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Belgrade WRF Lagoon Dredging and Liner Improvements P10052-2022-004 Flows & Loads Analysis & Projections I Parkson Biolac® EOPCC and Feasibility Analysis From: Brian Viall, PE – Project Manager Zach Frieling, EIT – Project Engineer Date: March 7, 2024 Influent Flows and Loads Data Analysis Recent Influent Data Analysis The influent data for the Oxidation Ditches from September 1, 2022 to February 6, 2024 were analyzed and can be found in Figure 1. Average Daily Flow, Maximum Month Flow, and Peak Day Flow were calculated from Figure 1, and Peak Hour Flow was calculated from the same influent data but was omitted from Figure 1 for clarity. The resulting analysis focused on the data from 2023 as the complete flow data could be found for this year. The identified flows based on a 2023 population of 12,792 can be found in Table 1. Figure 1: City of Belgrade Influent Flows to the Oxidation Ditches ---PAGE BREAK--- Page 2 of 8 Table 1: 2023 Influent Flows Parameter Result Average Daily Flow (MGD) 0.92 Average Daily Flow Per Capita (gpcd) 72 Maximum Month Flow (MGD) 1.07 Maximum Month Peaking Factor 1.16 Peak Day Flow (MGD) 1.19 Peak Day Peaking Factor 1.30 Peak Hour Flow (MGD) 1.73 Peak Hour Peaking Factor 1.88 The calculated Average Daily Flow per Capita of 72 is significantly less than previously identified in the 2018 Belgrade Montana Wastewater Master Plan (90 gpcd), and all peaking factors were also less than previously identified. To remain conservative, the future flows and loads projections required to obtain a preliminary basis of design for the Parkson Biolac® system were based on the per capita flow and peaking factors found in the 2018 Belgrade Montana Wastewater Master Plan. Future Flows and Loads Projections The following are the assumptions that were used to develop the future flows and loads projections found in Table 2 and Table 3. 1. 2030 City of Belgrade Population = 19,736 2. Projected Population Growth Rate = 4% 3. Preliminary Design Based on the Flows and Loads for 2049 4. Flow Parameters Used as Identified in the 2018 Belgrade Montana Wastewater Master Plan: a. Average Daily Flow per Capita = 90 gallons b. Maximum Month Peaking Factor = 1.25 c. Peak Day Peaking Factor = 1.42 5. Peak Hour Peaking Factor = 2.34 a. Calculated from the projected population using the following equation: = 18 + 1000 4 + 1000 6. Loading Parameters Used as Identified in the 2018 Belgrade Montana Wastewater Master Plan: a. Maximum Month TKN Concentration = 56 mg/L b. Maximum Month TP Concentration = 9.9 mg/L c. Maximum Month TSS Concentration = 268 mg/L ---PAGE BREAK--- Page 3 of 8 7. Maximum Month BOD Concentration = 325 mg/L d. Used to obtain BOD:TKN ratio of 4.0 for denitrification to occur. Table 2: Total Projected Belgrade Influent Flows in 2049 Parameter Flow (MGD) Average Daily Flow 3.7 Maximum Month Flow 4.7 Peak Day Flow 5.3 Peak Hour Flow 8.7 Table 3: Total Projected Belgrade Influent Maximum Month Loads in 2049 Parameter Load (lbs/day) Total Kjeldahl Nitrogen 2,292 BOD 12,623 Total Phosphorus 385 Total Suspended Solids 10,409 The hydraulic and treatment capacity of the existing oxidation ditches were subtracted from the total influent flows and loads found in the above tables to develop a preliminary basis of design for the Parkson Biolac® system. This preliminary basis of design can be found in Table 4. Table 4: Preliminary Basis of Design for the Parkson Biolac® System Based on 2049 Flows and Maximum Month Loads Parameter Result Average Daily Flow (MGD) 2.0 Maximum Month Flow (MGD) 2.5 Peak Day Flow (MGD) 2.8 Peak Hour Flow (MGD) 4.0 Total Kjeldahl Nitrogen (lbs/d) 1,218 BOD (lbs/d) 4,859 Total Phosphorus (lbs/d) 206 Total Suspended Solids (lbs/d) 5,544 ---PAGE BREAK--- Page 4 of 8 Parkson Biolac® Feasibility Study and EOPCC Conceptual Engineering Figure 2 shows the high-level graphical design of the conceptual installation of the Parkson Biolac® system in the footprint of the existing Facultative Sludge Lagoon. Parkson used the flows and loads described in Table 4 to size the Biolac® system and the results are found in Table 5. Table 5: Biolac® System Design Parameter Value Approximate Dimensions at Grade (ft) 397 x 221 Approximate Bottom Dimensions (ft) 371 x 169 Side Water Depth (ft) 10 Basin Volume (MG) 5.2 Clarifier Size (ft) 80 x 23 Number of Clarifiers 3 Estimated Air Requirements w/o Denitrification (SCFM) 6,909 Estimated Air Requirements w/ Denitrification (SCFM) 4,622 Figure 2: Conceptual Drawing ---PAGE BREAK--- Page 5 of 8 The high-level concepts modeled are: 1. Connection to future influent pipe for flows to Biolac® system. 2. Modulate flow to Biolac® system with an actuated valve and flowmeter. 3. Install new influent pumps in new WAS Handling Facility. 4. Install Biolac® System, all necessary process piping, and three concrete rectangular clarifiers for biological treatment. 5. Procure two new Inovair blowers for additional aeration requirements. 6. Install a new liner for a WAS Handling Basin (WHB) needed for WAS/SCUM storage. 7. Install process piping and valving to convey WAS from the WHB to the WAS Handling Building for ultimate disposal. The Parkson Biolac® system is preliminarily designed to produce effluent quality of 10 mg/L total nitrogen (TN). If this same effluent quality is conservatively assumed for the existing oxidation ditches, then the total effluent TN loading from both treatment processes can be compared to the existing MPDES permit. This comparison is shown in Table 6. Table 6: Effluent TN Loading Comparisons Average Daily Effluent TN Loading (lbs/d) Parkson Biolac® System 167 Existing Oxidation Ditches 145 Total Effluent TN Loading 312 Current MPDES TN Discharge Limit 227 Remaining TN Discharge Capacity (85) ---PAGE BREAK--- Page 6 of 8 Cost Evaluations The breakdown of the Class 4 Cost Estimate for the Parkson Biolac® system is found in Table 7. Table 7 also shows costs for the necessary WAS handling facility and lagoon dry-in-place operations that are needed for successful installation of the Biolac® system. Table 7: Total Class 4 EOPCC Costs Biolac® Constuction EOPCC $7,130,400 WAS Handling Facility EOPCC $9,420,000 Lagoon Dry-In-Place EOPCC $1,065,630 Construction Sub-total $17,616,030 Engineering Design $2,151,552 I&C/SCADA Programming/Integration $150,000 Construction Engineering $2,813,568 Contingency (10%) $2,273,115 Total Costs $25,004,265 ---PAGE BREAK--- Page 7 of 8 SWOT ANALYSIS: • Increase treatment capacity w/ a relatively low capital cost per unit of treatment. • Helps delay major upgrades (i.e. Phase II – Oxidation Ditches) to future years. • Relatively low Nitrogen Concentrations in dewatering recirculation (when compared to other digestion alternatives). • Treatment in lined-lagoon basins has relatively low construction complexity. • WAS Holding Basin (WHB) in lined-lagoon basin affords more solids equalization capacity for equipment and O&M optimization/savings in biosolids management operation. WEAKNESSES: • Operating two different secondary treatment technologies (Oxidation Ditches & Biolac®). o (Though both are based on the principles of activated sludge.) • Harder to retrofit Biolac® for biological nutrient removal (BNR) upgrades. • Equipment and facilities assumed in Biolac®’s standard offering come with less operator predictability, harder to control with I&C / SCADA, and less consistent performance: o (e.g. Airlift pumps for WAS & RAS flows; rectangular clarifiers) • Effluent Quality less predictable and less reactive to operational adjustments. • Construction Sequencing and effectiveness of Dry-In-Place Operation still not fully resolved. • Availability of fill material not yet quantified. • More water surface area per unit volume of treatment capacity when compared to Oxidation Ditches. o (May require further coordination with FAA). OPPORTUNITY: • Allows time for growth in utility revenue and rate payer base to ease the financial burden of more complex upgrades. • Leverage existing grant dollars to complete O&M backlog that is needed regardless of project scope. THREATS: • Belgrade’s existing groundwater discharge permit is due for renewal with no indication of where permit limits will go in the future. • In fact, daily nutrient loadings from Phase I Oxidation Ditch effluent PLUS Biolac® Effluent may exceed loading permissible under present Permit. o See Table 6. Assumptions: • Assumes 10 mg-TN/L (actual effluent quality may vary). ---PAGE BREAK--- Page 8 of 8 • Assumes Average Annual Flows and a disposal strategy that leverages EQ volume in Pond 3 to reduce impacts of Max Month Flows. • Does not give credit to additional disposal capacity in irrigation system. o May require or trigger construction of future IP Beds for increased disposal capacity. • Theoretical disposal capacity (hydraulic and nutrient loading) available at existing facility is unknown and needs to be studied under separate scope for hydrogeological analysis. ---PAGE BREAK--- Long Sludge Age Treatment System — Advanced, low-loaded activated sludge technology — Exceptional treatment efficiency from moving aeration chains — Simple, low-cost construction — Low production of stable biosolids — Wave-Ox™ single basin total nitrogen removal ---PAGE BREAK--- The Biolac® system is the first suspended growth, activated sludge process to use simple, long sludge age treatment to create an extremely stable, reliable and easily operated system. The advanced capabilities of this unique technology far exceed ordinary extended aeration treatment. Based on the excellent treatment efficiency of its moving aeration chains, the Biolac® system’s 40-60 day sludge age design maximizes process stability while delivering extremely high effluent quality. With the capability to utilize in-ground earthen basins, the Biolac system produces state-of-the-art treatment results at the lowest total plant cost. Over 800 successful installations throughout North America and around the world are a testimony to the excellent results from this proven process. Sludge age, also known as SRT (Solids Retention Time) or MCRT (Mean Cell Residence Time) defines the operating characteristics of any aerobic biological treatment system. A longer sludge age dramatically lowers effluent BOD and ammonia levels, especially in colder climates. The Biolac long sludge age process produces BOD levels well less than 10 mg/l, and complete nitrification (less than 1 mg/l NH3) year-round. More advanced process control strategies using Wave-Ox™ technology (see back page) extend its capabilities to denitrification and biological phosphorus removal with no treatment basin modifications. With the mixing efficiency of the moving aeration chains as the key building block, Parkson further enhances the Biolac system’s capabilities by coupling it with the EZ Clear™ secondary clarifier. The result is a smaller plant footprint and lower total plant cost. Operators benefit from the process stability provided by the large quantity of biomass present as the Biolac system treats widely fluctuating loads while requiring very few operational changes. With fewer process monitoring requirements and simple equipment design, both operating and maintenance requirements are greatly reduced. The extreme stability of the biomass allows sludge wasting to non-aerated sludge ponds or basins with no additional digestion, saving both capital and operating costs. Long sludge age biological treatment Treatment efficiency (BOD and NH3 removal) Process stability 10 20 30 40 50 60 Sludge Age (Days) Biolac System Conventional extended aeration, batch reactors and oxidation ditches Sludge production Operator attention ---PAGE BREAK--- System Components System Construction One major advantage of the Biolac system is its low construction cost. Most treatment systems require costly concrete tanks to construct the activated sludge portion of the process. Biolac systems are typically installed in lined earthen basins, greatly simplifying and reducing the cost of construction. The Biofuser® fine bubble diffuser assemblies are suspended from the Bioflex™ floating aeration chains and require no mounting or anchoring to the basin bottom. Therefore, concrete is not required to anchor or level aeration diffusers and piping. Bioflex™ Moving Aeration Chain The ability to mix large basin volumes using minimal energy is a critical function of the unique Bioflex moving aeration chains. They require 50-70% less energy to completely mix activated sludge than stationary diffuser systems, which make the moving aeration chains critical for long sludge age operation. The floating Bioflex aeration chains suspend Biofuser fine bubble diffuser assemblies approximately 12” above the basin bottom. The slow, oscillating movement of the flexible aeration chains is caused by the rising air bubbles and controlled by their tension as they distribute oxygen and mixing energy evenly throughout the basin. No additional airflow or mixing equipment is required to maintain complete mixing of mixed liquor concentrations as high as 7000 – 8000 mg/l. All equipment is accessible for service and maintenance without basin dewatering. Each Biofuser assembly holds up to five diffuser tubes, which provides the ability to customize each design and provide for future expansion as needed. EZ Clear™ Clarifier Efficient liquid-solids separation is critical to achieving high quality effluent, and the Biolac EZ Clear™ clarifier has proven to be extremely reliable. With hundreds of successful installations, many plants continue to produce effluent TSS between 5 and 10 mg/l. Using a common wall between the clarifier and Biolac treatment basin, the plant footprint is greatly reduced as connecting piping and splitter boxes are eliminated. A slide gate isolates the clarifier and allows mixed liquor to flow to the EZ Clear inlet distribution channel where the orifice design also provides in-basin equalization of peak flows. Using cross-flow hydraulics, the settled solids collect in the V-bottom of the clarifier and are continuously and rapidly removed all along the clarifier length. An airlift pump lifts the RAS to an elevation so that it flows by gravity back to the influent end of the treatment basin. A small amount of biomass is automatically wasted by gravity to control the MLSS concentration. Process flexibility is maintained while eliminating mechanical return and waste sludge pumps. Scum is prevented from flowing over the weir by a scum baffle, and is skimmed and automatically removed at the end of the clarifier. Mechanical RAS pump options are also available. All maintenance is performed from the surface without dewatering the clarifier. ---PAGE BREAK--- Fort Lauderdale Chicago Kansas City Denver Birmingham 1.888.PARKSON [EMAIL REDACTED] www.parkson.com BL Wave-Ox™ and Wave-Ox™ Plus Biological Nutrient Removal Biological nutrient removal (BNR) is simple and affordable with the Biolac® Wave-Ox™ and Wave-Ox™ Plus process. Proven by hundreds of successful installations, Wave-Ox and Wave-Ox Plus are simple, single basin nitrogen removal processes developed specifically for the unique Biolac system and moving aeration chain design. Automatic control of the air distribution to the Bioflex aeration chains creates moving waves of oxic and anoxic zones within the Biolac basin. This repeated cycling of environments nitrifies and denitrifies the wastewater without recycle of mixed liquor or additional treatment basins. Blower control using either aeration basin DO or secondary effluent ammonia as a continuous control signal optimizes the Biolac basin process to maximize total nitrogen removal. Effluent total nitrogen concentrations of 5 mg/l and less are typical. Biological phosphorus removal can also be accomplished by incorporating an independent anaerobic zone at the front end of the process. Wave-Ox™ Plus Schematic EZ Clear™ Clarifier DO DO CONTROLLER AIR Blowers Manipulated Variable Manipulated Variable (Timer / Grouping Setpoint) Manipulated Variable (DO Setpoint) Reference Variable (NH3 Setpoint) Measured Variable (Actual Value) Measured Variable (Actual Value) MA NH3 NH3 CONTROLLER DO f(NH3) Timer/Groupings f(NH3) ---PAGE BREAK--- Advanced Gravity Separation Biolac® EZClear™ Clarifier For years, a key part of the Biolac System has been the simple, common wall secondary clarifier that completes the system. Efficient liquid-solids separation is critical to maintaining high quality effluent and the Biolac® clarifier has proven to perform with excellent reliability. Many plants produce effluent TSS between 5 and 10 mg/l. Along with hundreds of successful installation over the past 25 years comes the experience and learning that leads to new innovation and development. The EZClear™ design builds on the successful innovation of the existing Biolac® clarifier while maintaining all the features and benefits that owners want. – – Low effluent TSS – – Rapid sludge removal – – Simple maintenance of all equipment from the surface – – Gravity RAS flow option – – Low hydraulic profile With up to 100 feet, the EZClear™ almost doubles the available surface area per clarifier, expanding the range of application and further reducing operation and maintenance requirements while improving effluent quality. ---PAGE BREAK--- Fort Lauderdale Chicago Montreal Kansas City Dubai 1.888.PARKSON [EMAIL REDACTED] www.parkson.com Biolac® EZClear™ Clarifier Features Benefits Effluent TSS guaranteed – as low as 10 mg/l TSS Provides the owner with the confidence and security of a successful EZClear™ installation Turned 90° from the original Biolac™ clarifier, the EZClear™ Clarifier is available in up to 100 feet. The surface area available per clarifier is increased by over 80%, providing higher flow capacity for lower total cost Vertical, common wall construction with the Biolac™ treatment basin and other structures Reduces the amount of concrete and excavation required, lowering the cost of construction. Clarifier/RAS footprint is at least 30% less than with separate circular clarifiers Low-velocity, equally distributed crossflow design Inlet distribution pipes ensure superior hydraulic efficiency and eliminates the density currents that destroy clarifier performance EZClear™ feed channel orifices control the flow into the clarifier Controlled equalization can automatically be provided in the Biolac® treatment basin, dampening short term peak clarifier loading, improving performance Feed channel slide gate Provides easy isolation of each EZClear™ from the Biolac® treatment basin Rapid sludge removal from the entire EZClear™ V-bottom Keeps sludge healthy and in the process treating wastewater – no danger of denitrification or P re-release in the sludge collection zone Automated sludge wasting Improves process stability and performance while reducing operator time and attention Surface wasting slide gate Allows for removal of poor settling floc/scum from the clarifier feed. The operator decides when and how much to waste this way Automated scum skimming and removal Minimizes scum flow while reducing operator time and attention Both airlift pumps with gravity RAS flow, and mechanical pumps with pumped RAS flow are available Design flexibility depending on plant hydraulics and operator preference EZClear™ feed channel orifices control the flow into the clarifier Feed channel slide gate Rapid sludge removal from the entire V-bottom EZClear™ Surface wasting slide gate Automated scum skimming and removal 1 2 3 4 5 1 2 3 4 5 BL-EZ ---PAGE BREAK--- Biological Nutrient Removal with MixMode™ Energy Reduction Technology (ERT) Biolac® System Wave-Ox™ Plus Biological nutrient removal (BNR) is simple and affordable with the Biolac® Wave-Ox™ Plus process. Proven by hundreds of successful installations, the Wave-Ox™ Plus process is a simple, single basin total nitrogen removal process developed specifically for the Biolac System’s unique, long sludge age process and moving aeration chain design. Automatic control of the air flow distribution to the moving aeration chains creates unique moving waves of multiple oxic and anoxic zones. This repeated cycling of environments nitrifies and denitrifies the wastewater in the long sludge age Biolac basin without nitrate recycle, separate staging or additional external basins. Nitrogen removal to 5 mg/l is typical with many municipal installations achieving <3 mg/l total N. Parkson has now taken this user-friendly solution to the next level in automatic operation and efficiency with the patent- pending Wave-Ox™ Plus process with MixMode™ energy reduction technology. Wave-Ox™ Plus process control automatically adjusts the oxic vs. anoxic conditions in the basin to continuous delivery optimized process performance at the lowest possible energy usage. Oxic Influent WAS Anoxic Oxic Blower Building Moving Aeration Chains Integral Clarifiers DO Control Anoxic ---PAGE BREAK--- Fort Lauderdale Chicago Montreal Kansas City Dubai 1.888.PARKSON [EMAIL REDACTED] www.parkson.com Wave-Ox™ Plus with MixMode™ Energy Reduction Technology (ERT) All wastewater treatment plants are dynamically loaded as influent flows and loads change depending on the time of day, day of the week and season of the year. The innovative Wave-Ox™ Plus process automatically optimizes the process conditions over a wide range of influent conditions to maximize total nitrogen removal at the lowest possible energy usage. Rather than relying on DO control of the process and manual aeration system adjustments, the Wave-Ox™ Plus process uses continuous online effluent NH3 measurement to automatically adjust the DO setpoint, the aeration chain timer and their sequence to maximize the total nitrogen removal capability of the process while minimizing air and energy usage. The result is an automatically tuned process that maximizes total nitrogen removal continuously without manual, operator intervention, even as influent loads to the process change dramatically. MixMode™ technology insures this optimum treatment is achieved with the lowest possible energy usage. Only enough air to consistently optimize the level of total nitrogen removal is used, and no more. MixMode™ automatically uses the minimum amount of air needed to mix the basin during times of low load. The aeration system automatically adjusts up and down as needed to maintain optimum total nitrogen removal and mixing with minimal energy usage. DO NH3 CONTROLLER DO f(NH3) Timer/Groupings f(NH3) DO CONTROLLER AIR Blowers Clarifier Manipulated Variable Manipulated Variable (Timer / Grouping Setpoint) Manipulated Variable (DO Setpoint) Rerference Variable (NH3 Setpoint) Measured Variable (Actual Value) Measured Variable (Actual Value) MA NH3 BL-WO