Other Criteria WATER QUALITY CRITERIA (in ug/L unless otherwise noted) PRIORCAR Water Quality Criteria Organoleptic Metals Translators ITY CIN Fresh Effects Freshwater Pollutant, CAS No. & NPDES Application Ref. No. acute chronic Fresh Acute Chronic CEIVING WATER TSS (IF UNKNOWN LEAVE BLANK) > 0 INSERT A, OR IF FROM CRITICAL PERIOD INSERT S> S ENTER HARDNESS>>>>>>>>> 60 ALKALINITY N N 20,000. AMMONIA unionized -see seperate spreadsheets for FW criteri N N ANTHRACENE 120127 3B Y N 9600 0.018 1.8 700 0.0028 0.0028 0.14 610 ARSENIC (dissolved) 7440382 2M Y Y 360 190 1.00 1.00 ARSENIC (inorganic) Y Y BACTERIA N N see document PHTHALATE 117817 13B Y Y CHLORINE (Total Residual) 7782505 N N 19 11 COPPER - 744058 6M Hardness dependent Y N 10.57 7.37 1000.00 0.996 0.996 Based on hardness in B201 60 CYANIDE 57125 14M Y N 22 5.20 DIBENZO(a,h)ANTHRACENE 53703 19B Y Y INDENO(1,2,3-cd)PYRENE 193395 37B Y Y MERCURY 7439976 8M Y N 2.10 0.012 0.85 NICKEL - 7440020 9M - Dependent on hardness Y N 922.63 102.47 0.998 0.997 Based on hardness in B201 60 OIL AND GREASE N N See Gold Book and EPA 440/9-76-023 OXYGEN DISSOLVED 7782447 N N See WAC 173-201A fresh water) Enter pH in next 7.80 pH N N 6.5 - 8.5 ZINC- 7440666 13M hardness dependent Y N 74.55 68.08 5000.00 0.996 0.996 Based on hardness in B201 60 Human Health Criteria e tional Toxics Rule (40 CFR 131. en font = Other source - see comm k font = WAC 173-201A (Nov. 2 = EPA National Recommended Water Quality Criteria:2002 (EPA 822 EPA Reasonable Potential Calculations Metal Criteria Translator as decimal Metal Criteria Translator as decimal Ambient Concentrati on (metals as dissolved) Acute Chronic Parameter Acute Chronic ug/L ug/L ug/L ug Acute Mixing Zone Chronic Mixing Zone LIMIT REQ'D? /L ug/L ammonia 1.00 1.00 34.0000 2593.0000 339.0000 292.05 127.20 NO TRC 1.00 1.00 19.0000 11.0000 7.86 2.84 NO Cyanide 1.00 1.00 22.0000 5.2000 2.58 0.93 NO Arsenic 1.00 1.00 1.2000 360.0000 190.0000 1.37 1.26 NO Copper 1.00 1.00 1.1800 10.5700 7.3700 3.09 1.87 NO Nickel 1.00 1.00 0.8750 922.6000 102.5000 1.04 0.93 NO Zinc 1.00 1.00 5.2660 74.6000 68.1000 12.58 7.89 NO ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 49 of 49 Effluent percentile value Multiplier Pn s 0.95 0.983 12620.00 0.55 180 0.76 37 103 1.00 0.779 180.00 0.55 12 1.63 37 103 1.00 0.224 25.20 0.55 2 3.79 37 103 1.00 0.224 2.00 0.55 2 3.79 37 103 1.00 0.224 19.00 0.55 2 3.79 37 103 1.00 0.224 1.80 0.55 2 3.79 37 103 1.00 0.224 73.00 0.55 2 3.79 37 103 Max effluent conc. measured (metals as total recoverable) Coeff Variation # of samples Acute Dil'n Factor Chronic Dil'n Factor ug/L CV n 0.60 0.60 0.60 0.60 0.60 0.60 0.60 ---PAGE BREAK--- FACT SHEET FOR NPDES PERMIT NO. WA-004478-4 CITY OF KENNEWICK POTW EXPIRATION DATE: NOVEMBER 30, 2013 Page 50 of 50 APPENDIX D--RESPONSE TO COMMENTS No comments were received by the Department of Ecology. ---PAGE BREAK--- AWC TOXICS TECH REPORT APPENDIX 4-C ---PAGE BREAK--- Treatment Technology Review and Assessment Association of Washington Business Association of Washington Cities Washington State Association of Counties December 4, 2013 500 108th Avenue NE Suite 1200 Bellevue, WA 98004-5549 (425) 450-6200 ---PAGE BREAK--- ---PAGE BREAK--- Association of Washington Business i Treatment Technology Review and Assessment 213512 Table of Contents Executive Summary ES-1 1.0 Introduction 1 2.0 Derivation of the Baseline Study Conditions and Rationale for Selection of Effluent 3 2.1 Summary of Water Quality Criteria 3 2.2 Background 3 2.3 Assumptions Supporting Selected Ambient Water Quality Criteria and Effluent Limitations 4 3.0 Wastewater Characterization Description 9 3.1 Summary of Wastewater Characterization 9 3.2 Existing Wastewater Treatment Facility 9 3.3 Toxic Constituents 10 4.0 Treatment Approaches and Costs 11 4.1 Summary of Treatment Approach and Costs 11 4.2 Constituent Removal – Literature Review 11 4.2.1 Biphenyls 11 4.2.2 Mercury 12 4.2.3 Arsenic 14 4.2.1 Aromatic Hydrocarbons 17 4.3 Unit Processes Evaluated 18 4.4 Unit Processes Selected 21 4.4.1 Baseline Treatment Process 22 4.4.2 Advanced Treatment – MF/RO Alternative 25 4.4.3 Advanced Treatment – MF/GAC Alternative 29 4.5 Steady-State Mass Balance 33 4.6 Adverse Environmental Impacts Associated with Advanced Treatment Technologies 34 4.7 Costs 36 4.7.1 Approach 36 4.7.2 Unit Cost Values 37 4.7.3 Net Present Value of Total Project Costs and Operations and Maintenance Cost in 2013 Dollars 38 4.7.4 Unit Cost Assessment 39 4.8 Pollutant Mass Removal 44 4.9 Sensitivity Analysis 45 5.0 Summary and Conclusions 46 6.0 References 48 7.0 Appendices 52 ---PAGE BREAK--- ii Association of Washington Business 213512 Treatment Technology Review and Assessment List of Tables Table 1: Summary of Effluent Discharge Toxics Limits 7 Table 2. General Wastewater Treatment Facility Characteristics 9 Table 3: Summary of Arsenic Removal Technologies1 14 Table 4. Contaminants Removal Breakdown by Unit Process 21 Table 5. Unit Processes Description for Each Alternative 23 Table 6. Brine Disposal Method Relative Cost Comparison 27 Table 7. Energy Breakdown for Each Alternative (5 mgd design flow) 35 Table 8. Economic Evaluation Variables 37 Table 9. Treatment Technology Total Project Costs in 2013 Dollars for a 5 mgd Facility 38 Table 10. Treatment Technology Total Project Costs in 2013 Dollars for a 0.5 mgd Facility and a 25 mgd Facility 42 Table 11. Pollutant Mass Removal by Contaminant for a 5 mgd Facility 44 Table 12. Unit Cost by Contaminant for a 5 mgd Facility Implementing Advanced Treatment using MF/RO 45 List of Figures Figure 1. Water Treatment Configuration for Arsenic Removal (WesTech) 15 Figure 2. WesTech Pressure Filters for Arsenic Removal 16 Figure 3. Baseline Flowsheet – Conventional Secondary Treatment 24 Figure 4. Advanced Treatment Flowsheet – Tertiary Microfiltration and Reverse Osmosis 28 Figure 5. Advanced Treatment Flowsheet – Tertiary Microfiltration and Granular Activated Carbon 32 Figure 6. Primary Clarifier Inputs/Outputs 33 Figure 7. Greenhouse Gas Emissions for Each Alternative 36 Figure 8: Capital Cost Curve Comparison for Baseline Treatment, MF/RO, and MF/GAC 43 Figure 9: NPV Cost Curve Comparison for Baseline Treatment, MF/RO, and MF/GAC 43 List of Appendices Appendix A - Unit Process Sizing Criteria Appendix B - Greenhouse Gas Emissions Calculation Assumptions ---PAGE BREAK--- Association of Washington Business iii Treatment Technology Review and Assessment 213512 Acronyms Acronym Definition AACE Association for the Advancement of Cost Engineering AOP advanced oxidation processes AWB Association of Washington Businesses BAC biological activated carbon BAP benzo(a)pyrene BOD biochemical oxygen demand BTU British thermal unit CEPT Chemically-enhanced primary treatment cf cubic feet CIP clean in place CRITFC Columbia River Inter-Tribal Fish Commission Ecology Washington Department of Ecology EPA U.S. Environmental Protection Agency FCR fish consumption rate g/day grams per day GAC granular activated carbon gal gallon gfd gallons per square foot per day GHG greenhouse gas gpd gallons per day gpm gallons per minute GWh giga watt hours HDR HDR Engineering, Inc. human health water quality criteria HRT hydraulic residence time IPCC Intergovernmental Panel on Climate Change kg kilogram KWh/MG kilowatt-hours per million gallons lb pound MBR membrane bioreactor MCL maximum contaminant level MF microfiltration mgd million gallons per day mg/L milligrams per liter MMBTU million British thermal units MWh/d megawatt-hours per day NF nanofiltration ng/L nanograms per liter NPDES National Pollutant Discharge Elimination System NPV net present value O&M operations and maintenance ODEQ Oregon Department of Environmental Quality PAC powdered activated carbon PAH aromatic hydrocarbons PCB biphenyls PE population equivalents PIX potable ion exchange ---PAGE BREAK--- iv Association of Washington Business 213512 Treatment Technology Review and Assessment Acronym Definition ppm parts per million RO reverse osmosis SDWA Safe Drinking Water Act sf square feet SGSP salinity gradient solar pond SRT solids retention time Study Partners Association of Washington Businesses/Association of Washington Cities and Washington State Association of Counties consortium TDS total dissolved solids TMDL total maximum daily load TSS total suspended solids UF ultrafiltration µg/L micrograms per liter USDA U.S. Department of Agriculture UV ultraviolet WAC Washington Administrative Code WAS waste activated sludge WLA waste load allocation WWTP wastewater treatment plant ZLD zero liquid discharge ---PAGE BREAK--- Association of Washington Business ES-1 Treatment Technology Review and Assessment 213512 Executive Summary This study evaluated treatment technologies potentially capable of meeting the State of Washington Department of Ecology’s (Ecology) revised effluent discharge limits associated with revised human health water quality criteria HDR Engineering, Inc. (HDR) completed a literature review of potential technologies and an engineering review of their capabilities to evaluate and screen treatment methods for meeting revised effluent limits for four constituents of concern: arsenic, benzo(a)pyrene (BAP), mercury, and biphenyls (PCBs). HDR selected two alternatives to compare against an assumed existing baseline secondary treatment system utilized by dischargers. These two alternatives included enhanced secondary treatment with membrane filtration/reverse osmosis (MF/RO) and enhanced secondary treatment with membrane filtration/granulated activated carbon (MF/GAC). HDR developed capital costs, operating costs, and a net present value (NPV) for each alternative, including the incremental cost to implement improvements for an existing secondary treatment facility. Currently, there are no known facilities that treat to the and anticipated effluent limits that are under consideration. Based on the literary review, research, and bench studies, the following conclusions can be made from this study: Revised based on state of Oregon (2001) and U.S. Environmental Protection Agency (EPA) “National Recommended Water Quality Criteria” will result in very low water quality criteria for toxic constituents. There are limited “proven” technologies available for dischargers to meet required effluent quality limits that would be derived from revised o Current secondary wastewater treatment facilities provide high degrees of removal for toxic constituents; however, they are not capable of compliance with water quality-based National Pollutant Discharge Elimination System (NPDES) permit effluent limits derived from the revised o Advanced treatment technologies have been investigated and candidate process trains have been conceptualized for toxics removal. Advanced wastewater treatment technologies may enhance toxics removal rates; however, they will not be capable of compliance with effluent limits for PCBs. The lowest levels achieved based on the literature review were between <0.00001 and 0.00004 micrograms per liter (µg/L), as compared to a of 0.0000064 µg/L. Based on very limited performance data for arsenic and mercury from advanced treatment information available in the technical literature, compliance with revised criteria may or may not be possible, depending upon site specific circumstances. Compliance with a for arsenic of 0.018 µg/L appears unlikely. Most treatment technology performance information available in the literature is based on drinking water treatment applications targeting a much higher Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) of 10 µg/L. Compliance with a for mercury of 0.005 µg/L appears to be potentially attainable on an average basis, but perhaps not if effluent limits are structured on a maximum maximum weekly or maximum daily basis. Some secondary treatment facilities attain average effluent mercury levels of 0.009 to 0.066 µg/L. Some treatment facilities with effluent filters attain average effluent mercury levels of 0.002 to 0.010 µg/L. Additional ---PAGE BREAK--- ES-2 Association of Washington Business 213512 Treatment Technology Review and Assessment advanced treatment processes are expected to enhance these removal rates, but little mercury performance data is available for a definitive assessment. Little information is available to assess the potential for advanced technologies to comply with revised BAP criteria. A municipal wastewater treatment plant study reported both influent and effluent BAP concentrations less than the of 0.0013 ug/L (Ecology, 2010). o Some technologies may be effective at treating identified constituents of concern to meet revised limits while others may not. It is therefore even more challenging to identify a technology that can meet all constituent limits simultaneously. o A that is one order-of-magnitude less stringent could likely be met for mercury and BAP; however, it appears PCB and arsenic limits would not be met. Advanced treatment processes incur significant capital and operating costs. o Advanced treatment process to remove additional arsenic, BAP, mercury, and PCBs would combine enhancements to secondary treatment with microfiltration membranes and reverse osmosis or granular activated carbon and increase the estimated capital cost of treatment from $17 to $29 in dollars per gallon per day of capacity (based on a 5.0-million-gallon-per-day (mgd) facility). o The annual operation and maintenance costs for the advanced treatment process train will be substantially higher (approximately $5 million - $15 million increase for a 5.0 mgd capacity facility) than the current secondary treatment level. Implementation of additional treatment will result in additional collateral impacts. o High energy consumption. o Increased greenhouse gas emissions. o Increase in solids production from chemical addition to the primaries. Additionally, the membrane and GAC facilities will capture more solids that require handling. o Increased physical space requirements at treatment plant sites for advanced treatment facilities and residuals management including reverse osmosis reject brine processing. It appears advanced treatment technology alone cannot meet all revised water quality limits and implementation tools are necessary for discharger compliance. o Implementation flexibility will be necessary to reconcile the difference between the capabilities of treatment processes and the potential for driven water quality based effluent limits to be lower than attainable with technology Table ES-1 indicates that the unit NPV cost for baseline conventional secondary treatment ranges from $13 to $28 per gallon per day of treatment capacity. The unit cost for the advanced treatment alternatives increases the range from the low $20s to upper $70s on a per gallon per- day of treatment capacity. The resulting unit cost for improving from secondary treatment to advanced treatment ranges between $15 and $50 per gallon per day of treatment capacity. Unit costs were also evaluated for both a 0.5 and 25 mgd facility. The range of unit costs for improving a 0.5 mgd from secondary to advanced treatment is $60 to $162 per gallon per day of treatment capacity. The range of unit costs for improving a 25 mgd from secondary to advanced treatment is $10 to $35 per gallon per day of treatment capacity. ---PAGE BREAK--- Association of Washington Business ES-3 Treatment Technology Review and Assessment 213512 Table ES-1. Treatment Technology Costs in 2013 Dollars for a 5-mgd Facility Alternative Total Construction Cost, 2013 dollars Million) O&M Net Present Value, 2013 dollars Million)*** Total Net Present Value, 2013 dollars Million) NPV Unit Cost, 2013 dollars ($/gpd) Baseline (Conventional Secondary Treatment)* 59 - 127 5 - 11 65 - 138 13 - 28 Incremental Increase to Advanced Treatment - MF/RO 48 - 104 26 - 56 75 - 160 15 - 32 Advanced Treatment - MF/RO** 108 - 231 31 - 67 139 - 298 28 - 60 Incremental Increase to Advanced Treatment - MF/GAC 71 - 153 45 - 97 117 - 250 23 - 50 Advanced Treatment - MF/GAC 131 - 280 50 - 108 181 - 388 36 - 78 * Assumed existing treatment for dischargers. The additional cost to increase the SRT to upwards of 30-days is about $12 - 20 million additional dollars in total project cost for a 5 mgd design flow. Assumes zero liquid discharge for RO brine management, followed by evaporation ponds. Other options are available as listed in Section 4.4.2. Does not include the cost for labor. mgd=million gallons per day MG=million gallons MF/RO=membrane filtration/reverse osmosis MF/GAC=membrane filtration/granulated activated carbon O&M=operations and maintenance Net Present Value = total financed cost assuming a 5% nominal discount rate over an assumed 25 year equipment life. Costs presented above are based on a treatment capacity of 5.0 mgd, however, existing treatment facilities range dramatically across Washington in size and flow treated. The key differences in cost between the baseline and the advanced treatment MF/RO are as follows: Larger aeration basins than the baseline to account for the longer SRT days versus <8 days). Additional pumping stations to pass water through the membrane facilities and granulated activated carbon facilities. These are based on peak flows. Membrane facilities (equipment, tanks chemical feed facilities, pumping, etc.) and replacement membrane equipment. Granulated activated carbon facilities (equipment, contact tanks, pumping, granulated activated carbon media, etc.) Additional energy and chemical demand to operate the membrane and granulated activated carbon facilities Additional energy to feed and backwash the granulated activated carbon facilities. Zero liquid discharge facilities to further concentrate the brine reject. o Zero liquid discharge facilities are energy/chemically intensive and they require membrane replacement every few years due to the brine reject water quality. Membrane and granulated activated carbon media replacement represent a significant maintenance cost. ---PAGE BREAK--- ES-4 Association of Washington Business 213512 Treatment Technology Review and Assessment Additional hauling and fees to regenerate granulated activated carbon off-site. The mass of pollutant removal by implementing advanced treatment was calculated based on reducing current secondary effluent discharges to revised effluent limits for the four pollutants of concern. These results are provided in Table ES-2 as well as a median estimated unit cost basis for the mass of pollutants removed. Table ES-2. Unit Cost by Contaminant for a 5-mgd Facility Implementing Advanced Treatment using Membrane Filtration/Reverse Osmosis Component PCBs Mercury Arsenic BAPs Required based Effluent Quality (µg/L) 0.0000064 0.005 0.018 0.0013 Current Secondary Effluent Concentration (µg/L) 0.002 0.025 7.5 0.006 Total Mass Removed (lbs) over 25 year Period 0.76 7.6 2,800 1.8 Median Estimated Unit Cost (NPV per total mass removed in pounds over 25 years) $290,000,000 $29,000,000 $77,000 $120,000,000 µg/L=micrograms per liter lbs=pounds NPV=net present value Collateral adverse environmental impacts associated with implementing advanced treatment were evaluated. The key impacts from this evaluation include increased energy use, greenhouse gas production, land requirements and treatment residuals disposal. Operation of advanced treatment technologies could increase electrical energy by a factor of 2.3 to 4.1 over the baseline secondary treatment system. Direct and indirect greenhouse gas emission increases are related to the operation of advanced treatment technologies and electrical power sourcing, with increases of at least 50 to 100 percent above the baseline technology. The energy and air emission implications of advanced treatment employing granulated activated carbon construction of advanced treatment facilities will require additional land area. The availability and cost of land adjacent to existing treatment facilities has not been included in cost estimates, but could be very substantial. It is noting residual materials from treatment may potentially be hazardous and their disposal may be challenging to permit. Costs assume zero liquid discharge from the facilities. ---PAGE BREAK--- Association of Washington Business 1 Treatment Technology Review and Assessment 213512 1.0 Introduction Washington’s Department of Ecology (Ecology) has an obligation to periodically review waterbody “designated uses” and to modify, as appropriate, water quality standards to ensure those uses are protected. Ecology initiated this regulatory process in 2009 for the human health- based water quality criteria in Washington’s Surface Water Quality Standards (Washington Administrative Code [WAC] 173-201A). are also commonly referred to as “toxic pollutant water quality standards.” Numerous factors will influence Ecology’s development of The expectation is that the adopted will be more stringent than current adopted criteria. National Pollutant Discharge Elimination System (NPDES) effluent limits for permitted dischargers to surface waters are based on U.S. Environmental Protection Agency (EPA) and state guidance. Effluent limits are determined primarily from reasonable potential analyses and waste load allocations (WLAs) from total maximum daily loads although the permit writer may use other water quality data. Water quality-based effluent limits are set to be protective of factors, including human health, aquatic uses, and recreational uses. Therefore, can serve as a basis for effluent limits. The presumption is that more stringent will, in time, drive lower effluent limits. The lower effluent limits will require advanced treatment technologies and will have a consequent financial impact on NPDES permittees. Ecology anticipates that a proposed revision to the water quality standards regulation will be issued in first quarter 2014, with adoption in late 2014. The Association of Washington Businesses (AWB) is recognized as the state’s chamber of commerce, manufacturing and technology association. AWB members, along with the Association of Washington Cities and Washington State Association of Counties (collectively referred to as Study Partners), hold NPDES permits authorizing wastewater discharges. The prospect of more stringent and the resulting needs for advanced treatment technologies to achieve lower effluent discharge limits, has led this consortium to sponsor a study to assess technology availability and capability, capital and operations and maintenance (O&M) costs, pollutant removal effectiveness, and collateral environmental impacts of candidate technologies. The “base case” for the study began with the identification of four nearly ubiquitous toxic pollutants present in many industrial and municipal wastewater discharges, and the specification of pollutant concentrations in well-treated secondary effluent. The pollutants are arsenic, benzo(a)pyrene (BAP), mercury and biphenyls (PCBs), which were selected for review based on available monitoring data and abundant presence in the environment. The purpose of this study is to review the potential water quality standards and associated treatment technologies able to meet those standards for four pollutants. A general wastewater treatment process and wastewater characteristics were used as the common baseline for comparison with all of the potential future treatment technologies considered. An existing secondary treatment process with disinfection at a flow of 5 million gallons per day (mgd) was used to represent existing conditions. Typical effluent biochemical oxygen demand (BOD) and total suspended solids (TSS) were assumed between 10 and 30 milligrams per liter (mg/L) for such a facility and no designed nutrient or toxics removal was assumed for the baseline existing treatment process. Following a literature review of technologies, two advanced treatment process options for toxics removal were selected for further evaluation based on the characterization of removal effectiveness from the technical literature review and Study Partners’ preferences. The two tertiary treatment options are microfiltration membrane filtration (MF) followed by either reverse osmosis (RO) or granular activated carbon (GAC) as an addition to an existing secondary treatment facility. ---PAGE BREAK--- 2 Association of Washington Business 213512 Treatment Technology Review and Assessment The advanced treatment technologies are evaluated for their efficacy and cost to achieve the effluent limitations implied by the more stringent Various sensitivities are examined, including for less stringent adopted and for a size range of treatment systems. Collateral environmental impacts associated with the operation of advanced technologies are also qualitatively described. ---PAGE BREAK--- Association of Washington Business 3 Treatment Technology Review and Assessment 213512 2.0 Derivation of the Baseline Study Conditions and Rationale for Selection of Effluent Limitations 2.1 Summary of Water Quality Criteria Surface water quality standards for toxics in the State of Washington are being updated based on revised human fish consumption rates (FCRs). The revised water quality standards could drive very low effluent limitations for industrial and municipal wastewater dischargers. Four pollutants were selected for study based on available monitoring data and abundant presence in the environment. The four toxic constituents are arsenic, BAP, mercury, and PCBs. 2.2 Background Ecology is in the process of updating the in the state water quality standards regulation. Toxics include metals, pesticides, and organic compounds. The human health criteria for toxics are intended to protect people who consume water, fish, and shellfish. FCRs are an important factor in the derivation of water quality criteria for toxics. The AWB/City/County consortium (hereafter “Study Partners”) has selected four pollutants for which more stringent are expected to be promulgated. The Study Partners recognize that Ecology probably will not adopt more stringent arsenic so the evaluation here is based on the current arsenic imposed by the National Toxics Rule. Available monitoring information indicates these pollutants are ubiquitous in the environment and are expected to be present in many NPDES discharges. The four pollutants include the following: Arsenic o Elemental metalloid that occurs naturally and enters the environment through erosion processes. Also widely used in batteries, pesticides, wood preservatives, and semiconductors. Other current uses and legacy sources in fungicides/herbicides, copper smelting, paints/dyes, and personal care products. Benzo(a)pyrene (BAP) o Benzo(a)pyrene is a aromatic hydrocarbon formed by a benzene ring fused to pyrene as the result of incomplete combustion. Its metabolites are highly carcinogenic. Sources include wood burning, coal tar, automobile exhaust, cigarette smoke, and char-broiled food. Mercury o Naturally occurring element with wide legacy uses in thermometers, electrical switches, fluorescent lamps, and dental amalgam. Also enters the environment through erosion processes, combustion (especially coal), and legacy industrial/commercial uses. is an organometallic that is a bioaccumulative toxic. In aquatic systems, an anaerobic methylation process converts inorganic mercury to Biphenyls (PCBs) o Persistent organic compounds historically used as a dielectric and coolant in electrical equipment and banned from production in the U.S. in 1979. Available information indicates continued pollutant loadings to the environment as a byproduct from the use of some pigments, paints, caulking, motor oil, and coal combustion. ---PAGE BREAK--- 4 Association of Washington Business 213512 Treatment Technology Review and Assessment 2.3 Assumptions Supporting Selected Ambient Water Quality Criteria and Effluent Limitations Clean Water Act regulations require NPDES permittees to demonstrate their discharge will “not cause or contribute to a violation of water quality criteria.” If a “reasonable potential analysis” reveals the possibility of a standards violation, the permitting authority is obliged to develop “water quality-based effluent limits” to ensure standards achievement. In addition, if ambient water quality monitoring or fish tissue assessments reveal toxic pollutant concentrations above levels, Ecology is required to identify that impairment (“303(d) listing”) and develop corrective action plans to force reduction in the toxic pollutant discharge or loading of the pollutant into the impaired water body segment. These plans, referred to as total maximum daily loads or water cleanup plans, establish discharge allocations and are implemented for point discharge sources through NPDES permit effluent limits and other conditions. The effect of more stringent will intuitively result in more NPDES permittees “causing or contributing” to a water quality standards exceedance, and/or more waterbodies being determined to be impaired, thus requiring 303(d) listing, the development of TMDL/water cleanup plans, and more stringent effluent limitations to NPDES permittees whose treated wastewater contains the listed toxic pollutant. The study design necessarily required certain assumptions to create a “baseline effluent scenario” against which the evaluation of advanced treatment technologies could occur. The Study Partners and HDR Engineering, Inc (HDR) developed the scenario. Details of the baseline effluent scenario are presented in Table 1. The essential assumptions and rationale for selection are presented below: Ecology has indicated proposed revisions will be provided in first quarter 2014. A Study Partners objective was to gain an early view on the treatment technology and cost implications. Ecology typically allows 30 or 45 days for the submission of public comments on proposed regulations. To wait for the proposed revisions would not allow sufficient time to complete a timely technology/cost evaluation and then to share the study results in the timeframe allowed for public involvement/public comments. Coincident with the issuance of the proposed regulation, Ecology has a statutory obligation to provide a Significant Legislative Rule evaluation, one element of which is a “determination whether the probable benefits of the rule are greater than its probable costs, taking into account both the qualitative and quantitative benefits and costs and the specific directives of the statute being implemented” (RCW 34.05.328(1)(d)). A statutory requirement also exists to assess the impact of the proposed regulation to small businesses. The implication is that Ecology will be conducting these economic evaluations in fourth quarter 2013 and early 2014. The Study Partners wanted to have a completed technology/cost study available to share with Ecology for their significant legislative rule/small business evaluations. The EPA, Indian tribes located in Washington, and various special interest groups have promoted the recently promulgated state of Oregon (2011) as the “model” for Washington’s revisions of The Oregon are generally based on a increased FCR of 175 grams per day (g/day) and an excess cancer risk of 10-6. While the Study Partners do not concede the wisdom or appropriateness of the Oregon criteria, or the selection of scientific/technical elements used to derive those criteria, the Study Partners nevertheless have selected the Oregon as a viable “starting point” upon which this study could be based. ---PAGE BREAK--- Association of Washington Business 5 Treatment Technology Review and Assessment 213512 The scenario assumes generally that Oregon’s for ambient waters will, for some parameters in fact, become effluent limitations for Washington NPDES permittees. The reasoning for this important assumption includes: o The state of Washington’s NPDES permitting program is bound by the Friends of Pinto Creek vs. EPA decision in the United States Court of Appeals for the Ninth Circuit (October 4, 2007). This decision held that no NPDES permits authorizing new or expanded discharges of a pollutant into a waterbody identified as impaired; i.e., listed on CWA section 303(d), for that pollutant, may be issued until such time as “existing dischargers” into the waterbody are “subject to compliance schedules designed to bring the (waterbody) into compliance with applicable water quality standards.” In essence, any new/expanded discharge of a pollutant causing impairment must achieve the at the point of discharge into the waterbody. o If a waterbody segment is identified as “impaired” not achieving a then Ecology will eventually need to produce a TMDL or water cleanup plan. For an existing NPDES permittee with a discharge of the pollutant for which the receiving water is impaired, the logical assumption is that any waste load allocation granted to the discharger will be at or lower than the numeric (to facilitate recovery of the waterbody to attainment). As a practical matter, this equates to an effluent limit established at the o Acceptance of Oregon as the baseline for technology/cost review also means acceptance of practical implementation tools used by Oregon. The for mercury is presented as a fish tissue methyl mercury concentration. For the purposes of NPDES permitting, however, Oregon has developed an implementation management directive which states that any confirmed detection of mercury is considered to represent a “reasonable potential” to cause or contribute to a water quality standards violation of the methyl mercury criteria. The minimum quantification level for total mercury is presented as 0.005 micrograms per liter (µg/L) (5.0 nanograms per liter o The assumed effluent limit for arsenic is taken from EPA’s National Recommended Water Quality Criteria (2012) (inorganic, water and organisms, 10-6 excess cancer risk). Oregon’s 2011 criterion is actually based on a less protective excess cancer risk (10-4). This, however, is the result of a state-specific risk management choice and it is unclear if Washington’s Department of Ecology would mimic the Oregon approach. o The assumption is that no mixing zone is granted such that will effectively serve as NPDES permit effluent limits. Prior discussion on the impact of the Pinto Creek decision, 303(d) impairment and TMDL Waste Load Allocations processes, all lend support to this “no mixing zone” condition for the parameters evaluated in this study. Consistent with Ecology practice in the evaluation of proposed regulations, the are assumed to be in effect for a 20-year period. It is assumed that analytical measurement technology and capability will continue to improve over this time frame and this will result in the detection and lower quantification of additional in ambient water and NPDES dischargers. This knowledge will trigger the Pinto Creek/303(d)/TMDL issues identified above and tend to pressure NPDES permittees to evaluate and install advanced treatment technologies. The costs and efficacy of treatment for these additional is unknown at this time. ---PAGE BREAK--- 6 Association of Washington Business 213512 Treatment Technology Review and Assessment Other elements of the Study Partners work scope, as presented to HDR, must be noted: The selection of four toxic pollutants and development of a baseline effluent scenario is not meant to imply that each NPDES permittee wastewater discharge will include those pollutants at the assumed concentrations. Rather, the scenario was intended to represent a composite of many NPDES permittees and to facilitate evaluation of advanced treatment technologies relying on mechanical, biological, physical, chemical processes. The scalability of advanced treatment technologies to wastewater treatment systems with different flow capacities, and the resulting unit costs for capital and O&M, is evaluated. Similarly, a sensitivity analysis on the unit costs for capital and O&M was evaluated on the assumption the adopted (and effectively, NPDES effluent limits) are one order-of-magnitude less stringent than the Table 1 values. ---PAGE BREAK--- Association of Washington Business 7 Treatment Technology Review and Assessment 213512 Table 1: Summary of Effluent Discharge Toxics Limits Constituent Human Health Criteria based Limits to be met with no Mixing Zone (µg/L) Basis for Criteria Typical Concentration in Municipal Secondary Effluent (µg/L) Typical Concentration in Industrial Secondary Effluent (µg/L) Existing Washington HHC (water + org.), NTR (µg/L) PCBs 0.0000064 Oregon Table 40 Criterion (water + organisms) at FCR of 175 grams/day 0.0005 to 0.0025b,c,d,e,f 0.002 to 0.005i 0.0017 Mercury 0.005 DEQ IMDa 0.003 to 0.050h 0.010 to 0.050h 0.140 Arsenic 0.018 EPA National Toxics Rule (water + organisms)k 0.500 to 5.0j 10 to 40j 0.018 Benzo(a)Pyrene 0.0013 Oregon Table 40 Criterion (water + organisms) at FCR of 175 grams/day 0.00028 to 0.006b,g 0.006 to1.9 0.0028 a Oregon Department of Environmental Quality (ODEQ). Internal Management Directive: Implementation of Criterion in NPDES Permits. January 8, 2013. b Control of Toxic Chemicals in Puget Sound, Summary Technical Report for Phase 3: Loadings from POTW Discharge of Treated Wastewater, Washington Department of Ecology, Publication Number 10-10-057, December 2010. c Spokane River PCB Source Assessment 2003-2007, Washington Department of Ecology, Publication No. 11-03-013, April 2011. d Lower Okanogan River Basin DDT and PCBs Total Maximum Daily Load, Submittal Report, Washington Department of Ecology, Publication Number 04- 10-043, October 2004. e Palouse River Watershed PCB and Dieldrin Monitoring, 2007-2008, Wastewater Treatment Plants and Abandoned Landfills, Washington Department of Ecology, Publication No. 09-03-004, January 2009 f A Total Maximum Daily Load Evaluation for Chlorinated Pesticides and PCBs in the Walla Walla River, Washington Department of Ecology, Publication No. 04-03-032, October 2004. g Removal of Aromatic Hydrocarbons and Heterocyclic Nitrogenous Compounds by A POTW Receiving Industrial Discharges, Melcer, Steel, P. and Bedford, W.K., Water Environment Federation, 66th Annual Conference and Exposition, October 1993. h Data provided by Lincoln Loehr's summary of WDOE Puget Sound Loading data in emails from July 19, 2013. i NCASI memo from Larry Lefleur, NCASI, to Llewellyn Matthews, NWPPA, revised June 17, 2011, summarizing available PCB monitoring data results from various sources. j Professional judgment, discussed in August 6, 2013 team call. k The applicable Washington Human Health Criteria cross-reference the EPA National Toxics Rule, 40 CFR 131.36. The EPA arsenic HHC is 0.018 ug/L for water and organisms. ---PAGE BREAK--- 8 Association of Washington Business 213512 Treatment Technology Review and Assessment This page left intentionally blank. ---PAGE BREAK--- Association of Washington Business 9 Treatment Technology Review and Assessment 213512 3.0 Wastewater Characterization Description This section describes the wastewater treatment discharge considered in this technology evaluation. Treated wastewater characteristics are described, including average and peak flow, effluent concentrations, and toxic compounds of concern. 3.1 Summary of Wastewater Characterization A general wastewater treatment process and wastewater characteristics were developed as the common baseline to represent the existing conditions as a starting point for comparison with potential future advanced treatment technologies and improvements. A secondary treatment process with disinfection at a flow of 5 mgd as the current, baseline treatment system for existing dischargers was also developed. Typical effluent biochemical oxygen demand (BOD) and total suspended solids (TSS) were assumed between 10 to 30 mg/L from such a facility and no nutrient or toxics removal was assumed to be accomplished in the existing baseline treatment process. 3.2 Existing Wastewater Treatment Facility The first step in the process is to characterize the existing wastewater treatment plant to be evaluated in this study. The goal is to identify the necessary technology that would need to be added to an existing treatment facility to comply with revised toxic pollutant effluent limits. Rather than evaluating the technologies and costs to upgrade multiple actual operating facilities, the Study Partners specified that a generalized municipal/industrial wastewater treatment facility would be characterized and used as the basis for developing toxic removal approaches. General characteristics of the facility’s discharge are described in Table 2. Table 2. General Wastewater Treatment Facility Characteristics Average Annual Wastewater Flow, mgd Maximum Month Wastewater Flow, mgd Peak Hourly Wastewater Flow, mgd Effluent BOD, mg/L Effluent TSS, mg/L 5.0 6.25 15.0 10 to 30 10 to 30 mgd=million gallons per day mg/L=milligrams per liter BOD=biochemical oxygen demand TSS=total suspended solids In the development of the advanced treatment technologies presented below, the capacity of major treatment elements are generally sized to accommodate the maximum month average wastewater flow. Hydraulic elements, such as pumps and pipelines, were selected to accommodate the peak hourly wastewater flow. The general treatment facility incorporates a baseline treatment processes including influent screening, grit removal, primary sedimentation, suspended growth biological treatment (activated sludge), secondary clarification, and disinfection using chlorine. Solids removed during primary treatment and secondary clarification are assumed to be thickened, stabilized, dewatered, and land applied to agricultural land. The biological treatment process is assumed to be activated sludge with a relatively short (less than 10-day) solids retention time. The baseline secondary treatment facility is assumed not to have processes dedicated to removing nutrients or toxics. However, some coincident removal of toxics will occur during conventional treatment. ---PAGE BREAK--- 10 Association of Washington Business 213512 Treatment Technology Review and Assessment 3.3 Toxic Constituents As described in Section 2.3, the expectation of more stringent will eventually trigger regulatory demands for NPDES permittees to install advanced treatment technologies. The Study Group and HDR selected four specific toxic pollutants reflecting a range of toxic constituents as the basis for this study to limit the constituents and technologies to be evaluated to a manageable level. The four toxic pollutants selected were PCBs, mercury, arsenic, and BAP, a aromatic hydrocarbon (PAH). Mercury and arsenic are metals, and PCBs and PAHs are organic compounds. Technologies for removing metals and organic compounds are in some cases different. Key information on each of the compounds, including a description of the constituent, the significance of each constituent, proposed basis for the proposed criteria, typical concentration in both municipal and industrial secondary effluent, and current Washington state water quality criteria, are shown in Table 1. It is assumed that compliance with the proposed criteria in the table would need to be achieved at the “end of pipe” and Ecology would not permit a mixing zone for toxic constituents. This represents a “worst–case,” but a plausible assumption about discharge conditions. ---PAGE BREAK--- Association of Washington Business 11 Treatment Technology Review and Assessment 213512 4.0 Treatment Approaches and Costs 4.1 Summary of Treatment Approach and Costs Two advanced treatment process options for toxics removal for further evaluation based on the characterization of removal effectiveness from the technical literature review and Study Group preferences. The two tertiary treatment options are microfiltration MF followed by either RO or GAC as an addition to an existing secondary treatment facility. Based on the literature review, it is not anticipated that any of the treatment options will be effective in reducing all of the selected pollutants to below the anticipated water quality criteria. A summary of the capital and operations and maintenance costs for tertiary treatment is provided, as well as a comparison of the adverse environmental impacts for each alternative. 4.2 Constituent Removal – Literature Review The evaluation of treatment technologies relevant to the constituents of concern was initiated with a literature review. The literature review included a desktop search using typical web-based search engines, and search engines dedicated to technical and research journal databases. At the same time, HDR’s experience with the performance of existing treatment technologies specifically related to the four constituents of concern, was used in evaluating candidate technologies. A summary of the constituents of concern and relevant treatment technologies is provided in the following literature review section. 4.2.1 Biphenyls PCBs are persistent organic pollutants that can be difficult to remove in treatment. PCB treatment in wastewater can be achieved using oxidation with peroxide, filtration, biological treatment or a combination of these technologies. There is limited information available about achieving ultra-low effluent PCB concentrations near the 0.0000064 µg/L range under consideration in the proposed rulemaking process. This review provides a summary of treatment technology options and anticipated effluent PCB concentrations. Research on the effectiveness of ultraviolet (UV) light and peroxide on removing PCBs was tested in bench scale batch reactions (Yu, Macawile, Abella, & Gallardo 2011). The combination of UV and peroxide treatment achieved PCB removal greater than 89 percent, and in several cases exceeding 98 percent removal. The influent PCB concentration for the batch tests ranged from 50 to 100 micrograms per liter (µg/L). The final PCB concentration (for the one congener tested) was <10 µg/L (10,000 ng/L) for all tests and <5 µg/L (5,000 ng/L) for some tests. The lowest PCB concentrations in the effluent occurred at higher UV and peroxide doses. Pilot testing was performed to determine the effectiveness of conventional activated sludge and a membrane bioreactor to remove PCBs (Bolzonella, Fatone, Pavan, & Cecchi 2010). EPA Method 1668 was used for the PCB analysis (detection limit of 0.01 ng/L per congener). Influent to the pilot system was a combination of municipal and industrial effluent. The detailed analysis was for several individual congeners. Limited testing using the Aroclor method (total PCBs) was used to compare the individual congeners and the total concentration of PCBs. Both conventional activated sludge and membrane bioreactor (MBR) systems removed PCBs. The effluent MBR concentrations ranged from <0.01 ng/L to 0.04 ng/L compared to <0.01 ng/L to 0.88 ng/L for conventional activated sludge. The pilot testing showed that increased solids retention time (SRT) and higher mixed liquor suspended solids concentrations in the MBR system led to increased removal in the liquid stream. Bench scale studies were completed to test the effectiveness of GAC and biological activated carbon (BAC) for removing PCBs (Ghosh, Weber, Jensen, & Smith 1999). The effluent from the ---PAGE BREAK--- 12 Association of Washington Business 213512 Treatment Technology Review and Assessment GAC system was 800 ng/L. The biological film in the BAC system was presumed to support higher PCB removal with effluent concentrations of 200 ng/L. High suspended sediment in the GAC influent can affect performance. It is recommended that filtration be installed upstream of a GAC system to reduce solids and improve effectiveness. Based on limited available data, it appears that existing municipal secondary treatment facilities in Washington state are able to reduce effluent PCBs to the range approximately 0.10 to 1.5 ng/L. It appears that the best performing existing municipal treatment facility in Washington state with a microfiltration membrane is able to reduce effluent PCBs to the range approximately 0.00019 to 0.00063 µg/L. This is based on a very limited data set and laboratory blanks covered a range that overlapped with the effluent results (blanks 0.000058 to 0.00061 µg/L). Addition of advanced treatment processes would be expected to enhance PCB removal rates, but the technical literature does not appear to provide definitive information for guidance. A range of expected enhanced removal rates might be assumed to vary widely from level of the reference microfiltration facility of 0.19 to 0.63 ng/L. Summary of PCB Technologies The literature review revealed there are viable technologies available to reduce PCBs but no research was identified with treatment technologies capable of meeting the anticipated human health criteria based limits for PCB removal. Based on this review, a tertiary process was selected to biologically reduce PCBs and separate the solids using tertiary filtration. Alternately, GAC was investigated as an option to reduce PCBs, although it is not proven that it will meet revised effluent limits. 4.2.2 Mercury Mercury removal from wastewater can be achieved using precipitation, adsorption, filtration, or a combination of these technologies. There is limited information available about achieving ultra- low effluent mercury concentrations near the 5 ng/L range under consideration in the proposed rulemaking process. This review provides a summary of treatment technology options and anticipated effluent mercury concentrations. Precipitation (and co-precipitation) involves chemical addition to form a particulate and solids separation, using sedimentation or filtration. Precipitation includes the addition of a chemical precipitant and pH adjustment to optimize the precipitation reaction. Chemicals can include metal salts (ferric chloride, ferric sulfate, ferric hydroxide, or alum), pH adjustment, lime softening, or sulfide. A common precipitant for mercury removal is sulfide, with an optimal pH between 7 and 9. The dissolved mercury is precipitated with the sulfide to form an insoluble mercury sulfide that can be removed through clarification or filtration. One disadvantage of precipitation is the generation of a mercury-laden sludge that will require dewatering and disposal. The mercury sludge may be considered a hazardous waste and require additional treatment and disposal at a hazardous waste site. The presence of other compounds, such as other metals, may reduce the effectiveness of mercury precipitation/co-precipitation. For low- level mercury treatment requirements, several treatment steps will likely be required in pursuit of very low effluent targets. EPA compiled a summary of facilities that are using precipitation/co-precipitation for mercury treatment (EPA 2007). Three of the full-scale facilities were pumping and treating groundwater and the remaining eight facilities were full-scale wastewater treatment plants. One of the pump and treat systems used precipitation, carbon adsorption, and pH adjustment to treat groundwater to effluent concentrations of 300 ng/L. ---PAGE BREAK--- Association of Washington Business 13 Treatment Technology Review and Assessment 213512 Adsorption treatment can be used to remove inorganic mercury from water. While adsorption can be used as a primary treatment step, it is frequently used for polishing after a preliminary treatment step (EPA 2007). One disadvantage of adsorption treatment is that when the adsorbent is saturated, it either needs to be regenerated or disposed of and replaced with new adsorbent. A common adsorbent is GAC. There are several patented and proprietary adsorbents on the market for mercury removal. Adsorption effectiveness can be affected by water quality characteristics, including high solids and bacterial growth, which can cause media blinding. A constant and low flow rate to the adsorption beds increases effectiveness (EPA 2007). The optimal pH for mercury adsorption on GAC is pH 4 to 5; therefore, pH adjustment may be required. EPA compiled a summary of facilities that are using adsorption for mercury treatment (EPA 2007). Some of the facilities use precipitation and adsorption as described above. The six summarized facilities included two groundwater treatment and four wastewater treatment facilities. The reported effluent mercury concentrations were all less than 2,000 ng/L (EPA 2007). Membrane filtration can be used in combination with a preceding treatment step. The upstream treatment is required to precipitate soluble mercury to a particulate form that can be removed through filtration. According to the EPA summary report, ultrafiltration is used to remove high- molecular weigh contaminants and solids (EPA 2007). The treatment effectiveness can depend on the source water quality since many constituents can cause membrane fouling, decreasing the effectiveness of the filters. One case study summarized in the EPA report showed that treatment of waste from a hazardous waste combustor treated with precipitation, sedimentation, and filtration achieved effluent mercury concentrations less than the detection limit of 200 ng/L. Bench-scale research performed at the Oak Ridge Y-12 Plant in Tennessee evaluated the effectiveness of various adsorbents for removing mercury to below the NPDES limit of 12 ng/L and the potential revised limit of 51 ng/L (Hollerman et al. 1999). Several proprietary adsorbents were tested, including carbon, polyacrylate, and polymer adsorption materials. The adsorbents with thiol-based active sites were the most effective. Some of the adsorbents were able to achieve effluent concentrations less than 51 ng/L but none of the adsorbents achieved effluent concentrations less than 12 ng/L. Bench-scale and pilot-scale testing performed on refinery wastewater was completed to determine treatment technology effectiveness for meeting very low mercury levels (Urgun- Demirtas, Benda, Gillenwater, Negri, Xiong & Snyder 2012) (Urgun-Demirtas, Negri, Gillenwater, Agwu Nnanna & Yu 2013). The Great Lakes Initiative water quality criterion for mercury is less than 1.3 ng/L for municipal and industrial wastewater plants in the Great Lakes region. This research included an initial bench scale test including membrane filtration, ultrafiltration, nanofiltration, and reverse osmosis to meet the mercury water quality criterion. The nanofiltration and reverse osmosis required increased pressures for filtration and resulted in increased mercury concentrations in the permeate. Based on this information and the cost difference between the filtration technologies, a pilot-scale test was performed. The 0.04 um PVDF GE ZeeWeed 500 series membranes were tested. The 1.3 ng/L water quality criterion was met under all pilot study operating conditions. The mercury in the refinery effluent was predominantly in particulate form which was well-suited for removal using membrane filtration. Based on available data, it appears that existing municipal treatment facilities are capable of reducing effluent mercury to near the range of the proposed on an average basis. Average effluent mercury in the range of 1.2 to 6.6 ng/L for existing facilities with secondary treatment and enhanced treatment with cloth filters and membranes. The Spokane County plant data range is an average of 1.2 ng/L to a maximum day of 3 ng/L. Addition of ---PAGE BREAK--- 14 Association of Washington Business 213512 Treatment Technology Review and Assessment advanced treatment processes such as GAC or RO would be expected to enhance removal rates. Data from the West Basin treatment facility in California suggests that at a detection limit of 7.99 ng/L mercury is not detected in the effluent from this advanced process train. A range of expected enhanced removal rates from the advanced treatment process trains might be expected to ranged from meeting the proposed standard at 5 ng/L to lower concentrations represented by the Spokane County performance level (membrane filtration) in the range of 1 to 3 ng/L, to perhaps even lower levels with additional treatment. For municipal plants in Washington, this would suggest that effluent mercury values from the two advanced treatment process alternatives might range from 1 to 5 ng/L (0.001 to 0.005 µg/L) and perhaps substantially better, depending upon RO and GAC removals. It is important to note that industrial plants may have higher existing mercury levels and thus the effluent quality that is achievable at an industrial facility would be of lower quality. Summary of Mercury Technologies The literature search revealed limited research on mercury removal technologies at the revised effluent limit of 0.005 µg/L. Tertiary filtration with membrane filters or reverse osmosis showed the best ability to achieve effluent criteria less than 0.005 µg/L. 4.2.3 Arsenic A variety of treatment technologies can be applied to capture arsenic (Table Most of the information in the technical literature and from the treatment technology vendors is focused on potable water treatment for compliance with a Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) of 10 µg/L. The most commonly used arsenic removal method for a wastewater application (tertiary treatment) is coagulation/ flocculation plus filtration. This method by itself could remove more than 90 to 95 percent of arsenic. Additional post-treatment through adsorption, ion exchange, or reverse osmosis is required for ultra-low arsenic limits in the 0.018 µg/L range under consideration in the proposed rulemaking process. In each case it is recommended to perform pilot-testing of each selected technology. Table 3: Summary of Arsenic Removal Technologies1 Technology Advantages Disadvantages Coagulation/filtration Simple, proven technology Widely accepted Moderate operator training pH sensitive Potential disposal issues of backwash waste As+3 and As+5 must be fully oxidized Lime softening High level arsenic treatment Simple operation change for existing lime softening facilities pH sensitive (requires post treatment adjustment) Requires filtration Significant sludge operation Adsorptive media High As+5 selectivity Effectively treats water with high total dissolved solids (TDS) Highly pH sensitive Hazardous chemical use in media regeneration High concentration SeO4 Cl-, and SO4 -2 may limit arsenic removal ---PAGE BREAK--- Association of Washington Business 15 Treatment Technology Review and Assessment 213512 Table 3: Summary of Arsenic Removal Technologies1 Technology Advantages Disadvantages Ion exchange Low contact times Removal of multiple anions, including arsenic, chromium, and uranium Requires removal of iron, manganese, sulfides, etc. to prevent fouling Brine waste disposal Membrane filtration High arsenic removal efficiency Removal of multiple contaminants Reject water disposal Poor production efficiency Requires pretreatment 1Adapted from WesTech The removal of arsenic in activated sludge is minimal (less than 20 percent) (Andrianisa et al. 2006), but biological treatment can control arsenic speciation. During aerobic biological process As (III) is oxidized to As Coagulation/flocculation/filtration removal, as well as adsorption removal methods, are more effective in removal of As(V) vs. As (III). A combination of activated sludge and post-activated sludge precipitation with ferric chloride (addition to MLSS and effluent) results in a removal efficiency of greater than 95 percent. This combination could decrease As levels from 200 µg/L to less than 5 µg/L (5,000 ng/L) (Andrianisa et al. 2008) compared to the 0.018 µg/L range under consideration in the proposed rulemaking process. Data from the West Basin facility (using MF/RO/AOP) suggests effluent performance in the range of 0.1 to 0.2 µg/L, but it could also be lower since a detection limit used there of 0.15 µg/l is an order of magnitude higher than the proposed A range of expected enhanced removal rates might be assumed to equivalent to that achieved at West Basin in 0.1 to 0.2 µg/L range. Review of Specific Technologies for Arsenic Removal Coagulation plus Settling or Filtration Coagulation may remove more than 95 percent of arsenic through the creation of particulate metal hydroxides. Ferric sulfite is typically more efficient and applicable to most wastewater sources compared to alum. The applicability and extent of removal should be pilot-tested, since removal efficiency is highly dependent on the water constituents and water characteristics pH, temperature, solids). Filtration can be added after or instead of settling to increase arsenic removal. Example treatment trains with filtration are shown in Figures 1 and 2, respectively. Figure 1. Water Treatment Configuration for Arsenic Removal (WesTech) ---PAGE BREAK--- 16 Association of Washington Business 213512 Treatment Technology Review and Assessment Figure 2. WesTech Pressure Filters for Arsenic Removal One system for treatment of potable water with high levels of arsenic in Colorado (110 parts per million [ppm]) consists of enhanced coagulation followed by granular media pressure filters that include anthracite/silica sand/garnet media (WesTech). The arsenic levels were reduced to less than the drinking water MCL, which is 10 µg/L (10,000 ng/L). The plant achieves treatment by reducing the pH of the raw water to 6.8 using sulfuric acid, and then adding approximately 12 to 14 mg/L ferric sulfate. The water is filtered through 16 deep bed vertical pressure filters, the pH is elevated with hydrated lime and is subsequently chlorinated and fed into the distribution system. (http://www.westechinc.com/public/uploads/global/2011/3/Fallon%20NV%20Installation%20ReportPressu reFilter.pdf). Softening (with lime) Removes up to 90 percent arsenic through co-precipitation, but requires pH to be higher than 10.2. Adsorption processes Activated alumina is considered an adsorptive media, although the chemical reaction is an exchange of arsenic ions with the surface hydroxides on the alumina. When all the surface hydroxides on the alumina have been exchanged, the media must be regenerated. Regeneration consists of backwashing, followed by sodium hydroxide, flushing with water and neutralization with a strong acid. Effective arsenic removal requires sufficient empty bed contact time. Removal efficiency can also be impacted by the water pH, with neutral or acidic conditions being considered optimum. If As (III) is present, it is generally advisable to increase empty bed contact time, as As (III) is adsorbed more slowly than As Alumina dissolves slowly over time due to contact with the chemicals used for regeneration. As a result, the media bed is likely to become compacted if it is not backwashed periodically. Granular ferric hydroxide works by adsorption, but when the media is spent it cannot be regenerated and must be replaced. The life of the media depends upon pH of the raw water, the concentrations of arsenic and heavy metals, and the volume of water treated daily. Periodic backwashing is required to prevent the media bed from becoming compacted and pH may need to be adjusted if it is high, in order to extend media life. For maximum arsenic removal, filters operate in series. For less stringent removal, filters can operate in parallel. One type of adsorption media has been developed for application to non-drinking water processes for arsenic, phosphate and for heavy metals removal by sorption (Severent Trent Bayoxide® E IN-20). This granular ferric oxide media has been used for arsenic removal from ---PAGE BREAK--- Association of Washington Business 17 Treatment Technology Review and Assessment 213512 mining and industrial wastewaters, selenium removal from refinery wastes and for phosphate polishing of municipal wastewaters. Valley Vista drinking water treatment with Bayoxide® E IN- 20 media achieves removal from 31-39 µg/L (31,000-39,000 ng/L) to below 10 µg/L MCL (http://www.severntrentservices.com/News/Successful_Drinking_Water_Treatment_in_an_Arsenic__Hot_ Another adsorptive filter media is greensand. Greensand is available in two forms: as glauconite with manganese dioxide bound ionically to the granules and as silica sand with manganese dioxide fused to the granules. Both forms operate in pressure filters and both are effective. Greensand with the silica sand core operates at higher water temperatures and higher differential pressures than does greensand with the glauconite core. Arsenic removal requires a minimum concentration of iron. If a sufficient concentration of iron is not present in the raw water, ferric chloride is added. WesTech filters with greensand and permanganate addition for drinking water systems can reduce As from 15-25 µg/L to non-detect. Sodium hypochlorite and/or potassium permanganate are added to the raw water prior to the filters. Chemical addition may be done continuously or intermittently, depending on raw water characteristics. These chemicals oxidize the iron in the raw water and also maintain the active properties of the greensand itself. Arsenic removal is via co-precipitation with the iron. Ion Exchange Siemens offers a potable ion exchange (PIX) arsenic water filtration system. PIX uses ion exchange resin canisters for the removal of organic and inorganic contaminants, in surface and groundwater sources to meet drinking water standards. Filtronics also uses ion exchange to treat arsenic. The technology allows removal for below the SWDA MCL for potable water of 10 µg/L (10,000 ng/L). Reverse osmosis Arsenic is effectively removed by RO when it is in oxidative state As(V) to approximately 1,000 ng/L or less (Ning 2002). Summary of Arsenic Technologies The current state of the technology for arsenic removal is at the point where all the processes target the SWDA MCL for arsenic in potable water. Current EPA maximum concentration level for drinking water is 10 ug/l; much higher than 0.0018 µg/L target for arsenic in this study. The majority of the methods discussed above are able to remove arsenic to either EPA maximum contaminant level or to the level of detection. The lowest detection limit of one of the EPA approved methods of arsenic measurements is 20 ng/l (0.020 µg/l) (Grosser, 2010), which is comparable to the 0.018 µg/L limit targeted in this study. 4.2.1 Aromatic Hydrocarbons BAP During Biological Treatment During wastewater treatment process, BAP tends to partition into sludge organic matter (Melcer et al. 1993). Primary and secondary processing could remove up to 60 percent of incoming PAHs and BAP in particular, mostly due to adsorption to sludge (Kindaichi et al., NA, Wayne et al. 2009). Biodegradation of BAP is expected to be very low since there are more than five benzene rings which are resistant to biological degradation. Biosurfactant addition to biological process could partially improve biodegradation, but only up to removal rates of 50 percent (Sponza et al. 2010). Existing data from municipal treatment facilities in Washington state have ---PAGE BREAK--- 18 Association of Washington Business 213512 Treatment Technology Review and Assessment influent and effluent concentrations of BAP of approximately 0.30 ng/L indicating that current secondary treatment has limited effectiveness at BAP removal. Methods to Enhance Biological Treatment of BAP Ozonation prior to biological treatment could potentially improve biodegradability of BAP (Zeng et al. 2000). In the case of soil remediation, ozonation before biotreatment improved biodegradation by 70 percent (Russo et al. 2012). The overall removal of BAP increased from 23 to 91 percent after exposure of water to 0.5 mg/L ozone for 30 minutes during the simultaneous treatment process and further to 100 percent following exposure to 2.5 mg/L ozone for 60 minutes during the sequential treatment mode (Yerushalmi et al. 2006). In general, to improve biodegradability of BAP, long exposure to ozone might be required (Haapea et al. 2006). Sonication pre-treatment or electronic beam irradiation before biological treatment might also make PAHs more bioavailable for biological degradation.. Recent studies reported that a MBR is capable of removing PAHs from wastewater (Rodrigue and Reilly 2009; Gonzaleza et al. 2012). None of the studies listed the specific PAHs constituents removed. Removal of BAP from Drinking Water Activated Carbon Since BAP has an affinity to particulate matter, it is removed from the drinking water sources by means of adsorption, such as granular activated carbon (EPA). Similarly, Oleszczuk et al. (2012) showed that addition of 5 percent activated carbon could remove 90 percent of PAHs from the wastewater. Reverse Osmosis Light (1981) (referenced by Williams, 2003) studied dilute solutions of PAHs, aromatic amines, and nitrosamines and found rejections of these compounds in reverse osmosis to be over 99 percent for polyamide membranes. Bhattacharyya et al. (1987) (referenced by Williams, 2003) investigated rejection and flux characteristics of FT30 membranes for separating various pollutants (PAHs, chlorophenols, nitrophenols) and found membrane rejections were high (>98 percent) for the organics under ionized conditions. Summary of BAP Technologies Current technologies show that BAP removal may be 90 percent or greater. The lowest detection limit for BAP measurements is 0.006 µg/L, which is also the assumed secondary effluent BAP concentration assumed for this study. If this assumption is accurate, it appears technologies may exist to remove BAP to a level below the proposed criteria applied as an effluent limit of 0.0013 µg/L; however, detection limits exceed this value and it is impossible to know this for certain. A municipal wastewater treatment plant study reported both influent and effluent BAP concentrations less than the of 0.0013 ug/L (Ecology, 2010). 4.3 Unit Processes Evaluated Based on the results of the literature review, a wide range of technologies were evaluated for toxic constituent removal. A listing of the technologies is as follows: Chemically enhanced primary treatment (CEPT): this physical and chemical technology is based on the addition of a metal salt to precipitate particles prior to primary treatment, followed by sedimentation of particles in the primary clarifiers. This technology has been ---PAGE BREAK--- Association of Washington Business 19 Treatment Technology Review and Assessment 213512 shown to effectively remove arsenic but there is little data supporting the claims. As a result, the chemical facilities are listed as optional. Activated sludge treatment (with a short SRT of approximately 8 days or less): this biological technology is commonly referred to as secondary treatment. It relies on converting dissolved organics into solids using biomass. Having a short SRT is effective at removing degradable organics referred to as BOD compounds for meeting existing discharge limits. Dissolved constituents with a high affinity to adsorb to biomass metals, high molecular weight organics, and others) will be better removed compared to smaller molecular weight organics and recalcitrant compounds which will have minimal removal at a short SRT. Enhanced activated sludge treatment (with a long SRT of approximately 8 days or more): this technology builds on secondary treatment by providing a longer SRT, which enhances sorption and biodegradation. The improved performance is based on having more biomass coupled with a more diverse biomass community, especially nitrifiers, which have been shown to assist in removal of some of the more recalcitrant constituents not removed with a shorter SRT lower molecular weight PAHs). There is little or no data available on the effectiveness of this treatment for removing BAP. Additional benefits associated with having a longer SRT are as follows: o Lower BOD/TSS discharge load to receiving water o Improved water quality and benefit to users o Lower effluent nutrient concentrations which reduce algal growth potential in receiving waters o Reduced receiving water dissolved oxygen demand due to ammonia removal o Reduced ammonia discharge, which is toxic to aquatic species o Improved water quality for habitat, especially as it relates to biodiversity and eutrophication o Secondary clarifier effluent more conditioned for filtration and disinfection o Greater process stability from the anaerobic/anoxic zones serving as biological selectors Coagulation/Flocculation and Filtration: this two-stage chemical and physical process relies on the addition of a metal salt to precipitate particles in the first stage, followed by the physical removal of particles in filtration. This technology lends itself to constituents prone to precipitation arsenic). Lime Softening: this chemical process relies on increasing the pH as a means to either volatilize dissolved constituents or inactivate pathogens. Given that none of the constituents being studied are expected to volatilize, this technology was not carried forward. Adsorptive Media: this physical and chemical process adsorbs constituents to a combination of media and/or biomass/chemicals on the media. There are several types of media, with the most proven and common being GAC. GAC can also serve as a coarse roughing filter. Ion Exchange: this chemical technology exchanges targeted constituents with a resin. This technology is common with water softeners where the hard divalent cations are ---PAGE BREAK--- 20 Association of Washington Business 213512 Treatment Technology Review and Assessment exchanged for monovalent cations to soften the water. Recently, resins that target arsenic and mercury removal include activated alumina and granular ferric hydroxides have been developed. The resin needs to be cleaned and regenerated, which produces a waste slurry that requires subsequent treatment and disposal. As a result, ion exchange was not considered for further. Membrane Filtration: This physical treatment relies on the removal of particles larger than the membranes pore size. There are several different membrane pore sizes as categorized below. o Microfiltration (MF): nominal pore size range of typically between 0.1 to 1 micron. This pore size targets particles, both inert and biological, and bacteria. If placed in series with coagulation/flocculation upstream, dissolved constituents precipitated out of solution and bacteria can be removed by the MF membrane. o Ultrafiltration (UF): nominal pore size range of typically between 0.01 to 0.1 micron. This pore size targets those solids removed with MF (particles and bacteria) plus viruses and some colloidal material. If placed in series with coagulation/flocculation upstream, dissolved constituents precipitated out of solution can be removed by the UF membrane. o Nanofiltration (NF): nominal pore size range of typically between 0.001 to 0.010 micron. This pore size targets those removed with UF (particles, bacteria, viruses) plus colloidal material. If placed in series with coagulation/flocculation upstream, dissolved constituents precipitated out of solution can be removed by the NF membrane. MBR (with a long SRT): this technology builds on secondary treatment whereby the membrane (microfiltration) replaces the secondary clarifier for solids separation. As a result, the footprint is smaller, the mixed liquor suspended solids concentration can be increased to about 5,000 – 10,000 mg/L, and the physical space required for the facility reduced when compared to conventional activated sludge. As with the activated sludge option operated at a longer SRT, the sorption and biodegradation of organic compounds are enhanced in the MBR process. The improved performance is based on having more biomass coupled with a more diverse biomass community, especially nitrifiers which have been shown to assist in removal of persistent dissolved compounds some PAHs). There is little or no data available on effectiveness at removing BAP. Although a proven technology, MBRs were not carried further in this technology review since they are less likely to be selected as a retrofit for an existing activated sludge (with a short SRT) secondary treatment facility. The MBR was considered to represent a treatment process approach more likely to be selected for a new, greenfield treatment facility. Retrofits to existing secondary treatment facilities can accomplish similar process enhancement by extending the SRT in the activated sludge process followed by the addition of tertiary membrane filtration units. RO: This physical treatment method relies on the use of sufficient pressure to osmotically displace water across the membrane surface while simultaneously rejecting most salts. RO is very effective at removing material smaller than the size ranges for the membrane filtration list above, as well as salts and other organic compounds. As a result, it is expected to be more effective than filtration and MBR methods described above at removing dissolved constituents. Although effective, RO produces a brine reject water that must be managed and disposed. ---PAGE BREAK--- Association of Washington Business 21 Treatment Technology Review and Assessment 213512 Advanced Oxidation Processes (AOPs): this broad term considers all chemical and physical technologies that create strong hydroxyl-radicals. Examples of AOPs include Fenton’s oxidation, ozonation, ultraviolet/hydrogen peroxide (UV-H2O2), and others. The radicals produced are rapid and highly reactive at breaking down recalcitrant compounds. Although effective at removing many complex compounds such as those evaluated in this study, AOPs does not typically have as many installations as membranes and activated carbon technologies. As a result, AOPs were not carried forward. Based on the technical literature review discussed above, a summary of estimated contaminant removal rated by unit treatment process is presented in Table 4. Table 4. Contaminants Removal Breakdown by Unit Process Unit Process Arsenic BAP Mercury Biphenyls Activated Sludge Short SRT No removal Partial Removal by partitioning 80% removal; effluent <0.88 ng/L Activated Sludge Long SRT No removal Partial removal by partitioning and/or partially biodegradation; MBR could potentially remove most of BAP >90% removal with a membrane bioreactor, <0.04 ng/L (includes membrane filtration) Membrane Filtration (MF) More than 90 % removal (rejection of bound arsenic) No removal <1.3 ng/L >90% removal with a membrane bioreactor, <0.04 ng/L (includes membrane filtration) Reverse Osmosis (RO) More than 90% removal (rejection of bound arsenic and removal of soluble arsenic) More than 98% removal Granular Activated Carbon (GAC) No removal, removal only when carbon is impregnated with iron 90 % removal <300 ng/L (precipitation and carbon adsorption) <51 ng/L (GAC) <800 ng/L Likely requires upstream filtration Disinfection 4.4 Unit Processes Selected The key conclusion from the literature review was that there is limited, to no evidence, that existing treatment technologies are capable of simultaneously meeting all four of the revised discharge limits for the toxics under consideration. Advanced treatment using RO or GAC is expected to provide the best overall removal of the constituents of concern. It is unclear whether these advanced technologies are able to meet revised effluent limits, however these processes may achieve the best effluent quality of the technologies reviewed. This limitation in the findings is based on a lack of an extensive dataset on treatment removal effectiveness in the technical literature for the constituents of interest at the low levels relevant to the proposed criteria, which ---PAGE BREAK--- 22 Association of Washington Business 213512 Treatment Technology Review and Assessment approach the limits of reliable removal performance for the technologies. As Table 4 highlights, certain unit processes are capable of removing a portion, or all, of the removal requirements for each technology. The removal performance for each constituent will vary from facility to facility and require a site-specific, detailed evaluation because the proposed criteria are such low concentrations. In some cases, a facility may only have elevated concentrations of a single constituent of concern identified in this study. In other cases, a discharger may have elevated concentrations of the four constituents identified in this study, as well as others not identified in this study but subject to revised water quality criteria. This effort is intended to describe a planning level concept of what treatment processes are required to comply with discharge limits for all four constituents. Based on the literature review of unit processes above, two different treatment trains were developed for the analysis that are compared against a baseline of secondary treatment as follows: Baseline: represents conventional secondary treatment that is most commonly employed nationwide at wastewater treatment plants. A distinguishing feature for this treatment is the short solids residence time (SRT) days) is intended for removal of BOD with minimal removal for the toxic constituents of concern. Advanced Treatment – MF/RO: builds on baseline with the implementation of a longer SRT days) and the addition of MF and RO. The longer SRT not only removes BOD, but it also has the capacity to remove nutrients and a portion of the constituents of concern. This alternative requires a RO brine management strategy which will be discussed in sub-sections below. Advanced Treatment – MF/GAC: this alternative provides a different approach to advanced treatment with MF/RO by using GAC and avoiding the RO reject brine water management concern. Similar to the MF/RO process, this alternative has the longer SRT days) with the capacity to remove BOD, nutrients, and a portion of the toxic constituents of concern. As a result, the decision was made to develop costs for both advanced treatment options. A description of each alternative is provided in Table 5. The process flowsheets for each alternative are presented in Figure 3 to Figure 5. 4.4.1 Baseline Treatment Process A flowsheet of the baseline treatment process is provided in Figure 3. The baseline treatment process assumes the current method of treatment commonly employed by dischargers. For this process, water enters the headworks and undergoes primary treatment, followed by conventional activated sludge (short SRT) and disinfection. The solids wasted in the activated sludge process are thickened, followed by mixing with primary solids prior to entering the anaerobic digestion process for solids stabilization. The digested biosolids are dewatered to produce a cake and hauled off-site. Since the exact process for each interested facility in Washington is unique, this baseline treatment process was used to establish the baseline capital and O&M costs. The baseline costs will be compared against the advanced treatment alternatives to illustrate the magnitude of the increased costs and environmental impacts. ---PAGE BREAK--- Association of Washington Business 23 Treatment Technology Review and Assessment 213512 Table 5. Unit Processes Description for Each Alternative Unit Process Baseline Advanced Treatment – MF/RO Advanced Treatment - GAC Influent Flow 5 mgd 5 mgd 5 mgd Chemically Enhanced Primary Treatment (CEPT); Optional Metal salt addition (alum) upstream of primaries Metal salt addition (alum) upstream of primaries Activated Sludge Hydraulic Residence Time (HRT): 6 hrs Short Solids Residence Time (SRT): <8 days Hydraulic Residence Time (HRT): 12 hrs (Requires more tankage than the Baseline) Long Solids Residence Time (SRT): >8 days (Requires more tankage than the Baseline) Hydraulic Residence Time (HRT): 12 hrs (Requires more tankage than the Baseline) Long Solids Residence Time (SRT): >8 days (Requires more tankage than the Baseline) Secondary Clarifiers Hydraulically Limited Solids Loading Limited (Larger clarifiers than Baseline) Solids Loading Limited (Larger clarifiers than Baseline) Microfiltration (MF) Membrane Filtration to Remove Particles and Bacteria Membrane Filtration to Remove Particles and Bacteria Reverse Osmosis (RO) Treat 50% of the Flow by RO to Remove Metals and Dissolved Constituents. Sending a portion of flow through the RO and blending it with the balance of plant flows ensures a stable non-corrosive, non-toxic discharge. Reverse Osmosis Brine Reject Mgmt Several Options (All Energy or Land Intensive) Granular Activated Carbon (GAC) Removes Dissolved Constituents Disinfection Not shown to remove any of the constituents Not shown to remove any of the constituents Not shown to remove any of the constituents ---PAGE BREAK--- 24 Association of Washington Business 213512 Treatment Technology Review and Assessment Figure 3. Baseline Flowsheet – Conventional Secondary Treatment WAS Primary Clarifiers Headworks Aeration Basins (Short SRT <2 days) Secondary Clarifiers RAS Primary Sludge Influent GBT Discharge CCT Centrate Centrifuge Anaerobic Digester Sodium Hypochlorite NaHSO3 Natural Gas to Cogeneration ---PAGE BREAK--- Association of Washington Business 25 Treatment Technology Review and Assessment 213512 4.4.2 Advanced Treatment – MF/RO Alternative A flowsheet of the advanced treatment – MF/RO alternative is provided in Figure 4. This alternative builds on the baseline secondary treatment facility, whereby the SRT is increased in the activated sludge process, and MF and RO are added prior to disinfection. The solids treatment train does not change with respect to the baseline. Additionally, a brine management strategy must be considered. The RO process concentrates contaminants into a smaller volume reject stream. Disposing of the RO reject stream can be a problem because of the potentially large volume of water involved and the concentration of contaminants contained in the brine. For reference, a 5 mgd process wastewater flow might result in 1 mgd of brine reject requiring further management. The primary treatment/handling options for RO reject are as follows: Zero liquid discharge Surface water discharge Ocean discharge Haul and discharge to coastal location for ocean discharge Sewer discharge Deep well injection Evaporate in a pond Solar pond concentrator Many of the RO brine reject management options above result in returning the dissolved solids to a “water of the state” such as surface water, groundwater, or marine waters. Past rulings in Washington State have indicated that once pollutants are removed from during treatment they are not to be re-introduced to a water of the state. As a result, technologies with this means for disposal were not considered viable options for management of RO reject water in Washington. Zero Liquid Discharge Zero liquid discharge (ZLD) is a treatment process that produces a little or no liquid brine discharge but rather a dried residual salt material. This process improves the water recovery of the RO system by reducing the volume of brine that must be treated and disposed of in some manner. ZLD options include intermediate treatment, thermal-based technologies, pressure driven membrane technologies, electric potential driven membrane technologies, and other alternative technologies. Summary There are many techniques which can be used to manage reject brine water associated with RO treatment. The appropriate alternative is primarily governed by geographic and local constraints. A comparison of the various brine management methods and potential costs are provided in Table 6. Of the listed options, ZLD was considered for this analysis as the most viable approach to RO reject water management. An evaporation pond was used following ZLD. The strength in this combination is ZLD reduces the brine reject volume to treat, which in turn reduces the required evaporation pond footprint. The disadvantage is that evaporation ponds require a substantial amount of physical space which may not be available at existing treatment plant sites. It is also important to recognize that the greenhouse gas (GHG) emissions vary widely for the eight brine management options listed above based on energy and chemical intensity. ---PAGE BREAK--- 26 Association of Washington Business 213512 Treatment Technology Review and Assessment ---PAGE BREAK--- Association of Washington Business 27 Treatment Technology Review and Assessment 213512 Table 6. Brine Disposal Method Relative Cost Comparison Disposal Method Description Relative Capital Cost Relative O&M Cost Comments Zero Liquid Discharge (ZLD) Further concentrates brine reject for further processing High High This option is preferred as an intermediate step. This rationale is based on the reduction in volume to handle following ZLD. For example, RO reject stream volume is reduced on the order of 50-90%. Surface Water Discharge Brine discharge directly to surface water. Requires an NPDES permit. Lowest Lowest Both capital and O&M costs heavily dependent on the distance from brine generation point to discharge. Not an option for nutrient removal. Ocean Discharge Discharge through a deep ocean outfall. Medium Low Capital cost depends on location and availability of existing deep water outfall. Sewer Discharge Discharge to an existing sewer pipeline for treatment at a wastewater treatment plant. Low Low Both capital and O&M costs heavily dependent on the brine generation point to discharge distance. Higher cost than surface water discharge due to ongoing sewer connection charge. Not an option for wastewater treatment. Deep Well Injection Brine is pumped underground to an area that is isolated from drinking water aquifers. Medium Medium Technically sophisticated discharge and monitoring wells required. O&M cost highly variable based on injection pumping energy. Evaporation Ponds Large, lined ponds are filled with brine. The water evaporates and a concentrated salt remains. Low – High Low Capital cost highly dependent on the amount and cost of land. Salinity Gradient Solar Ponds (SGSP) harness solar power from pond to power an evaporative unit. Low – High Lowest Same as evaporation ponds plus added cost of heat exchanger and pumps. Lower O&M cost due to electricity production. Advanced Thermal Evaporation Requires a two-step process consisting of a brine concentrator followed by High Highest Extremely small footprint, but the energy from H2O removal is by far the most energy intensive unless waste heat is used. ---PAGE BREAK--- 28 Association of Washington Business 213512 Treatment Technology Review and Assessment Figure 4. Advanced Treatment Flowsheet – Tertiary Microfiltration and Reverse Osmosis ---PAGE BREAK--- Association of Washington Business 29 Treatment Technology Review and Assessment 213512 4.4.3 Advanced Treatment – MF/GAC Alternative A flowsheet of the advanced treatment – MF/GAC alternative is provided in Figure 5. Following the MF technology, a GAC contactor and media are required. This alternative was developed as an option that does not require a brine management technology ZLD) for comparison to the MF/RO advanced treatment alternative. However, this treatment alternative does require that the GAC be regenerated. A baseline secondary treatment facility can be retrofitted for MF/GAC. If an existing treatment facility has an extended aeration lagoon, the secondary effluent can be fed to the MF/GAC. The longer SRT in the extended aeration lagoon provides all the benefits associated with the long SRT in an activated sludge plant as previously stated: Lower BOD/TSS discharge load Higher removal of recalcitrant constituents and heavy metals Improved water quality and benefit to users Less algal growth Reduced receiving water dissolved oxygen demand due to ammonia removal Reduced ammonia discharge loads, which is toxic to several aquatic species Improved water quality for habitat, especially as it relates to biodiversity and eutrophication Secondary clarifier effluent more conditioned for filtration and disinfection Greater process stability from the anaerobic/anoxic zones serving as a selector If an existing treatment facility employs a high rate activated sludge process (short SRT) similar to the baseline, it is recommended that the activated sludge process SRT be increased prior to the MF/GAC unit processes. The longer SRT upstream of the MF is preferred to enhance the membrane flux rate, reduce membrane biofouling, increase membrane life, and reduce the chemicals needed for membrane cleaning. The key technical and operational challenges associated with the tertiary add-on membrane filtration units are as follows: The membrane filtration technology is a proven and reliable technology. With over 30 years of experience, it has made the transition in recent years from an emerging technology to a proven and reliable technology. Membrane durability dependent on feed water quality. The water quality is individual facility specific. Membranes are sensitive to particles, so upstream screening is critical. The newer generations of membranes have technical specifications that require a particular screen size. Membrane area requirements based on peak flows as water must pass through the membrane pores. Additionally, membranes struggle with variable hydraulic loading. Flow equalization upstream can greatly reduce the required membrane surface area and provide uniform membrane loading. ---PAGE BREAK--- 30 Association of Washington Business 213512 Treatment Technology Review and Assessment Membrane tanks can exacerbate any foam related issues from the upstream biological process. Foam entrapment in the membrane tank from the upstream process can reduce membrane filtration capacity and in turn result in a plant-wide foam problem. Reliable access to the membrane modules is key to operation and maintenance. Once PLC is functionary properly, overall maintenance requirements for sustained operation of the system are relatively modest. The membranes go through frequent membrane relaxing or back pulse and a periodic deep chemical clean in place (CIP) process. Sizing of membrane filtration facilities governed by hydraulic flux. Municipal wastewaters have flux values that range from about 20 to 40 gallons per square foot per day (gfd) under average annual conditions. The flux associated with industrial applications is wastewater specific. Following the MF is the activated carbon facilities. There are two kinds of activated carbon used in treating water: powdered activated carbon (PAC) and GAC. PAC is finely-ground, loose carbon that is added to water, mixed for a short period of time, and removed. GAC is larger than PAC, is generally used in beds or tanks that permit higher adsorption and easier process control than PAC allows, and is replaced periodically. PAC is not selective, and therefore, will adsorb all active organic substances making it an impractical solution for a wastewater treatment plant. As a result, GAC was considered for this analysis. The type of GAC bituminous and subbituminous coal, wood, walnut shells, lignite or peat), gradation, and adsorption capacity are determined by the size of the largest molecule/ contaminant that is being filtered (AWWA, 1990). As water flows through the carbon bed, contaminants are captured by the surfaces of the pores until the carbon is no longer able to adsorb new molecules. The concentration of the contaminant in the treated effluent starts to increase. Once the contaminant concentration in the treated water reaches an unacceptable level (called the breakthrough concentration), the carbon is considered "spent" and must be replaced by virgin or reactivated GAC. The capacity of spent GAC can be restored by thermal reactivation. Some systems have the ability to regenerate GAC on-site, but in general, small systems haul away the spent GAC for off-site regeneration (EPA 1993). For this study, off-site regeneration was assumed. The basic facilities and their potential unit processes included in this chapter are as follows: GAC supply and delivery Influent pumping o Low head feed pumping o High head feed pumping (assumed for this study as we have low limits so require high beds) Contactors and backwash facilities o Custom gravity GAC contactor o Pre-engineered pressure GAC contactor (Used for this study) o Backwash pumping GAC transport facilities o Slurry pumps o Eductors (Used for this study) ---PAGE BREAK--- Association of Washington Business 31 Treatment Technology Review and Assessment 213512 Storage facilities o Steel tanks o Concrete tanks (Used for this study; larger plants would typically select concrete tanks) Spent carbon regeneration o On-site GAC regeneration o Off-Site GAC regeneration Following the MF is the GAC facility. The GAC contactor provides about a 12-min hydraulic residence time for average annual conditions. The GAC media must be regenerated about twice per year in a furnace. The constituents sorbed to the GAC media are removed during the regeneration process. A typical design has full redundancy and additional storage tankage for spent and virgin GAC. Facilities that use GAC need to decide whether they will regenerate GAC on-site or off-site. Due to challenges associated with receiving air emission permits for new furnaces, it was assumed that off-site regeneration would be evaluated. The key technical and operational challenges associated with the tertiary add-on GAC units are as follows: Nearest vendor to acquire virgin GAC – How frequently can they deliver virgin GAC and what are the hauling costs? Contactor selection is typically based on unit cost and flow variation. The concrete contactor is typically more cost effective at higher flows so it was used for this evaluation. The pre-engineered pressure contactor can handle a wider range of flows than a concrete contactor. Additionally, a pressure system requires little maintenance as they are essentially automated Periodical contactor backwashing is critical for maintaining the desired hydraulics and control biological growth Eductors are preferred over slurry pumps because they have fewer mechanical components. Additionally, the pump with eductors is not in contact with the carbon, which reduces wear. Off-site GAC regeneration seems more likely due to the challenges with obtaining an air emissions permit. ---PAGE BREAK--- 32 Association of Washington Business 213512 Treatment Technology Review and Assessment Figure 5. Advanced Treatment Flowsheet – Tertiary Microfiltration and Granular Activated Carbon ---PAGE BREAK--- Association of Washington Business 33 Treatment Technology Review and Assessment 213512 4.5 Steady-State Mass Balance HDR used its steady-state mass balance program to calculate the flows and loads within the candidate advanced treatment processes as a means to size facilities. The design of wastewater treatment facilities are generally governed by steady-state mass balances. For a steady-state mass balance, the conservation of mass is calculated throughout the entire wastewater treatment facility for defined inputs. Dynamic mass balance programs exist for designing wastewater facilities, but for a planning level study such as this, a steady state mass balance program is adequate. A dynamic program is generally used for detailed design and is site-specific with associated requirements for more detailed wastewater characterization. The set of model equations used to perform a steady-state mass balance are referred to as the model. The model equations provide a mathematical description of various wastewater treatment processes, such as an activated sludge process, that can be used to predict unit performance. The program relies on equations for each unit process to determine the flow, load, and concentration entering and leaving each unit process. An example of how the model calculates the flow, load, and concentration for primary clarifiers is provided below. The steady-state mass balance equation for primary clarifiers has a single input and two outputs as shown in the simplified Figure 6. The primary clarifier feed can exit the primary clarifiers as either effluent or sludge. Solids not removed across the primaries leave as primary effluent, whereas solids captured leave as primary sludge. Scum is not accounted for. Figure 6. Primary Clarifier Inputs/Outputs The mass balance calculation requires the following input: Solids removal percentage across the primaries (based on average industry accepted performance) Primary solids thickness percent solids) (based on average industry accepted performance) The steady-state mass balance program provides a reasonable first estimate for the process performance, and an accurate measure of the flows and mass balances at various points throughout the plant. The mass balance results were used for sizing the facility needs for each alternative. A listing of the unit process sizing criterion for each unit process is provided in Appendix A. By listing the unit process sizing criteria, a third-party user could redo the analysis and end up with comparable results. The key sizing criteria that differ between the baseline and treatment alternatives are as follows: Aeration basin mixed liquor is greater for the advanced treatment alternatives which in turn requires a larger volume The secondary clarifiers are sized based on hydraulic loading for the baseline versus solids loading for the advanced treatment alternatives Primary Influent Primary Effluent Primary Sludge ---PAGE BREAK--- 34 Association of Washington Business 213512 Treatment Technology Review and Assessment The MF/GAC and MF/RO sizing is only required for the respective advanced treatment alternatives. 4.6 Adverse Environmental Impacts Associated with Advanced Treatment Technologies The transition from the baseline (conventional secondary treatment) to either advanced treatment alternatives has some environmental impacts that merit consideration, including the following: Land area for additional system components (which for constrained facility sites, may necessitate land acquisition and encroachment into neighboring properties with associated issues and challenges, etc.). Increased energy use and atmospheric emissions of greenhouse gases and criteria air contaminants associated with power generation to meet new pumping requirements across the membrane filter systems (MF and RO) and GAC. Increased chemical demand associated with membrane filters (MF and RO). Energy and atmospheric emissions associated with granulated charcoal regeneration. RO brine reject disposal. The zero liquid discharge systems are energy intensive energy and increase atmospheric emissions as a consequence of the electrical power generation required for removing water content from brine reject. Increase in sludge generation while transitioning from the baseline to the advanced treatment alternatives. There will be additional sludge captured with the chemical addition to the primaries and membrane filters (MF and RO). Additionally, the GAC units will capture more solids. Benefits to receiving water quality by transitioning from a short SRT days) in the baseline to a long SRT days) for the advanced treatment alternatives (as previously stated): o Lower BOD/TSS discharge load o Higher removal of recalcitrant constituents and heavy metals o Improved water quality and benefit to users o Reduced nutrient loadings to receiving waters and lower algal growth potential o Reduced receiving water dissolved oxygen demand due to ammonia removal o Reduced ammonia discharge loads, which is toxic to aquatic species o Improved water quality for habitat, especially as it relates to biodiversity and eutrophication o Secondary clarifier effluent better conditioned for subsequent filtration and disinfection o Greater process stability from the anaerobic/anoxic zones serving as a biological selectors HDR calculated GHG emissions for the baseline and advanced treatment alternatives. The use of GHG emissions is a tool to normalize the role of energy, chemicals, biosolids hauling, and fugitive emissions methane) in a single unit. The mass balance results were used to quantify energy demand and the corresponding GHG emissions for each alterative. Energy ---PAGE BREAK--- Association of Washington Business 35 Treatment Technology Review and Assessment 213512 demand was estimated from preliminary process calculations. A listing of the energy demand for each process stream, the daily energy demand, and the unit energy demand is provided in Table 7. The advanced treatment options range from 2.3 to 4.1 times greater than the baseline. This large increase in energy demand is attributed to the energy required to pass water through the membrane barriers and/or the granular activated carbon. Additionally, there is energy required to handle the constituents removed as either regenerating the GAC or handling the RO brine reject water. This additional energy required to treat the removed constituents is presented in Table 7. Table 7. Energy Breakdown for Each Alternative (5 mgd design flow) Parameter Units Baseline Advanced Treatment – MF/GAC Advanced Treatment – MF/RO Daily Liquid Stream Energy Demand MWh/d 11.6 23.8 40.8 Daily Solids Stream Energy Demand MWh/d -1.6 -1.1 -1.1 Daily Energy Demand MWh/d 10.0 22.7 39.7 Unit Energy Demand kWh/MG Treated 2,000 4,500 7,900 MWh/d = megawatt hours per day kWh/MG = kilowatt hours per million gallons Details on the assumptions used to convert between energy demand, chemical demand and production, as well as biologically-mediated gases CH4 and N2O) and GHG emissions are provided in Appendix B. A plot of the GHG emissions for each alternative is shown in Figure 7. The GHG emissions increase from the baseline to the two advanced treatment alternatives. The GHG emissions increase about 50 percent with respect to baseline when MF/GAC is used and the GHG emissions increase over 100 percent with respect to baseline with the MF/RO advanced treatment alternative. The MF/GAC energy demand would be larger if GAC regeneration was performed on-site. The GHG emissions do not include the energy or air emissions that result from off-site GAC regeneration. Only the hauling associated with moving spent GAC is included. The energy associated with operating the furnace would exceed the GHG emissions from hauling spent GAC. The zero liquid discharge in the MF/RO alternative alone is comparable to the Baseline. This contribution to increased GHG emissions by zero liquid discharge brine system highlights the importance of the challenges associated with managing brine reject. ---PAGE BREAK--- 36 Association of Washington Business 213512 Treatment Technology Review and Assessment Figure 7. Greenhouse Gas Emissions for Each Alternative The use of GHG emissions as a measure of sustainability does not constitute a complete comparison between the baseline and advanced treatment alternatives. Rather, it is one metric that captures the impacts of energy, chemical demand and production, as well as biologically- mediated gases CH4 and N2O). The other environmental impacts of advanced treatment summarized in the list above should also be considered in decision making beyond cost analysis. 4.7 Costs Total project costs along with the operations and maintenance costs were developed for each advanced treatment alternative for a comparison with baseline secondary treatment. 4.7.1 Approach The cost estimates presented in this report are planning level opinions of probable construction costs for a nominal 5 mgd treatment plant design flow representing a typical facility without site specific details about local wastewater characteristics, physical site constraints, existing infrastructure, etc. The cost estimates are based on wastewater industry cost references, technical studies, actual project cost histories, and professional experience. The costs presented in this report are considered planning level estimates. A more detailed development of the advanced treatment process alternatives and site specific information would be required to further refine the cost estimates. Commonly this is accomplished in the preliminary design phase of project development for specific facilities following planning. The cost opinion includes a range of costs associated with the level of detail used in this analysis. Cost opinions based on preliminary engineering can be expected to follow the Association for the Advancement of Cost Engineering (AACE International) Recommended Practice No. 17R-97 Cost Estimate Classification System estimate Class 4. A Class 4 estimate is based upon a 5 to 10 percent project definition and has an expected accuracy range of -30 to +50 percent and typical end usage of budget authorization and cost control. It is considered an -2,000 -1,000 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 CO2 equivalent mt/yr N2O Emissions Hauling Biosolids and GAC Zero Liquid Discharge Aeration Chemicals Pumping/ Mixing/ Heating Miscellaneous Cogeneration ---PAGE BREAK--- Association of Washington Business 37 Treatment Technology Review and Assessment 213512 “order-of-magnitude estimate.” The life-cycle costs were prepared using the net present value (NPV) method. The cost associated for each new unit process is based on a unit variable, such as required footprint, volume, demand lb O2/hr), and others. This approach is consistent with the approach developed for the EPA document titled “Estimating Water Treatment Costs: Volume 2- Cost Curves Applicable to 1 to 200 mgd Treatment Plants” dated August 1979. The approach has been updated since 1979 to account for inflation and competition, but the philosophy for estimating costs for unit processes has not changed. For example, the aeration system sizing/cost is governed by the maximum month airflow demand. Additionally, the cost associated constructing an aeration basin is based on the volume. The cost considers economies of scale. The O&M cost estimates were calculated from preliminary process calculations. The operations cost includes energy and chemical demand. For example, a chemical dose was assumed based on industry accepted dosing rates and the corresponding annual chemical cost for that particular chemical was accounted for. The maintenance values only considered replacement equipment, specifically membrane replacement for the Advanced Treatment Alternatives. 4.7.2 Unit Cost Values The life-cycle cost evaluation was based on using the economic assumptions shown in Table 8. The chemical costs were based on actual values from other projects. To perform detailed cost evaluations per industry, each selected technology would need to be laid out on their respective site plan based on the location of the existing piping, channels, and other necessary facilities. Table 8. Economic Evaluation Variables Item Value Nominal Discount Rate 5% Inflation Rate: General 3.5% Labor 3.5% Energy 3.5% Chemical 3.5% Base Year 2013 Project Life 25 years Energy $0.06/kWh Natural Gas $0.60/therm Chemicals: Alum $1.1/gal Polymer $1.5/gal Hypochlorite $1.5/gal Salt $0.125/lb Antiscalant $12.5/lb Acid $0.35/lb Deionized Water $3.75/1,000 gal Hauling: ---PAGE BREAK--- 38 Association of Washington Business 213512 Treatment Technology Review and Assessment Table 8. Economic Evaluation Variables Item Value Biosolids Hauling Distance 100 miles (one way) Biosolids Truck Volume 6,000 gal/truck Biosolids Truck Hauling $250/truck trip GAC Regeneration Hauling Distance 250 miles (round trip) GAC Regeneration Truck Volume $20,000 lb GAC/truck GAC Regeneration Truck Hauling Included in cost of Virgin GAC kWh= kilowatt hours; lbs=pounds; GAC=granulated activated carbon; gal=gallon 4.7.3 Net Present Value of Total Project Costs and Operations and Maintenance Cost in 2013 Dollars An estimate of the net present value for the baseline treatment process and the incremental cost to implement the advanced treatment alternatives is shown in Table 9. The cost for the existing baseline treatment process was estimated based on new construction for the entire conventional secondary treatment process (Figure The incremental cost to expand from existing baseline secondary treatment to advanced treatment was calculated by taking the difference between the baseline and the advanced treatment alternatives. These values serve as a benchmark for understanding the prospective cost for constructing advanced treatment at the planning level of process development. Table 9. Treatment Technology Total Project Costs in 2013 Dollars for a 5 mgd Facility Alternative Total Construction Cost, 2013 dollars Million) O&M Net Present Value, 2013 dollars Million)* Total Net Present Value, 2013 dollars Million) NPV Unit Cost, 2013 dollars ($/gpd) Baseline (Conventional Secondary Treatment)* 59 - 127 5 - 11 65 – 138 13 - 28 Advanced Treatment – MF/RO** 108 - 231 31 - 67 139 - 298 28 - 60 Advanced Treatment – MF/GAC 131 - 280 50 - 108 181 - 388 36 - 78 Incremental Increase to Advanced Treatment MF/RO 48 - 104 26 - 56 75 - 160 15 - 32 Incremental Increase to Advanced Treatment MF/GAC 71 - 153 45 - 97 117 - 250 23 - 50 * The additional cost to increase the SRT to upwards of 30-days is about $12 - 20 million additional dollars in total project cost for a 5 mgd design flow Assumes zero liquid discharge for RO brine management, followed by evaporation ponds. Other options are available as listed in Section 4.4.2. O&M=operations and maintenance; MF/RO=membrane filtration/reverse osmosis; MF/GAC=membrane filtration/granulated activated carbon; gpd=gallons per day ---PAGE BREAK--- Association of Washington Business 39 Treatment Technology Review and Assessment 213512 4.7.4 Unit Cost Assessment Costs presented above are based on a treatment capacity of 5.0 mgd, however, existing treatment facilities range dramatically across Washington in size and flow treated. Table 9 indicates that the unit capital cost for baseline conventional secondary treatment for 5.0 mgd ranges between $13 to 28 per gallon per day of treatment capacity. The unit cost for the advanced treatment alternatives increases the range from the low $20s to upper $70s on a per- gallon per-day of capacity. The increase in cost for the advanced treatment alternatives is discussed in the sub-sections below. Advanced Treatment MF/RO The advanced treatment MF/RO alternative has a total present worth unit cost range of $28 to $60 million in per gallon per day of capacity. This translates to an incremental cost increase with respect to the baseline of $15 to $32 million dollars in per gallon per day treatment capacity. The key differences in cost between the baseline and the advanced treatment MF/RO are as follows: Larger aeration basins than the baseline to account for the longer SRT days versus >8 days). Additional pumping stations to pass water through the membrane facilities (MF and RO). These are based on peak flows. Membrane facilities (MF and RO; equipment, tanks chemical feed facilities, pumping, etc.) and replacement membrane equipment. Additional energy and chemical demand to operate the membrane facilities (MF and RO) and GAC. Zero liquid discharge facilities to further concentrate the brine reject. Zero liquid discharge facilities are energy/chemically intensive and they require membrane replacement every few years due to the brine reject water quality. An evaporation pond to handle the brine reject that has undergone further concentration by zero liquid discharge. The advanced treatment MF/RO assumes that 100 percent of the flow is treated by MF, followed by 50 percent of the flow treated with RO. Sending a portion of flow through the RO and blending it with the balance of plant flows ensures a stable water to discharge. The RO brine reject (about 1.0 mgd) undergoes ZLD pre-treatment that further concentrates the brine reject to about 0.1-0.5 mgd. The recovery for both RO and ZLD processes is highly dependent on water quality silicate levels). ZLD technologies are effective at concentrating brine reject, but it comes at a substantial cost ($17.5 per gallon per day of ZLD treatment capacity of brine reject). The zero liquid discharge estimate was similar in approach to the demonstration study by Burbano and Brandhuber (2012) for La Junta, Colorado. The ability to further concentrate brine reject was critical from a management standpoint. Although 8 different options were presented for managing brine reject in Section 4.4.2, none of them is an attractive approach for handling brine reject. ZLD provides a viable pre-treatment step that requires subsequent treatment. Evaporation ponds following ZLD were used for this study. Without ZLD, the footprint would be 3-5 times greater. Roughly 30 acres of evaporation ponds, or more, may be required to handle the ZLD concentrate, depending upon concentrator effectiveness, local climate conditions, residuals ---PAGE BREAK--- 40 Association of Washington Business 213512 Treatment Technology Review and Assessment accumulation, residual removal, etc. Precipitation throughout Washington is highly variable which can greatly influence evaporation pond footprint. The approach for costing the evaporation pond was in accordance with Mickley et al. (2006) and the cost was about $2.6 million. Recent discussions with an industry installing evaporation ponds revealed that they will use mechanical evaporators to enhance evaporation rates. The use of mechanical evaporators was not included in this study, but merits consideration if a facility is performing a preliminary design that involves evaporation ponds. The mechanical evaporators have both a capital costs and annual energy costs. Advanced Treatment MF/GAC The advanced treatment MF/GAC alternative has a total present worth unit cost range of $36 to $78 million in per gallon per day capacity. This translates to an incremental cost increase with respect to the baseline of $23 to $50 million dollars on a per gallon per day of treatment capacity basis. The key differences in cost between the baseline and the advanced treatment MF/GAC are as follows: Larger aeration basins than the baseline to account for the longer SRT days versus >8 days). Additional pumping stations to pass water through the MF membrane and GAC facilities. These are based on peak flows. GAC facilities (equipment, contact tanks, pumping, GAC media, etc.) Additional energy to feed and backwash the GAC facilities. GAC media replacement was the largest contributor of any of the costs. Additional hauling and fees to regenerate GAC off-site. The advanced treatment MF/GAC assumes that 100 percent of the flow is treated by MF, followed by 100 percent of the flow treated with GAC. The GAC technology is an established technology. The costing approach was in accordance with EPA guidelines developed in 1998. The critical issue while costing the GAC technology is whether a GAC vendor/regeneration facility is located within the region. On-site regeneration is an established technology with a furnace. However, there are several concerns as listed in Section 4.4.3: Ability to obtain an air emissions permit Additional equipment to operate and maintain Energy and air emissions to operate a furnace on-site Operational planning to ensure that furnace is operating 90-95 percent of the time. Otherwise, operations is constantly starting/stopping the furnace which is energy intensive and deleterious to equipment If not operated properly, the facility has the potential to create hazardous/toxic waste to be disposed If located within a couple hundred miles, off-site regeneration is preferred. For this study, off-site regeneration was assumed with a 250-mile (one-way) distance to the nearest vendor that can provide virgin GAC and a regeneration facility. ---PAGE BREAK--- Association of Washington Business 41 Treatment Technology Review and Assessment 213512 Incremental Treatment Cost The difference in costs between the baseline and the advanced treatment alternatives is listed in Table 10. The incremental cost to retrofit the baseline facility to the advanced treatment was calculated by taking the difference between the two alternatives. These values should serve as a planning level benchmark for understanding the potential cost for retrofitting a particular facility. The incremental cost is unique to a particular facility. Several reasons for the wide range in cost in retrofitting a baseline facility to advanced treatment are summarized as follows: Physical plant site constraints. A particular treatment technology may or may not fit within the constrained particular plant site. A more expensive technology solution that is more compact may be required. Alternately, land acquisition may be necessary to enlarge a plant site to allow the addition of advanced treatment facilities. An example of the former is stacking treatment processes vertically to account for footprint constraints. This is an additional financial burden that would not be captured in the incremental costs presented in Table 10. Yard piping. Site specific conditions may prevent the most efficient layout and piping arrangement for an individual facility. This could lead to additional piping and pumping to convey the wastewater through the plant. This is an additional financial burden that would not be captured in the incremental costs presented in Table 10. Pumping stations. Each facility has unique hydraulic challenges that might require additional pumping stations not captured in this planning level analysis. This is an additional financial burden that would not be captured in the incremental costs presented in Table 10. A cursory unit cost assessment was completed to evaluate how costs would compare for facilities with lower (0.5 mgd) and higher capacity (25 mgd), as presented in Table 10. Capital costs were also evaluated for a 0.5 mgd and 25 mgd facility using non-linear scaling equations with scaling exponents. The unit capital cost for baseline conventional secondary treatment for 0.5 mgd and 25 mgd is approximately $44 and $10 per gallon per day of treatment capacity, respectively. The incremental unit costs to implement an advanced treatment retrofit for 0.5 mgd would range between $30 to $96 per gallon per day of treatment capacity and would be site and discharger specific. The incremental unit costs to implement an advanced treatment retrofit for 25 mgd would range between $10 to 35 per gallon per day of treatment capacity and would be site and discharger specific. The larger flow, 25 mgd, is not as expensive on a per gallon per day of treatment capacity. This discrepancy for the 0.5 and 25 mgd cost per gallon per day of treatment capacity is attributed to economies of scale. Cost curve comparisons (potential total construction cost and total net present value) for the baseline and the two tertiary treatment options (MF/RO and MF/GAC) are shown in Figure 8 and Figure 9 between the flows of 0.5 and 25 mgd. It is important to note that while the economies of scale suggest lower incremental costs for the larger size facilities, some aspects of the advanced treatment processes may become infeasible at larger capacities due to factors such as physical space limitations and the large size requirements for components such as RO reject brine management. ---PAGE BREAK--- 42 Association of Washington Business 213512 Treatment Technology Review and Assessment Table 10. Treatment Technology Total Project Costs in 2013 Dollars for a 0.5 mgd Facility and a 25 mgd Facility Alternative Total Construction Cost, 2013 dollars Million) O&M Net Present Value, 2013 dollars Million)* Total Net Present Value, 2013 dollars Million) NPV Unit Cost, 2013 dollars ($/gpd) 0.5 mgd: Baseline (Conventional Secondary Treatment) 15 - 32 0.5 - 1.1 15 - 33 31 - 66 Advanced Treatment – MF/RO** 27 - 58 3.2 - 6.8 30 - 65 60 - 130 Advanced Treatment – MF/GAC 33 - 70 5 - 10.8 38 - 81 76 - 162 Incremental Increase to Advanced Treatment MF/RO 12 - 26 2.7 - 5.7 15 - 32 30 - 64 Incremental Increase to Advanced Treatment MF/GAC 18 - 38 4.6 - 9.8 22 - 48 45 - 96 25 mgd: Baseline (Conventional Secondary Treatment) 156 - 335 25 - 54 182 - 389 7 - 16 Advanced Treatment – MF/RO** 283 - 606 157 - 336 440 - 942 18 - 38 Advanced Treatment – MF/GAC 343 - 735 252 - 541 595 - 1276 24 - 51 Incremental Increase to Advanced Treatment MF/RO 127 - 272 131 - 281 258 - 553 10 - 22 Incremental Increase to Advanced Treatment MF/GAC 187 - 401 226.9 - 486 414 - 887 17 - 35 * Does not include the cost for labor. Assumes zero liquid discharge for RO brine management, followed by evaporation ponds. Other options are available as listed in Section 4.4.2. MF/RO=membrane filtration/reverse osmosis MF/GAC=membrane filtration/granulated activated carbon O&M=operations and maintenance gpd=gallons per day ---PAGE BREAK--- Association of Washington Business 43 Treatment Technology Review and Assessment 213512 Figure 8: Capital Cost Curve Comparison for Baseline Treatment, MF/RO, and MF/GAC Figure 9: NPV Cost Curve Comparison for Baseline Treatment, MF/RO, and MF/GAC 0 10 20 30 40 50 60 70 80 90 100 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 Capita Cost ($/gpd Treatment Capacity) Flow (mgd) Baseline Reverse Osmosis Granular Activated Carbon 0 20 40 60 80 100 120 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 Net Present Value Cost ($/gpd) Flow (mgd) Baseline Reverse Osmosis Granular Activated Carbon ---PAGE BREAK--- 44 Association of Washington Business 213512 Treatment Technology Review and Assessment 4.8 Pollutant Mass Removal An estimate of the projected load removal for the four constituents of concern was developed and is presented in Table 11. The current secondary effluent and advanced treatment effluent data is based on the only available data to HDR and is from municipal treatment plant facilities. Data is not available for advanced treatment facilities such as MF/RO or MF/GAC. Due to this lack of data, advanced treatment using MF/RO or MF/GAC was assumed to remove an additional zero to 90 percent of the constituents presented resulting in the range presented in Table 11. It is critical to note these estimates are based on limited data and are presented here simply for calculating mass removals. Current secondary effluent for industrial facilities would likely be greater than the data presented here and as a result, the projected effluent quality for industrial facilities would likely be higher as well. Based on the limited actual data from municipal treatment facilities, Table 11 indicates that mercury and BAP effluent limits may potentially be met using advanced treatment at facilities with similar existing secondary effluent quality. Table 11. Pollutant Mass Removal by Contaminant for a 5 mgd Facility Component PCBs Mercury Arsenic BAP Required based Effluent Quality (µg/L) 0.0000064 0.005 0.018 0.0013 Current Secondary Effluent Concentration (µg/L)* 0.0015 0.025 7.5 0.00031 Projected Effluent Quality (µg/L) from Advanced Treatment (MF/RO or MF/GAC)* 0.000041 – 0.00041 0.00012 – 0.0012 0.38 – 3.8 0.000029 - 0.00029 Mass Removed 21 - 28 451 - 471 71,000 – 135,000 0.4 – 5.0 Mass Removed 0.000045 – 0.000061 0.00099 – 0.0010 0.16 – 0.30 0.0000010 – 0.0000012 * Based on or estimated for actual treatment plant data from municipal facilities. Data sets are limited and current secondary effluent for industrial facilities would likely be greater than the data presented here. 1 lb = 454,000 mg health-based water quality criteria MF/RO=membrane filtration/reverse osmosis MF/GAC=membrane filtration/granulated activated carbon µg/L=micrograms per liter mg/d=milligrams per day lb/d=pounds per day Unit costs were developed based on required mass removal from a 5 mgd facility for each of the four constituents of concern to reduce discharges from current secondary effluent quality to the assumed required effluent quality It important to note that this study concludes it is unclear if existing technology can meet the required effluent quality, however, the information presented in Table 12 assumes would be met for developing unit costs. The unit costs are expressed as dollars in NPV (over a 25 year period) per pound of constituent removed over the same 25 year period using advanced treatment with MF/RO. The current secondary effluent quality data presented are based on typical secondary effluent quality expected for a municipal/industrial discharger. Table 12 suggests unit costs are most significant in meeting the PCB, mercury, and PAH required effluent quality. ---PAGE BREAK--- Association of Washington Business 45 Treatment Technology Review and Assessment 213512 Table 12. Unit Cost by Contaminant for a 5 mgd Facility Implementing Advanced Treatment using MF/RO Component PCBs Mercury Arsenic PAHs Required based Effluent Quality (µg/L) 0.0000064 0.005 0.018 0.0013 Current Secondary Effluent Concentration (µg/L)* 0.002 0.025 7.5 0.006 Total Mass Removed (lbs) over 25-year Period 0.76 7.6 2,800 1.8 Unit Cost (NPV per total mass removed in pounds over 25 years) $290,000,000 $29,000,000 $77,000 $120,000,000 *Derived from data presented in Table 3. **Based on assumed 25-year NPV of $219,000,000 (average of the range presented in Table 10) and advanced treatment using MF/RO. NPV=net present value health-based water quality criteria µg/l=micrograms per liter 4.9 Sensitivity Analysis The ability of dischargers to meet a one order of magnitude less stringent (than presented in Table 3 and used in this report) was considered. The same advanced treatment technologies using MF/RO or MF/GAC would still be applied to meet revised effluent quality one order-of-magnitude less stringent despite still not being able to meet less stringent effluent limits. As a result, this less stringent effluent quality would not impact costs. Based on available data, it appears the mercury and BAP limits would be met at a less stringent PCB effluent quality could potentially be met if advanced treatment with RO or GAC performed at the upper range of their projected treatment efficiency. It does not appear the less stringent arsenic would be met with advanced treatment. It is important to note that a discharger’s ability to meet these less stringent limits depends on existing secondary effluent characteristics and is facility specific. Facilities with higher secondary effluent constituent concentrations will have greater difficulty meeting ---PAGE BREAK--- 46 Association of Washington Business 213512 Treatment Technology Review and Assessment 5.0 Summary and Conclusions This study evaluated treatment technologies potentially capable of meeting revised effluent discharge limits associated with revised HDR completed a literature review of potential technologies and engineering review of their capabilities to evaluate and screen treatment methods for meeting revised effluent limits for four constituents of concern: arsenic, BAP, mercury, and PCBs. HDR selected two alternatives to compare against a baseline, including enhanced secondary treatment, enhanced secondary treatment with MF/RO, and enhanced secondary treatment with MF/GAC. HDR developed capital costs, operating costs, and a NPV for each alternative, including the incremental cost to implement from an existing secondary treatment facility. The following conclusions can be made from this study. Revised based on state of Oregon (2001) and EPA “National Recommended Water Quality Criteria” will result in very low water quality criteria for toxic constituents. There are limited “proven” technologies available for dischargers to meet required effluent quality limits that would be derived from revised o Current secondary wastewater treatment facilities provide high degrees of removal for toxic constituents; however, they will not be capable of compliance with water quality-based NPDES permit effluent limits derived from revised o Advanced treatment technologies have been investigated and candidate process trains have been conceptualized for toxics removal. Advanced wastewater treatment technologies may enhance toxics removal rates, however they will not be capable of compliance with based effluent limits for PCBs. The lowest levels achieved based on the literature review were between <0.00001 and 0.00004 µg/L, as compared to a of 0.0000064 µg/L. Based on very limited performance data for arsenic and mercury from advanced treatment information available in the technical literature, compliance with revised criteria may or may not be possible, depending upon site specific circumstances. Compliance with a for arsenic of 0.018 µg/L appears unlikely. Most treatment technology performance information available in the literature is based on drinking water treatment applications targeting a much higher SDWA MCL of 10 µg/L. Compliance with a for mercury of 0.005 µg/L appears to be potentially attainable on an average basis but perhaps not if effluent limits are structured on a maximum weekly or daily basis. Some secondary treatment facilities attain average effluent mercury levels of 0.009 to 0.066 µg/L. Some treatment facilities with effluent filters attain average effluent mercury levels of 0.002 to 0.010 µg/L. Additional advanced treatment processes are expected to enhance these removal rates, but little mercury performance data is available for a definitive assessment. Little information is available to assess the potential for advanced technologies to comply with revised benzo(a)pyrene criteria. A municipal wastewater treatment plant study reported both influent and effluent BAP concentrations less than the of 0.0013 ug/L (Ecology, 2010). ---PAGE BREAK--- Association of Washington Business 47 Treatment Technology Review and Assessment 213512 o Some technologies may be effective at treating identified constituents of concern to meet revised limits while others may not. It is therefore even more challenging to identify a technology that can meet all constituent limits simultaneously. o A that is one order-of-magnitude less stringent could likely be met for mercury and PAHs however it appears PCB and arsenic limits would not be met. Advanced treatment processes incur significant capital and operating costs. o Advanced treatment process to remove additional arsenic, benzo(a)pyrene, mercury, and PCBs would combine enhancements to secondary treatment with microfiltration membranes, reverse osmosis, and granular activated carbon and increase the estimated capital cost of treatment from $17 to $29 in dollars per gallon per day of capacity (based on a 5.0 mgd facility). o The annual operation and maintenance costs for the advanced treatment process train will be substantially higher (approximately $5 million - $15 million increase for a 5.0 mgd capacity facility) than the current secondary treatment level. Implementation of additional treatment will result in additional collateral impacts. o High energy consumption. o Increased greenhouse gas emissions. o Increase in solids production from chemical addition to the primaries. Additionally, the membrane and GAC facilities will capture more solids that require handling. o Increased physical space requirements at treatment plant sites for advanced treatment facilities and residuals management including reverse osmosis reject brine processing. It appears advanced treatment technology alone cannot meet all revised water quality limits and implementation tools are necessary for discharger compliance. o Implementation flexibility will be necessary to reconcile the difference between the capabilities of treatment processes and the potential for driven water quality based effluent limits to be lower than attainable with technology ---PAGE BREAK--- 48 Association of Washington Business 213512 Treatment Technology Review and Assessment 6.0 References Ahn, Kim, S, Park, Rahm, Pagilla, Chandran, K. 2010. N2O emissions from activated sludge processes, 2008-2009: Results of a national surveying program in the United States. Environ. Sci. Technol., 44(12):4505-4511. Andrianisa, Ito, Sasaki, Aizawa, and Umita, T. 2008. Biotransformation of arsenic species by activated sludge and removal of bio-oxidised arsenate from wastewater by coagulation with ferric chloride. Water Research, 42(19), pp. 4809-4817 Andrianisa, Ito, Sasaki, Ikeda, Aizawa, and Umita, T. 2006. Behaviour of arsenic species in batch activated sludge process: biotransformation and removal. Water Science and Technology, 54(8), pp. 121-128. Burbano, A and Brandhuber, P. (2012) Demonstration of membrane zero liquid discharge for drinking water systems. Water Environment Research Federation (WERF) Report WERF5T10. California Air Resources Board, ICLEI, California Climate Action Registry, The Climate Registry. 2008. Local Government Operations Protocol. For the quantification and reporting of greenhouse gas emissions inventories, Version 1.1. Chung, Cho, Song, and Park, B. Degradation of naturally contaminated aromatic hydrocarbons in municipal sewage sludge by electron beam irradiation. Bulletin of Environmental Contamination and Toxicology, 81(1), pp. 7-11. CRITFC (Columbia River Inter-Tribal Fish Commission). 1994. A fish consumption survey of the Umatilla, Nez Perce, Yakama and Warm Springs Tribes of the Columbia River Basin. Columbia River Inter-Tribal Fish Commission Report reference #94-03, Portland, Oregon. Eckenfelder, W.W., Industrial Water Pollution Control, 2nd ed. (New York: McGraw-Hill, 1989). Ecology. 2010. (Lubliner, M. Redding, and D. Ragsdale). Pharmaceuticals and Personal Care Products in Municipal Wastewater and Their Removal by Nutrient Treatment Technologies. Washington State Department of Ecology, Olympia, WA. Publication Number 10-03-004. González, Ruiz, L.M., Garralón, Plaza, Arévalo, Parada, Péreza, Morenoa, and Ángel Gómez, M. 2012. Wastewater aromatic hydrocarbons removal by membrane bioreactor. Desalination and Water Treatment, 42, pp. 94–99 Grosser, J. 2010. The Challenge: Measure Arsenic in Drinking Water. White paper. Haapeaa, and Tuhkanen, T. 2006. Integrated treatment of PAH contaminated soil by soil washing, ozonation and biological treatment . Journal of Hazardous Materials,136(21), pp. 244–250 Intergovernmental Panel on Climate Change. 2006. 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Prepared by the National Greenhouse Gas Inventories Programme, Eggleston, Buendia, Miwa, Ngara, Tanabe, K. (eds.) Published: IGES, Japan. LaGrega, M.D., Buckingham P.L. and Evans J.C., Hazardous Waste Management, 1st ed. (New York: McGraw-Hill, 1994). ---PAGE BREAK--- Association of Washington Business 49 Treatment Technology Review and Assessment 213512 Melcer, Steel, and Bedford, W.K. 1993. Removal of aromatic hydrocarbons and nitrogenous compounds by a POTW receiving industrial discharges. Proceeding of WEFTEC 1993. Mickley and Associates. 2006. Membrane Concentrate Disposal: Practices and Regulations. U.S. Department of the Interior, Bureau of Reclamation, Contract No. 98-FC-81-0054. National Council for Air and Stream Improvement, Inc. (NCASI). 1998. Technical and economic feasibility assessment of metals reduction in pulp and paper mill wastewaters. Technical Bulletin No. 756. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc., 1998. National Council for Air and Stream Improvement, Inc. (NCASI). 2004. Investigation of advanced techniques to remove low-level mercury from pulp and paper mill effluents. Technical Bulletin No. 870. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc. National Council for Air and Stream Improvement, Inc. (NCASI). 2000. Memorandum: Information on PCB Water Quality Criteria, Analytical Methods, and Measurement Results for Point Sources and Ambient Waters. Technical Bulletin No. 807. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc. National Council for Air and Stream Improvement, Inc. (NCASI). 2000. Bench scale testing of processes to reduce metals concentrations in pulp and paper mill wastewaters. Technical Bulletin No. 807. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc. Ning, R. 2002. Arsenic removal by reverse osmosis. Desalination, 143 pp. 237–241 Oleszczuk, Hale, S. Lehmann, and Cornelissen, G. 2012. Activated carbon and biochar amendments decrease pore-water concentrations of aromatic hydrocarbons (PAHs) in sewage sludge. Bioresource Technology, 111, pp. 84–91 Oregon Department of Environmental Quality. 2011. Table 40: Human Health Water Quality Criteria for Toxic Pollutants, Effective October 17, 2011. Available on-line at: http://www.deq.state.or.us/wq/standards/toxics.htm Owen, W.F. 1982. Energy in Wastewater Treatment. Prentice-Hall, Englewood Cliffs, New Jersey. Parker, Monteith, and Pileggi, V. 2009. Estimation of Biodegradation and Liquid-Solid Partitioning Coefficients for Complex PAHs in Wastewater Treatment. Proceedings of the Water Environment Federation 2009, pp. 2537-2554. Rodrigue, and Rielly, A. 2009. Effectiveness of a membrane bioreactor on weak domestic wastewater containing biphenyls. Proceedings of the Water Environment Federation, Microconstituents and Industrial Water Quality 2009, pp. 174-184(11) Russo, Rizzo, and Belgiorno, V. 2012. Ozone oxidation and aerobic biodegradation with spent mushroom compost for detoxification and benzo(a)pyrene removal from contaminated soil. Chemosphere, 87(6), pp. 595-601 SimaPro 6. 2008. Life Cycle Analysis Software. The Netherlands. Sponza, and Oztekin, R. 2010. Effect of sonication assisted by titanium dioxide and ferrous ions on polyaromatic hydrocarbons (PAHs) and toxicity removals from a petrochemical industry wastewater in Turkey. Journal of Chemical Technology & Biotechnology, 85(7), pp. 913-925 ---PAGE BREAK--- 50 Association of Washington Business 213512 Treatment Technology Review and Assessment U.S. Environmental Protection Agency (EPA). 2003. Arsenic Treatment Technology Handbook for Small Systems, EPA 816R03014. U.S. Environmental Protection Agency. 2000. Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health. EPA‐ 822‐B‐00‐004, October 2000. U.S. Environmental Protection Agency. 2007. The Emissions & Generation Resource Integrated Database – eGrid WebVersion1.0. United States Environmental Protection Agency, Washington, D.C. U.S. Department of Agriculture (USDA). 1998. Continuing survey of food intakes by individuals: 1994-96, 1998. U.S. Department of Agriculture, Agricultural Research Service. Water Environment Federation. 2009. Design of Municipal Wastewater Treatment Plants, WEF Manual of Practice 8, Fourth Edition, ASCE Manuals and Reports on Engineering Practice No. 76, Volume 1. Alexandria, VA. Water Environment Research Foundation (WERF). 2012. Demonstration of Membrane Zero Liquid Discharge for Drinking Water Systems, A Literature Review. WERF5T10. Water Environment Research Foundation (WERF). 2011. Striking the Balance Between Nutrient Removal in Wastewater Treatment and Sustainability. NUTR1R06n. WesTech brochure. Victorville case study. Vendor Brochure. Williams, M. 2003. A Review of Wastewater Treatment by Reverse Osmosis. White paper Yerushalmi, Nefil, Hausler, and Guiot, S. 2006. Removal of pyrene and benzo(a)pyrene from contaminated water by sequential and simultaneous ozonation and biotreatment. Water Environment Research, 78 ( 11). Zeng, Hong, and Wavrek, D. 2000. Integrated chemical-biological treatment of benzo[a]pyrene. Environmental Science and Technology, 34 pp 854–862 ---PAGE BREAK--- Association of Washington Business 51 Treatment Technology Review and Assessment 213512 This page left intentionally blank. ---PAGE BREAK--- 52 Association of Washington Business 213512 Treatment Technology Review and Assessment 7.0 Appendices Appendix A - Unit Process Sizing Criteria Appendix B - Greenhouse Gas Emissions Calculation Assumptions ---PAGE BREAK--- Association of Washington Business 53 Treatment Technology Review and Assessment 213512 This page left intentionally blank. ---PAGE BREAK--- ---PAGE BREAK--- Association of Washington Business A-1 Treatment Technology Review and Assessment 213512 APPENDIX A - UNIT PROCESS SIZING CRITERIA Table A-1. Unit Processes Sizing Criteria for Each Alternative Unit Process Units Baseline Treatment Advanced Treatment Comment Influent Pumping Station unitless 3 Times Ave Flow 3 Times Ave Flow This is peaking factor used to size the pumps (peak flow:average flow) Alum Dose for CEPT (optional) mg/L 20 20 This is the metal salt upstream of the primaries Primary Clarifiers gpd/sf 1000 1000 This is for average annual flows Primary Solids Pumping Station unitless 1.25 Times Ave Flow 1.25 Times Ave Flow This is peaking factor used to size the pumps (maximum month flow:average flow) Aeration System Oxygen Uptake Rate (OUR) mg/L/hr 25 25 Average annual OUR is used in tandem with mixed liquor to determine the required aeration basin volume (the limiting parameter governs the activated sludge basin volume) Aeration Basin Mixed Liquor mg/L 1250 2500 Average annual mixed liquor is used in tandem with OUR (see next row) to determine the required aeration basin volume (the limiting parameter governs the activated sludge basin volume) Secondary Clarifiers Hydraulic Loading gpd/sf 650 Only use for Baseline as clarifiers governed hydraulically with short SRT days) Secondary Clarifiers Solids Loading lb/d/sf 24 Only use for Advanced Treatment as clarifiers governed by solids with long SRT days) Return Activated Sludge (RAS) Pumping Station unitless 1.25 Times Ave Flow 1.25 Times Ave Flow RAS must have capacity to meet 100% influent max month Flow. The influent flow is multiplied by this peaking factor to determine RAS pumping station capacity. Waste Activated Sludge (WAS) Pumping Station gpm 1.25 Times Ave Flow 1.25 Times Ave Flow WAS must have capacity to meet max month WAS flows. The average annual WAS flow is multiplied by this peaking factor to determine WAS pumping station capacity. Microfiltration (MF) Flux gfd 25 Based on average annual pilot experience in Coeur D’Alene, ID MF Backwash Storage Tank unitless 1.25 Storage tanks must have capacity to meet maximum month MF backwash flows. The average annual MF backwash volume is multiplied by this peaking factor to determine required volume. ---PAGE BREAK--- A-2 Association of Washington Business 213512 Treatment Technology Review and Assessment Table A-1. Unit Processes Sizing Criteria for Each Alternative Unit Process Units Baseline Treatment Advanced Treatment Comment MF Backwash Pumps unitless 1.25 Backwash pumps must have capacity to meet maximum month MF backwash flows. The average annual MF backwash flow is multiplied by this peaking factor to determine required flows. Reverse Osmosis (RO) gallon per square foot per day (gfd) 10 RO Reject % 20 This represents the percentage of feed flow that is rejected as brine Chlorination Dose mg/L 15 15 Chlorination Storage Capacity days 14 14 Chlorine Contact Tank min 30 30 This is for average annual conditions. Dechlorination Dose mg/L 15 15 Dechlorination Storage Capacity days 14 14 Gravity Belt Thickener gpm/m 200 200 This is for maximum month conditions using the 1.25 peaking factor from average annual to maximum month Anaerobic Digestion Hydraulic residenc e time (HRT) 18 18 This is for average annual conditions Dewatering Centrifuge gpm 120 120 This is for maximum month conditions using the 1.25 peaking factor from average annual to maximum month gpd=gallons per day; sf=square feet; gpm=gallons per minute ---PAGE BREAK--- Association of Washington Business B-1 Treatment Technology Review and Assessment 213512 Appendix B – Greenhouse Gas Emissions Calculation Assumptions The steady state mass balance results were used to calculate GHG emissions. The assumptions used to convert between energy demand, chemical demand and production, as well as biologically-mediated gases CH4 and N2O) and GHG emissions are provided in Table B-1. The assumptions are based on EPA (2007) values for energy production, an adaptation of the database provided in Ahn et al. (2010) for N2O emissions contribution, Intergovernmental Panel on Climate Change (IPCC) (2006) for fugitive CH4 emissions, and various resources for chemical production and hauling from production to the wastewater treatment plant (WWTP). Additionally, the biogas produced during anaerobic digestion that is used as a fuel source is converted to energy with MOP8 (2009) recommended waste-to-energy values. Table B-1. Greenhouse Gas Emissions Assumptions Parameters Units Value Source N2O to CO2 Conversion lb CO2/lb N2O 296 IPCC, 2006 CH4 to CO2 Conversion lb CO2/lb CH4 23 IPCC, 2006 Energy Production CO2 lb CO2/MWh 1,329 USEPA (2007) N2O lb N2O/GWh 20.6 USEPA (2007) CH4 lb CO2/GWh 27.3 USEPA (2007) Sum Energy Production lb CO2/MWh 1336 USEPA (2007) GHGs per BTU Natural Gas CO2 lb CO2/MMBTU Natural Gas 52.9 CA Climate Action Registry Reporting Tool N2O lb N2O/MMBTU Natural Gas 0.0001 CA Climate Action Registry Reporting Tool CH4 lb CO2/MMBTU Natural Gas 0.0059 CA Climate Action Registry Reporting Tool Sum Natural Gas 53.1 CA Climate Action Registry Reporting Tool Non-BNR N2O Emissions g N2O/PE/yr 32 Ahn et al. (2010) BNR N2O Emissions g N2O/PE/yr 30 Ahn et al. (2010) Biogas Purity % Methane 65 WEF, 2009 Biogas to Energy BTU/cf CH4 550 WEF, 2009 Digester Gas to Electrical Energy Transfer Efficiency % 32 HDR Data ---PAGE BREAK--- B-2 Association of Washington Business 213512 Treatment Technology Review and Assessment Table B-1. Greenhouse Gas Emissions Assumptions Parameters Units Value Source Chemical Production Alum lb CO2/lb Alum 0.28 SimaPro 6.0 - BUWAL250, Eco- indicator 95 Polymer lb CO2/lb Polymer 1.18 Owen (1982) Sodium Hypochlorite lb CO2/lb Sodium Hypochlorite 1.07 Owen (1982) Building Energy Efficiency kBTU/sf/yr 60 Calif. Commercial End-Use Survey (2006) Hauling Distance - Local miles 100 - Hauling Emissions Fuel Efficiency miles per gallon 8 CO2 kg CO2/gal diesel 10.2 CA Climate Action Registry Reporting Tool N2O kg N2O/gal diesel 0.0001 CA Climate Action Registry Reporting Tool CH4 kg CH4/gal diesel 0.003 CA Climate Action Registry Reporting Tool Sum Hauling Fuel kg CO2/gal diesel 10.2 CA Climate Action Registry Reporting Tool GWh = Giga Watt Hours MWh = Mega Watt Hours MMBTU = Million British Thermal Units BTU = British Thermal Unit PE = Population Equivalents kBTU/sf/yr = 1,000 British Thermal Units per Square Foot per Year cf = cubic feet lb = pound kg = kilogram gal = gallon ---PAGE BREAK--- PROCESS CALCULATIONS APPENDIX 5-A ---PAGE BREAK--- Project: Kennewick WWTP Description: Mass Balance: Concept Level 2014 Conditions Project Number: 30-13-056 Design By: LTS Flow Condition: Average Day Loading Condition: Average Day No. in operation 2 Influent w/ RAS Return Basin volume 3.00 MG / EA Intermediate Clarifier Effluent Final Clarifier Effluent Final Effluent Flow 5.35 mgd Flow 6.95 mgd MLSS 2,000 mg/L Flow 5.37 mgd Flow 5.37 mgd Flow 5.37 mgd BOD 11,500 ppd % 80% BOD 288 ppd BOD 216 ppd BOD 216 ppd 258 mg/L 1,600 mg/L No. in operation 2 6 mg/L No. in operation 5 5 mg/L 5 mg/L TSS 13,020 ppd Yield (VSS basis) 0.81 Total # of clarifiers 2 TSS 391 ppd Length, ft 100 TSS 195 ppd TSS 195 ppd 292 mg/L WAS (VSS), ppd 9,315 ppd No. 1 diameter, ft 90 9 mg/L Width, ft 28 4 mg/L 4 mg/L TN 1,940 ppd SRT 8.60 day No. 2 diameter, ft 120 TN 1,152 ppd Surface area, each, sf 2800 TN 1,152 ppd TN 1,152 ppd 43 mg/L HRT 1.09 day Surface area, total, sf 17,671 26 mg/L Surface area, total, sf 14000 26 mg/L 26 mg/L TP 360 ppd F:M 0.14 Overflow rate, 304 TP 171 ppd Overflow rate, 384 TP 171 ppd TP 171 ppd 8 mg/L Solids loading, #/hr/sf 0.27 4 mg/L Solids loading, #/hr/sf 0.00 4 mg/L 4 mg/L RAS Return Flow 1.44 mgd WAS 30% * Q(avg) Flow 0.140 mgd TSS 115,984 ppd BOD - ppd 9,638 mg/L - mg/L TSS 11,268 ppd 9,638 mg/L VSS 9,315 ppd Thicken WAS? No Thickened Solids Flow 0.000 mgd TSS - ppd Dewatered Solids mg/L Flow 0.0000 mgd Solids Not Thickened Feed to Dewatering 0 gpd Flow 0.140 mgd Flow 0.000 mgd Cake solids 20% TSS 11,463 ppd HRT, days 571 TSS 0 ppd cy / day 0 9,805 mg/L Volume, Mgal 80 #DIV/0! mg/L dry tons / d 0.00 VS destruction 35% Volumetric Loading 0.871 lb-VSS / ft^3-day Return Flows Flow 0.14 mgd BOD 12 ppd 10 mg/L TSS 92 ppd 79 mg/L Thickening Overflow Flow 0.000 mgd Feed to Sludge Lagoons Dewatering Overflow Flow 0.140 mgd Flow 0.000 mgd TSS 11,463 ppd 9,805 mg/L Total VSS 9,315 ppd Total NVSS 2,148 ppd Total SS 11,463 ppd Headworks Biological Process Intermediate Clarification UV Disinfection Thickening Dist Box Aerated Sludge Lagoons Dewatering Return Flows Outfall Disposal This mass balance is for planning level efforts only and is not intended for detailed design. The process schamatic shown herein is a simplified model and may therefore not represent all processes, locations, and return streams exactly. Final Clarification Report Figure \\kwkfiles\PUBLIC\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\_process schematic\KWK-mass balance-planning level--2014.xls 9/16/2014 ---PAGE BREAK--- Project: Kennewick WWTP Description: Mass Balance: Concept Level 2014 Conditions Project Number: 30-13-056 Design By: LTS Flow Condition: Maximum Month Loading Condition: Maximum Month No. in operation 2 Influent w/ RAS Return Basin volume 3.00 MG / EA Intermediate Clarifier Effluent Final Clarifier Effluent Final Effluent Flow 6.34 mgd Flow 7.97 mgd MLSS 2,000 mg/L Flow 6.36 mgd Flow 6.36 mgd Flow 6.36 mgd BOD 15,900 ppd % 80% BOD 398 ppd BOD 298 ppd BOD 298 ppd 301 mg/L 1,600 mg/L No. in operation 2 7 mg/L No. in operation 5 6 mg/L 6 mg/L TSS 16,000 ppd Yield (VSS basis) 0.81 Total # of clarifiers 2 TSS 480 ppd Length, ft 100 TSS 240 ppd TSS 240 ppd 303 mg/L WAS (VSS), ppd 12,879 ppd No. 1 diameter, ft 90 9 mg/L Width, ft 28 5 mg/L 5 mg/L TN 2,520 ppd SRT 6.22 day No. 2 diameter, ft 120 TN 1,403 ppd Surface area, each, sf 2800 TN 1,403 ppd TN 1,403 ppd 48 mg/L HRT 0.92 day Surface area, total, sf 17,671 26 mg/L Surface area, total, sf 14000 26 mg/L 26 mg/L TP 460 ppd F:M 0.20 Overflow rate, 360 TP 212 ppd Overflow rate, 455 TP 212 ppd TP 212 ppd 9 mg/L Solids loading, #/hr/sf 0.31 4 mg/L Solids loading, #/hr/sf 0.00 4 mg/L 4 mg/L RAS Return Flow 1.44 mgd WAS 30% * Q(avg) Flow 0.166 mgd TSS 132,993 ppd BOD - ppd 11,051 mg/L - mg/L TSS 15,279 ppd 11,051 mg/L VSS 12,879 ppd Thicken WAS? No Thickened Solids Flow 0.000 mgd TSS - ppd Dewatered Solids mg/L Flow 0.0000 mgd Solids Not Thickened Feed to Dewatering 0 gpd Flow 0.166 mgd Flow 0.000 mgd Cake solids 20% TSS 15,519 ppd HRT, days 483 TSS 0 ppd cy / day 0 11,224 mg/L Volume, Mgal 80 #DIV/0! mg/L dry tons / d 0.00 VS destruction 35% Volumetric Loading 1.204 lb-VSS / ft^3-day Return Flows Flow 0.17 mgd BOD 14 ppd 10 mg/L TSS 122 ppd 88 mg/L Thickening Overflow Flow 0.000 mgd Feed to Sludge Lagoons Dewatering Overflow Flow 0.166 mgd Flow 0.000 mgd TSS 15,519 ppd 11,224 mg/L Total VSS 12,879 ppd Total NVSS 2,640 ppd Total SS 15,519 ppd Headworks Biological Process Intermediate Clarification UV Disinfection Thickening Dist Box Aerated Sludge Lagoons Dewatering Return Flows Outfall Disposal This mass balance is for planning level efforts only and is not intended for detailed design. The process schamatic shown herein is a simplified model and may therefore not represent all processes, locations, and return streams exactly. Final Clarification Report Figure \\kwkfiles\PUBLIC\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\_process schematic\KWK-mass balance-planning level--2014.xls 9/16/2014 ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 5/12/2015 Subject: Aeration System Evaluation: 2014 Conditions Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 5.35 258 11,500 5 223 43 1,940 Maximum Month 6.34 301 15,900 15 793 48 2,520 Peak Day 8.37 267 18,630 20 1,396 61 4,260 intra-day peak = 1.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 9,000 ppd VSS, average day = 1,600 mg/l biomass = 12,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 100% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 7,900 8,800 1,100 840 3,850 20,600 Maximum Month 10,550 8,800 1,450 1,070 4,900 24,300 Peak Day 12,050 8,800 1,450 2,810 12,850 33,700 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 75 x 75 2.8 210 2 75 x 75 2.8 210 3 75 x 75 2.8 210 4 75 x 75 2.8 210 5 100 x 100 2.8 280 6 100 x 100 2.8 280 Total hp per lagoon 500 Total SOTR 1,400 # O2 / hr / lagoon No. of lagoons 2 Total HP 1000 Total SOTR 2,800 # O2 / hr Total AOTR 1,522 # O2 / hr 1.5 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 67,200 67,200 67,200 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 2.0 2.0 2.0 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.54 0.54 0.54 Avg Day Max Month Peak Day AOTR (provided) = 36,500 36,500 36,500 lbs O2/day AOTR (required) = 20,600 24,300 33,700 lbs O2/day Avg Day okay - - Max Month - okay - Peak Day - - okay BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛−𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆𝑖𝑛𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 5/12/2015 O2 Supply-2013 BOD+NH3 \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 5/12/2015 Subject: Aeration System Evaluation: 2014 Conditions - Peak Hour Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 5.35 258 11,500 5 223 43 1,940 Maximum Month 6.34 301 15,900 15 793 48 2,520 Peak Day 8.37 267 18,630 20 1,396 61 4,260 intra-day peak = 2.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 9,000 ppd VSS, average day = 1,600 mg/l biomass = 12,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 100% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 15,800 8,800 1,100 840 7,700 32,300 Maximum Month 21,150 8,800 1,450 1,070 9,800 39,800 Peak Day 24,150 8,800 1,450 2,810 25,700 58,700 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 75 x 75 2.8 210 2 75 x 75 2.8 210 3 75 x 75 2.8 210 4 75 x 75 2.8 210 5 100 2.8 6 100 2.8 Total hp per lagoon 300 Total SOTR 840 # O2 / hr / lagoon No. of lagoons 2 Total HP 600 Total SOTR 1,680 # O2 / hr Total AOTR 1,162 # O2 / hr 1.9 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 40,320 40,320 40,320 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 0.5 0.5 0.5 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.69 0.69 0.69 Avg Day Max Month Peak Day AOTR (provided) = 27,900 27,900 27,900 lbs O2/day AOTR (required) = 32,300 39,800 58,700 lbs O2/day Avg Day too low - - Max Month - too low - Peak Day - - too low BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛−𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆𝑖𝑛𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 5/12/2015 O2 Supply-2013 BOD+NH3 PEAK \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- WWTP PROCESS DATA APPENDIX 5-B ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- PROCESS CALCULATIONS APPENDIX 6-A ---PAGE BREAK--- Project: Kennewick WWTP Description: Mass Balance: Concept Level 2034 Conditions Project Number: 30-13-056 Design By: LTS Flow Condition: Average Day Loading Condition: Average Day No. in operation 2 Influent w/ RAS Return Basin volume 3.00 MG / EA Intermediate Clarifier Effluent Final Clarifier Effluent Final Effluent Flow 7.94 mgd Flow 10.56 mgd MLSS 2,000 mg/L Flow 7.91 mgd Flow 7.91 mgd Flow 7.91 mgd BOD 22,000 ppd % 80% BOD 550 ppd BOD 413 ppd BOD 413 ppd 332 mg/L 1,600 mg/L No. in operation 2 8 mg/L No. in operation 5 6 mg/L 6 mg/L TSS 23,000 ppd Yield (VSS basis) 0.76 Total # of clarifiers 2 TSS 690 ppd Length, ft 100 TSS 345 ppd TSS 345 ppd 347 mg/L WAS (VSS), ppd 16,720 ppd No. 1 diameter, ft 90 10 mg/L Width, ft 28 5 mg/L 5 mg/L TN 3,400 ppd SRT 4.79 day No. 2 diameter, ft 120 TN 2,074 ppd Surface area, each, sf 2800 TN 2,074 ppd TN 2,074 ppd 51 mg/L HRT 0.73 day Surface area, total, sf 17,671 31 mg/L Surface area, total, sf 14000 31 mg/L 31 mg/L TP 520 ppd F:M 0.27 Overflow rate, 447 TP 174 ppd Overflow rate, 565 TP 174 ppd TP 174 ppd 8 mg/L Solids loading, #/hr/sf 0.40 3 mg/L Solids loading, #/hr/sf 0.00 3 mg/L 3 mg/L RAS Return Flow 2.38 mgd WAS 30% * Q(avg) Flow 0.273 mgd TSS 176,144 ppd BOD - ppd 8,867 mg/L - mg/L TSS 20,170 ppd 8,867 mg/L VSS 16,720 ppd Thicken WAS? No Thickened Solids Flow 0.000 mgd TSS - ppd Dewatered Solids mg/L Flow 0.0000 mgd Solids Not Thickened Feed to Dewatering 0 gpd Flow 0.273 mgd Flow 0.000 mgd Cake solids 20% TSS 20,515 ppd HRT, days 293 TSS 0 ppd cy / day 0 9,018 mg/L Volume, Mgal 80 #DIV/0! mg/L dry tons / d 0.00 VS destruction 35% Volumetric Loading 1.563 lb-VSS / ft^3-day Return Flows Flow 0.27 mgd BOD 23 ppd 10 mg/L TSS 164 ppd 72 mg/L Thickening Overflow Flow 0.000 mgd Feed to Sludge Lagoons Dewatering Overflow Flow 0.273 mgd Flow 0.000 mgd TSS 20,515 ppd 9,018 mg/L Total VSS 16,720 ppd Total NVSS 3,795 ppd Total SS 20,515 ppd Headworks Biological Process Intermediate Clarification UV Disinfection Thickening Dist Box Aerated Sludge Lagoons Dewatering Return Flows Outfall Disposal This mass balance is for planning level efforts only and is not intended for detailed design. The process schamatic shown herein is a simplified model and may therefore not represent all processes, locations, and return streams exactly. Final Clarification Report Figure \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\_process schematic\KWK-mass balance-planning level--2034.xls 9/16/2014 ---PAGE BREAK--- Project: Kennewick WWTP Description: Mass Balance: Concept Level 2034 Conditions Project Number: 30-13-056 Design By: LTS Flow Condition: Maximum Month Loading Condition: Maximum Month No. in operation 2 Influent w/ RAS Return Basin volume 3.00 MG / EA Intermediate Clarifier Effluent Final Clarifier Effluent Final Effluent Flow 9.40 mgd Flow 12.06 mgd MLSS 2,000 mg/L Flow 9.36 mgd Flow 9.36 mgd Flow 9.36 mgd BOD 30,400 ppd % 80% BOD 760 ppd BOD 570 ppd BOD 570 ppd 388 mg/L 1,600 mg/L No. in operation 2 10 mg/L No. in operation 5 7 mg/L 7 mg/L TSS 28,300 ppd Yield (VSS basis) 0.76 Total # of clarifiers 2 TSS 849 ppd Length, ft 100 TSS 425 ppd TSS 425 ppd 361 mg/L WAS (VSS), ppd 23,104 ppd No. 1 diameter, ft 90 11 mg/L Width, ft 28 5 mg/L 5 mg/L TN 4,400 ppd SRT 3.47 day No. 2 diameter, ft 120 TN 2,508 ppd Surface area, each, sf 2800 TN 2,508 ppd TN 2,508 ppd 56 mg/L HRT 0.62 day Surface area, total, sf 17,671 32 mg/L Surface area, total, sf 14000 32 mg/L 32 mg/L TP 680 ppd F:M 0.38 Overflow rate, 530 TP 191 ppd Overflow rate, 668 TP 191 ppd TP 191 ppd 9 mg/L Solids loading, #/hr/sf 0.46 2 mg/L Solids loading, #/hr/sf 0.00 2 mg/L 2 mg/L RAS Return Flow 2.38 mgd WAS 30% * Q(avg) Flow 0.324 mgd TSS 201,228 ppd BOD - ppd 10,129 mg/L - mg/L TSS 27,349 ppd 10,129 mg/L VSS 23,104 ppd Thicken WAS? No Thickened Solids Flow 0.000 mgd TSS - ppd Dewatered Solids mg/L Flow 0.0000 mgd Solids Not Thickened Feed to Dewatering 0 gpd Flow 0.324 mgd Flow 0.000 mgd Cake solids 20% TSS 27,774 ppd HRT, days 247 TSS 0 ppd cy / day 0 10,287 mg/L Volume, Mgal 80 #DIV/0! mg/L dry tons / d 0.00 VS destruction 35% Volumetric Loading 2.160 lb-VSS / ft^3-day Return Flows Flow 0.32 mgd BOD 27 ppd 10 mg/L TSS 218 ppd 81 mg/L Thickening Overflow Flow 0.000 mgd Feed to Sludge Lagoons Dewatering Overflow Flow 0.324 mgd Flow 0.000 mgd TSS 27,774 ppd 10,287 mg/L Total VSS 23,104 ppd Total NVSS 4,670 ppd Total SS 27,774 ppd Headworks Biological Process Intermediate Clarification UV Disinfection Thickening Dist Box Aerated Sludge Lagoons Dewatering Return Flows Outfall Disposal This mass balance is for planning level efforts only and is not intended for detailed design. The process schamatic shown herein is a simplified model and may therefore not represent all processes, locations, and return streams exactly. Final Clarification Report Figure \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\_process schematic\KWK-mass balance-planning level--2034.xls 9/16/2014 ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 3/24/2014 Subject: Aeration System Evaluation: 2034 Conditions assume nitrification is supported Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 7.94 332 22,000 20 1,324 51 3,400 Maximum Month 9.40 388 30,400 20 1,568 56 4,400 Peak Day 12.40 345 35,700 20 2,068 73 7,500 intra-day peak = 1.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 16,500 ppd VSS, average day = 1,600 mg/l biomass = 23,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 100% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 14,450 8,800 2,000 1,400 6,400 29,700 Maximum Month 20,200 8,800 2,750 1,650 7,550 36,600 Peak Day 23,550 8,800 2,750 4,750 21,700 54,100 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 75 x 75 2.8 210 2 75 x 75 2.8 210 3 75 x 75 2.8 210 4 75 x 75 2.8 210 5 100 x 100 2.8 280 6 100 x 100 2.8 280 Total hp per lagoon 500 Total SOTR 1,400 # O2 / hr / lagoon No. of lagoons 2 Total HP 1000 Total SOTR 2,800 # O2 / hr Total AOTR 1,522 # O2 / hr 1.52 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 67,200 67,200 67,200 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 2.0 2.0 2.0 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.54 0.54 0.54 Avg Day Max Month Peak Day AOTR (provided) = 36,500 36,500 36,500 lbs O2/day AOTR (required) = 29,700 36,600 54,100 lbs O2/day Avg Day okay - - Max Month - too low - Peak Day - - too low BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛− 𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆 𝑖𝑛 𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 9/16/2014 O2 Supply-2034 BOD+NH3 \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 3/24/2014 Subject: Aeration System Evaluation: 2034 Conditions at Peak Hour assume nitrification is supported Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 7.94 332 22,000 20 1,324 51 3,400 Maximum Month 9.40 388 30,400 20 1,568 56 4,400 Peak Day 12.40 345 35,700 20 2,068 73 7,500 intra-day peak = 2.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 16,500 ppd VSS, average day = 1,600 mg/l biomass = 23,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 100% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 28,950 8,800 2,000 1,400 12,800 50,600 Maximum Month 40,350 8,800 2,750 1,650 15,100 64,300 Peak Day 47,100 8,800 2,750 4,750 43,400 99,300 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 100 x 100 2.8 280 2 100 x 100 2.8 280 3 100 x 100 2.8 280 4 100 x 100 2.8 280 5 150 x 150 2.8 420 6 150 x 150 2.8 420 Total hp per lagoon 700 Total SOTR 1,960 # O2 / hr / lagoon No. of lagoons 2 Total HP 1400 Total SOTR 3,920 # O2 / hr Total AOTR 2,712 # O2 / hr 1.9 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 94,080 94,080 94,080 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 0.5 0.5 0.5 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.69 0.69 0.69 Avg Day Max Month Peak Day AOTR (provided) = 65,100 65,100 65,100 lbs O2/day AOTR (required) = 50,600 64,300 99,300 lbs O2/day Avg Day okay - - Max Month - okay - Peak Day - - too low BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛− 𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆 𝑖𝑛 𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 9/16/2014 O2 Supply-2034 BOD+NH3 PEAK \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 3/24/2014 Subject: Aeration System Evaluation: 2034 Conditions BOD only Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 7.94 332 22,000 20 1,324 51 3,400 Maximum Month 9.40 388 30,400 20 1,568 56 4,400 Peak Day 12.40 345 35,700 20 2,068 73 7,500 intra-day peak = 1.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 16,500 ppd VSS, average day = 1,600 mg/l biomass = 23,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 0% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 14,450 8,800 2,000 0 0 23,300 Maximum Month 20,200 8,800 2,750 0 0 29,000 Peak Day 23,550 8,800 2,750 0 0 32,400 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 75 x 75 2.8 210 2 75 x 75 2.8 210 3 75 x 75 2.8 210 4 75 x 75 2.8 210 5 100 x 100 2.8 280 6 100 2.8 Total hp per lagoon 400 Total SOTR 1,120 # O2 / hr / lagoon No. of lagoons 2 Total HP 800 Total SOTR 2,240 # O2 / hr Total AOTR 1,217 # O2 / hr 1.52 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 53,760 53,760 53,760 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 2.0 2.0 2.0 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.54 0.54 0.54 Avg Day Max Month Peak Day AOTR (provided) = 29,200 29,200 29,200 lbs O2/day AOTR (required) = 23,300 29,000 32,400 lbs O2/day Avg Day okay - - Max Month - okay - Peak Day - - too low BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛− 𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆 𝑖𝑛 𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 9/16/2014 O2 Supply-2034 BOD only \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed bLevi Shoolroy Date: 3/24/2014 Subject: Aeration System Evaluation: 2034 Conditions BOD only at Peak Hour Checked by: 1) Given Loading Condition Flow (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) Average Day 7.94 332 22,000 20 1,324 51 3,400 Maximum Month 9.40 388 30,400 20 1,568 56 4,400 Peak Day 12.40 345 35,700 20 2,068 73 7,500 intra-day peak = 2.0 2) Operating Conditions MLSS = 2,000 mg/l Yield = 0.80 (VSS basis) % VSS = 80% biomass = 16,500 ppd VSS, average day = 1,600 mg/l biomass = 23,100 ppd VSS, max month Basin volume = 6.6 *10^ gal 1º removal = 0% Mass of 88,070 lb % nitrification = 0% 3) Governing Equation BOD conversion a` * (BODin - BODout) a` = 0.45 to 0.70 …use 0.70 endogenous decay b` * (mass of b` = 0.05 to 0.15 …use 0.10 nitrification demand % N in biomass = 12% oyxgen demand = 4.57 lb O2/lb N oxidized 4) Oxygen Demand Condition BOD Conversion endogenous decay Nitrogen in biomass Nitrogen Oxidized O2 Demand for N Total O2 Demand (ppd) (ppd) (ppd) (ppd) (ppd) (ppd) Average Day 28,950 8,800 2,000 0 0 37,800 Maximum Month 40,350 8,800 2,750 0 0 49,200 Peak Day 47,100 8,800 2,750 0 0 55,900 5) Oxygen Transfer Efficiency: mechanical surface aerators Eq. 5-62, Metcalf & Eddy, 3rd Ed., 1991, p. 572 Where: N = Actual Oxygen Transfer Rate Under Field Conditions No = Standard Oxygen Transfer Rate at 20ºC and Zero DO b = Correction Factor for Wastewater Characteristics; typically = 0.90 to 1.0 a = Correction Factor for Mixing and Basin Geometry; typically 0.82 (influent) to 0.98 (effluent) for municipal waste q = Correction Factor for Temperature; typically 1.024 Cw alt = Oxygen saturation concentration for Tap Water at Field Temperature and Pressure Cs20 = Oxygen Saturation Concentration for Tap Water at 20ºC and 1 atm CL = Operating Oxygen Concentration in Wastewater T = Wastewater Temperature under Field Conditions establish mixers in operation: Mixer No hp mixers in operation total horsepower SOTR / hp*hr SOTR 1 75 x 75 2.8 210 2 75 x 75 2.8 210 3 75 x 75 2.8 210 4 75 x 75 2.8 210 5 100 x 100 2.8 280 6 100 2.8 Total hp per lagoon 400 Total SOTR 1,120 # O2 / hr / lagoon No. of lagoons 2 Total HP 800 Total SOTR 2,240 # O2 / hr Total AOTR 1,550 # O2 / hr 1.94 # O2 / hp*hr Site specific conditions: Elevation 400 ft AMSL MLSS Temperature 23.8 º C Avg Day Max Month Peak Day Unit Determine SOTR SOTR 53,760 53,760 53,760 lbs O2/day Determine diffuser efficiency b 0.90 0.90 0.90 a 0.82 0.82 0.82 q 1.024 1.024 1.024 Cs20 9.08 9.08 9.08 mg/L CL 0.5 0.5 0.5 mg/L Atm. Press. @ Site 14.5 14.5 14.5 psi Std. Press. 14.7 14.7 14.7 psi Cs @ Site Temp 8.43 8.43 8.43 mg/L F (elevation correction) 0.99 0.99 0.99 Cw ult corrected for site conditions (Cs*F) 8.33 8.33 8.33 mg/L system efficiency (AOTR/SOTR) 0.69 0.69 0.69 Avg Day Max Month Peak Day AOTR (provided) = 37,200 37,200 37,200 lbs O2/day AOTR (required) = 37,800 49,200 55,900 lbs O2/day Avg Day too low - - Max Month - too low - Peak Day - - too low BOD5 Influent BOD5 Effluent Total Nitrogen 𝑂2 = 𝑎` 𝐵𝑂𝐷𝑖𝑛− 𝐵𝑂𝐷𝑜𝑢𝑡+ 𝑏` 𝑀𝐿𝑉𝑆𝑆 𝑖𝑛 𝑏𝑎𝑠𝑖𝑛+ 4.57 ∆𝑁 𝑁= 𝑁𝑜 𝛽𝐶𝑤𝑎𝑙𝑡−𝐶𝐿 𝐶𝑠20 1.024𝑇−20𝛼 9/16/2014 O2 Supply-2034 BOD only at PEAK \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\aeration design.xlsx ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed by: Levi Shoolroy Date: 1/31/2014 Subject: HRT Lagoons: HRT and SRT calculations - 2034 conditions Checked by: 1) Influent Parameters Current Conditions To Prevent Nitrification Condition Flow BOD5 Influent BOD5 Effluent TSS Influent hyd det time hyd det time (mgd) (mg/L) (ppd) (mg/L) (ppd) (mg/L) (ppd) (hrs) (hrs) Average Day 7.94 332 22,000 20 1,324 347 23,000 18.1 9.1 Maximum Month 9.40 388 30,400 20 1,568 388 30,400 15.3 7.7 Peak Day 12.40 345 35,700 20 2,068 345 35,700 11.6 5.8 2) Assumptions Inert TSS = 15% Inert TSS = 15% MLSS = 2,000 mg/L MLSS = 1,750 mg/L % = 80% % = 80% = 1,600 mg/L = 1,400 mg/L V(HRT cells) = 3 MG V(HRT cells) = 3 MG No of HRT cells = 2 No of HRT cells = 1 Mass of VSS = 80,064 lb Mass of VSS = 35,028 lb F:M = 0.27 average day F:M = 0.63 average day Volumetric Loading = 27.4 ppd BOD / 1000 ft^3 Volumetric Loading = 54.9 ppd BOD / 1000 ft^3 3) SRT estimates at various yields - Current Basin Operation SRT estimates at various yields - To prevent nitrification HRT Y P(x, VSS) SRT P(x, Total) HRT Y P(x, VSS) SRT P(x, Total) (days) (#VSS/#BOD) (ppd) (days) (ppd) (days) (#VSS/#BOD) (ppd) (days) (ppd) Average Day Conditions 0.76 0.6 12,405 6.5 15,855 Average Day Co 0.76 0.6 12,405 2.8 15,855 Maximum Month Conditions 0.64 0.6 17,299 4.6 21,859 Maximum Mont 0.64 0.6 17,299 2.0 21,859 HRT Y P(x, VSS) SRT P(x, Total) HRT Y P(x, VSS) SRT P(x, Total) (days) (#VSS/#BOD) (ppd) (days) (ppd) (days) (#VSS/#BOD) (ppd) (days) (ppd) Average Day Conditions 0.76 0.8 16,540 4.8 19,990 Average Day Co 0.76 0.8 16,540 2.1 19,990 Maximum Month Conditions 0.64 0.8 23,066 3.5 27,626 Maximum Mont 0.64 0.8 23,066 1.5 27,626 HRT Y P(x, VSS) SRT P(x, Total) HRT Y P(x, VSS) SRT P(x, Total) (days) (#VSS/#BOD) (ppd) (days) (ppd) (days) (#VSS/#BOD) (ppd) (days) (ppd) Average Day Conditions 0.76 1.0 20,676 3.9 24,126 Average Day Co 0.76 1.0 20,676 1.7 24,126 Maximum Month Conditions 0.64 1.0 28,832 2.8 33,392 Maximum Mont 0.64 1.0 28,832 1.2 33,392 critical SRT in the winter (coldest month) 6.6 days SRT > 6.6 8.0 The lagoon will nitrify in the coldest month of the winter critical SRT in the summer (max month) 2.0 days SRT > 2 3.0 The lagoon will nitrify in the summer 1.0 The lagoon will NOT nitrify SRT 2034-no nitrification \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\SRT calcs.xlsx 9/16/2014 ---PAGE BREAK--- Project: Kennewick WWTP Facility Plan Project 30-13-056 (100-005) Designed by: Levi Shoolroy Date: 1/31/2014 Subject: HRT Lagoons: HRT and SRT calculations - 2034 conditions Checked by: temperature min SRT for nitrification (º C) (day) 8 8.5 10 6.9 12 5.7 14 4.7 16 3.9 18 3.2 20 2.6 22 2.1 24 1.8 Condition Temp SRT(min) C) (days) min 7-day 8.7 7.9 min month 10.5 6.6 yearly average 16.7 3.6 max month 23.8 1.8 max day 26.0 1.4 SRT 2034-no nitrification \\kwkfiles\public\Project\JUB\30-13-056 - COK Wastewater Treatment Plant\Model_Calcs\Spreadsheets\HRT-biological\SRT calcs.xlsx 9/16/2014 ---PAGE BREAK--- PROJECT NAME: ¯ Kennewick WWTP: Facility Plan DESIGN TASK: - 2014 Diffused Aeration System ¯ average day ENGINEER: ¯ Levi Shoolroy BUDGET NO.: ¯ 30¯13¯056 (100¯006) CHECKED BY: - Definitions: mgd 106 gal day cfs ft3 sec fps ft sec gpm gal min γw 62.4 lbf ft3 cfm ft3 min ppd lb day gpd gal day psi lbf in2 pcf lbf ft3 Pstd 14.7psi For Fine or Coarse Bubble Diffused Aeration Systems Governing equation: ε AOTR SOTR = τ β ⋅ Ω ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ = source: Metcalf and Eddy (5th Edition) Section 5-11 (pp 419 - 424) and Example 8-3 (pp. 760 and 761) Parameters α = relative oxygen transfer rate in process water versus clean water typically 0.50 to 0.60 for fine bubble • typically 0.70 to 0.80 for coarse bubble • α 0.50 β = relative DO saturation to clean water; typically 0.95 to 0.98 β 0.95 Fouling = fouling factor; typically 0.65 to 0.90 Fouling 0.90 Temp = field temperature, ºC Temp 23.8 θ = empirical temperature correction factor θ 1.024 C(target) = bulk DO concentration in MLSS Ctarget 2.0 mg L \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 1 12:54 PM, 9/16/2014 ---PAGE BREAK--- τ = temperature correction factor Cstar(st) = DO surface saturation concentration at operating temperature (M&E Appendix E) Cstarst 8.43 mg L τ Cstarst Cstars20 = Cstar(s20) = DO surface saturation concentration at standard temperature (20ºC) (M&E Appendix E) Cstars20 9.09 mg L τ Cstarst Cstars20 0.927 = G(p) = pressure correction factor P(b) = barometric pressure at site Ωp Pb Pstd = P(s) = standard barometric pressure Pstd 14.7 psi ⋅ = Ωp exp g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ = g 32.174 ft s 2 − ⋅ = gravitational constant M 28.97 lb mole molecular weight of air, per mole zsite 400ft site elevation gc 32.2 ft lb ⋅ lbf sec2 ⋅ slug conversion Rgas 1544 ft lbf ⋅ mole R ⋅ universal gas constant Tempatm Temp°C Tempatm 23.8 °C ⋅ = air temperature ¯ assume equal to wastewater temperature solving... Ωp e g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ Ωp 0.986 = Cstar(inf20) = standard DO value at sea level and standard temperature (20º C) for diffused aeration Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ = Cstars20 9.09 mg L ⋅ = from above de 0.40 d(e) = mid¯depth correction factor; typically 0.25 to 0.45 Df 20.5ft depth to diffusers Ps 10.33m standard barometric pressure as a check--> Ps γw ⋅ 14.7 psi ⋅ = see next page... \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 2 12:54 PM, 9/16/2014 ---PAGE BREAK--- Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ 11.29 mg L ⋅ = Determine diffused aeration efficiency ε τ β ⋅ Ωp ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ ε 34.1 % ⋅ = typical values: fine bubble diffused aeration: 0.33 • coarse bubble diffused aeration: 0.50 • Note: increased MLSS concentrations will lower alpha (e.g. in MBRs) and will lower the oxygen transfer efficiency. Determine required oxygen transfer (AOTR) oxygen demand is given by the following equation: AOTR a' BODin BODout − ( ) b' ⋅ Vr ⋅ + 4.57 ∆N ⋅ + = a` = BOD conversion factor; typically 0.45 to 0.70 a' 0.70 BOD(in) and BOD(out) = influent and effluent BOD, respectively; units of ppd BODin 22000ppd BODout 1330ppd b` = endogenous decay coefficient; typically 0.05 to 0.15 /day b' 0.10 1 day ⋅ = mixed liquor volatile solids concentration in the bioreactor; units of mg/L 1600 mg L V(r) = reactor volume Vr 6.6 106gal ⋅ ∆N = nitrification component in the biological process, accounting for nitrogen assimilation into the biomass. ∆N TKNin PN − ( ) NH3removal ⋅ = P(N) is the fraction on nitrogen in the biomass Nbiomass 12% Y 0.80 volatile yield average biomass generated on a daily basis Px Y BODin BODout − ( ) ⋅ 16536 ppd ⋅ = PN Nbiomass Px ⋅ PN 1984 ppd ⋅ = TKNin 3400ppd NH3removal 100% ∆N TKNin PN − ( ) NH3removal ⋅ 1416 ppd ⋅ = AOTR a' BODin BODout − ( ) ⋅ b' ⋅ Vr ⋅ + 4.57 ∆N ⋅ + 29751 ppd ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 3 12:54 PM, 9/16/2014 ---PAGE BREAK--- Determine standard oxygen transfer (SOTR) and air flow SOTR AOTR ε 87359 ppd ⋅ = density of air at standard conditions: γair_std 0.0808 lb ft3 density at site pressure and temperature: γa Pb M ⋅ Rgas Tempatm ⋅ = Pb Ωp Pstd ⋅ 14.5 psi ⋅ = γa Pb M ⋅ Rgas Tempatm ⋅ 0.0733 lb ft3 ⋅ = estimated diffuser efficiency per foot of depth: η 1.70 % ft Df 20.5 ft ⋅ = depth to diffusers (from above) E η Df ⋅ 34.8 % ⋅ = percent oxygen in air: percentO2 23.18% required airflow at standard conditions: airflow SOTR E percentO2 ⋅ γa ⋅ 10249 cfm ⋅ = Estimate the number of diffusers and floor coverage standard air flow per diffuser at above efficiency, E qsair 2cfm typical: 2 scfm average; 3¯4 scfm at peak conditions estimated number of diffusers: nodif airflow qsair 5125 = estimate area of diffusers: assuming each diffuser has the following surface area: areadif π 4 9in ( )2 ⋅ Adif nodif areadif ⋅ 2264 ft2 ⋅ = basin area, each: Lbasin 106ft Wbasin 76ft Abasin Lbasin Wbasin ⋅ 8056 ft2 ⋅ = number of basins: nobasins 2 calculate total area divided by diffuser area: AT_AD Abasin Adif nobasins 7.12 = per Sanitaire's guidance, this should be above 4.5 as a practical limit \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 4 12:54 PM, 9/16/2014 ---PAGE BREAK--- Determine mixing level Emixing airflow nobasins Abasin 0.64 cfm ft2 ⋅ = compare to a minimum recommended value of 0.12 scfm/sf Estimate blower horsepower Pblower wair Rgas ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ = w(air) = weight flow of air wair airflow γa ⋅ 12.516 lb sec ⋅ = engineering gas constant in terms of pounds of air Rc Rgas M 53.297 ft lbf ⋅ lb R ⋅ ⋅ = Tempinlet 110 °F estimated inlet temperature n k 1 − k = where k is the specific heat ratio; for centrifugal blowers k 1.395 n k 1 − k 0.283 = p1 Pb 14.50 psi ⋅ = absolute inlet pressure as determined above p(2) = the discharge pressure of the blower, estimated as follows (more detailed calculations required): p2 p1 Df γw ⋅ + ∆Hair_pipe + ∆Hdif + = Df γw ⋅ 8.883 psi ⋅ = ∆Hair_pipe 1.5psi ∆Hdif 2ft γw ⋅ 0.867 psi ⋅ = other terms as previously defined p2 p1 Df γw ⋅ + ∆Hair_pipe + 24.88 psi ⋅ = εblower 75% estimated blower efficiency Pblower wair Rc ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ 538 hp ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 5 12:54 PM, 9/16/2014 ---PAGE BREAK--- PROJECT NAME: ¯ Kennewick WWTP: Facility Plan DESIGN TASK: - 2014 Diffused Aeration System ¯ maximum month ENGINEER: ¯ Levi Shoolroy BUDGET NO.: ¯ 30¯13¯056 (100¯006) CHECKED BY: - Definitions: mgd 106 gal day cfs ft3 sec fps ft sec gpm gal min γw 62.4 lbf ft3 cfm ft3 min ppd lb day gpd gal day psi lbf in2 pcf lbf ft3 Pstd 14.7psi For Fine or Coarse Bubble Diffused Aeration Systems Governing equation: ε AOTR SOTR = τ β ⋅ Ω ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ = source: Metcalf and Eddy (5th Edition) Section 5-11 (pp 419 - 424) and Example 8-3 (pp. 760 and 761) Parameters α = relative oxygen transfer rate in process water versus clean water typically 0.50 to 0.60 for fine bubble • typically 0.70 to 0.80 for coarse bubble • α 0.50 β = relative DO saturation to clean water; typically 0.95 to 0.98 β 0.95 Fouling = fouling factor; typically 0.65 to 0.90 Fouling 0.90 Temp = field temperature, ºC Temp 23.8 θ = empirical temperature correction factor θ 1.024 C(target) = bulk DO concentration in MLSS Ctarget 2.0 mg L \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 1 12:56 PM, 9/16/2014 ---PAGE BREAK--- τ = temperature correction factor Cstar(st) = DO surface saturation concentration at operating temperature (M&E Appendix E) Cstarst 8.43 mg L τ Cstarst Cstars20 = Cstar(s20) = DO surface saturation concentration at standard temperature (20ºC) (M&E Appendix E) Cstars20 9.09 mg L τ Cstarst Cstars20 0.927 = G(p) = pressure correction factor P(b) = barometric pressure at site Ωp Pb Pstd = P(s) = standard barometric pressure Pstd 14.7 psi ⋅ = Ωp exp g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ = g 32.174 ft s 2 − ⋅ = gravitational constant M 28.97 lb mole molecular weight of air, per mole zsite 400ft site elevation gc 32.2 ft lb ⋅ lbf sec2 ⋅ slug conversion Rgas 1544 ft lbf ⋅ mole R ⋅ universal gas constant Tempatm Temp°C Tempatm 23.8 °C ⋅ = air temperature ¯ assume equal to wastewater temperature solving... Ωp e g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ Ωp 0.986 = Cstar(inf20) = standard DO value at sea level and standard temperature (20º C) for diffused aeration Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ = Cstars20 9.09 mg L ⋅ = from above de 0.40 d(e) = mid¯depth correction factor; typically 0.25 to 0.45 Df 20.5ft depth to diffusers Ps 10.33m standard barometric pressure as a check--> Ps γw ⋅ 14.7 psi ⋅ = see next page... \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 2 12:56 PM, 9/16/2014 ---PAGE BREAK--- Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ 11.29 mg L ⋅ = Determine diffused aeration efficiency ε τ β ⋅ Ωp ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ ε 34.1 % ⋅ = typical values: fine bubble diffused aeration: 0.33 • coarse bubble diffused aeration: 0.50 • Note: increased MLSS concentrations will lower alpha (e.g. in MBRs) and will lower the oxygen transfer efficiency. Determine required oxygen transfer (AOTR) oxygen demand is given by the following equation: AOTR a' BODin BODout − ( ) b' ⋅ Vr ⋅ + 4.57 ∆N ⋅ + = a` = BOD conversion factor; typically 0.45 to 0.70 a' 0.70 BOD(in) and BOD(out) = influent and effluent BOD, respectively; units of ppd BODin 30400ppd BODout 1570ppd b` = endogenous decay coefficient; typically 0.05 to 0.15 /day b' 0.10 1 day ⋅ = mixed liquor volatile solids concentration in the bioreactor; units of mg/L 1600 mg L V(r) = reactor volume Vr 6.6 106gal ⋅ ∆N = nitrification component in the biological process, accounting for nitrogen assimilation into the biomass. ∆N TKNin PN − ( ) NH3removal ⋅ = P(N) is the fraction on nitrogen in the biomass Nbiomass 12% Y 0.80 volatile yield average biomass generated on a daily basis Px Y BODin BODout − ( ) ⋅ 23064 ppd ⋅ = PN Nbiomass Px ⋅ PN 2768 ppd ⋅ = TKNin 4400ppd NH3removal 100% ∆N TKNin PN − ( ) NH3removal ⋅ 1632 ppd ⋅ = AOTR a' BODin BODout − ( ) ⋅ b' ⋅ Vr ⋅ + 4.57 ∆N ⋅ + 36453 ppd ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 3 12:56 PM, 9/16/2014 ---PAGE BREAK--- Determine standard oxygen transfer (SOTR) and air flow SOTR AOTR ε 107038 ppd ⋅ = density of air at standard conditions: γair_std 0.0808 lb ft3 density at site pressure and temperature: γa Pb M ⋅ Rgas Tempatm ⋅ = Pb Ωp Pstd ⋅ 14.5 psi ⋅ = γa Pb M ⋅ Rgas Tempatm ⋅ 0.0733 lb ft3 ⋅ = estimated diffuser efficiency per foot of depth: η 1.70 % ft Df 20.5 ft ⋅ = depth to diffusers (from above) E η Df ⋅ 34.8 % ⋅ = percent oxygen in air: percentO2 23.18% required airflow at standard conditions: airflow SOTR E percentO2 ⋅ γa ⋅ 12558 cfm ⋅ = Estimate the number of diffusers and floor coverage standard air flow per diffuser at above efficiency, E qsair 2cfm typical: 2 scfm average; 3¯4 scfm at peak conditions estimated number of diffusers: nodif airflow qsair 6279 = estimate area of diffusers: assuming each diffuser has the following surface area: areadif π 4 9in ( )2 ⋅ Adif nodif areadif ⋅ 2774 ft2 ⋅ = basin area, each: Lbasin 106ft Wbasin 76ft Abasin Lbasin Wbasin ⋅ 8056 ft2 ⋅ = number of basins: nobasins 2 calculate total area divided by diffuser area: AT_AD Abasin Adif nobasins 5.81 = per Sanitaire's guidance, this should be above 4.5 as a practical limit \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 4 12:56 PM, 9/16/2014 ---PAGE BREAK--- Determine mixing level Emixing airflow nobasins Abasin 0.78 cfm ft2 ⋅ = compare to a minimum recommended value of 0.12 scfm/sf Estimate blower horsepower Pblower wair Rgas ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ = w(air) = weight flow of air wair airflow γa ⋅ 15.336 lb sec ⋅ = engineering gas constant in terms of pounds of air Rc Rgas M 53.297 ft lbf ⋅ lb R ⋅ ⋅ = Tempinlet 110 °F estimated inlet temperature n k 1 − k = where k is the specific heat ratio; for centrifugal blowers k 1.395 n k 1 − k 0.283 = p1 Pb 14.50 psi ⋅ = absolute inlet pressure as determined above p(2) = the discharge pressure of the blower, estimated as follows (more detailed calculations required): p2 p1 Df γw ⋅ + ∆Hair_pipe + ∆Hdif + = Df γw ⋅ 8.883 psi ⋅ = ∆Hair_pipe 1.5psi ∆Hdif 2ft γw ⋅ 0.867 psi ⋅ = other terms as previously defined p2 p1 Df γw ⋅ + ∆Hair_pipe + 24.88 psi ⋅ = εblower 75% estimated blower efficiency Pblower wair Rc ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ 659 hp ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 5 12:56 PM, 9/16/2014 ---PAGE BREAK--- PROJECT NAME: ¯ Kennewick WWTP: Facility Plan DESIGN TASK: - 2014 Diffused Aeration System ¯ peak hour ENGINEER: ¯ Levi Shoolroy BUDGET NO.: ¯ 30¯13¯056 (100¯006) CHECKED BY: - Definitions: mgd 106 gal day cfs ft3 sec fps ft sec gpm gal min γw 62.4 lbf ft3 cfm ft3 min ppd lb day gpd gal day psi lbf in2 pcf lbf ft3 Pstd 14.7psi For Fine or Coarse Bubble Diffused Aeration Systems Governing equation: ε AOTR SOTR = τ β ⋅ Ω ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ = source: Metcalf and Eddy (5th Edition) Section 5-11 (pp 419 - 424) and Example 8-3 (pp. 760 and 761) Parameters α = relative oxygen transfer rate in process water versus clean water typically 0.50 to 0.60 for fine bubble • typically 0.70 to 0.80 for coarse bubble • α 0.50 β = relative DO saturation to clean water; typically 0.95 to 0.98 β 0.95 Fouling = fouling factor; typically 0.65 to 0.90 Fouling 0.90 Temp = field temperature, ºC Temp 23.8 θ = empirical temperature correction factor θ 1.024 C(target) = bulk DO concentration in MLSS Ctarget 0.5 mg L \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 1 12:57 PM, 9/16/2014 ---PAGE BREAK--- τ = temperature correction factor Cstar(st) = DO surface saturation concentration at operating temperature (M&E Appendix E) Cstarst 8.43 mg L τ Cstarst Cstars20 = Cstar(s20) = DO surface saturation concentration at standard temperature (20ºC) (M&E Appendix E) Cstars20 9.09 mg L τ Cstarst Cstars20 0.927 = G(p) = pressure correction factor P(b) = barometric pressure at site Ωp Pb Pstd = P(s) = standard barometric pressure Pstd 14.7 psi ⋅ = Ωp exp g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ = g 32.174 ft s 2 − ⋅ = gravitational constant M 28.97 lb mole molecular weight of air, per mole zsite 400ft site elevation gc 32.2 ft lb ⋅ lbf sec2 ⋅ slug conversion Rgas 1544 ft lbf ⋅ mole R ⋅ universal gas constant Tempatm Temp°C Tempatm 23.8 °C ⋅ = air temperature ¯ assume equal to wastewater temperature solving... Ωp e g M ⋅ zsite 0ft − ( ) ⋅ − gc Rgas ⋅ Tempatm ⋅ Ωp 0.986 = Cstar(inf20) = standard DO value at sea level and standard temperature (20º C) for diffused aeration Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ = Cstars20 9.09 mg L ⋅ = from above de 0.40 d(e) = mid¯depth correction factor; typically 0.25 to 0.45 Df 20.5ft depth to diffusers Ps 10.33m standard barometric pressure as a check--> Ps γw ⋅ 14.7 psi ⋅ = see next page... \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 2 12:57 PM, 9/16/2014 ---PAGE BREAK--- Cstarinf_20 Cstars20 1 de Df Ps ⋅ + ⋅ 11.29 mg L ⋅ = Determine diffused aeration efficiency ε τ β ⋅ Ωp ⋅ Cstarinf_20 ⋅ Ctarget − ( ) Cstarinf_20 θTemp 20 − ( ) ⋅ α ⋅ Fouling ⋅ ε 40.6 % ⋅ = typical values: fine bubble diffused aeration: 0.33 • coarse bubble diffused aeration: 0.50 • Note: increased MLSS concentrations will lower alpha (e.g. in MBRs) and will lower the oxygen transfer efficiency. Determine required oxygen transfer (AOTR) oxygen demand is given by the following equation: AOTR a' BODin BODout − ( ) b' ⋅ Vr ⋅ + 4.57 ∆N ⋅ + = a` = BOD conversion factor; typically 0.45 to 0.70 a' 0.70 BOD(in) and BOD(out) = influent and effluent BOD, respectively; units of ppd BODin 30400ppd BODout 1570ppd b` = endogenous decay coefficient; typically 0.05 to 0.15 /day b' 0.10 1 day ⋅ = mixed liquor volatile solids concentration in the bioreactor; units of mg/L 1600 mg L V(r) = reactor volume Vr 6.6 106gal ⋅ ∆N = nitrification component in the biological process, accounting for nitrogen assimilation into the biomass. ∆N TKNin PN − ( ) NH3removal ⋅ = P(N) is the fraction on nitrogen in the biomass Nbiomass 12% Y 0.80 volatile yield average biomass generated on a daily basis Px Y BODin BODout − ( ) ⋅ 23064 ppd ⋅ = PN Nbiomass Px ⋅ PN 2768 ppd ⋅ = TKNin 4400ppd NH3removal 100% ∆N TKNin PN − ( ) NH3removal ⋅ 1632 ppd ⋅ = Peaking factor: PF 2.0 AOTR PF a' ⋅ BODin BODout − ( ) ⋅ b' ⋅ Vr ⋅ + PF 4.57 ⋅ ∆N ⋅ + 64094 ppd ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 3 12:57 PM, 9/16/2014 ---PAGE BREAK--- Determine standard oxygen transfer (SOTR) and air flow SOTR AOTR ε 157869 ppd ⋅ = density of air at standard conditions: γair_std 0.0808 lb ft3 density at site pressure and temperature: γa Pb M ⋅ Rgas Tempatm ⋅ = Pb Ωp Pstd ⋅ 14.5 psi ⋅ = γa Pb M ⋅ Rgas Tempatm ⋅ 0.0733 lb ft3 ⋅ = estimated diffuser efficiency per foot of depth: η 1.70 % ft Df 20.5 ft ⋅ = depth to diffusers (from above) E η Df ⋅ 34.8 % ⋅ = percent oxygen in air: percentO2 23.18% required airflow at standard conditions: airflow SOTR E percentO2 ⋅ γa ⋅ 18522 cfm ⋅ = Estimate the number of diffusers and floor coverage standard air flow per diffuser at above efficiency, E qsair 4cfm typical: 2 scfm average; 3¯4 scfm at peak conditions estimated number of diffusers: nodif airflow qsair 4630 = estimate area of diffusers: assuming each diffuser has the following surface area: areadif π 4 9in ( )2 ⋅ Adif nodif areadif ⋅ 2046 ft2 ⋅ = basin area, each: Lbasin 106ft Wbasin 76ft Abasin Lbasin Wbasin ⋅ 8056 ft2 ⋅ = number of basins: nobasins 2 calculate total area divided by diffuser area: AT_AD Abasin Adif nobasins 7.88 = per Sanitaire's guidance, this should be above 4.5 as a practical limit \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 4 12:57 PM, 9/16/2014 ---PAGE BREAK--- Determine mixing level Emixing airflow nobasins Abasin 1.15 cfm ft2 ⋅ = compare to a minimum recommended value of 0.12 scfm/sf Estimate blower horsepower Pblower wair Rgas ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ = w(air) = weight flow of air wair airflow γa ⋅ 22.619 lb sec ⋅ = engineering gas constant in terms of pounds of air Rc Rgas M 53.297 ft lbf ⋅ lb R ⋅ ⋅ = Tempinlet 110 °F estimated inlet temperature n k 1 − k = where k is the specific heat ratio; for centrifugal blowers k 1.395 n k 1 − k 0.283 = p1 Pb 14.50 psi ⋅ = absolute inlet pressure as determined above p(2) = the discharge pressure of the blower, estimated as follows (more detailed calculations required): p2 p1 Df γw ⋅ + ∆Hair_pipe + ∆Hdif + = Df γw ⋅ 8.883 psi ⋅ = ∆Hair_pipe 1.5psi ∆Hdif 2ft γw ⋅ 0.867 psi ⋅ = other terms as previously defined p2 p1 Df γw ⋅ + ∆Hair_pipe + 24.88 psi ⋅ = εblower 75% estimated blower efficiency Pblower wair Rc ⋅ Tempinlet ⋅ n εblower ⋅ p2 p1 n 1 − ⋅ 972 hp ⋅ = \\kwkfiles\public\Project\JUB\30¯13¯056 ¯ COK Wastewater Treatment Plant \Model_Calcs\Spreadsheets\HRT¯biological Page 5 12:57 PM, 9/16/2014 ---PAGE BREAK--- UV EVALUATION APPENDIX 6-B ---PAGE BREAK--- 1218 THIRD AVENUE, SUITE 1600 • SEATTLE, WASHINGTON 98101 • P. [PHONE REDACTED] • F. [PHONE REDACTED] pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx CITY OF KENNEWICK WASTEWATER TREATMENT PLANT TECHNICAL MEMORANDUM NO. 1 UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS FINAL September 2014 Preliminary ---PAGE BREAK--- September 2014 – Final i pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx CITY OF KENNEWICK WASTEWATER TREATMENT PLANT TECHNICAL MEMORANDUM NO. 1 UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS TABLE OF CONTENTS Page No. 1.0 INTRODUCTION 1-3 2.0 EXISTING SYSTEM PERFORMANCE AND CAPACITY 1-3 2.1 System Performance and Capability 1-5 3.0 SYSTEM OPERATION EVALUATION 1-13 3.1 Efficiency Concerns 1-13 3.2 Operational 1-14 3.3 UV Parts Replacement Issues 1-14 4.0 ALTERNATIVES DEVELOPMENT 1-15 4.1 Projected Flows 1-15 4.2 Effluent Requirements 1-16 4.3 Alternative Description 1-16 5.0 ALTERNATIVES EVALUATION 1-19 5.1 Project Cost Evaluation 1-19 5.2 Alternatives Evaluation Matrix 1-21 6.0 1-21 LIST OF TABLES Table 1 KWTP UV System Design Criteria and System Configuration 1-3 Table 2 Dose Comparison 1-10 Table 3 Existing and Projected Flows 1-16 Table 4 Disinfection Requirements 1-16 Table 5 Name of Table - Auto Numbering is on for Tables 1-19 Table 6 UV System Alternatives Project Cost 1-21 Table 7 Cost and Non-cost Evaluation 1-22 LIST OF FIGURES Figure 1 KWTP System Components 1-4 Figure 2 Daily, Weekly Fecal Coliform Effluent Concentration 1-6 Figure 3 KWTP Daily Measured UVT data 1-7 Figure 4 KWTP Collimated Beam Results 1-9 Figure 5 Carollo Optics Bench for Lamps Output Testing 1-12 Figure 6 Performance Measures 1-20 ---PAGE BREAK--- September 2014 – Final 1-3 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx Technical Memorandum No. 1 UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS 1.0 INTRODUCTION The City of Kennewick (City) owns and operates the Kennewick Wastewater Treatment Plant (KWTP). The KWTP liquid stream process consists of a high-rate aerated lagoon system with return activated sludge, intermediate and final clarification, followed by UV disinfection prior to being discharged into the Columbia River. This Technical Memorandum (TM) will be included as part of a larger facilities plan. The two main objectives of this TM are: • Evaluation of the capacity and performance of the existing UV system. • Development and comparison of UV system upgrade alternatives to improve energy efficiency and ease of operation and/or meet disinfection requirements for current and projected flows. 2.0 EXISTING SYSTEM PERFORMANCE AND CAPACITY The existing UV system, a Trojan UV3000 system, is one of the first generation of UV systems that Trojan manufactured in mid 1990s. The system was installed at KWTP in 2000. The system is stand-alone, without monitoring or control functions available at SCADA. The system currently operates at full-power, due to insufficient controls for reliable turn-down. The system is composed of four UV banks, a power distribution center, and a control panel, as shown in Figure 1. The design criteria and existing system configuration is described in Table 1. Table 1 KWTP UV System Design Criteria and System Configuration UV System Evaluation and Alternatives Analysis City of Kennewick Criteria Configuration Peak instantaneous flow rate 12.2 million gallons per day (mgd) UVT 60% Dose 22 mJ/cm2 Number of Channels 2 Number of Banks 2 per channel Number of Modules 13 per bank Number of Lamps 8 per module (416 total lamps) Plant staff report that the system has not been modified since the original installation. Currently all available channels are in-use. ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_01.docx KWTP UV SYSTEM COMPONENTS FIGURE 1 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS CONTROL PANEL HMI INTERFACE (NOT SHOWN IN SECTION) ---PAGE BREAK--- September 2014 – Final 1-5 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx 2.1 System Performance and Capability Before UV system improvement/replacement options can be identified and evaluated, it is critical to understand the performance of the existing system, in terms of both system efficiency and water quality impacts. 2.1.1 System Performance Current removal performance for average day, week, and month is shown in Figure 2. As 200 coliform forming units (CFU)/100 ml is the current permit limit and 400 CFU/100 ml the weekly limit, the data indicates the existing system adequately meets the permitted disinfection requirements of KWTP. 2.1.2 Treatment Capabilities To determine the ultimate capacity of a UV system, influent bacterial loads, influent particle counts, and UV transmittance (UVT) must be measured and analyzed. To that end, a series of water quality samples were collected over a three-week period between March 22, 2014 to April 04, 2014. 2.1.2.1 UV System Influent Transmittance. UVT is a critical evaluative property of the UV system influent, which determines how effectively UV light is transmitted through the water for bacterial inactivation. For a three- week period between March 22, 2014 to April 04, 2014, KWTP plant staff collected daily samples from the UV influent channel for UVT measurement by Carollo staff. UVT measurements were performed using a calibrated bench-scale spectrophotometer. The UVT values ranged between 60 and 65 percent. Figure 3 shows the results of the daily samples by time of day. These results are generally within the expected range for an unfiltered secondary effluent. The values dropped during the end of the sampling period. Plant staff indicated that this may be associated with the supernatant return from the waste active sludge (WAS) storage lagoon that occurs when a significant amount of WAS is dumped to the lagoon. The lagoon overflow is mixed with the secondary effluent prior to UV treatment. UVT samples of the secondary effluent, collected upstream of the addition of the lagoon overflow, was only higher than the mixed effluent (64.8 percent vs. 63.4 percent before and after mixing, respectively). As reported in the 1999 MWH report titled “Preliminary Design Memorandum of UV Disinfection System”, the UVT varied from less than 50 percent to greater than 70 percent. At that time, there was a Welch’s juice processing plant that discharged to the KWTP; however, a few years ago this plant was shut down, thus the reduced UVT impact is not expected. No other major industrial discharges feed into the plant currently and thus it appears the UVT has stabilized. Therefore, based upon the limited data, a conservative UVT of 60 percent will be assumed for this analysis. ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_02.docx 1 10 100 1000 February 2008 July 2009 November 2010 April 2012 August 2013 December 2014 Effluent Fecal Coliform, CFU per 100 mL Daily Average Weekly Average 30‐day running Average DAILY, WEEKLY FECAL COLIFORM EFFLUENT CONCENTRATION FIGURE 2 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS 400 200 Weekly Fecal Coliform Permit Limit Fecal Coliform Permit Limit ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_03.docx 50 55 60 65 70 Mar‐20 Mar‐22 Mar‐24 Mar‐26 Mar‐28 Mar‐30 Apr‐01 Apr‐03 Apr‐05 UV Transmittance % KWTP DAILY MEASURED UV TRANSMITTANCE DATA FIGURE 3 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS ---PAGE BREAK--- September 2014 – Final 1-8 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx 2.1.2.2 Microbe Inactivation Another property of the UV influent is the UV dose required to inactivate the bacteria present in the influent. To understand the relationship between target microbe inactivation and UV dose, collimated beam testing was performed on undisinfected secondary effluent from KWTP. Collimated beam tests are used to relate the log removal of total coliform to a specific UV dose expressed in mille joules per square cm (mJ/cm2). This data can then be used to calculate the dose of an operational system. Collimated beam tests are a standard method of the UV industry and are critical to understanding the required UV dose to meet permit. Four sets of collimated beam results from KWTP (Figure 4) show that low UV doses (as low as 10 mJ/cm2) are sufficient to meet effluent standards (200 CFU /100 mL) and that a dose of 15 - 25 mJ/cm2 would be sufficient to meet one log below the permit standards (with some level of variability also shown). Concurrent with the sampling for the collimated beam analysis, Carollo collected UV effluent samples for fecal coliform analysis. The red dots in Figure 4 shows the results of the UV effluent sampling. Superimposing the collimated beam graph and the effluent samples, the existing system operating at 100 percent capacity (all channels and all banks were operational) is delivering a dose between 10 and 15 mJ/cm2. All of the microbiological data presented herein were sampled by Carollo staff, and then analyzed by Gap Laboratories, Inc. (GAP). 2.1.2.3 Comparison to UV3000 Validation Testing The measured doses (Figure 4) are compared to results of detailed UV3000 reactor performance testing (often called validation testing). This comparison can reveal, if the measured dose does not match the expected doses, inefficiencies in the current UV operation and design. In 2007, Trojan performed validation testing of a pilot-scale UV3000 reactor in London, Ontario. The goal of this testing was to accurately estimate the dose delivery performance of the UV3000 for a range of applications. This testing resulted in a UV dose algorithm that can predict the MS2 coliphage reduction equivalent dose (RED, mJ/cm2) based on inputs of end of lamp life (EOLL) and sleeve fouling factors (FF), flowrate, and UVT. The specifics of that validation are confidential to Trojan, but our team has an understanding of performance from that testing which is incorporated here. Related to the differences in test organisms, testing has shown that different organisms respond differently to UV disinfection, called a reduction equivalent dose bias (RED bias). For example, viruses tend to be more resistant to UV disinfection than bacteria. MS2 coliphage is a surrogate for virus and T1 coliphage is a surrogate for bacteria. Sizing UV systems based upon T1 validation is ideal and more accurate for KWTP, but the UV3000 was tested using MS2. In such cases where manufacturers have not validated their system based on T1 (or coliform), MS2 validations can be allowed. To account for the difference between the dose responses of the organisms, higher doses will be specified for systems validated with MS2. Based on systems that have been validated by Carollo using ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_04.docx 1 10 100 1,000 10,000 100,000 0 5 10 15 20 25 30 35 40 45 50 Fecal Colifrom, CFU/100 mL UV Dose, mJ/cm2 Fecal Coliform, UVT = 61.6, Time =11:30 am Fecal Coliform, UVT = 61.6, Time =11:30 am Fecal Coliform, UVT = 63.4, Time =2:30 pm Fecal Coliform, UVT = 63.4, Time =2:30 pm Fecal Coliform Permit Limit The red dots shows the results of the samples collected from the UV effluent channels .Based upon the collimated beam graph and the effluent samples, the exisiting system is delivering a dose between 10 and 15 mJ/cm2. KWTP COLLIMATED BEAM RESULTS FIGURE 4 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS Permit of 200 CFU/100 ml ---PAGE BREAK--- September 2014 – Final 1-10 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx both MS2 and T1/fecal coliform, the ratio between the two (the RED bias) tends to be between 1.3 and 1.7, meaning that a T1/fecal coliform estimated inactivation delivered of one is equivalent to an MS2 inactivation delivered dose between 1.3 and 1.7, with a reasonable RED bias estimate of 1.5. The anticipated UV dose delivery (from the UV dose algorithm developed for the UV3000 unit) is compared to the calculated dose delivery from the collimated beam testing on the unit at KWTP (Table The comparison demonstrates that the predicted dose formula developed by Trojan from their validation testing does not accurately represent the performance of the KWTP UV reactor (off by a factor of 1.7 to 2.1). The observed lower than expected UV dose of the KWTP UV system can be due to multiple variables, including RED bias, very limited sample data size, channel imperfections, flow split, UV influent water levels, or uniformity of flow to the upstream UV reactors (short circuiting). Each of these, with the exception of RED bias, which is reviewed previously, is addressed in subsequent sections. Table 2 Dose Comparison UV System Evaluation and Alternatives Analysis City of Kennewick Design Condition Estimated Dose(1), mJ/cm(2) Dose based effluent samples(2), mJ/cm(2) Ratio Total Flow =6.15 mgd, UVT=61.6% 25 ~11 2.1 Total Flow =6.15 mgd, UVT =61.6% 26 ~12 2.0 Total Flow =6.96 mgd, UVT =63.4% 24 ~14 1.7 Total Flow =6.96 mgd, UVT =63.4% 26 ~15 1.7 Notes: The above doses are calculated based upon an understanding of the UV3000 performance from the 2007 validation testing with a lamp aging factor of 0.50 and a sleeve-fouling factor of 0.92 (channel 1) or 0.97 (channel Aging and fouling numbers are based upon field measurements of the existing UV equipment at the KWTP. The actual fecal coliform UV dose is based upon the effluent fecal coliform concentrations for each test condition as shown in Figure 3. 2.1.2.4 Headloss and Water Level Measurements The Trojan UV3000 at the KWTP has 8 lamps per module, with a 3-inch lamp centerline to lamp centerline spacing. The 3-inch spacing allows for efficient operation of the UV3000, with neither too little space between lamps (resulting in an overlap of UV intensity fields and thus reduced energy efficiency) and too much spacing between lamps (resulting in insufficient UV light to a portion of the water resulting in treatment compliance problems). The perimeter lamps are thus ideally spaced 1.5 inches from the centerline of each ---PAGE BREAK--- September 2014 – Final 1-11 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx perimeter lamp to the edge of the disinfection field (top of water, side wall, channel floor). As the protective quartz sleeve on each lamp has a diameter of 0.9 inches, the ideal thickness of water between the quartz sleeves and the edge of the disinfection field (again, top of water, side wall, channel floor) is 1 inch (1.5 inch-0.9”/2). Ideally, the water level in the UV channel would be maintained between 23 inches (to avoid the top lamp being exposed) and 24 inches (to avoid potential short-circuiting above the lamps). The water depth at the KWTP is measured with ultrasonic level indicators installed after the inlet baffle plate and before first UV bank on the upstream end of each channel. At the time of the site inspection/audit, the ultrasonic meters displayed a water depth of 24.8 inches for channel 2 and 25 inches for channel 1. The reduced performance of the existing UV system is in part due to excessive water depth over the top of the upstream UV reactors, resulting in passage of partially disinfected water through the system to the effluent sampling location. As reviewed above, the ideal variation in water level across the UV3000 is 1 inch (24 -23 inches), which then becomes the target maximum acceptable headloss through both the UV banks. As the system does meet permit with the higher water level, we recognize that this head loss range is only a recommendation to increase performance efficiency. Estimates from other sites suggest that a flow of greater than 7.5 mgd through both channels (3.75 mgd in one channel) will result in greater than 1 inch of head loss across the channel (across both banks). The 7.5 mgd does not represent the capacity of the existing system, rather the theoretical hydraulic capacity of a system operating at ideal conditions. The capacity of the system to treat current and future flows is determined by the current performance and CFU data, which indicates suitable capacity to meet permit under projected flows and loads. 2.1.2.5 Lamp Aging The Trojan UV3000 utilizes standard low-pressure low output (LP) lamps. The historical performance of LP lamps supplied by Trojan for the UV3000 is high, with the lamps losing approximately 10-15 percent of their output over 11,000+ hours of operation. Carollo has seen these same lamps provide disinfection at up to 18,000 hours of operation. The current lamps installed at the KWTP are provided by Livingston Micrographics, a reduced cost product compared to the lamps supplied by Trojan. The performance of those lamps, both in terms of long-term output and lamp life, are not well quantified in the industry. Lamp output testing was done on two sets of aged lamps using the optics bench techniques developed by Carollo (Figure The lamps currently in operation (Livingston Micrographics) showed significant reduction in output (50 percent reduction) after only 5,000 hours of operation. The 50 percent reduction in intensity was included into the UV dose delivery analysis reviewed above, and has a significant impact on overall capacity of the UV3000 system. ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_05.docx CAROLLO OPTICS BENCH FOR LAMPS OUTPUT TESTING FIGURE 5 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS ---PAGE BREAK--- September 2014 – Final 1-13 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx 2.1.2.6 Sleeve Fouling The fouling of the protective quartz sleeves, either due to mineral deposition or biofilms, results in a drop of UV intensity and thus a drop in UV disinfection performance. For some facilities, fouling can drop the UV intensity by 5 to 10 percent per day, resulting in disinfection compliance problems after only a few days of operation. For other facilities, sleeve fouling may be only a few percent per month, allowing for long run times between cleaning. Once the fouling rate is quantified, treatment plant staff can set the sleeve- cleaning interval to maintain performance. Our typical recommendation is to keep the quartz sleeves cleaned to within about 90 percent of a new and clean sleeve. Sleeve fouling was measured on sleeves from both channels. The sleeves from channel 2 had been manually cleaned three weeks prior to the site visit, while those from channel 1 had not been cleaned for approximately 3 months prior to the site visit. Results from sleeve fouling analyses showed that fouling resulted in a reduction of light transmission of 3 percent and 8 percent for channel 2 and 1, respectively. This indicates that fouling is not a significant problem for KWTP, and cleaning the sleeves every two to three months appears to be a sufficient interval for long-term operation. 3.0 SYSTEM OPERATION EVALUATION Although current operations and maintenance practices have consistently met the disinfection water quality requirements, the existing controls do not include critical monitoring such as UVT and UV dose. Currently, the PLC’s HMI displays only a UV intensity value, which has no direct bearing on actual dose provided and the disinfection potential of the UV reactor. This UV intensity value, using inaccurate sensors, is used to calculate dose based upon a simple (and inaccurate) dose model from Trojan, which met the standard of the industry at the time of installation. Therefore, it does not provide a real- time indication of the performance of the UV banks. The system also does not have the capability to monitor details such as individual bulb outages. 3.1 Efficiency Concerns With no online UV intensity or UVT monitors, there is currently no accurate way for plant staff to adjust the number of operational banks to meet the treatment goals based on real- time UVT, UV intensity, and flowrate measurements, resulting in periodic or continual UV doses in excess of what is needed. Upgrading the control system with better sensors, online UVT, and a more accurate system control method would allow the UV system to more efficiently meet the disinfection water quality requirements. Remote monitoring is limited to major faults and alarms that require operations staff to physically access the local control panel, where additional detail is shown. While the KWTP consistently meets its effluent permit requirements, the equipment and controls can results in excess energy use at the facility and more frequent UV system maintenance (such as bulb and ballast replacement) than would otherwise be necessary. ---PAGE BREAK--- September 2014 – Final 1-14 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx Because of the model of the UV reactor (LP), there is not an ability to modulate power to each bank to more closely meet the required UV dose and run with better efficiency. Newer UV system technologies offer the ability to modulate power to a bank of lamps (rather than a simple on/off control), which would provide KWTP staff further ability to match the UV dose delivery with actual requirements and achieve additional energy savings. 3.2 Operational Concerns Currently, the UV disinfection system requires two-channel operation at all times for flows greater than 2 mgd. The total power requirement for the existing system, which consists of 416 lamps, is 40 kilowatts. Thus, an updated control system could run only one channel (208 lamps) for 50 percent time, and two channels for the remaining 50 percent of the time (50 percent is an assumption), cutting back UV reactor usage by 10 kilowatts. The primary concern of plant staff regarding the operation of the UV system is lack of system monitoring and control at SCADA. Currently, SCADA only reports sensor intensity alarms from the UV system. No operating data is available at SCADA. Another significant problem is the unpredictable loss of the first bank of lamps in an operating channel. The loss of the influent bank is for no apparent reason, and a Trojan field technician has not been able to fix the problem. This is a possible fatal flaw of the UV system, particularly with the inaccurate controls of the entire UV system. Losing 50 percent of dose in one channel is a significant drop, and should be considered acceptable only if the second bank can provide sufficient dose to meet permit. 3.3 UV Parts Replacement Issues The reliable operation of the UV system requires the ability to quickly and cost effectively obtain replacement parts. Typically, these parts, except for lamps and ballast, must be obtained from the UV system manufacturer. 3.3.1 Lamps and Ballasts The two major replacement items for the existing UV system is lamps and ballasts. Of the two, the lamps are the major cost component. Lamp replacement is generally done when the lamps reach there maximum life expectancy. Over the years of operation, several lamp suppliers have been utilized by KWTP. Trojan lamps have generally performed well, lasting from 12,000 to as high as 26,000 hours. Due to the high Trojan lamps cost ($115 per lamp), aftermarket lamps from the UV Doctor ($55 per lamp) were utilized for some time period. These lamps had shorter lamp life, running for about 8,000 hours before a significant rise in fecal coliform counts was observed, at which time new Trojan lamps were installed. Currently, the plant is using lamps from Livingston Micrographics, these lamps are guaranteed for 12,000 hours. However, during the site visit, an analysis of the currently installed lamps from Livingston Micrographics shows that the lamp output is approximately only 50 percent compared to new lamps. Significant lamp darkening, uniformly distributed along the length of the lamps, was observed for these lamps, currently operating with only ---PAGE BREAK--- September 2014 – Final 1-15 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx 5,000 hours of usage. Our experience with Trojan lamps is a reduction of approximately 10 to 15 percent over 11,000+ hours of operation. The Trojan lamps typically have only limited lamp darkening except at the point of the lamp electrode. Six to eight ballasts are replaced in the system every 1 to 2 years. The plant is currently using ballast and quartz sleeves from the UV Doctor and have had no complaints with these components. Costs for replacement ballasts from UV doctor are $115 each, and quartz sleeves are approximately $25, which is half the quoted price from Trojan. 3.3.2 Proprietary Panel Electronics Although failure and replacement of communication and power regulating electronic boards is unexpected, especially in newer systems, delays in replacement can adversely affect the reliable operation of the UV system to meet permitted disinfection requirements. Subsequent to the performance and capability evaluation of the existing UV system, Trojan notified the City on March 26, 2014 that support, including parts, for the existing UV3000 unit will be discontinued as of March 31, 2015. This notification limits the longevity of the existing UV system. 4.0 ALTERNATIVES DEVELOPMENT The development and evaluation of alternatives effort focused on improvements to the UV system to increase energy efficiency and ease of operation, while meeting disinfection demands at the projected 2034 flows. Three categories of alternatives were evaluated: • Alternative 1: “Do Nothing” includes modification of lamp procurement (using Trojan supplied lamps), and optimization/control of water level by limiting flows through each channel (as possible). • Alternative 2 “Upgrade Controls and Monitoring” includes control system and instrumentation upgrades to allow better operational control of the UV system. • Alterative 3 “System Replacement” replaces the existing system with a more energy efficient second generation UV technology. 4.1 Projected Flows The KWTP consistently operates at average flow of approximately 5 mgd. The original UV system design criteria was for a peak flow capacity of 12.2 mgd. On the day of the site audit, the flow through the UV system was about 6 to 7 mgd. Existing and predicted future average day, maximum month, peak day, and peak hour flows are shown in Table 3. ---PAGE BREAK--- September 2014 – Final 1-16 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx Table 3 Existing and Projected Flows UV System Evaluation and Alternatives Analysis City of Kennewick Flow Condition Existing (mgd) Year 2034 (mgd) Average Day 5.35 7.94 Maximum Month 6.34 9..40 Peaking Factor 1.19 1.19 Peak Day 8.37 12.40 Peaking Factor 1.56 1.56 Peak Hour 10.7 15.90 Peaking Factor 2.00 2.00 4.2 Effluent Requirements Table 4 summarizes effluent limitations related to disinfection. These limitations are not expected to change over the 20-year planning period and have been adopted for the basis of the evaluation of future system capacity. Changes in KWTP plant influent sources or secondary treatment processes may increase or decrease the capacity of the existing system. Table 4 Disinfection Requirements UV System Evaluation and Alternatives Analysis City of Kennewick Parameter(1) Average Maximum Average Weekly Total Suspended Solids 30 mg/L, 2,552 lbs/day 85% removal of influent TSS 45 mg/L, 3,828 lbs/day Fecal Coliform Bacteria 200 /100 mL 400/100 mL Notes: The average and weekly limitations for fecal coliform bacteria are equal to the geometric mean of the samples taken. 4.3 Alternative Description 4.3.1 Alternative 1: “Do Nothing” This alternative includes changes to operational practices to maintain 1 inch of hydraulic loss in the unit and/or lamp replacement protocols to assure more reliable UV treatment as flows increase. Installation of wet sensors to monitor and extend lamp life is also included as a minor improvement. Replacement of the current aftermarket lamps as required to maintain useful with Trojan lamps is also assumed. The “Do Nothing” altenative will reliably treat the existing and projected flows given the UV system influent characteristics to the UV do not substantially vary from current values. ---PAGE BREAK--- September 2014 – Final 1-17 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx 4.3.2 Alternative 2: Upgraded Monitoring and Control The communications and electrical components of the Trojan UV3000 are limited in functionality. Current UV reactors rely on real-time measurements of flowrate, UVT, and UV lamp intensity measurements to adjust the number of lamps in operation to meet a UV dose or effluent water quality goal. The existing system is controlled strictly on flowrate and does not account for water quality or lamp performance (age and fouling). Installation of wet sensors in each channel will allow for more dose delivery confidence, and allow monitoring of lamp output decay. Use of calibrated, reliable sensors in this way can result in an extension of lamp life to 18,000 hours and a more accurate determination of sleeve cleaning intervals. In addition to adding wet sensors in the UV channels, upgrading the Programmable Logic Controller (PLC) and HMI would be required to provide continuous real time dose monitoring of the system and better define alarm conditions and necessary responses. Together, the PLC and the HMI are referred to as the System Control Center (SCC). Carollo did not contact the UV supplier to provide the cost of upgrading current system for this project. Based upon the recent estimate for a similar size project (Aurora Colorado, owners of the identical UV technology), the UV supplier’s estimate to upgrade the controls was in the range of $80,000 to $120,000, depending upon specific requested items. In all, the potential upgrade of the existing monitoring and control system may include: addition of calibrated wet sensors, replacement of the existing SCC, addition of an online UVT meter, and SCADA modifications to address the improved/added monitoring and control features. These features will not allow the UV system to “turn-down” to meet varying demands except by turning entire banks on and off. This alternative will not replace all the electronics that will become obsolete per the Trojan letter dated 3/26/2014. In discussions with Trojan, the replacement of the “guts” of the UV3000 is not a feasible alternative and would be more costly and result in a less reliable hybrid system then full replacement. 4.3.3 Alternative 3: UV Equipment Replacement The existing UV equipment is effective in meeting current and future permit requirements, but with substantial limitations related to efficiency, operational control, and maintenance as previously described. The system is also 14 years old, and there have been major advancements in UV technologies since the original installation. As a basis of comparison, a review of potential UV replacement technologies is presented here. UV reactors from three different UV equipment manufacturers were considered (Trojan, Xylem/Wedeco, and Calgon). All manufacturers listed are suitable for use in the existing KWTP channels. A preliminary evaluation of each manufacturer indicates that these manufacturers could competitively bid the work and make their respective system suitable at KWTP. ---PAGE BREAK--- September 2014 – Final 1-18 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx New equipment from Trojan, Xylem/Wedeco, or Calgon would include several improvements that are now considered industry standard. These improvements include automatic lamp cleaning systems, the ability to modulate power to a bank of lamps, online (and accurate) UV intensity sensors, and higher intensity lamps that result in a need for less equipment than the LP UV lamps in the UV3000 reactor. An online UVT meter is recommended for the existing system or any potential replacement alternatives. The design criteria for a new system are as follows: • Peak Design Flow –16.1 mgd (peak hour flow of 2034) with no redundancy and replace the entire UV system. • Design UVT – 60 percent. • T1 Design Dose – 20 mJ/cm2 using a T1 coliphage sizing model, which is ~30 mJ/cm2 using an MS2 coliphage sizing model. 4.3.3.1 Trojan 3000Plus The Trojan UV3000Plus system, with significantly fewer lamps than the existing system, could be employed based upon the design criteria presented above. With an lamp wattage of ~250W, these lamps emit about 3 times the UV radiation per lamp as the existing LP system. In addition to the cost of new UV equipment, this option will also require modifications to the existing channels and likely to the effluent weir. Because power to the Trojan UV3000Plus is fed in a similar manner to the UV3000 (via PDCs located above the banks), significant electrical work should not be required. 4.3.3.2 Xylem/Wedeco TAK55 UV Systems The Xylem/Wedeco TAK 55 reactor is similar to the UV3000Plus in terms of efficiency, orientation (horizontal lamps in an open channel reactor), # of lamps, and cost. One difference between the two systems is how power is fed to the UV reactors. While the PDCs for the Trojan system are located directly above the banks, the Wedeco PDCs are located in stand-alone cabinets. This offers both advantages and disadvantages in general, but in this case will add complexity to the electrical design for the new system. 4.3.3.3 Calgon C3500 The Calgon C3500 is a newer high-efficiency UV technology, with 575W per lamp. The lamp spacing for the C3500 reactor centerline to centerline) is larger than for either the UV3000Plus or the TAK 55. Therefore, the system hydraulics are not impacted as much by the reduced number of lamps. In addition to the cost of new UV equipment, this option may require modifications to the existing channels. Changes to the effluent weir may also be required. This option will also ---PAGE BREAK--- September 2014 – Final 1-19 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx require more significant electrical modification than the UV3000Plus alternative in order to feed power to the UV banks. 5.0 ALTERNATIVES EVALUATION Alternatives being developed for the KWTP will require a balance between cost control, operational goals, and other non-economic criteria. Each UV improvement alternative will be evaluated against the full list of criteria using the performance measures developed in the workshop on April 15, 2014 with the City and presented in Figure 6. Please note modifications to this table to eliminate safety in the matrix, as all proposed alternatives will be developed and priced to assure safe equipment operation and maintenance. 5.1 Project Cost Evaluation Estimated project costs for each alternative were developed based on manufacturers’ equipment supply estimates and associated direct costs for installation and/or upgrade of existing facilities. Mark-ups to the direct costs are shown in Table 5. Table 5 Name of Table - Auto Numbering is on for Tables UV System Evaluation and Alternatives Analysis City of Kennewick Project Element Cost Contractor General Conditions 12.5% Contractor Overhead and Profit 10% Design contingency 30% Engineering (Design and ESDC) 20% Present Worth Rate 3% Sales Tax 8.3% Legal and Administration 3% Table 6 lists the project cost for each alternative in 2014 dollars assuming implementation of the improvements in 2015-2016. Alternative 3 is the most costly, but provides the most reliable disinfection system over the planning period. Alternative 2 would have been an attractive option to extend the life of the existing system, had Trojan not discontinued its support of various UV components. Without the support for critical electronics in the existing UV3000 system, the City would need to be comfortable with accepting the risk of the system being out of service for an extended period of time in the future for component ---PAGE BREAK--- pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/Fig_06.docx Criteria A) Present Worth Cost B) Permit Compliance C) Reliability D) Safety E) Ability to Expand F) Sustainability G) Odor Potential H) Ease of Operations I) None J) None K) None Total Score Weight Rank A) Present Worth Cost x 1 2 1 3 4 1 2 14 8.3% 7 B) Permit Compliance 5 x 4 3 4 4 4 4 28 16.7% 3 C) Reliability 4 2 x 2 3 4 1 3 19 11.3% 4 D) Safety 5 3 4 x 5 5 4 4 30 17.9% 1 E) Ability to Expand 3 2 3 1 x 4 1 3 17 10.1% 6 F) Sustainability 2 2 2 1 2 x 1 2 12 7.1% 8 G) Odor Potential 5 2 5 2 5 5 x 5 29 17.3% 2 H) Ease of Operations 4 2 3 2 3 4 1 x 19 11.3% 4 I) None x 0 0.0% J) None x 0 0.0% K) None x 0 0.0% Each criteria in the first column is compared against remaining criteria in the top row to establish relative importance as follows: 5 – significantly more important 4 – more important 3 – equally important 2 – less important 1 – significantly less important PERFORMANCE MEASURES FIGURE 6 CITY OF KENNEWICK UV SYSTEM EVALUATION AND ALTERNATIVES ANALYSIS ---PAGE BREAK--- September 2014 – Final 1-21 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx replacement. This risk is only compounded by the sporadic and unintentional shutdown of UV banks. Table 6 UV System Alternatives Project Cost UV System Evaluation and Alternatives Analysis City of Kennewick Alternative Project Cost Alternative 1: Do Nothing $30,000 Alternative 2: Upgrade Monitoring and Controls $390,000 Alternative 3: Replace UV System $2,300,000 5.2 Alternatives Evaluation Matrix Table 8 shows the results of the evaluation matrix for cost and non-cost items for the UV System Improvement Alternatives developed with the City. At the workshop on May 15, 2014 the City selected Alternative 3 UV System Replacement as the preferred alternative to move forward into the Capital Improvements Program. 6.0 CONCLUSIONS The conclusions summarized below are a result of a planning level analysis. • The existing system reliably meets permit. • The dose delivery of the existing system is in the range of 12 to 15 mJ/cm2, which is above the estimated minimum required dose of 10mJ/cm2. The system is providing less dose than anticipated based upon the latest science on the UV3000. Reasons for performance problems are speculated within the report. ---PAGE BREAK--- September 2014 – Final 1-22 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx Table 7 Cost and Non-cost Evaluation UV System Evaluation and Alternatives Analysis City of Kennewick Criteria Definition Alternative 1: Do Nothing Alternative 2: UV System Control Upgrades Alternative 3: New UV System Weight A. Present Worth Cost Planning level capital cost plus expected life-cycle cost of an alternative, both in 2014 dollars. 5.0 4.5 1.0 8.3% B. Permit Compliance Ability to satisfy existing and projected permit requirements over the course of the study period. 1 5 5 16.7% C. Reliability Probability of adequate performance over the expected range of loading and operating conditions in the study period. 1 1 5 11.3% D. Safety Degree to which operators are exposed to hazardous conditions that could result in injury - - - 17.9% E. Ability to Expand Ability to expand and adapt a process for greater loading and/or to address changes in permit requirements. 1 1 5 10.1% F. Sustainability Energy Efficiency Overall efficiency of the alternative, energy use, carbon footprint, and consumption of non-renewable resources 1 3 5 7.1% G. Odor Potential Potential of an alternative to cause foul odors during operations through the course of a year. - - - 17.3% H. Ease of Operations Ease of operations and complexity of the process, including the need for specialized operators and process control / testing 2 3 5 11.3% I. None 0.0% J. None 0.0% K. None 0.0% Weighted Score(1) 1.10 1.98 2.91 100.0% Ranking 3 2 1 Notes: Each alternative is scored from 1 (worst or most negative impact) to 5 (best or least impact) ---PAGE BREAK--- September 2014 – Final 1-23 pw://Carollo/Documents/Client/WA/Kennewick/9384A00/Deliverables/TM1 UV System Eval.docx • The water level in the upstream UV banks is approximately 1 inch above acceptable levels. The ideal water level is 24 inches, and current operation results in a water level of ~25- inches. The likely impact of this increased water level is reactor short- circuiting and a reduction in disinfection efficiency. • Ideally, the water level in the UV channel would be maintained between 23 inches (to avoid the top lamp being exposed) and 24 inches (to avoid potential short-circuiting above the lamps). The maximum acceptable total headloss through both the UV banks is 1 inch (24 inches – 23 inches). The headloss of the existing UV system is estimated to be more than 1 inch if the total flow is greater than 7.5 mgd. Based upon this headloss criteria, the existing UV system is hydraulically limited to 7.5 mgd, but can operate with lower dose effectiveness at higher flows up to 16.1 mgd • Our measurements show that the lamps currently installed have lost 50 percent of their output after only 5,000 hours of operation, significantly impacting reactor disinfection efficiency. Returning to a higher performance (and higher cost) lamp is recommended. • The primary concern of plant staff regarding the operation of the UV system is lack of system monitoring and control at SCADA. Replacement of system controls and the addition of online monitoring of lamp intensity and UVT will substantially increase the accuracy and control of the system, but not to the same level of the latest UV reactors. • The random and inadvertent shutting down of the influent bank, which has not been remedied by Trojan, is a potential fatal flaw in the existing UV system. • Based upon the Trojan letter dated March 26, 2014, the TrojanUV3000 disinfection system would only be supported until March 31, 2015 and some of the UV parts will have limited availability. • New equipment from Trojan, Xylem/Wedeco, or Calgon would include several improvements that are now considered industry standard. The new system can be sized for peak design flow of 16.1 mgd (peak hour flow of 2034) with no redundancy and replace the entire existing UV system. • The preferred alternative is the replacement of the existing UV system with a new UV system. • The new UV system can be competitively bid among multiple manufacturers. • The planning level estimated project costs for a new system is approximately $2.3 million. This cost does not include the installation of a redundant energy supply, but does include upgrading to the existing electrical UV distribution system. ---PAGE BREAK--- ---PAGE BREAK--- ---PAGE BREAK--- LIQUID STREAM COST OPINIONS APPENDIX 6-C ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 New Bypass Structure in Kingwood Street 2 Bypass plug / pumping 1 LS $5,000 $5,000 3 Pre-cast structure 1 LS $35,000 $35,000 4 Excavation & backfill 1 LS $25,000 $25,000 5 Gate to bypass line / Influent Pump Station 1 LS $15,000 $15,000 6 Asphalt Removal and Surface Repair 230 SY $25 $5,750 7 Traffic Control 1 LS $2,500 $2,500 8 Interceptor Tie-in 1 LS $7,000 $7,000 9 Influent Pump Station $0 10 3-ton bridge crane & hoist, electric operating 1 LS $35,000 $35,000 11 Bridge crane support structure 1 LS $30,000 $30,000 12 Ship ladder for valve vault access 1 LS $10,000 $10,000 13 Grit trap (cross-flow floor-mount baffles) 1 LS $15,000 $15,000 14 Items Not Included: $0 15 Cover valve vault $0 16 Valve vault ventilation system $0 17 Rebuild check valves $0 18 $0 19 $0 20 $0 21 Additional Elements (estimated as % of above) 22 Contractor mobilization and administration 10.0% $19,000 23 Yard Piping 2.5% $5,000 24 Site Civil 2.5% $5,000 25 Electrical and instrumentation 10.0% $19,000 26 Bonding 2.5% $5,000 27 Contractor overhead and profit 10.0% $19,000 SUBTOTAL 257,000 $ Contingency: 30% 77,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 28,000 $ Design / CMS: 20% 67,000 $ Legal and Administrative: 1% 3,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 430,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages General Upgrades to Bypass Structure and Influent Pump Station COK WWTP facility plan - cost opinion.xlsx / Prelim Trt-General J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Grit Dewatering Building 2 Block Building/Roof System 1,200 SF $175 $210,000 3 Concrete: slab-on-grade 30 CY $600 $18,000 4 Concrete: walls 70 CY $1,000 $70,000 5 Concrete: elevated slab 30 CY $1,200 $36,000 6 HVAC Equipment 1 LS $25,000 $25,000 7 Grit Removal System 8 Equipment (2-vortex, 2-pump, 2-classifier) 1 LS $485,000 $485,000 9 Installation & mark-up 15% $72,750 10 Gates 6 EA $10,000 $60,000 11 Mechanical piping & valves 1 LS $50,000 $50,000 12 Grit Chamber & Channels 13 Excavation 1 LS $40,000 $40,000 14 Structural fill 5,000 CY $25 $125,000 15 Concrete: slab-on-grade 50 CY $600 $30,000 16 Concrete: walls 80 CY $1,000 $80,000 17 Concrete: elevated slab 10 CY $1,200 $12,000 18 19 Additional Elements (estimated as % of above) 20 Contractor mobilization and administration 10.0% $131,000 21 Yard Piping 5.0% $66,000 22 Site Civil 5.0% $66,000 23 Electrical and instrumentation 30.0% $394,000 24 Bonding 2.5% $33,000 25 Contractor overhead and profit 10.0% $131,000 SUBTOTAL 2,135,000 $ Contingency: 30% 641,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 230,000 $ Design / CMS: 20% 555,000 $ Legal and Administrative: 1% 28,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 3,590,000 $ Notes: Grit Removal ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Prelim Trt-Grit J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. Other Other Capital Cost $485,000 Hours per day 1 Year 1 HP demand 10 Year 1 Cost $0 Maintenance / yr 2.5% Cost per hour $45 Cost per kW-hr $0.05 Increased use / yr 0.0% Salary adjustment / yr 3.0% Increased use / yr 3.3% Increased use / yr 0.0% Discount Rate Electric increase / yr 4.0% Chemical increase / yr 4.0% 5.0% Year Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Total by Year Present Worth 1 $12,125 $11,700 $3,266 $0 $0 $0 $27,091 $27,091 2 $12,125 $12,051 $3,509 $0 $0 $0 $27,685 $26,367 3 $12,125 $12,413 $3,770 $0 $0 $0 $28,307 $25,675 4 $12,125 $12,785 $4,050 $0 $0 $0 $28,960 $25,017 5 $12,125 $13,168 $4,351 $0 $0 $0 $29,644 $24,388 6 $12,125 $13,564 $4,674 $0 $0 $0 $30,363 $23,790 7 $12,125 $13,970 $5,022 $0 $0 $0 $31,117 $23,220 8 $12,125 $14,390 $5,395 $0 $0 $0 $31,909 $22,677 9 $12,125 $14,821 $5,796 $0 $0 $0 $32,742 $22,161 10 $12,125 $15,266 $6,226 $0 $0 $0 $33,617 $21,670 11 $12,125 $15,724 $6,689 $0 $0 $0 $34,538 $21,203 12 $12,125 $16,196 $7,186 $0 $0 $0 $35,507 $20,760 13 $12,125 $16,681 $7,720 $0 $0 $0 $36,527 $20,340 14 $12,125 $17,182 $8,294 $0 $0 $0 $37,601 $19,941 15 $12,125 $17,697 $8,911 $0 $0 $0 $38,733 $19,563 16 $12,125 $18,228 $9,573 $0 $0 $0 $39,926 $19,205 17 $12,125 $18,775 $10,284 $0 $0 $0 $41,184 $18,867 18 $12,125 $19,338 $11,049 $0 $0 $0 $42,512 $18,548 19 $12,125 $19,918 $11,870 $0 $0 $0 $43,913 $18,247 20 $12,125 $20,516 $12,752 $0 $0 $0 $45,393 $17,964 440,000 $ 1 2 3 NET PRESENT WORTH - TOTAL O&M (2014 DOLLARS) Assume tote delivery for alum at $0.40 per lb (at 11.14 lb/gal) ENGINEER'S OPINION OF PROBABLE COST - Operation and Maintenance City of Kennewick WWTP Facility Plan Grit Removal Equipment Maintenance Labor Electrical Use Chemical Use Present Worth COK WWTP facility plan - cost opinion.xlsx / Prelim Trt-Grit-O&M J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Mechanical aerator (100-hp) misc mechanical work 2 EA $10,000 $20,000 2 Installation & mark-up 20% $4,000 3 Aerator drives (VFDs) 2 EA $50,000 $100,000 4 Boat launch safety upgrades - by City 5 6 Additional Elements (estimated as % of above) 7 Contractor mobilization and administration 10.0% $12,000 8 Yard Piping 0.0% $0 9 Site Civil 2.5% $3,000 10 Electrical and instrumentation 25.0% $31,000 11 Bonding 2.5% $3,000 12 Contractor overhead and profit 10.0% $12,000 SUBTOTAL 185,000 $ Contingency: 30% 56,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 20,000 $ Design / CMS: 20% 48,000 $ Legal and Administrative: 1% 2,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 310,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Add 100-hp Mechanical Aerators to Existing HRTs Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Biological-HRT short-term J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. Other Other Capital Cost $550,000 Hours per day 4 Year 1 HP demand 600 Year 1 Cost $0 Replace Aerators Dredge Lagoons Maintenance / yr 2.5% Cost per hour $45 Cost per kW-hr $0.05 - every 5 years - one in year 7 Increased use / yr 0.0% Salary adjustment / yr 3.0% Increased use / yr 3.3% Increased use / yr 0.0% 3% inflation - one in year 15 Discount Rate Electric increase / yr 4.0% Chemical increase / yr 4.0% 5.0% Year Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Total by Year Present Worth 1 $13,750 $46,800 $195,970 $0 $0 $0 $256,520 $256,520 2 $13,750 $48,204 $210,534 $0 $0 $0 $272,488 $259,513 3 $13,750 $49,650 $226,181 $0 $0 $0 $289,581 $262,659 4 $13,750 $51,140 $242,991 $0 $0 $0 $307,881 $265,959 5 $13,750 $52,674 $261,050 $0 $638,000 $0 $965,474 $794,298 6 $13,750 $54,254 $280,452 $0 $0 $0 $348,456 $273,024 7 $13,750 $55,882 $301,295 $0 $0 $50,000 $420,926 $314,102 8 $13,750 $57,558 $323,687 $0 $0 $0 $394,995 $280,716 9 $13,750 $59,285 $347,743 $0 $0 $0 $420,778 $284,799 10 $13,750 $61,063 $373,588 $0 $739,000 $0 $1,187,401 $765,409 11 $13,750 $62,895 $401,353 $0 $0 $0 $477,998 $293,449 12 $13,750 $64,782 $431,181 $0 $0 $0 $509,713 $298,019 13 $13,750 $66,726 $463,227 $0 $0 $0 $543,702 $302,754 14 $13,750 $68,727 $497,654 $0 $0 $0 $580,131 $307,656 15 $13,750 $70,789 $534,639 $0 $857,000 $50,000 $1,526,178 $770,824 16 $13,750 $72,913 $574,374 $0 $0 $0 $661,036 $317,970 17 $13,750 $75,100 $617,061 $0 $0 $0 $705,911 $323,386 18 $13,750 $77,353 $662,921 $0 $0 $0 $754,024 $328,978 19 $13,750 $79,674 $712,189 $0 $0 $0 $805,613 $334,749 20 $13,750 $82,064 $765,119 $0 $993,000 $0 $1,853,933 $733,664 7,770,000 $ 1 2 3 NET PRESENT WORTH - TOTAL O&M (2014 DOLLARS) Assume tote delivery for alum at $0.40 per lb (at 11.14 lb/gal) ENGINEER'S OPINION OF PROBABLE COST - Operation and Maintenance City of Kennewick WWTP Facility Plan HRT Do Nothing Equipment Maintenance Labor Electrical Use Chemical Use Present Worth COK WWTP facility plan - cost opinion.xlsx / Biological-Do Nothing O&M J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Prepare existing HRTs 2 Remove and salvage existing aerators 10 EA $2,500 $25,000 3 Drain and remove biosolids / grit 2 EA $25,000 $50,000 4 Fine gravel / sand at bottom of basin (12-in thick) 650 CY $35 $22,750 5 Concrete slab-on-grade (8-in thick) 400 CY $500 $200,000 6 Reline lagoon slopes 66,500 SF $2.00 $133,000 7 Steel stairs to HRT bottom 2 EA $50,000 $100,000 8 Steel stairs to HRT bottom - epoxy coating 2 EA $15,000 $30,000 9 Aeration System 10 Blowers 5 EA $225,000 $1,125,000 11 Installation & mark-up 20% $225,000 12 Mechanical piping in blower room 5 EA $75,000 $375,000 13 Air distribution piping to basins (24" dia) 600 LF $300 $180,000 14 Isolation valves 2 EA $20,000 $40,000 15 Drop legs 360 LF $200 $72,000 16 Drop leg isolation valves 6 EA $5,000 $30,000 17 Diffuser System (floor coverage) 6,750 EA $50 $337,500 18 Installation & mark-up 20% $67,500 19 Retrofit abandoned RAS building 840 SF $100 $84,000 20 Emergency Generator 1 LS $225,000 $225,000 21 22 Additional Elements (estimated as % of above) 23 Contractor mobilization and administration 5.0% $166,000 24 Yard Piping 5.0% $166,000 25 Site Civil 2.5% $83,000 26 Electrical and instrumentation 25.0% $830,000 27 Bonding 2.5% $83,000 28 Contractor overhead and profit 10.0% $332,000 SUBTOTAL 4,982,000 $ Contingency: 30% 1,495,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 538,000 $ Design / CMS: 20% 1,295,000 $ Legal and Administrative: 1% 65,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 8,380,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Retrofit HRTs with Diffused Aeration System Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Biological-HRT retrofit J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. Other Other Capital Cost $1,293,750 Hours per day 4 Year 1 HP demand 400 Year 1 Cost $0 Maintenance / yr 2.5% Cost per hour $45 Cost per kW-hr $0.05 Increased use / yr 0.0% Salary adjustment / yr 3.0% Increased use / yr 3.3% Increased use / yr 0.0% Discount Rate Electric increase / yr 4.0% Chemical increase / yr 4.0% 5.0% Year Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Total by Year Present Worth 1 $32,344 $46,800 $130,647 $0 $0 $0 $209,790 $209,790 2 $32,344 $48,204 $140,356 $0 $0 $0 $220,904 $210,385 3 $32,344 $49,650 $150,788 $0 $0 $0 $232,781 $211,140 4 $32,344 $51,140 $161,994 $0 $0 $0 $245,477 $212,053 5 $32,344 $52,674 $174,034 $0 $0 $0 $259,051 $213,122 6 $32,344 $54,254 $186,968 $0 $0 $0 $273,565 $214,346 7 $32,344 $55,882 $200,863 $0 $0 $0 $289,089 $215,722 8 $32,344 $57,558 $215,791 $0 $0 $0 $305,693 $217,250 9 $32,344 $59,285 $231,829 $0 $0 $0 $323,457 $218,929 10 $32,344 $61,063 $249,058 $0 $0 $0 $342,466 $220,756 11 $32,344 $62,895 $267,568 $0 $0 $0 $362,807 $222,732 12 $32,344 $64,782 $287,454 $0 $0 $0 $384,580 $224,856 13 $32,344 $66,726 $308,818 $0 $0 $0 $407,887 $227,127 14 $32,344 $68,727 $331,769 $0 $0 $0 $432,840 $229,544 15 $32,344 $70,789 $356,426 $0 $0 $0 $459,559 $232,109 16 $32,344 $72,913 $382,916 $0 $0 $0 $488,172 $234,819 17 $32,344 $75,100 $411,374 $0 $0 $0 $518,818 $237,676 18 $32,344 $77,353 $441,947 $0 $0 $0 $551,644 $240,681 19 $32,344 $79,674 $474,793 $0 $0 $0 $586,810 $243,832 20 $32,344 $82,064 $510,079 $0 $0 $0 $624,487 $247,131 4,480,000 $ 1 2 3 Retrofit HRTs with Diffused Aeration System - assumes year-round nitrification NET PRESENT WORTH - TOTAL O&M (2014 DOLLARS) Assume tote delivery for alum at $0.40 per lb (at 11.14 lb/gal) ENGINEER'S OPINION OF PROBABLE COST - Operation and Maintenance City of Kennewick WWTP Facility Plan Equipment Maintenance Labor Electrical Use Chemical Use Present Worth COK WWTP facility plan - cost opinion.xlsx / Biological-HRT retrofit O&M J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Influent Flow Distribution Box 2 Excavation 1 LS $25,000 $25,000 3 Structural fill 5,000 CY $25 $125,000 4 Concrete: slab-on-grade 30 CY $500 $15,000 5 Concrete: walls 100 CY $750 $75,000 6 Concrete: lean fill 50 CY $250 $12,500 7 Metal fabrications (weirs) 1 LS $35,000 $35,000 8 Basin isolation gates 2 EA $7,500 $15,000 9 Influent gate 1 EA $20,000 $20,000 10 Inlet - 36" dia 100 LF $200 $20,000 11 18" RAS line extension and connection 100 LF $150 $15,000 12 Biological Treatment 13 Remove and salvage existing aerators 5 EA $2,500 $12,500 14 Demo HRT Cells 1 LS $100,000 $100,000 15 Excavation 1 LS $100,000 $100,000 16 Shoring - not required 0 SF $35 $0 17 Basins, complete 3,000,000 GAL $1.25 $3,750,000 18 Scum removal piping and pump vault 1 LS $350,000 $350,000 19 Aeration System 20 Blowers 5 EA $225,000 $1,125,000 21 Installation & mark-up 20% $225,000 22 Mechanical piping per blower 5 EA $75,000 $375,000 23 Air distribution piping to basins (24" dia) 600 LF $300 $180,000 24 Isolation valves 2 EA $20,000 $40,000 25 Drop legs 360 LF $200 $72,000 26 Drop leg isolation valves 6 EA $5,000 $30,000 27 Diffuser System 6,750 EA $75 $506,250 28 Installation & mark-up 20% $101,300 29 Retrofit abandoned RAS building 840 SF $100 $84,000 30 Emergency Generator 1 LS $225,000 $225,000 31 32 Additional Elements (estimated as % of above) 33 Contractor mobilization and administration 5.0% $382,000 34 Yard Piping 2.5% $191,000 35 Site Civil 2.5% $191,000 36 Electrical and instrumentation 20.0% $1,527,000 37 Bonding 2.5% $191,000 38 Contractor overhead and profit 10.0% $763,000 SUBTOTAL 10,879,000 $ Contingency: 30% 3,264,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 1,174,000 $ Design / CMS: 20% 2,829,000 $ Legal and Administrative: 1% 141,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 18,290,000 $ ENGINEER'S OPINION OF PROBABLE COST New Concrete Aeration Basins with Diffused Aeration COK WWTP facility plan - cost opinion.xlsx / Biological-New Basins J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- Notes: Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Biological-New Basins J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. Other Other Capital Cost $1,378,125 Hours per day 4 Year 1 HP demand 400 Year 1 Cost $0 Maintenance / yr 2.5% Cost per hour $45 Cost per kW-hr $0.05 Increased use / yr 0.0% Salary adjustment / yr 3.0% Increased use / yr 3.3% Increased use / yr 0.0% Discount Rate Electric increase / yr 4.0% Chemical increase / yr 4.0% 5.0% Year Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Total by Year Present Worth 1 $34,453 $46,800 $130,647 $0 $0 $0 $211,900 $211,900 2 $34,453 $48,204 $140,356 $0 $0 $0 $223,013 $212,394 3 $34,453 $49,650 $150,788 $0 $0 $0 $234,891 $213,053 4 $34,453 $51,140 $161,994 $0 $0 $0 $247,587 $213,875 5 $34,453 $52,674 $174,034 $0 $0 $0 $261,160 $214,857 6 $34,453 $54,254 $186,968 $0 $0 $0 $275,675 $215,998 7 $34,453 $55,882 $200,863 $0 $0 $0 $291,198 $217,296 8 $34,453 $57,558 $215,791 $0 $0 $0 $307,802 $218,749 9 $34,453 $59,285 $231,829 $0 $0 $0 $325,567 $220,356 10 $34,453 $61,063 $249,058 $0 $0 $0 $344,575 $222,116 11 $34,453 $62,895 $267,568 $0 $0 $0 $364,917 $224,027 12 $34,453 $64,782 $287,454 $0 $0 $0 $386,689 $226,089 13 $34,453 $66,726 $308,818 $0 $0 $0 $409,996 $228,301 14 $34,453 $68,727 $331,769 $0 $0 $0 $434,950 $230,663 15 $34,453 $70,789 $356,426 $0 $0 $0 $461,668 $233,174 16 $34,453 $72,913 $382,916 $0 $0 $0 $490,282 $235,834 17 $34,453 $75,100 $411,374 $0 $0 $0 $520,927 $238,643 18 $34,453 $77,353 $441,947 $0 $0 $0 $553,754 $241,601 19 $34,453 $79,674 $474,793 $0 $0 $0 $588,920 $244,708 20 $34,453 $82,064 $510,079 $0 $0 $0 $626,597 $247,966 4,510,000 $ 1 2 3 NET PRESENT WORTH - TOTAL O&M (2014 DOLLARS) Assume tote delivery for alum at $0.40 per lb (at 11.14 lb/gal) ENGINEER'S OPINION OF PROBABLE COST - Operation and Maintenance City of Kennewick WWTP Facility Plan Retrofit HRTs with Diffused Aeration System Equipment Maintenance Labor Electrical Use Chemical Use Present Worth COK WWTP facility plan - cost opinion.xlsx / Biological-New Basins O&M J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Rebuild walkway between FC 1 and 2 2 Lean concrete fill 84 CY $350 $29,400 3 Slab-on-grade 10 CY $1,200 $12,000 4 Rehab concrete walls 5 Sandblast, high-build epoxy in top 4 feet 6,000 SF $20 $120,000 6 Solids Pumping from Final Clarifiers 7 Replace solids pump 1 LS $10,000 $10,000 8 Mechanical piping 1 LS $7,500 $7,500 9 Final Clarifier Bypass 10 Diversion at manhole upstream of Flash Mix basin 1 LS $7,500 $7,500 11 Actuator on existing gate at Flash Mix basin 1 LS $10,000 $10,000 12 30" bypass line 225 LF $200 $45,000 13 60" diameter manhole 2 EA $5,000 $10,000 14 $0 15 Additional Elements (estimated as % of above) 16 Contractor mobilization and administration 10.0% $25,000 17 Yard Piping 2.5% $6,000 18 Site Civil 2.5% $6,000 19 Electrical and instrumentation 10.0% $25,000 20 Bonding 2.5% $6,000 21 Contractor overhead and profit 10.0% $25,000 SUBTOTAL 344,000 $ Contingency: 30% 103,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 37,000 $ Design / CMS: 20% 89,000 $ Legal and Administrative: 1% 4,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 580,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Final Clarifier Upgrades: bypass; solids pumping improvements; rehabilitation of Final Clarifiers 1 and 2 Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Floc-FC--General J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Cover Final Clarifiers (aluminum plank) 21,400 SF $30 $642,000 2 $0 3 $0 4 Additional Elements (estimated as % of above) 5 Contractor mobilization and administration 10.0% $64,000 6 Yard Piping 0.0% $0 7 Site Civil 0.0% $0 8 Electrical and instrumentation 2.5% $16,000 9 Bonding 2.5% $16,000 10 Contractor overhead and profit 10.0% $64,000 SUBTOTAL 802,000 $ Contingency: 30% 241,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 87,000 $ Design / CMS: 20% 209,000 $ Legal and Administrative: 1% 10,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 1,350,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Cover Final Clarifiers Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / Floc-FC--Cover FCs J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Reference Carollo Technical Memorandum $30,000 2 3 Additional Elements (estimated as % of above) 4 Contractor mobilization and administration included 5 Yard Piping included 6 Site Civil included 7 Electrical and instrumentation included 8 Bonding included 9 Contractor overhead and profit included SUBTOTAL 30,000 $ Contingency: % included Prevailing Wages: N/A - State Sales Tax: % included Design / CMS: % included Legal and Administrative: % included TOTAL PROBABLE COST (2014 DOLLARS) 30,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST UV System: Do Nothing Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / UV-Do Nothing J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Reference Carollo Technical Memorandum $390,000 2 3 Additional Elements (estimated as % of above) 4 Contractor mobilization and administration included 5 Yard Piping included 6 Site Civil included 7 Electrical and instrumentation included 8 Bonding included 9 Contractor overhead and profit included SUBTOTAL 390,000 $ Contingency: % included Prevailing Wages: N/A - State Sales Tax: % included Design / CMS: % included Legal and Administrative: % included TOTAL PROBABLE COST (2014 DOLLARS) 390,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages UV System: Upgraded Monitoring and Control COK WWTP facility plan - cost opinion.xlsx / UV-Monitoring and Control J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Reference Carollo Technical Memorandum $2,300,000 2 3 Additional Elements (estimated as % of above) 4 Contractor mobilization and administration included 5 Yard Piping included 6 Site Civil included 7 Electrical and instrumentation included 8 Bonding included 9 Contractor overhead and profit included SUBTOTAL 2,300,000 $ Contingency: % included Prevailing Wages: N/A - State Sales Tax: % included Design / CMS: % included Legal and Administrative: % included TOTAL PROBABLE COST (2014 DOLLARS) 2,300,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST UV System: System Replacement Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / UV-System Replacement J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Raise existing manhole 1 LS $2,500 $2,500 2 Simplex Lift Station 3 Submersible pump 1 LS $10,000 $10,000 4 Mechanical piping (no valve vault) 1 LS $10,000 $10,000 5 Electrical control panel 1 LS $20,000 $20,000 6 Isolation gate 1 LS $5,000 $5,000 7 6-in Return line 400 LF $65 $26,000 8 Connection to HRT Inlet Structure 1 LS $3,500 $3,500 9 10 11 12 13 14 Additional Elements (estimated as % of above) 15 Contractor mobilization and administration 10.0% $8,000 16 Yard Piping 2.5% $2,000 17 Site Civil 5.0% $4,000 18 Electrical and instrumentation 15.0% $12,000 19 Bonding 2.5% $2,000 20 Contractor overhead and profit 10.0% $8,000 SUBTOTAL 113,000 $ Contingency: 30% 34,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 12,000 $ Design / CMS: 20% 29,000 $ Legal and Administrative: 1% 1,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 190,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Aerated Sludge Lagoon Discharge Lift Station Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / ASL-Lift Station J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. Other Other Capital Cost $40,000 Hours per day 0.25 Year 1 HP demand 5 Year 1 Cost $0 Maintenance / yr 2.5% Cost per hour $45 Cost per kW-hr $0.05 Increased use / yr 0.0% Salary adjustment / yr 3.0% Increased use / yr 3.3% Increased use / yr 0.0% Discount Rate Electric increase / yr 4.0% Chemical increase / yr 4.0% 5.0% Year Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Cost in Year i Total by Year Present Worth 1 $1,000 $2,925 $1,633 $0 $0 $0 $5,558 $5,558 2 $1,000 $3,013 $1,754 $0 $0 $0 $5,767 $5,493 3 $1,000 $3,103 $1,885 $0 $0 $0 $5,988 $5,431 4 $1,000 $3,196 $2,025 $0 $0 $0 $6,221 $5,374 5 $1,000 $3,292 $2,175 $0 $0 $0 $6,468 $5,321 6 $1,000 $3,391 $2,337 $0 $0 $0 $6,728 $5,272 7 $1,000 $3,493 $2,511 $0 $0 $0 $7,003 $5,226 8 $1,000 $3,597 $2,697 $0 $0 $0 $7,295 $5,184 9 $1,000 $3,705 $2,898 $0 $0 $0 $7,603 $5,146 10 $1,000 $3,816 $3,113 $0 $0 $0 $7,930 $5,112 11 $1,000 $3,931 $3,345 $0 $0 $0 $8,276 $5,080 12 $1,000 $4,049 $3,593 $0 $0 $0 $8,642 $5,053 13 $1,000 $4,170 $3,860 $0 $0 $0 $9,031 $5,029 14 $1,000 $4,295 $4,147 $0 $0 $0 $9,443 $5,008 15 $1,000 $4,424 $4,455 $0 $0 $0 $9,880 $4,990 16 $1,000 $4,557 $4,786 $0 $0 $0 $10,344 $4,975 17 $1,000 $4,694 $5,142 $0 $0 $0 $10,836 $4,964 18 $1,000 $4,835 $5,524 $0 $0 $0 $11,359 $4,956 19 $1,000 $4,980 $5,935 $0 $0 $0 $11,915 $4,951 20 $1,000 $5,129 $6,376 $0 $0 $0 $12,505 $4,949 100,000 $ 1 2 3 NET PRESENT WORTH - TOTAL O&M (2014 DOLLARS) Assume tote delivery for alum at $0.40 per lb (at 11.14 lb/gal) ENGINEER'S OPINION OF PROBABLE COST - Operation and Maintenance City of Kennewick WWTP Facility Plan Aerated Sludge Lagoon Discharge Lift Station Equipment Maintenance Labor Electrical Use Chemical Use Present Worth COK WWTP facility plan - cost opinion.xlsx / ASL-Lift Station O&M J-U-B ENGINEERS, Inc. 2810 W. Clearwater Ave. I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Aug-14 PROJECT DESCRIPTION: CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 150KW Generator 1 EA $45,000 $45,000 2 Installation and mark-up 25% $11,250 3 600A ATS 1 EA $7,500 $7,500 4 SCADA Interconnection 1 LS $2,500 $2,500 5 Site Electrical Work 1 LS $15,000 $15,000 6 Foundation 1 LS $8,000 $8,000 7 Service Modification 1 LS $5,000 $5,000 8 Conduit and Wire 1 LS $15,000 $15,000 9 Start Up and Commissioning 1 LS $5,000 $5,000 10 11 12 13 14 Additional Elements (estimated as % of above) 15 Contractor mobilization and administration 10.0% $11,000 16 Yard Piping 0.0% $0 17 Site Civil 0.0% $0 18 Electrical and instrumentation 0.0% $0 19 Bonding 2.5% $3,000 20 Contractor overhead and profit 10.0% $11,000 SUBTOTAL 139,000 $ Contingency: 30% 42,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 15,000 $ Design / CMS: 20% 36,000 $ Legal and Administrative: 1% 2,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 230,000 $ Notes: ENGINEER'S OPINION OF PROBABLE COST Standby Power System for UV Disinfection Building Contingency is applied to Subtotal Prevailing Wages is applied to Subtotal + Contingency Sales Tax, as applicable, is applied to Subtotal + Contingency + Prevailing Wages Design / CMS is an estimate based on Subtotal + Contingency Legal and Administrative is an estimate based on Subtotal + Contingency + Prevailing Wages COK WWTP facility plan - cost opinion.xlsx / UV Generator J-U-B ENGINEERS, Inc. 2810 Clearwater Ave I Suite 201 Kennewick, WA 99336 (509) 783-2144 ---PAGE BREAK--- BIOSOLIDS COST OPINIONS APPENDIX 7-A ---PAGE BREAK--- PROJECT: DATE: 9/16/2014 City of Kennewick WWTP Facility Plan PROJECT DESCRIPTION: Rotary Drum Concentrators (Thickening WAS) CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Rotary Drum Concentrators 2 EA $150,000 $300,000 2 In line Polymer / Sludge Mixer included $0 3 Control Panels included $0 4 Polymer Make up System included $0 5 Feed Pump included $0 6 Wash Water Booster Pump included $0 7 Freight included $0 8 $0 9 Installation 15% $45,000 10 Mechanical Piping 1 LS $350,000 $350,000 11 Building with HVAC, odor control 3000 SF $250 $750,000 12 Filtrate Pump Station 1 LS $500,000 $500,000 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $195,000 15 Yard Piping 5.0% $97,000 16 Site Civil 5.0% $97,000 17 Electrical and instrumentation 30.0% $584,000 18 Bonding 2.5% $49,000 18 Contractor overhead and profit 10.0% $195,000 SUBTOTAL 3,162,000 $ Contingency: 30% 949,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 341,000 $ Design / CMS: 20% 822,000 $ Legal and Administrative: 1% 41,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 5,315,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 163,000 kw/yr $0.06 $9,780 Labor 500 hr/yr $110.00 $55,000 Chemical 55 ton/yr $4,300.00 $235,425 Misc. repair and parts 2.5% $7,500 Total = $307,705 Present Value of Annual Cost = $3,834,684 Alternative Present Value Cost Estimate = $9,100,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Belt Filter Press Dewatering Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Belt Filter Press - 2 Meter - BDP 2 EA $418,000 $836,000 2 In line Polymer / Sludge Mixer included $0 3 2.0 meter 3DP Belt Presses included $0 4 One Hydraulic Power units included $0 5 One Control Panel included $0 6 Fluid Dynamics Polymer Make up System included $0 7 Feed Pump, Seepex or equal included $0 8 Wash Water Booster Pump included $0 9 12” Screw Conveyor included $0 10 Freight to Job Site included $0 11 $0 12 $0 13 Installation 15.0% $125,400 14 Conveyor 4 EA $80,000 $320,000 15 Catwalk 4 EA $20,000 $80,000 16 Mechanical Piping 1 LS $450,000 $450,000 17 Building with HVAC, odor control 3000 SF $250 $750,000 18 Filtrate Pump Station 1 LS $500,000 $500,000 19 Additional Elements (estimated as % of above) 20 Contractor mobilization and administration 10.0% $306,000 21 Yard Piping 5.0% $153,000 22 Site Civil 5.0% $153,000 23 Electrical and instrumentation 30.0% $918,000 24 Bonding 2.5% $77,000 25 Contractor overhead and profit 10.0% $306,000 SUBTOTAL 4,974,000 $ Contingency: 30% 1,492,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 537,000 $ Design / CMS: 20% 1,293,000 $ Legal and Administrative: 1% 65,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 8,361,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 200,000 kw/yr $0.06 $12,000 Labor 440 hr/yr $110.00 $48,400 Chemical 60 ton/yr $4,300.00 $258,000 Misc. repair and parts 2.5% $20,900 Total = $339,300 Present Value of Annual Cost = $4,228,428 Alternative Present Value Cost Estimate = $12,600,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal S C ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Belt Filter Press Dewatering Un-Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Belt Filter Press - 2 Meter - BDP 4 EA $418,000 $1,672,000 2 In line Polymer / Sludge Mixer included $0 3 2.0 meter 3DP Belt Presses included $0 4 One Hydraulic Power units included $0 5 One Control Panel included $0 6 Fluid Dynamics Polymer Make up System included $0 7 Feed Pump, Seepex or equal included $0 8 Wash Water Booster Pump included $0 9 12” Screw Conveyor included $0 10 Freight to Job Site included $0 11 $0 12 $0 13 Installation 15.0% $250,800 14 Conveyor 4 EA $80,000 $320,000 15 Catwalk 4 EA $20,000 $80,000 16 Mechanical Piping 1 LS $450,000 $450,000 17 Building with HVAC, odor control 6000 SF $250 $1,500,000 18 Filtrate Pump Station 1 LS $500,000 $500,000 19 Additional Elements (estimated as % of above) 20 Contractor mobilization and administration 10.0% $477,000 21 Yard Piping 5.0% $239,000 22 Site Civil 5.0% $239,000 23 Electrical and instrumentation 30.0% $1,432,000 24 Bonding 2.5% $119,000 25 Contractor overhead and profit 10.0% $477,000 SUBTOTAL 7,756,000 $ Contingency: 30% 2,327,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 837,000 $ Design / CMS: 20% 2,017,000 $ Legal and Administrative: 1% 101,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 13,038,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 400,000 kw/yr $0.06 $24,000 Labor 880 hr/yr $110.00 $96,800 Chemical 60 ton/yr $4,300.00 $258,000 Misc. repair and parts 2.5% $41,800 Total = $420,600 Present Value of Annual Cost = $5,241,606 Alternative Present Value Cost Estimate = $18,300,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal S C ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Lime Post-Treatment CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Mixer (mix lime into biosolids) 2 EA $100,000 $200,000 2 Lime Feed system 2 EA $100,000 $200,000 3 Control Panel 4 EA $45,000 $180,000 4 $0 5 $0 6 Freight 1 LS $10,000 $10,000 7 $0 8 Installation 1 LS $60,000 $60,000 9 $0 10 Mechanical Piping 1 LS $75,000 $75,000 11 Building with HVAC, odor control 2000 SF $250 $500,000 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $123,000 15 Yard Piping 5.0% $61,000 16 Site Civil 5.0% $61,000 17 Electrical and instrumentation 30.0% $368,000 18 Bonding 2.5% $31,000 18 Contractor overhead and profit 10.0% $123,000 SUBTOTAL 1,992,000 $ Contingency: 30% 598,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 215,000 $ Design / CMS: 20% 518,000 $ Legal and Administrative: 1% 26,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 3,349,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 150,000 kw/yr $0.06 $9,000 Labor 440 hr/yr $110 $48,400 Chemical / Lime 1,800 Ton/yr $25 $45,000 Misc. repair and parts 2.5% $14,500 Total = $116,900 Present Value of Annual Cost = $1,456,832 Alternative Present Value Cost Estimate = $4,800,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Anaerobic Digester CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Digester 2 Digester Volume 2,000,000 Gallons $2 $3,000,000 3 Mechanical 1 LS $800,000 $800,000 4 Mixing included 5 Heating included 6 7 8 Biogas management 1 LS $550,000 $550,000 9 Control Building 2500 SF $250 $625,000 10 11 12 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $498,000 15 Yard Piping 5.0% $249,000 16 Site Civil 5.0% $249,000 17 Electrical and instrumentation 30.0% $1,493,000 18 Bonding 2.5% $124,000 18 Contractor overhead and profit 10.0% $498,000 SUBTOTAL 8,086,000 $ Contingency: 30% 2,426,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 872,000 $ Design / CMS: 20% 2,102,000 $ Legal and Administrative: 1% 105,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 13,591,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 650,000 kw/yr $0.06 $39,000 Labor 1,040 hr/yr $110 $114,400 Misc. repair and parts 2.5% $108,750 $0 Total = $262,150 Present Value of Annual Cost = $3,266,968 Alternative Present Value Cost Estimate = $16,900,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Chemical Treatment CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Bioset Unit Process 2 EA $800,000 $1,600,000 2 Lime Silo & Feed Screw included $0 3 Sulfamic Acid Feeder included $0 4 Twin-Screw Mixer included $0 5 Reactor Feed Pump included $0 6 Hydraulic Power Unit included $0 7 Reactor Vessel included $0 8 Ammonia Scrubber included $0 9 Control Panel included $0 10 Freight included $0 11 $0 12 Installation 15% $240,000 13 Conveyor 2 LS $80,000 $160,000 14 Mechanical Piping 1 LS $250,000 $250,000 15 Building with HVAC, odor control 5260 SF $250 $1,315,000 16 $0 17 Additional Elements (estimated as % of above) 18 Contractor mobilization and administration 10.0% $357,000 19 Yard Piping 5.0% $178,000 20 Site Civil 5.0% $178,000 21 Electrical and instrumentation 30.0% $1,070,000 22 Bonding 2.5% $89,000 23 Contractor overhead and profit 10.0% $357,000 SUBTOTAL 5,794,000 $ Contingency: 30% 1,738,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 625,000 $ Design / CMS: 20% 1,506,000 $ Legal and Administrative: 1% 75,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 9,738,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 2,500 kw/yr $0.06 $150 Labor 440 hr/yr $110 $48,400 Chemical 5 ton/yr $200 $1,000 Misc. repair and parts 2.5% $40,000 Total = $89,550 Present Value of Annual Cost = $1,115,991 Alternative Present Value Cost Estimate = $10,900,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Solar Dryer Unit Process, Without Supplemental Heat Un-Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Solar Dryer Unit Process (Installed) 11 EA $1,000,000 $11,000,000 2 Turning Device included $0 3 Controls included $0 4 Rails included $0 5 Greenhouse with HVAC included $0 6 Coneyors included $0 7 $0 8 $0 9 Concrete Pad (40 X 500 each) 5400 CY $150 $810,000 10 $0 11 $0 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration included $0 15 Yard Piping included $0 16 Site Civil included $0 17 Electrical and instrumentation included $0 18 Bonding included $0 18 Contractor overhead and profit included $0 SUBTOTAL 11,810,000 $ Contingency: 30% 3,543,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 1,274,000 $ Design / CMS: 20% 3,071,000 $ Legal and Administrative: 1% 154,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 19,852,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 1,650,000 kw/yr $0.06 $99,000 Labor 4,840 hr/yr $110 $532,400 Misc. repair and parts 1.0% $110,000 Total = $741,400 Present Value of Annual Cost = $9,239,483 Alternative Present Value Cost Estimate = $29,100,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Solar Dryer Unit Process, Without Supplemental Heat Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Solar Dryer Unit Process (Installed) 7 EA $1,000,000 $7,000,000 2 Turning Device included $0 3 Controls included $0 4 Rails included $0 5 Greenhouse with HVAC included $0 6 Coneyors included $0 7 $0 8 $0 9 Concrete Pad (40 X 500 each) 3500 CY $150 $525,000 10 $0 11 $0 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration included $0 15 Yard Piping included $0 16 Site Civil included $0 17 Electrical and instrumentation included $0 18 Bonding included $0 18 Contractor overhead and profit included $0 SUBTOTAL 7,525,000 $ Contingency: 30% 2,258,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 812,000 $ Design / CMS: 20% 1,957,000 $ Legal and Administrative: 1% 98,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 12,650,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 1,050,000 kw/yr $0.06 $63,000 Labor 3,080 hr/yr $110 $338,800 Misc. repair and parts 1.0% $70,000 Total = $471,800 Present Value of Annual Cost = $5,879,671 Alternative Present Value Cost Estimate = $18,500,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Solar Dryer Unit Process, With Supplemental Heat CLIENT: City of Kennewick, WA Un-Digested Biosolids CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Solar Dryer Unit Process (Installed) 8 EA $1,000,000 $8,000,000 2 Turning Device included $0 3 Controls included $0 4 Rails included $0 5 Greenhouse with HVAC included $0 6 Conveyorus included $0 7 Concrete Pad (40 X 500 each) 4000 CY $150 $600,000 8 Radiant Floor Heat System 175000 SF $2 $350,000 9 Boiler 4 EA $80,000 $320,000 10 Mechanical Piping 1 EA $60,000 $60,000 11 Heating Controls 4 EA $75,000 $300,000 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration included $0 15 Yard Piping included $0 16 Site Civil included $0 17 Electrical and instrumentation included $0 18 Bonding included $0 18 Contractor overhead and profit included $0 SUBTOTAL 9,630,000 $ Contingency: 30% 2,889,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 1,039,000 $ Design / CMS: 20% 2,504,000 $ Legal and Administrative: 1% 125,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 16,187,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 1,200,000 kw/yr $0.06 $72,000 Labor 3,520 hr/yr $110 $387,200 Natural Gas 36,000 BTU/yr $1.15 $41,400 Misc. repair and parts 1.0% $80,000 Total = $580,600 Present Value of Annual Cost = $7,235,559 Alternative Present Value Cost Estimate = $23,400,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Solar Dryer Unit Process, With Supplemental Heat CLIENT: City of Kennewick, WA Digested Biosolids CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Solar Dryer Unit Process (Installed) 5 EA $1,000,000 $5,000,000 2 Turning Device included $0 3 Controls included $0 4 Rails included $0 5 Greenhouse with HVAC included $0 6 Conveyorus included $0 7 Concrete Pad (40 X 500 each) 2500 CY $150 $375,000 8 Radiant Floor Heat System 175000 SF $2 $350,000 9 Boiler 2.5 EA $80,000 $200,000 10 Mechanical Piping 1 EA $60,000 $60,000 11 Heating Controls 2.5 EA $75,000 $187,500 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration included $0 15 Yard Piping included $0 16 Site Civil included $0 17 Electrical and instrumentation included $0 18 Bonding included $0 18 Contractor overhead and profit included $0 SUBTOTAL 6,173,000 $ Contingency: 30% 1,852,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 666,000 $ Design / CMS: 20% 1,605,000 $ Legal and Administrative: 1% 80,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 10,376,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 750,000 kw/yr $0.06 $45,000 Labor 2,200 hr/yr $110 $242,000 Natural Gas 22,500 BTU/yr $1.15 $25,875 Misc. repair and parts 1.0% $50,000 Total = $362,875 Present Value of Annual Cost = $4,522,225 Alternative Present Value Cost Estimate = $14,900,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan Sep-14 PROJECT DESCRIPTION: Thermal Drying Process, Non Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Thermal Belt Dryer (BT16) 1 EA $3,750,000 $3,750,000 2 Control Panels 1 EA $25,000 $25,000 3 $0 4 $0 5 Freight 1 LS $15,000 $15,000 6 $0 7 $0 8 Installation 15% $562,500 9 Conveyor 1 LS $80,000 $80,000 10 $0 11 Building with HVAC, odor control 3500 SF $250 $875,000 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $531,000 15 Yard Piping 5.0% $265,000 16 Site Civil 5.0% $265,000 17 Electrical and instrumentation 30.0% $1,592,000 18 Bonding 2.5% $133,000 18 Contractor overhead and profit 10.0% $531,000 SUBTOTAL 8,625,000 $ Contingency: 30% 2,588,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 931,000 $ Design / CMS: 20% 2,243,000 $ Legal and Administrative: 1% 112,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 14,499,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity $75,468 Labor 800 hr/yr $110 $88,000 Misc. repair and parts 2.5% $94,375 $0 Total = $257,843 Present Value of Annual Cost = $3,213,297 Alternative Present Value Cost Estimate = $17,700,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/16/2014 PROJECT DESCRIPTION: Thermal Drying Unit Process, Digested Biosolids CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Thermal Belt Dryer (BT16) 1 EA $3,750,000 $3,750,000 2 Control Panels 1 EA $25,000 $25,000 3 $0 4 $0 5 Freight 1 LS $15,000 $15,000 6 $0 7 $0 8 Installation 15% $562,500 9 Conveyor 1 LS $80,000 $80,000 10 $0 11 Building with HVAC, odor control 3500 SF $250 $875,000 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $531,000 15 Yard Piping 5.0% $265,000 16 Site Civil 5.0% $265,000 17 Electrical and instrumentation 30.0% $1,592,000 18 Bonding 2.5% $133,000 18 Contractor overhead and profit 10.0% $531,000 SUBTOTAL 8,625,000 $ Contingency: 30% 2,588,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 931,000 $ Design / CMS: 20% 2,243,000 $ Legal and Administrative: 1% 112,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 14,499,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity $49,054 Labor 800 hr/yr $110 $88,000 Misc. repair and parts 2.5% $94,375 $0 Total = $231,429 Present Value of Annual Cost = $2,884,122 Alternative Present Value Cost Estimate = $17,400,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- PROJECT: DATE: City of Kennewick WWTP Facility Plan 9/19/2014 PROJECT DESCRIPTION: Aerobic Digester CLIENT: City of Kennewick, WA CLIENT PROJ. NO. ITEM SCHEDULE OF VALUES NO. DESCRIPTION QNTY UNIT UNIT PRICE TOTAL COST 1 Aerobic Digester 2 Digester Volume 6,000,000 gallon $0.65 $3,900,000 3 Mechanical 1 LS $50,000 $50,000 4 Mixing/Aeration 1 LS $550,000 $550,000 5 $0 6 $0 7 $0 8 $0 9 $0 10 $0 11 $0 12 $0 13 Additional Elements (estimated as % of above) 14 Contractor mobilization and administration 10.0% $450,000 15 Yard Piping 5.0% $225,000 16 Site Civil 5.0% $225,000 17 Electrical and instrumentation 15.0% $675,000 18 Bonding 2.5% $113,000 18 Contractor overhead and profit 10.0% $450,000 SUBTOTAL 6,638,000 $ Contingency: 30% 1,991,000 $ Prevailing Wages: N/A - State Sales Tax: 8.3% 716,000 $ Design / CMS: 20% 1,726,000 $ Legal and Administrative: 1% 86,000 $ TOTAL PROBABLE COST (2014 DOLLARS) 11,157,000 $ Notes: Major Operation and Maintenance Annual Cost Electricity 6,500,000 kw/yr $0.06 $390,000 Labor 800 hr/yr $110 $88,000 Misc. repair and parts 2.5% $15,000 $0 Total = $493,000 Present Value of Annual Cost = $6,143,870 Alternative Present Value Cost Estimate = $17,300,000 ENGINEER'S OPINION OF PROBABLE COST Contingency is applied to Subtotal P ili W i li d S b l C i ---PAGE BREAK--- ESI ENERGY EFFICIENCY REVIEW APPENDIX 8-A ---PAGE BREAK--- 123 NE THIRD AVENUE [PHONE REDACTED] PORTLAND OR 97232 September 16, 2014 Mr. Alex Fazzari Project Manager J-U-B Engineers, Inc. 2810 W. Clearwater Ave., Ste. 201 Kennewick, WA 99336 RE: City of Kennewick WWTP Facility Plan – Energy Efficiency Review and Recommendations Dear Mr. Fazzari, The ESI program, through its partnership with local public power providers, can provide reviews of planning level and design documents in the interest of identifying potential energy efficiency measures (EEMs) that may qualify for incentives offered by the facility’s energy utility, in this case Benton PUD. Typically, this review has satisfied Washington’s statutory requirements for an Investment Grade Efficiency Audit (IGEA) on projects that utilize State funding sources. Thank you for providing the draft copy of the Kennewick WWTP Facility Plan (the “Plan”) for our review. At the facility plan level, detailed energy consumption and savings estimates are difficult to calculate, since equipment sizing has not typically been completed. In some cases, we have information gathered from our own visits that can be used, and in some cases, the facility plan itself will provide direction (e.g. the plan may state that 1,000 hp of firm blower capacity is required for one alternative, where only 600 hp will be required for another). When possible, we will utilize this information to provide an estimate of the energy savings potential. Where that information is not available, a more qualitative approach is used with EEM’s shown as a percentage reduction, etc. In the Plan, alternatives for substantial improvements to three major are described: secondary aeration, solids handling, and effluent disinfection. Less extensive improvements are discussed for other process areas within the plant as well. The final chapter provides a suggested phasing schedule for the improvements showing initial projects that will be completed in the next two years (Phase 1) and final (Phase 4) improvements under construction more than 10 years from now. The goal of our program review is “selfish” in that we’d like to encourage energy efficient design and operation of wastewater systems within the region, and more specifically, we’d like to make sure that designers and owners are aware of the incentives that are available to help make the more efficient installations economically viable. So, our hope is that at least some of the ideas discussed here will be implemented by the project team into upcoming capital projects. By working with the ESI program and Benton PUD, the City can receive incentives to help offset any costs incurred by the implementation of energy efficiency measures. The current incentive rate for conservation EEMs in Benton PUD is 25 cents per kWh saved in the first year of operation. The incentive is capped at 70% of the EEM costs. So, if a project saves one million kWh annually, the calculated incentive would be $250,000. If it cost $100,000 to achieve those savings, then the incentive would be capped at $70,000. What this means is that in the best case, the City receives the benefits of the advanced system while effectively paying only 30 cents on the dollar. As a reminder, the incentives are paid ---PAGE BREAK--- 2 after the measurement and verification process, so the incentives are rebates rather than up-front grants. And, engineering costs associated with the EEMs can also count as part of the project costs eligible for incentives. ESI program staff is available to help with the paperwork and calculations, though we rely to some extent on information provided by the Owner or their design consultants. A. Plant Capacity vs. Current Conditions The design year for the plant is 2034 (20 years out). One of the most common inefficiencies we see in new infrastructure is a lack of efficient turn-down capability. This is due in part to the requirement to design for future flows and loads, as well as a “stacking up” of safety factors and worst case scenarios (e.g. hottest day of the year, fouled diffusers, worn blowers, and a peak day load when sizing blowers). The Plan indicates the design average annual flow is 7.94 MGD, and maximum month flow is 9.4 MGD. Design BOD loading is 22,000 lb./day and maximum month BOD load (basis of most process design) is 30,400 lb./day. The peak hourly flow (basis of hydraulic design) in 2034 is 15.9 MGD. The Plan also provides the current operating conditions of 5.35 MGD annual average flow. The average annual BOD loading is currently 11,500 lb./day. The maximum month flow and load currently is 6.34 MGD and 15,900 lb./day. Peak hourly flow is currently 10.7 MGD. Table 1 summarizes this data. Table 1: Current vs. Design Flows and Loads Annual Avg. Daily Flow (MGD) Annual Avg. Daily BOD Load (lb./day) Max. Mo. Daily Flow (MGD) Max. Month Daily BOD Load (lb./day) Design 7.94 22,000 9.4 30,400 Current 5.35 11,500 6.34 15,900 Current Value as Percent of Design Value 67% 52% 67% 52% Current Average Daily Value as Percent of Max Month Design Value 57% 38% The table above is helpful from an energy management standpoint. Hydraulically, the Plan indicates only a few improvements are required to meet design criteria. To meet the design BOD loading, however, significant improvements will be required. At start-up, the improved plant will run at just over 50% capacity on a daily basis. If one compares the current load to the maximum month design load, it will be running at roughly 38% of the design capability. To the extent that equipment and basin sizes (such as blowers and aeration basins) are based on meeting max month conditions in 2034, the new systems will be sized for at least double their required initial capacity, and probably above this to account for safety factors and conservative assumptions. ---PAGE BREAK--- 3 This approach is required by the regulations as well as sound engineering, but it also presents opportunities for conservation as described in the items listed below. B. Non-process Energy Efficiency Measures The focus of this letter is on process energy opportunities, but in any construction project, there are opportunities to reduce long term energy costs with appropriate equipment selection. Lighting: The cost of LED lighting has dropped to the point where it is often cost effective even without incentives, but the lighting incentives through Benton PUD can really help on the payback for new construction. And, if you have electricians on site for new construction, this can often be the best time for lighting retrofits, as there should be no mobilization costs. Outside lighting qualifies for incentives, too, and can be a source of good savings. Use timers, motion sensors, and photosensors where ever possible. HVAC Systems: Many buildings within wastewater plants are ventilated with supply and/or exhaust fans that run continuously. For new construction, consider ducted HVAC systems where a heat recovery unit can be used to pre-heat the incoming air with the heat from the exhaust air. Similarly, investigate using warm air from electrical rooms as a heat source for the equipment areas on the other side of the wall. There are also plants that have utilized effluent as a heat source/sink for heat pump units. For hazardous areas, investigate including LEL sensors to take advantage of the NFPA provision that allows the number of air changes to be reduced from 12 ACH to 6 ACH during cold weather. While heating and cooling loads are a small percentage of the electrical load at a plant this size, the amount of energy consumed is surprising. Also included with most new HVAC installations is a test and balance specification. Consider using the new construction project as an opportunity to recommission the existing HVAC systems which often haven’t been tested since they were installed. This can often lead to significant reduction in energy use as well as improvements in comfort for the plant staff. Similar to lighting, if there are HVAC systems in the new areas, then it might be a cost-effective time to retrofit antiquated air conditioning units, heaters, etc. Motors: While “Premium Efficiency” motors are now the minimum standard for new equipment sold in the US, there are in some cases “Super-premium” motors that have even higher efficiency. Since the operating costs of a motor are something like 80% of the total cost of ownership, it makes good sense to have strict motor specs and to enforce them during the submittal process. C. Potential EEM’s – Based on Plan Chapter 8 Listing of Recommended Capital Improvements 1. Preliminary Treatment (Phase 1) Planned improvements include a new influent bypass gate, a bridge crane, and a grit trap upstream of the pumps. No EEMs are associated with these improvements, though it should be noted that improved grit removal will extend the life of the influent pump impellers and help them maintain their efficiency for a longer period of time. 2. Biological Treatment (Phase 1) Planned improvements for the near term are the addition of one 100-hp floating aerator in each HRT cell. This will bring the total aerator horsepower to 500 hp in each cell (4 @ 75-hp, 2 @ 100-hp). This addition will eliminate the dissolved oxygen (DO) sag that occurs during high loading events and should provide enough capacity to treat all flows for the next eight to ten years. This is a relatively low-cost improvement because the plant’s electrical system is already configured for the new aerators and the plant has spare aerators on hand. ---PAGE BREAK--- 4 As described in Chapter 6 of the plan (and our earlier site visit), the plant currently has a simple, semi- automated DO control strategy. When DO levels are above 4.5 mg/l, the central 100-hp aerator is turned off. When DO levels drop below the lower set point (2.5 mg/l), the 100-hp units are turned on. During my visit this spring, the 100-hp units were off roughly half the time. This is a definite improvement from our 2011 visit, when all units were running continuously, regardless of load. EEM 2.1: Utilize VFD’s on new units and improve the DO control system. Though not often implemented, floating aerators can be modulated with VFDs provided that the manufacturer is consulted regarding harmonics. There are certain speeds to be avoided due to shaft harmonics, so the VFDs need to be programmed to accelerate or decelerate through those speeds. And, there is a minimum speed at which the units stop throwing water. Within those constraints, however, the units can be operated at less than 100% speed. While aerators do not have perfectly cubic power-speed curves, they do have a better than linear power:speed relationship. Since the additional aerators will already require wiring and electrical work, the additional cost of VFDs and the associated programming costs over and above that would be the “project cost” of this EEM. As an example, the Cathcart Landfill Leachate Pretreatment Facility in Snohomish County utilized VFD’s on their 100- and 75-hp Aqua Aerobic brand aerators in conjunction with DO monitoring and were able to reduce energy consumption by 35%. The 100-hp units were turned down from 885 to 700 RPM, the 75-hp units were turned down from 1220 to 900 RPM. To maximize the energy savings associated with the VFD, the new aerator & VFD should be operated continuously as the trimming aeration unit to maintain a DO level of 1.5 to 2.0 mg/l in the HRT. The current 100-hp unit, then, would only be called if the new unit was at 100% speed AND the DO level had dropped below set point for a sufficient period. This would occur during the summer peak hours. Additionally, the DO control system should be incorporated into the smaller unit operations as well. That is, if the variable unit is turned down to minimum speed, and the DO is still above the set point, then a 75-hp unit should be shut down. The “off” small unit would be rotated to prevent sludge build-up in any one area of the HRT. The estimated current baseline energy consumption for the aeration system is: 8760 hr/yr x 700 hp x 90% load x 0.746 kW/hp = 4.1 million kWh / year baseline energy (assumes 8 x 75-hp run continuous, 2 x 100-hp run 50% each, and the motors are sized for 90% load). For estimating savings, we assume that the average DO under the existing control system is 3.0 ppm when the 100-hp unit is ON (4,380 hours) and 5.0 ppm when the unit is OFF (4,380 hours) for an overall average DO of 4.0 ppm, and that the new system would maintain an average DO of 2.0 ppm continuously. A rule of thumb is that aeration energy is reduced by 5% to 6% for each 0.5 mg/l drop in average DO level. Assuming 20% savings for the reduction from 4.0 to 2.0 ppm, then the VFD and improved controls would result in savings of: 4.1 million kWh x 20% = 820,000 kWh estimated annual savings. At 25 cents/kWh, an incentive of up to roughly $205,000 would be available to help implement these improvements. Annual energy costs in the first year would be reduced by roughly $32,000 at 4 cents/kWh. 3. Biological Treatment (Phase 3) Planned improvements include a conversion from the mechanical aeration system described above to a diffused air system located within new, concrete aeration basins with common-wall construction. The timing of this expansion is determined in part by the ability of the mechanical aeration system to cope with increasing ---PAGE BREAK--- 5 loads, but nominally the Phase 3 work would take place in 8 to 10 years. The costs for these improvements are roughly $20 million. The new aeration basin operating and control strategies are not fully described in the Plan. Provided below is a list of the current “best practices” that ought to be considered during the design of the new basins. A note on incentives and project costs: For the aeration basin, the “project cost” for the EEM would not be the total cost of the installation. Rather, it is the difference in cost between the baseline, lower capital cost option and the more efficient, higher cost option. For example, if ultrafine bubble panel diffusers at $700,000 were used in lieu of fine bubble diffusers at $500,000, the “project cost” of that EEM would be $200,000. EEM 3.1: Optimize Basin Depth. In general, the deeper the better for oxygen transfer efficiency (OTE) with diffused air systems. The energy tradeoff between increased discharge pressure and reduced SCFM (due to improved OTE) should be evaluated. EEM 3.2: Provide Flexibility for Anoxic & Swing Zones. The more ability a basin has to be reconfigured, the easier it is for operators to either stay out of nitrification or implement denitrification within the basin. As the Plan states, staying out of nitrification altogether can cut oxygen demand by roughly one-third. If nitrification is unavoidable, configurable anoxic zones can set up portions of the basin for denitrification, which returns roughly 40% of the oxygen consumed for nitrification back to the mixed liquor. EEM 3.3: Utilize More, Smaller Aeration Basins Wastewater unit processes are typically sized in halves, thirds, or quarters, particularly in smaller plants. As flows come up, the operator is faced with the necessity to put the next unit on line. With aeration basins, the smaller the step, the less “excess” capacity is brought on with each step. That allows aeration air volumes to stay closer to optimum levels without mixing requirements becoming the lower limit. EEM 3.4: Utilize Efficient Mixing Systems with VFDs For anoxic and swing zones, small mixers are generally running continuously. Experience has shown that most mixers can be turned down to roughly 50% power (~80% speed) before the mixed liquor starts to separate. The costs of small VFDs are such that the payback, even without incentives, is under 5 years in most cases. For larger mixers, investigate new mixing systems such as the Invent™ vertical shaft mixers which have lower operating power than traditional mixing systems. Assuming 10 horsepower of mixing per aeration train, the estimated baseline energy without VFDs in the first year of operation with two trains active is: 8760 hr/yr x 20 hp x 90% load x .746 kW/hp = 118,000 kWh / year baseline energy Assuming a 45% reduction in energy, the annual savings would be: 118,000 kWh x 45% reduction = 53,000 kWh annual savings. At 25 cents/kWh, an incentive of up to roughly $13,000 would be available to help implement these improvements. Annual energy costs in the first year would be reduced by roughly $2,120 at 4 cents/kWh. ---PAGE BREAK--- 6 EEM 3.5: Utilize Ultra-fine Bubble Diffusers and High Coverage Ratios The move from coarse to fine bubble diffusers typically reduces aeration energy 40 to 50%. Similarly, the move from fine to ultrafine bubble diffusers reduces energy from 25 to 35% through the improved OTE associated with small diameter bubbles. In addition, both fine and ultra-fine bubble diffuser OTE is inversely proportional to airflow – that is, the lower the airflow per diffuser, the smaller the bubble and the higher the OTE. Additionally, the more floor coverage provided by the diffuser system, the “chimney effect” is reduced and each air bubble stays in the mixed liquor water column longer. We have recent experience with an ultrafine bubble retrofit of a relatively new fine bubble system with good DO control, and airflow within the system was reduced by about 30%, with a corresponding decrease in energy consumption. EEM 3.6: Utilize Appropriately Sized High Efficiency Blower(s) for Normal Operations Dual-control single stage blowers, turbo blowers, and the new “hybrid” blowers all offer about the same efficiency at close to full capacity. They tend to be more efficient as they are turned down than multi-stage centrifugal blowers, but all blowers lose efficiency as they are turned down. However, there is no rule that says every blower in the plant has to be identical style or size. Similar to the basin sizing EEM, utilizing an additional “jockey size” blower can help the aeration system match airflow to demand while staying out of extreme turn-down scenarios. The additional cost of the additional blower (because it won’t count as “firm” capacity) can be offset by utilizing a lower-cost, nominally less efficient blower for those rare, high-load days that may or may not ever occur. At close to full capacity, multi-stage blowers are fairly close to the other blower styles in efficiency. The Plan (Chapter 6, Table 6-4) shows that the designers are considering a “jockey” size blower in the 100- to 200-hp range to complement a line-up of 400-hp blowers. The capital costs of this smaller blower can be incentivized by calculating the savings due to increased efficiency in the first year’s operations. EEM 3.7: Utilize Advanced Controls Staggered aeration, multiple DO sensors, flow-based rather than pressure-based valve and blower control algorithms, online ammonia and nitrite sensors, and feed-forward active DO set point manipulation are all being utilized to some degree in larger treatment plants today. These kinds of techniques have been shown to reduce aeration energy from 15 to 30% compared to pre-retrofit conditions. Interestingly, most of these new controls have been installed on systems which already have a well-tuned DO control system, so to get a 20% improvement on those types of systems is impressive. Estimated Savings on Aeration System from Aeration Basin EEM’s: The Plan (Chapter 6, Table 6-5) states that 600 hp will be required for 2034 average load with the new concrete aeration basins and fine bubble diffusers. From an energy metric standpoint, that works out to roughly: 600 hp x 0.7457 kW/hr x 24 hrs / 7.94 MGD = 1350 kWh/MG treated. For comparison, that number is about 50% higher than WEF’s MOP32 “Energy Conservation in Water and Wastewater Facilities” lists as an estimate for aeration energy at a facility with nitrification (878 kWh/MG; Table C.4). Assuming that at least some of the measures above are implemented, it would not be unreasonable to obtain a reduction of 25 to 35% over a traditional, fine-bubble aeration design. A 30% reduction would mean an ---PAGE BREAK--- 7 energy intensity of 945 kWh/MG treated. Estimated first year savings, assuming 6.6 MGD average daily flow in year 2024, is: 6.6 MGD x 365 days x (1350 – 945) kWh/MG = 980,000 kWh annual savings. At 25 cents/kWh, an incentive of up to roughly $245,000 would be available to help implement these improvements. Annual energy costs in the first year would be reduced by roughly $39,000 at 4 cents/kWh. EEM 3.8 Primary Clarification One item mentioned briefly in the Plan is the addition of primary clarification to the plant. If the plant is moving to anaerobic digestion of sludge, then primary clarification is the most efficient BOD removal tool that can be used to improve the kWh/lb. BOD removed metric. A 30% reduction in BOD at the clarifier, for the energy cost of a clarifier drive, sludge pump, and spray water, removes 30% of the load on the aeration basin, meaning the most energy intensive process in the plant can be reduced by almost one-third. Again, using the 600 blower horsepower at average daily conditions in 2034 as shown in Table 6-5, the expected kWh/1000 lb. BOD removed for the aeration system is: 600 hp x 0.7457 kW/hr x 24 hr / (22,000 lb. BOD/day x 90% removal) = 540 kWh/1000 lb. BOD. If the BOD load was reduced 30%, the resulting energy savings at the blowers can be estimated as: 540 kWh/Klb. BOD x (22 Klb. BOD/day x 90% removal) x 30% x 365 days/yr = 1.2 million kWH/yr savings At 25 cents/kWh, an incentive of up to roughly $300,000 would be available to help implement these improvements. Annual energy costs in the first year would be reduced by roughly $48,000 at 4 cents/kWh. Assuming the plant utilizes primary clarification, then presumably the aeration basin and associated equipment would be reduced, further offsetting the incremental cost of the clarifier. In addition, if a cogeneration or compressed-biogas fleet fueling system is envisioned, primary sludge provides more biogas production compared to secondary sludge. EEM 3.9 Primary Clarifier Improvements If primary clarification is utilized, then every effort should be made to optimize BOD removal within the primaries, including all the usual tricks for making secondary clarifiers more efficient (baffles, energy dissipation wells, etc.). The incremental energy savings in the aeration basin can produce incentives to help pay for the incremental costs of these improvements. Finally, a somewhat unconventional approach to primary treatment was brought to our attention by a colleague in New York State. A start-up called ClearCove Systems received some funding from NYSERDA (New York’s energy efficiency research agency) for testing its version of chemically enhanced primary treatment (CEPT) which incorporates the entire headworks (screening, grit, and primary) and claims to provide high levels of BOD and TSS removal. It will be interesting to follow the results of the test in Ithaca. Again, the energy reduction at the secondary process would provide the basis for incentives to help pay for the additional costs. 4. Final Clarifiers (Phase 1) Planned improvements include a bypass channel, a new solids-return pump, and potentially covering the clarifiers. ---PAGE BREAK--- 8 EEM 4.1: Clarifier Drive Savings If the bypass channel and cover allows the clarifier drives to be turned off, then the energy savings associated with that can be included as an EEM. One thought on the covers: would this be a potential place for the installation of solar shades such as those used in parking lots? EEM 4.2: Clarifier Drive Intermittent Operation If the clarifier drives remain in operation, consider moving them to a simple automatic control system in which the flights advance one position then stop for 30 minutes to an hour. While this saves energy, it also significantly cuts down on chain, gear, and flight wear while still rotating the units to minimize UV damage and algae build-up. 5. UV Disinfection (Phase 1) Planned improvements include a complete demolition and replacement of the existing UV system which is no longer supported by the manufacturer. EEM 5.1: Utilize Low-pressure/High-output UV System There are currently two main types of UV systems marketed, medium-pressure (MP) and low-pressure/high output (LPHO). The major trade-off is footprint vs. energy consumption, where MP systems use fewer, higher intensity bulbs and LPHO systems use many more smaller bulbs. Because the LPHO systems have greater turndown and more efficient bulbs, the installed energy consumption is significantly less than an equivalent MP system (on the order of one-fourth the energy consumption). Again, the trade-off is the increased footprint, concrete, and enclosures required due to the number of channels, etc. in the LPHA system. According to the Kennedy/Jenks report in Chapter 6 appendix, the total power requirement for the existing system is 40 kW. It is not clear if this was measured or calculated or taken from the equipment literature. During our earlier site visit, we found that each bulb was 70W nominal and assumed a 10% loss for controls and ballasts, giving a total system load of roughly 32 kW. With any new system installation, the bulbs will operate with variable intensity based on transmissivity and flow. Assuming that a LPHO system would operate at an average of 8 kW and a MP system would operate at 24 kW, the LPHO system savings (compared to the lower installed cost MP system) would be: (24 – 8) kW x 8760 hr/yr = 140,000 kWh annual savings. At 25 cents/kWh, an incentive of up to roughly $35,000 would be available to help offset the cost difference between the LPHO and MP system. Annual energy costs in the first year would be reduced by roughly $5,600 at 4 cents/kWh. EEM 5.2 Utilize Real-time Coliform Counts to Control UV System (and Aeration Blowers) The new LiquID™ Station from ZAPS Technologies provides real-time monitoring of e. coli in the secondary effluent. Corvallis, Oregon piloted this equipment and was able to reduce its chemical costs by 62% (the plant uses chlorination/dechlorination disinfection). In a plant using UV, the UV dosage can be varied, in real time, in response to actual effluent counts rather than flow or transmissivity. Note that these units can be used for multiple parameter testing, so they might be utilized for aeration basin process control by monitoring BOD, nitrites, nitrates, etc. Real-time lab results, once proven, will allow operators to tune their plants to actual conditions and reduce the energy costs of over-treatment. Advanced ---PAGE BREAK--- 9 process monitoring will be more common in the coming years; it is likely worth investigating now for a major upgrade such as this. 6. Biosolids Management (Phase 1) Planned improvements include dredging solids and construction of a pump station on the lagoon effluent line to return low quality effluent to the HRT Cells for treatment. Given the low runtime expected for the pumps, no specific EEMs are recommended. 7. Biosolids Management (Phase 2) Planned improvements include the wholesale conversion from aerated sludge lagoons to anaerobic digestion, including thickening waste activated sludge (WAS) prior to digestion and dewatering after digestion. The cost for these improvements is roughly $25 million. EEM 7.1 Thickening Equipment Chapter 7 of the Plan describes alternatives for sludge thickening prior to digestion. A screw press, a belt filter press (BFP), and a thickening centrifuge are discussed. The cost analysis between the screw press and the BFP was pretty close. Assuming the screw press has a higher capital cost than the BFP, the energy savings provided by the screw press can provide incentives to offset the cost differential. The incentives should be figured into the cost analysis as part of the life-cycle cost. EEM 7.2 Anaerobic vs. Aerobic Digestion Provided that anaerobic digestion is more capital intensive than an equivalent aerobic digestion system, then presumably the energy savings of the anaerobic system can be used to generate incentives to help cover the cost differential. The Plan states briefly in 7.4.4 that aerobic digestion would require 1000 hp of aeration, but it doesn’t indicate if that is at max month 2034 or average day. Assuming 1000 hp is based on average day BOD loads of 22,000 lb., then the estimated baseline requirement for the first year’s operation is: 11,500 lb./day x 1,000 Hp/22,000 lb. = 522 hp x 0.746 kW/hp x 8760 = 3.4 million kWh annually. Assuming the anaerobic system would operate at a combined horsepower of 20 hp for mixing, 30 hp in boiler fans and water circulation, and 40 hp in additional sludge pumping for heating, then the estimated energy associated with the anaerobic system is roughly: 90 hp x 0.746 kW/hp x 8760 = 600,000 kWh annually, for a savings of 2.8 million kWH. At 25 cents/kWh, an incentive of up to roughly $700,000 would be available to help offset the cost difference between the aerobic and anaerobic systems. Annual energy costs in the first year would be reduced by roughly $112,000 at 4 cents/kWh. EEM 7.3 Digester Mixing Systems Several mixing systems are available for anaerobic digestion. One relatively new system is the linear mixer. The City of Gresham has had one each installed on two digesters now for two years and has had no problems. The original design had dedicated 40 hp gas compressors to provide mixing for each digester; the linear vendor determined that 10 hp was sufficient for each digester. The unit actually requires less than 5 hp in operation. Mixing has been excellent with improved volatiles reduction. ---PAGE BREAK--- 10 If external draft tube (EDT) mixers are utilized, experience at other plants has shown that continuous, full power mixing is not needed. One facility, MWMC in Eugene, utilizes one VFD for each pair of mixers, and regularly runs at roughly 50% of normal power. They incorporate an automatic sequencing program where the units ramp to 0, reverse at 100% speed for 30 minutes, then run at 100% forward for 30 minutes, then return to lower speed, low power setting for 23 hours. They are staggered so that no two VFD’s are drawing maximum power at the same time, thus managing demand charges as well as energy. 8. Biosolids Management (Phase 4) Planned improvements include a system to produce Class A biosolids on-site, such as a solar dryer facility. However, Section 7.6.1 makes it apparent that this is something of a “placeholder” and more evaluations of specific technologies and management plants will be needed. No EEM’s can be developed for this phase of the project at this time. D. Concluding Remarks The ESI program and Benton PUD staff are available to review the information presented in this letter with you and the City at your convenience. We believe that there are multiple EEMs that are either already included in the design or could be included that would result in substantial incentives, but more importantly, they would result many times in a process which can be “tuned” by the operators to be most efficient given the flows and loads present at any time. We visit many wastewater plants each year where the operators’ hands are essentially tied by systems that don’t have turndown or other flexibility built into them. Thank you for engaging the conservation program at this early stage; we sincerely look forward to working with you and the City on this important project. Sincerely, Layne McWilliams Water/Wastewater Sector Specialist