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City of Puyallup Comprehensive Sewer Plan February 2016 8-16 The majority of the other major process equipment was installed in the 1998 to 2000 upgrade, so it is about 15 years old. Most of this equipment will need to be replaced during the planning period due to age and condition. Because of the extent of this replacement it should be budgeted as a capital improvement project rather than on-going maintenance. 8.8.3 Equipment Obsolescence In addition to age and condition issues, some equipment is functionally obsolete. An example would be the previously discussed UV system. Newer, more energy efficient UV lamps may justify replacement of the existing system. Likewise, replacement of the existing centrifugal aeration blowers with more efficient variable high-speed turbine blowers and fine bubble panel diffusers may be justified on the basis of energy savings. The plants Supervisory Control and Data Acquisition (SCADA) system should also be reviewed for functional obsolescence as it is 15 years old. Programmable logic controllers (PLCs), computers and other instrumentation and control equipment is generally functionally obsolete in less than 10 years, making service of older systems increasing difficult. 8.9 Treatment Plant Conclusions and Recommendations In conclusion, the plant has sufficient capacity to treat the projected flows and loads throughout the planning period. The plant is capable of meeting current effluent permit conditions and no changes are required to meet permit conditions at least through the next permit cycle (through 2020). Some plant improvement will likely be necessary during the planning period due to structure and equipment age, condition and/or obsolescence. It is recommended that a Facility Plan be prepared to explore and address the following issues in detail: Ability to meet future copper limits with increasing flows to secondary clarifiers and need for very low effluent suspended solids concentrations Use of primary clarifier bank no. 2 structure for other purposes, such as: o Flow equalization o Effluent filtration facility Reconfiguration and/or replacement of the Sludge Handling Building functions, including: o Sludge storage o Grit removal o Gravity primary sludge thickening o Plant site drainage Major process equipment replacement, including schedule and capital cost estimates ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-1 Chapter 9 Comprehensive Plan and Capital Improvements 9.1 Introduction Four major components make up the Capital Improvements Projects (CIP) Program, 1) those reoccurring maintenance issues that can be solved with a project, 2) that infrastructure that has known deficiencies or integrity issues, 3) mechanical and electrical infrastructure that is approaching the end of its expected life (obsolescence) and 4) that infrastructure that needs to be upsized resulting from population growth and the associated increase in flow values. Together these four components comprise the CIP. This chapter provides a compilation of specific projects, improvements, and programs the City should implement and an estimation of the cost to complete the improvements. These projects are derived primarily from the system hydraulic analysis and discussions with the City’s operations and engineering staff. Other non-project recommendations can be found throughout the preceding chapters. The City should review the CIP periodically to adjust for significant changes in the priority of each project, its cost, and scope. A discussion of these four components follows: Operations & Maintenance O&M projects will replace facilities identified by the City O&M staff as having unacceptably high maintenance requirements, both in terms of frequency and in magnitude. It is understood that some O&M problems cannot be solved with a capital project and just requires continued vigilance. Other O&M issues can be eliminated or lessened by a capital project. For example a pipe segment that is chronically seeing occluded flow due to grease build up, might be rectified by improving the flow characteristics, improving the slope of the pipe or changing the pipe material from concrete to PVC. Similarly some solutions might address the source of the problem. In this example that would include the City’s FOG source control program of increasing oversight and enforcement. Known Deficiencies and Integrity: The City’s knowledge of their system and identification of the deficiencies form the basis for this element. Known areas of root intrusion, damaged and cracked piping systems, protruding stubs and localized bellies would be included in this category. Obsolescence: Improvements classified as obsolete are based on the age of the infrastructure. Pump station mechanical and electrical equipment is expected to have a typical usable life of 25 years; wastewater treatment plant mechanical and electrical equipment is expected to have a typical usable life of 15 to 20 years. Structures are expected to have a typical usable life of 50 years. Modern pipes are expected to have a typical usable life of 100 years. Capacity: Improvements classified as insufficient in capacity are determined based on whether or not the infrastructure can effectively convey the incoming flow. Gravity sewer pipes are considered to have insufficient capacity when the depth in the manhole is more than 200 percent or more of the pipe diameter (d/D > 2.0). Force mains are considered to have insufficient capacity when the velocities exceed 8 feet per second. Pump stations are considered to have insufficient capacity when inflow exceeds the flow produced by the pump station with the largest pump out of service. As described in Chapter 6, the conveyance system was evaluated using existing flows and flows projected for 2021, 2035, and build-out conditions. The evaluations determined system ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-2 deficiencies when subjected to these existing and future flow conditions. Following identification of system deficiencies, the computer model was used to evaluate and select system improvements to alleviate the system deficiencies. When possible, system improvement projects should be coordinated with other utilities to minimize disruption and reduce associated costs such as road and surface restoration. 9.2 Capital Improvement Projects The Capital Improvement Plan (CIP) is presented for three timeframes: 6-Year CIP from 2015 to 2021 6-year CIP that were postponed to the 2021 to 2035 period 20-year CIP from 2021 to 2035 These three groupings have been color matched throughout the document. The 6-year CIPs are depicted in orange. The 6-year CIPs that were postponed to the 2021 to 2035 period are represented in yellow. And the 20-year CIPs (2021 to 2035) are shown in blue. The projects recommended for the CIP are summarized in Table 9-1, and illustrated for the collection and conveyance system on Figure 9.1. Individual mini-basin maps found in Appendix E more clearly show the extent of the proposed improvements. The CIP for the WWTP is presented on Figure 9.2 The mini-basin mapping in Appendix E includes the CIPs by the three time periods and also the extensions of sewers to each unsewered parcel in the Service Area. The sewer extensions are expected to be privately funded by developers and consequently are not listed in the CIP Table 9-1. Prior to the City’s approval to extend these lines to the unsewered parcels, the City should revisit the routing, or require the developer to re-evaluate the routing and sizing to reflect any changes that have occurred since this document was finalized. It is advisable to confirm pipe sizes that are listed in the CIP through flow monitoring before making these improvements. Extending the collection and conveyance system to all parcels was done based on existing mapping and available contours. Except for extremely steep slopes, sewer service was provided to every parcel. In several cases service to certain parcels was identified as needing individual grinder pumps. The routing and the service schemes are based on the topographic mapping. Where possible, future line extensions followed existing rights-of-way. Where large parcels are undeveloped the sewer line extensions attempt to follow parcel boundaries. When topographic constraints prevented alignments along parcel boundaries, it was necessary to show an alignment that bisected the properties. Development of large parcels is strongly influenced by lot layout and the roads to serve those lots. Without that insight the sewer service scheme within the large parcels is difficult to define. Consequently, the large parcels have been presented with sewer service to the nearest corner. ---PAGE BREAK--- Description CIP No. 2015 Cost Basis remaining 2015 Conveyance System 6 year Improvements Replacement of approximately 1900 linear feet of pipe due to aging conditions - 9th Ave NE between South Meridian and 4th St NE and 4th Ave NE between 9th Ave NE and 5th Ave NE Puy-3B J-3 $1,000,000 Replacement/Failing Pipe $200,000 $800,000 $1,000,000 $0 Replacement of approximately 1200 linear feet of pipe due to aging conditions - East Main, 23rd ST SE east towards Riverside LS Puy-7A J-7 $660,000 Replacement/Failing Pipe $660,000 $660,000 $0 Replacement of approximately 1900 linear feet of pipe due to aging conditions - East of 3rd St Se, between 7th Ave SE and 9th Ave SE Puy-14D J-14 $340,000 Replacement/Failing Pipe $340,000 $340,000 $0 7th ave SW; 14th st SW to 18th St SW (Sinkhole) $450,000 $450,000 $450,000 Replacement of approximately 2000 linear feet of pipe due to aging conditions - Tacoma Road, between 23rd and Tacoma St discharge manhole to 19th St NW Puy-23A J-23 $1,040,000 Replacement/Failing Pipe $210,000 $830,000 $1,040,000 $0 Elimination of S. Hill Mall LS (LS 6) - See feasibility study options and costs Puy-10A J-10 $400,000 Eliminate need for LS 6 $500,000 $500,000 $0 Fruitland Ave sewer main extension - W Pioneer Way to 9th AVE SW Puy-21A J-21 $1,130,000 O&M/Capacity/Environmental $135,000 $995,000 $1,130,000 $0 Fruitland Ave sewer Main Extension - 9th Ave SW to 85th St E Puy-21B J-21 $910,000 O&M/Capacity/Environmental $110,000 $800,000 $910,000 $0 Fruitland Ave sewer Main Extension - 85th St E to 96th St E Puy-21C J-21 $1,060,000 O&M/Capacity/Environmental $125,000 $125,000 $935,000 Small Pumping Station to pump to Fruitland Ave Trunk Line Puy-21E J-21 $1,030,000 O&M/Capacity/Environmental $130,000 $130,000 $900,000 Aging Pipe Replacement Program N/A N/A $750,000 per annum Replacement/Failing Pipe $750,000 $750,000 $750,000 $750,000 $3,000,000 $10,500,000 Re-route gravity system to resolve accessibility issued in wetland area - intercept line in 9th St SE and redirect to 10-inch Parkwood sewer Puy-20A J-20 $160,000 Improve Access w $160,000 $160,000 $0 20 year Improvements Small Pumping Station to pump to Fruitland Ave Trunk Line Puy-21D J-21 $1,110,000 O&M/Capacity/Environmental $0 $1,110,000 Approximately 1400 lf gravity upsize - 10 and 12-inch to 15-inch. SR-512 Crossing - S. Meridian to 5th St SW Puy-19A J-19 $1,090,000 Capacity $0 $1,090,000 Re-route gravity sewer main north of Lowes/abandon Bradley Lake line - Install new parallel main along 5th St SE Puy-10B J-10 $770,000 Improve Access, Reduce Environmental Concerns due to Lake Proximity (O&M) $0 $770,000 Approximately 2400 lf gravity upsize - 10 and 12-inch to 15-inch - W Pioneer Way 18th St SW to 12th St NW Puy-22A J-22 $1,400,000 Capacity $0 $1,400,000 Relay approximately 850 lf of 36-inch gravity due to adverse slope issues - 14th St SW between 7th Ave SW and 9th Ave SW and 9th Ave SW one pipe east Puy-27A J-27 $850,000 Replacement/Failing Pipe $0 $850,000 Approximately 1940 lf gravity upsize - 24-inch to 36-inch - 9th Ave SW between 14th St SW and 9th St SW Puy-14A J-14 $1,820,000 Capacity $0 $1,820,000 Approximately 1590 lf gravity upsize - 24-inch to 36-inch - 9th Ave SW between 9th St SW and 5th St SW Puy-14B J-14 $1,410,000 Capacity $0 $1,410,000 Approximately 2125 lf gravity upsize - 24-inch to 36-inch - 5th St SW between 9th Ave SW and 7th Ave SW, 7th Ave SW between 5th St SW and S Meridian Puy-14C J-14 $1,770,000 Capacity $0 $1,770,000 Approximately 1100 lf gravity upsize - 10-inch to 12-inch - 28th St SE between Manorwood Dr and Shaw Rd Puy-1A J-1 $640,000 Capacity $0 $640,000 Approximately 850 lf gravity upsize - 12-inch to 18-inch - 5th St SW between 9th Ave SW and Fairgrounds Puy-25A J-25 $550,000 Capacity $0 $550,000 Replace Aging Pipe Across Clark's Creek - 7th Ave SW Bridge Crossing Puy-27B J-27 $1,400,000 Replacement/Failing Pipe $0 $1,400,000 Approximately 810 lf gravity upsize - 18-inch to 24-inch - 5th St SE between E Pioneer and 4th Ave SE Puy-14E J-14 $590,000 Capacity $0 $590,000 Approximately 2450 lf gravity upsize - 36-inch to 42-inch - 14th St SW between 5th St SW and 9th Ave SW, 9th Ave SW between 14th St SW and 12th St SW Puy 27-C J-27 $1,900,000 Capacity $0 $1,900,000 Approximately 1850 lf gravity upsize - 8-inch to 12-inch - Shaw Rd between 31st Ave SE and 26th Ave SE Puy-1B J-1 $1,020,000 Capacity $0 $1,020,000 Approximately 1265 lf gravity upsize - 24-inch to 36-inch - 13th Ave NW between 18th St NW and 15th St NW Puy-3C J-3 $1,230,000 Capacity $0 $1,230,000 Approximately 550 lf gravity upsize - 24-inch to 36-inch - 9th Ave NW between 9th St NW and 8th St NW, 8th St NW south to 8th Ave NW Puy-3D J-3 $590,000 Capacity $0 $590,000 Approximately 3400 lf gravity upsize - 8-inch to 12-inch - Shaw Road between 23rd Ave SE and Dunhill Lane Puy-4A J-4 $1,770,000 Capacity $0 $1,770,000 Approximately 3200 lf gravity upsize - 8-inch to 12-inch - 24th St Place SE between 20th Ave SE and 12th Ave SE Puy-5A J-5 $1,800,000 Capacity $0 $1,800,000 Approximately 1000 lf gravity upsize - 24-inch to 36-inch - Fairgrounds between Fairview Drive and 5th St SW Puy-25B J-25 $990,000 Capacity $0 $990,000 Subtotal $1,910,000 $2,215,000 $1,745,000 $910,000 $860,000 $1,805,000 $9,445,000 $35,035,000 Capital Improvement Plan Table 9.1 2018 2019 2020 2015 - 2020 TOTAL 2021-2034 Total 9 Figure Ref See Appendix J Base Year Cost (2015 dollars) See Appendix E Reason for Improvement Projected Year of Improvement All costs in 2015 dollars (i.e. no adjustments for inflation) 2016 2017 11/9/2015 S:\Projects\Puyallup, City of\Comp Sewer Plan\Comp Plan Document (Working)\Tables\Table 9.1 CIP through 2040_Scen B+1_Final_10-30-15.xlsx ---PAGE BREAK--- Description CIP No. 2015 Cost Basis remaining 2015 Capital Improvement Plan Table 9.1 2018 2019 2020 2015 - 2020 TOTAL 2021-2034 Total 9 Figure Ref See Appendix J Base Year Cost (2015 dollars) See Appendix E Reason for Improvement Projected Year of Improvement All costs in 2015 dollars (i.e. no adjustments for inflation) 2016 2017 Lift Stations 6 year Improvements Cherokee Pump Station (#34) Replacement Puy-11A J-11 $690,000 Replacement/Capacity $690,000 $690,000 Riverside Pump Station (#24) Improvements Puy-7B J-7 $750,000 Replacement/Capacity $750,000 $750,000 4th and River Road (#38) Pump Station Improvements Puy-3A J-3 $1,680,000 Replacement/Capacity $200,000 $1,480,000 $1,680,000 Clarks Creek Pump Station (#25) Replacement Puy-24A J-24 $640,000 Replacement/Capacity $640,000 $640,000 Candlewood Pump Station (#26) Replacement Puy-2A J-2 $640,000 Replacement/Capacity $640,000 $640,000 20 year Improvements North Levee Pump Station Improvements Puy-6A J-6 $1,010,000 Replacement/Capacity $0 $1,010,000 Costco Pump Station (#10) Upgrades Puy-16A J-16 500,000 Replacement/Capacity $0 $500,000 Subtotal $1,440,000 $0 $200,000 $1,480,000 $1,280,000 $0 $4,400,000 $1,510,000 Wastewater Treatment Plant (WWTP) 6 year Improvements Aging Equipment Replacement WWTP-1 Figure 8.2 $500,000 per year Replace Aging/Deficient Equipment $500,000 $500,000 $500,000 $500,000 $500,000 $500,000 $3,000,000 Vactor Unloading Station WWTP-2 Figure 8.2 $250,000 Replace Aging/Deficient Equipment $250,000 $250,000 Outfall Header Cleaning/Diffuser Replacement WWTP-3 Figure 8.2 $150,000 Replace Aging/Deficient Equipment $150,000 $150,000 Flood Wall WWTP-4 Figure 8.2 $300,000 Replace Aging/Deficient Equipment $300,000 $300,000 Biosolids Dewatering Improvements Project WWTP-5 Figure 8.2 $5,854,594 Replace Aging/Deficient Equipment $2,854,594 $3,000,000 $5,854,594 Construction Engineering Dewatering project @ 10% WWTP-6 Figure 8.2 $209,480 Replace Aging/Deficient Equipment $109,480 $100,000 $209,480 WWTP Facility Plan WWTP-7 Figure 8.2 $500,000 Replacement $225,000 $225,000 Replace Aeration Blower WWTP-8 Figure 8.2 $388,000 Replace Aging/Deficient Equipment $388,000 $388,000 Replace Grit Removal Equipment WWTP-9 Figure 8.2 $300,000 Anticipated Regulatory Requirement $300,000 $300,000 Replace UV disinfection system WWTP-10 Figure 8.2 $2,200,000 Replace Aging/Deficient Equipment $2,200,000 $2,200,000 New headworks odor system WWTP-11 Figure 8.2 $200,000 Replace Aging/Deficient Equipment $200,000 $200,000 Replace non-potable water pump system WWTP-12 Figure 8.2 $60,000 Replace Aging/Deficient Equipment $60,000 $60,000 Effluent cloth disc filters WWTP-13 Figure 8.2 $3,000,000 Anticipated Regulatory Requirement $3,000,000 $3,000,000 Replace generator bldg blowers WWTP-14 Figure 8.2 $90,000 Replace Aging/Deficient Equipment $90,000 $90,000 Replace PLC based control & SCADA system WWTP-15 Figure 8.2 $300,000 Replace Aging/Deficient Equipment $300,000 $300,000 Primary clarifier # 1 & # 2 new drives WWTP-16 Figure 8.2 $50,000 Replace Aging/Deficient Equipment $50,000 $50,000 Primary clarifier # 1 thru 4 new flights WWTP-17 Figure 8.2 $80,000 Replace Aging/Deficient Equipment $80,000 $80,000 Aeration basin discharge channel mixing WWTP-18 Figure 8.2 $20,000 Replace Aging/Deficient Equipment $20,000 $20,000 Replacement of Influent Sluice Gates WWTP-19 Figure 8.2 $200,000 Anticipated Regulatory Requirement $200,000 $200,000 Replace Structural I-Beams in Aeration Selector Zones WWTP-20 Figure 8.2 $250,000 Replace Aging/Deficient Equipment $250,000 $250,000 Replace all Aeration Basin Air Line Knee Braces WWTP-21 Figure 8.2 $250,000 Anticipated Regulatory Requirement $250,000 $250,000 20 year Improvements Additional Anaerobic Digester WWTP-22 Figure 8.2 $7,731,000 Replace Aging/Deficient Equipment $0 $7,731,000 Additional Secondary Clarifier WWTP-23 Figure 8.2 $4,422,000 Replace Aging/Deficient Equipment $0 $4,422,000 Replace influent screw pumps WWTP-24 Figure 8.2 $1,100,000 Replace Aging/Deficient Equipment $0 $1,100,000 Miscellaneous Valve Replacements WWTP-25 Figure 8.2 $200,000 Replace Aging/Deficient Equipment $0 $200,000 Subtotal $4,164,074 $4,213,000 $6,260,000 $890,000 $650,000 $1,200,000 $17,377,074 $13,453,000 TOTAL - Conveyance, Lift Station and WWTP $7,514,074 $6,428,000 $8,205,000 $3,280,000 $2,790,000 $3,005,000 $31,222,074 $49,998,000 6-year Capital Improvement Projects 6-year Capital Improvement Projects postponed to the 2021 - 2035 period for financial reasons 20-year capital Improvement Projects 11/9/2015 S:\Projects\Puyallup, City of\Comp Sewer Plan\Comp Plan Document (Working)\Tables\Table 9.1 CIP through 2040_Scen B+1_Final_10-30-15.xlsx ---PAGE BREAK--- TP TP TP " " " " " " " " " " " " " " " " " " " " " Puy-6 Puy-20 Puy-3 Puy-4 Puy-16 Puy-33 Puy-5 Puy-7 Puy-14 Puy-26 Puy-27 Puy-10 Puy-1 Puy-21 Puy-17 Puy-24 Puy-32 Puy-2 Puy-34 Puy-9 Puy-18 Puy-13 Puy-25 Puy-15 Puy-8 Puy-12 Puy-35 Puy-28 Puy-31 Puy-22 Puy-11 Puy-19 Puy-23 Puy-29 Puy-36 Puy-37 Puy-30 Puy-25 PUY-3D PUY14E PUY-25B PUY-3C PUY-1B PUY-27C PUY-4A PUY-5A PUY-27B PUY-27A PUY-1A PUY-25A PUY-10B PUY-19A PUY-14B PUY-14A PUY-21D PUY-14C PUY-22A PUY-20A PUY-14D PUY-10A PUY-7A PUY-21E PUY-23A PUY-3B PUY-21B PUY-21A 104TH ST E W TAPPS D R E W EST TAPP S DR E 128TH ST E 122ND ST E S TAPPS DR E SOUT H TAPPS D R E 122ND AV E SHAW RD E 96TH ST E ORTING HWY E SR162 E 84TH ST E 72ND ST E M ILITARY RD E 118TH ST E E VALLEY H W Y E EAST VALLEY H WY E 80TH ST E BONNEY LAKE BLVD E SR410 HWY E 64TH ST E 94TH AV E 39TH AV SE 31ST AV SW VALLEY AV E WOODLAND AV E 23RD AV SE S MERIDIAN SHAW RD 5TH ST NE SR512 HWY E 112TH ST E E MAIN 86TH AV E 111TH AV E 48TH ST E 39TH AV SW FREEMAN RD E RH ODES LAKE RD E MAIN ST E MILWAUK EE AV E 62ND AV E N LEVEE RD E NORT H LE VEE RD E VALLEY AV RIVER RD E SR410 HWY W N MERIDIAN S WOODLAND E PIONEER W PIONEER 52ND ST E MAIN S T 56TH ST E VALLEY AV NW 43RD AV SE STEWART AV E 90TH ST E 78TH AV E SR16 1 W STEWART PI ONEER WY E 9TH ST SW BINGHAM AV E N LE VEE R D SR410 E M CCUT CHE ON RD E ANGELINE RD E 12TH AV SW FRYAR AV 37TH A V SE SR512 HWY W R IVER R D 114TH AV E BE N S TON DR E 70TH AV E 34TH AV E 160TH AV E SR 5 1 2 C I OF W VAL L EY AV N E 142ND AV E RAMP SR512 R PF1 E MERIDIAN E EDGE W O O D D R E WALLER RD E S U M N ER-TAP PS HW Y E TR A FFIC AV CANYON RD E 166TH AV E S F R UITLA N D F R U ITLAND A V E 48TH AV E VICKERY AV E 44TH AV E CHRIS ELLA RD E 66TH A V E MYERS RD E 50TH AV E S R167 HWY S LOCUST AV E RIVERSIDE DR E 110TH AV E WEST VAL LEY HW Y E ME R IDI A N A V E S R 1 6 7 CIOF S Puyallup WWTP Sumner WWTP Cherrywood MHP WWTP PUY-3A PUY-7B PUY-2A PUY-24A PUY-11A PUY-16A 4 5 6 8 10 16 18 20 24 25 26 27 29 30 32 34 35 38 39 40 PUY-6A Legend TP Treatment Plant " Pump Station Mini-Basins City Boundary Urban Growth Area Sanitary Sewer Service Area Puyallup First Right of Refusal P:\Mapping\Maps_Generated\Puyallup\13-10323.00\013 - Assemble Draft Plan\maps\Fig 9.1 Composite CIP Map - 11x17.mxd £ ¤ 2 1 5 £ ¤ 7 6 1 £ ¤ 0 1 4 £ ¤ 2 6 1 0 1 0.5 Miles Pump Stations & Mini-Basins: City of Puyallup 2013 Pierce County base data 2013 Data sources supplied may not reflect current or actual conditions. This map is a geographic representation based on information available. It does not represent survey data. No warranty is made concerning the accuracy, currency, or completeness of data depicted on this map. BHC Consultants LLC., assumes no responsibility for the validity of any information presented herein, nor any responsibility for the use or misuse of the data. COPYRIGHT © 2015 BHC CONSULTANTS LLC., ALL RIGHTS RESERVED : Sanitary Sewer System Comprehensive Plan City of Puyallup, Washington Figure Composite CIP Map 9.1 Capital Improvement Number PUY-1A 2015 - 2020 CIP 6-Yr CIP Postponed to 2021-2035 2021 - 2035 CIP July 2015 Detailed representations can be found in Appendix E ---PAGE BREAK--- " ( & # :;,31 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-7 It is understood that there may be other alternatives to providing sewer service to the unsewered parcels. The City will consider other alternatives when other such options are presented. The delineation of wetlands and sensitive areas may create obstacles to the installation of the lines. The details of final alignment and design are beyond the scope of this document. 9.3 Basis for CIP Cost Estimates Construction cost estimates were prepared for most of the CIP projects listed in Table 9.1. Documentation for these estimates can be found in Appendix F. Those projects that do not have supporting cost estimates are based on actual bid amounts or detailed cost estimating done during the design phases. Certain assumptions needed to be made in terms of quantities and unit prices. Those assumptions are presented below. Several unit price items were used to determine the cost estimates. Quantities were estimated for each item and unit prices were estimated from recent bid results. An estimated construction cost was developed for each project including contingencies and sales tax. Total project costs were then estimated for each improvement. All costs are 2015 dollars and summarized on Table 9.1. 9.3.1 Construction Estimates-Assumptions 10% of the construction costs are Mobilization. Traffic control at 2% of hard asset costs (doesn’t apply to WWTP capital improvements). Trench dewatering estimated at $10 to $20/LF of pipe installed. Sheeting, shoring and bracing estimated at $5/LF. Pavement removal is limited to a trench width of 6 feet inches, plus an allowance of 12 inches on both sides of the trench, for a total width of 96 inches. Temporary sewer bypass estimated to be $5,000 for each required bypass. Import trench backfill is estimated based on the assumption that 50% of all excavation will require imported material. Average width is 48 inches and an average depth of 8 feet. Crushed surfacing, base course is assumed to be 8 inches deep and a maximum pay width of 72 inches. General restoration at 2% of the hard asset costs Temporary erosion and sediment control at 4% of the hard asset costs Crushed surfacing, top course is assumed to be 4 inches deep and a maximum pay width of 72 inches. HMA is based on a maximum thickness of 4 inches applied over a width of 8 feet for the entire length of all mainline sewers in right-of-way. Manholes - It is assumed that the terminal manholes will be salvaged and only the intermediate manholes will be replaced or modified. Lift station rehabilitation assumes that no excavation will be necessary and that the needed increase in the capacity can be accomplished with pump and motor changes, and electrical revisions. 9.3.2 Allied and Other Costs – Assumptions 30% contingency to address pre-design level of cost estimating. 9.4% State Sales Tax. 15% of the estimated construction cost is for engineering design, survey, and permits. 7% of the estimated construction cost is for construction services. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-8 3% of the estimated construction cost is for City Administration and legal costs. 9.4 Wastewater Reuse RCW 90.48.112 requires consideration of reclaimed water in wastewater plans. Although the law does not specifically require implementation of a reclaimed water alternative, it strongly encourages it. RCW 90.46.005 states, in part, that to the extent that reclaimed water is appropriate for beneficial uses, it should be so used to preserve potable water for drinking purposes. 9.4.1 Regulatory Requirements Beneficial use of reclaimed water for irrigation of crops, supplemental stream or wetland flow enhancement, groundwater recharge, toilet and urinal flushing, etc. requires treatment to reclamation and reuse standards, which are more stringent than the conventional secondary standards required for surface water disposal using an outfall. The added treatment facilities required include effluent coagulation, filtration, additional disinfection and more treatment facility redundancy and reliability requirements. The use of reclaimed water is permitted in the State of Washington, and is jointly regulated by the State Departments of Health (Division of Drinking Water); and Department of Ecology. The “State of Washington Reclamation and Reuse Standards”, September, 1997 (Publication #97- 23) provides the guidance for acceptable reclaimed water treatment and use. The specific language that addresses Reclaimed Water is found in WAC 173-219. Proposed modification of the rules governing the use of reclaimed water is slated to be vetted through a public hearing process through the last quarter of 2015. The schedule for formal adoption is yet to be determined, but likely will extend into 2016. Under all reuse options, the proposal must demonstrate the beneficial uses being made of the reclaimed water. The new rules identify two classes of reclaimed water, Class A and Class B. Class A specifically includes membrane filtration in addition to traditional coagulation and filtration. Class B does not require filtration. The previous standards defined four levels of treatment required depending on the final use of the reclaimed water. Class A reclaimed water is the highest quality and can be utilized for any of the permitted uses. In addition to conventional secondary activated sludge treatment (oxidation and sedimentation), Class A reclaimed water requires coagulation, filtration, and disinfection to less than 2.2 total coliform per 100 ml, which is a very stringent disinfection standard. The MBR treatment process (with disinfection) will also produce Class A reclaimed water (with added disinfection), because the coagulation occurs within the activated sludge process itself and filtration is provided through the fine pore membranes. Classes B, C, and D reclaimed water do not require filtration, and Class C and D have less stringent disinfection requirements. Use of these classes is generally restricted to irrigation of non-food crops (such as forest land) with restricted public exposure. This report finds itself between the old and new regulations and standards. Because the new regulations are likely to be adopted, the following analysis will follow the proposed new regulations. The most logical uses of this reclaimed water involve irrigation of golf courses and public parks, which are subject to human exposure, treatment to Class A reclaimed water standards is recommended. In addition, the reclaimed water must be reliably generated. Emergency storage or alternative discharge options must be provided for upset conditions. Excess flow will continue to be discharged to the Puyallup River. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-9 The standards also require automatic alarms, treatment unit redundancy, and qualified operations staffing. 9.4.2 Potential Uses and Demands While reuse of reclaimed wastewater treatment plant effluent is becoming more and more common, the demand for year-round reclaimed effluent in the Pacific Northwest is very limited, particularly in a suburban setting. However, the City has made accommodations for use of reclaimed water for WWTP operations. In assessing the potential use of Class A reclaimed water, sites were identified for irrigation and/or industrial, commercial and public use. Irrigation can include parks, commercial nurseries, golf courses, and cemeteries. Industrial uses of reclaimed water can include boiler feed, cooling, process water, sewer flushing, and processing plant wash down. There were no potential industrial users identified in the City’s service area. Thus, the main uses of reclaimed water from the WWTP would be irrigation of open access areas. The City recognizes that there are some users of the water and sewer systems that are responsible for comparatively more usage. Table 9.2 details the top water users and then sorts that group by the volume of irrigational water they annually use based on their irrigation meter records. These top irrigational water users are presented on Figure 9.3. Nine of the 14 high water users are within a two mile radius of the plant and collectively these user comprise an annual total of irrigational demand of 16,133 ccf, or approximately an annual volume of 12.1 million gallons. ---PAGE BREAK--- No. Customer Service Address 2013 Annual Water Consumption (ccf) 2013 Irrigational Usage -based on irrigation meters only (ccf) 1 Benaroya 1023 39th Avenue SE, Puyallup 6,283 5,925 2 City of Puyallup - Rec Center 808 Valley Avenue NW, Puyallup 5,057 4,685 3 Good Samaritan Hospital 400 15th Avenue SE, Puyallup, WA 98 48,260 3,435 4 Kroger Utilities 2200 N Meridian, Puyallup 14,658 2,861 5 Kia of Puyallup 111 Valley Avenue NE, Puyallup 3,452 2,134 6 Pierce County College 1601 39th Ave SE, Puyallup 4,940 1,978 7 Cintas 631 Valley Avenue NW, Puyallup 17,514 1,575 8 City of Puyallup - City Hall 333 S Meridian, Puyallup 1,709 1,521 9 IAC - VABP 914 Valley Avenue, Puyallup 4,055 1,265 10 Unifirst 1025 N Levee Rd, Puyallup 18,788 989 11 Crossland Hotel 2101 N Meridian, Puyallup 5,752 924 12 City of Puyallup - Library & Activity Center 324 S Meridian, Puyallup 3,230 179 13 Revera, Inc 400 29th St NE, Puyallup 6,231 91 14 Western Washington Fair Grounds 110 9th Avenue SW, Puyallup 9,860 9 Within a two mile radius of the WWTP Table 9.2 Top Water Users Sorted by their Irrigational Usage ---PAGE BREAK--- 1 3 7 5 4 8 9 10 11 12 6 2 13 14 104TH ST E W TAPPS D R E W EST TAPP S DR E 128TH ST E 122ND ST E S TAPPS DR E SOUT H TAPPS D R E 122ND AV E SHAW RD E 96TH ST E ORTING HWY E SR162 E 84TH ST E 72ND ST E M ILITARY RD E 118TH ST E E VALLEY H W Y E EAST VALLEY H WY E 80TH ST E BONNEY LAKE BLVD E SR410 HWY E 64TH ST E 94TH AV E 39TH AV SE 31ST AV SW VALLEY AV E WOODLAND AV E 23RD AV SE S MERIDIAN SHAW RD 5TH ST NE SR512 HWY E 112TH ST E E MAIN 86TH AV E 111TH AV E 2ND ST NE 48TH ST E 39TH AV SW FREEMAN RD E RH ODES LAKE RD E MAIN ST E MILWAUK EE AV E 62ND AV E N LEVEE RD E NORT H LE VEE RD E VALLEY AV RIVER RD E SR410 HWY W N MERIDIAN S WOODLAND E PIONEER W PIONEER 52ND ST E MAIN S T 56TH ST E 43RD AV SE STEWART AV E 90TH ST E 78TH AV E SR16 1 W STEWART PI ONEER WY E 9TH ST SW BINGHAM AV E SR410 E M CCUT CHE ON RD E ANGELINE RD E 12TH AV SW FRYAR AV 37TH A V SE SR512 HWY W R IVER R D 114TH AV E BE N S TON DR E 70TH AV E 34TH AV E 160TH AV E SR 5 1 2 C I OF W 142ND AV E RAMP SR512 R PF1 E MERIDIAN E EDGE W O O D D R E WALLER RD E S U M N ER-TAP PS HW Y E TR A FFIC AV CANYON RD E 166TH AV E S F R UITLA N D F R U ITLAND A V E 48TH AV E VICKERY AV E 44TH AV E CHRIS ELLA RD E 66TH A V E MYERS RD E 50TH AV E S R167 HWY S LOCUST AV E RIVERSIDE DR E 110TH AV E WEST VAL LEY HW Y E ME R IDI A N A V E S R 1 6 7 CIOF S Puyallup WWTP Legend Water Users Routing of Reuse Conveyance Piping TP Treatment Plant Mini-Basins City Boundary Urban Growth Area Sanitary Sewer Service Area Puyallup First Right of Refusal 2 Mile Radius from WWTP P:\Mapping\Maps_Generated\Puyallup\13-10323.00\013 - Assemble Draft Plan\maps\Fig 9.3 Potential Reclaimed Water Users - 11x17.mxd £ ¤ 2 1 5 £ ¤ 7 6 1 £ ¤ 0 1 4 £ ¤ 2 6 1 0 1 0.5 Miles Pump Stations & Mini-Basins: City of Puyallup 2013 Pierce County base data 2013 Data sources supplied may not reflect current or actual conditions. This map is a geographic representation based on information available. It does not represent survey data. No warranty is made concerning the accuracy, currency, or completeness of data depicted on this map. BHC Consultants LLC., assumes no responsibility for the validity of any information presented herein, nor any responsibility for the use or misuse of the data. COPYRIGHT © 2015 BHC CONSULTANTS LLC., ALL RIGHTS RESERVED : Sanitary Sewer System Comprehensive Plan City of Puyallup, Washington Figure Potential Reclaimed Water Users 9.3 September 2015 # TOP IRRIGATIONAL WATER USERS (see Table 9.2) NO. NAME 1 BENAROYA 2 CITY OF PUYALLUP - RECREATION CENTER 3 GOOD SAMARITAN HOSPITAL 4 KROGER UTILITIES 5 KIA OF PUYALLUP 6 PIERCE COUNTY COLLEGE 7 CINTAS 8 CITY OF PUYALLUP - CITY HALL 9 IAC - VABP 10 UNIFIRST 11 CROSSLAND HOTEL 12 CITY OF PUYALLUP - LIBRARY & ACTIVITY CENTER 13 REVERA, INC. 14 WESTERN WASHINGTON FAIR GROUNDS ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-12 9.4.3 Reclaimed Water Treatment Facilities at WWTP Effluent Quality The CIPs identified for the WWTP already include an effluent filter to help the plant reach its effluent standards. However, coagulation and flocculation facilities would need to be added as described in Section 9.4.1 to meet the Class A criteria. This system could potentially be designed within the space constraints at the WWTP. It is assumed that the reclaimed water will be pumped to off-site irrigation users, and that no additional on-site storage will be provided. 9.4.4 Reclaimed Water Conveyance and Distribution Conveyance Alternatives Conveyance of reclaimed water by pumping is the only logical and practical conveyance method. Truck hauling could be considered for other general uses, such as sewer flushing, street washing, dust control, roadside planter watering, etc. But this expected volume of usage is likely to be very small. Conveyance and Distribution Facilities The clustering of potential reuse customers along Valley Avenue NE (see Figure 9.3) would require approximately 16,000 feet of 4-inch diameter conveyance piping from the WWTP to the identified users. 9.4.5 Economic Analysis of Reuse The Capital Recovery Factor of 0.0736 based on 4% interest rate and 20-year project life is used for economic analysis. Estimated Capital Cost of Treatment and Conveyance Flocculation and Coagulation Equipment $400,000 Reclaimed water booster station 400,000 Conveyance (with restoration) 16,000 lf @ $100 1,600,000 Distribution and connection to irrigation systems 100,000 Subtotal 2,500,000 Contingencies @ 30% 750,000 Subtotal 3,250,000 State Sales Tax @ 9.4% 220,000 Total Construction $3,470,000 Engineering @ 15% $520,000 Construction Management @ 7% 240,000 City Administration @ 3% 100,000 Total Capital $4,330,000 Amortized Annual Capital Cost $319,000 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 9-13 Estimated Annual O&M Cost of Treatment and Conveyance Treatment & Conveyance Chemicals $7,000 Electricity 1,000 Equipment maintenance and replacement 13,000 Labor 40,000 Total Annual O&M Cost $61,000 Total Annual Cost $380,000 Based on an annual usage of 16,133 ccf and the current unit price $2.52/ccf of City water, the total annual cost to purchase this water would only be $ 40,700. Consequently, the cost of treating and conveying reclaimed water for irrigational uses does not appear to be financially feasible. The other option of constructing and siting a satellite plant closer to the end user was considered but was rejected due to much higher capital and operational costs. This plant would intercept untreated wastewater and process Class A water. All solids would be reintroduced into the liquid stream and collected at the main WWTP. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-1 Chapter 10 Operations and Maintenance Program 10.1 City Management and Personnel The City’s Public Works Department is led by Rob Andreotti and is composed of several distinct divisions. The division heads report to the Public Works Director who is responsible for the overall management of the Sewer Division. 10.1.1 Organization Two divisions of the Public Works Department have specific functions that are vital to the inner workings and function of the wastewater utility – the City’s Collection Division and the City’s Wastewater Treatment Plant Division The City’s Sewer Collection Division is under the general management of Jonathan Wikander. The City’s Wastewater Treatment Plant Division is under the general management of Kirk Elliott. 10.1.2 Certification and Training The City encourages its employees to obtain certification and training for skills relevant to operating and maintaining the sewer system. All staff must, at a minimum, have the following: A high school diploma or GED. A driver’s license. In addition, the City provides employees with opportunities for training and certification relative to their position function. Each staff member annually receives some training. Depending on the employee’s function, training may include safety, confined space entry, record keeping, pump station electrical and instrumentation, pump station operation, public relations, vactor truck operations and emergency response. Training is provided in varying mixes of the following categories: Manufacturer training by various equipment suppliers and representatives. On-the-job training in the field, the shop, or in the office. In-house class room training. Industry-wide training at conferences and seminars away from the City. To promote the improvement of its employees, the City may elect to pay for annual certification fees, employee time and tuition during certification training courses and provides time off for certification testing. The City also provides staff opportunities to receive the continuing education necessary to maintain certification. Professional growth requirements for certification are met through continuing education units (CEU). 10.2 Operations and Maintenance Activities and Programs This section presents the operations and maintenance activities, including preventive and corrective routines, procedures and wastewater related programs. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-2 10.2.1 Collection System Maintenance Lift Stations The City has a crew that is responsible for the lift station maintenance and incident response. This crew visits every lift station a minimum of twice per week. Those stations that are older or that have a tendency to be a source of problems are visited more frequently. The emergency generators are exercised a minimum of once per week. Typically the generators are exercised for a 1 to 2 hour period. Approximately half of the wet wells are washed down every month. These wet wells are those that have a high incident of grease accumulation. The remaining wet wells are washed down on a frequency. Sanitary Sewers The City’s staff has established a plan to conduct regular internal inspection (closed circuit televising) of approximately 6% to 7% of the system every year. The digital records of these inspections are reviewed by the technicians and any segment that is identified as needing repair, slip lining or replacement is noted. Similarly, those segments that are structurally sound, but in need of routine attention are also tracked and, if warranted, added to the ‘frequent flushing’ list. Those lines that have deficiencies are logged and tracked on the City’s O&M tracking software. There are certain segments that require regular and reoccurring maintenance. These areas of chronic and frequent attention and flushing are identified in Tables 10.1 (flushing) and 10.2 (root intrusion). These segments, depending on the severity of the problem require attention that varies from weekly to annual flushing. Where possible these chronic sewer collection problems have been identified as a potential CIP. However, most of these reoccurring maintenance issues simply require continued vigilance. Figures 10-1 and 10-2 show the locations of the Trouble Spots and Root Intrusion areas respectively. Many of the areas that have heavy root intrusion are those older areas of the City and are most prevalent in the older clay and concrete pipes. The staff is also alert to the potential of odor concerns, though odor complaints in the collection system are extremely rare. The crews will also hydraulically jet the lines at the time of internal inspections if needed. The areas designated as chronic maintenance problems that are more frequently cleaned. In some cases, the cleaning is conducted as often as every three months. ---PAGE BREAK--- Frequency Location Issue Weekly 2100 23rd St PL SE Slope, Solids Weekly 2000 Tacoma RD Slope,FOG, Solids Weekly 400 E Pioneer Slope, Solids Weekly 1700 7th Ave SE Slope, FOG Weekly 300 9th Ave NE Slope, FOG, Solids Weekly 200 9th Ave SE Slope, FOG, Solids Weekly 1900 Tacoma RD Slope, Defect,Utility confilct in MH Weekly 1000 9th St SW Slope, FOG,Solids 100 Elm Place Slope, Solids, Defect 100 E Pioneer Slope, Defect 319 3rd St SE Slope,Solids 1016 4th Ave SW Slope, Solids Quarterly 611 2nd St NW Roots Bi-Annual 1414 W. Pioneer Slope, Solids Bi-Annual 1104 11th St NW Slope, Solids Bi-Annual 2205 7th Ave. SW Slope, FOG, Solids Bi-Annual 2119 W. Pioneer Slope, FOG, Solids Bi-Annual 304 2nd St NE Slope, FOG, Solids Bi-Annual 815 2nd St NE Slope, FOG, Solids Bi-Annual N. Meridian I River Road FOG,Solids Bi-Annual 2900 E Main Slope, FOG,Solids Bi-Annual 2900 E Main Slope, FOG,Solids Bi-Annual 2900 E Main Slope,FOG,Solids Bi-Annual 314 27th St NE Slope,FOG,Solids Bi-Annual 314 27th St NE Slope,FOG,Solids Bi-Annual 314 27th St NE Slope,FOG,Solids Bi-Annual 1843 E Main Slope,FOG,Solids Bi-Annual 1803 S. Meridian FOG,Solids Bi-Annual 37th S. Meridian Slope,FOG,Solids Bi-Annual 900 S. Meridian FOG,Solids Bi-Annual 900 S. Meridian FOG,Solids Bi-Annual Fairgrounds Freeway Line Slope,FOG, Solids Bi-Annual 2200 E Main Slope, Solids, Defect Bi-Annual 2300 E Main Slope, Solids, Defect Bi-Annual 2700 E Main Slope, Solids Bi-Annual 1825 9th St SE Slope, FOG, Solids Bi-Annual 517 10th Street SE Slope, FOG, Solids Bi-Annual 1412 11th Ave SE Slope, FOG, Solids Bi-Annual 800 blk 3rd St SE FOG, Solids Bi-Annual 3028 Forest Rim Ct. S Slope, FOG, Solids Bi-Annual 712 21st St SE Slope, FOG, Solids Bi-Annual 1200 18th ST NW Slope, FOG, Solids Bi-Annual 914 11th Ave NW Slope, FOG Bi-Annual 1000 21st St NW Slope, FOG, Solids Bi-Annual 400 7th Ave NW Structural, Solids Annual 1600 5th St SW Roots Table 10.1 Chronic and Frequent Sewer Problem Areas ---PAGE BREAK--- Laterals Mains 701 21st St NW 400 5th St NW 418 TO 420 5th St NW 400 6th St NW 417 3rd St NW Alley between 7th St, 8th St , W Stewart, 5th Ave NW 507 11th St NW 900 11th St NW 522 11th St NW 1300 W Stewart 603 11th St NW 700 5th St NE 711 11th St NW 1400 15th Ave SW 600 12th St NW 2000 7th St SW 608 12th St NW 1600 7th St SW 315 17th St NW 1500 7th St SW 403 17th St NW 1500 5th St SW 909 22nd St NW 700 5th Ave SW 925 22nd St NW 600 4th Ave SW 1535 4th Ave NW 400 10th St SW 1909 4th Ave NW Alley between W Meeker,W Main, 5th St SW, 6th St SW 204 6th Ave NW 900 8th Ave SW 1118 7th Ave NW 1600 S Fruitland at manhole 1124 7th Ave NW 1500 Firland DR easement to the west 1117 7th Ave NW 200 14th Ave SW 1801 11th Ave NW 2000 9th St SE at manhole 413 6th St NW 1500 11th Ave SE easement to the south 825 3rd Ave NW 2200 12th Ave SE 408 9th St NW 2300 12th Ave SE 608 9th St NW 2400 12th Ave SE 1315 W STEWART 800 23rd Ave SE easement to the north 2111 RICHARDSON DR 600 17th St SE 115 2nd St NE 500 10th Ave SE easement to the north 421 4th Ave NE 3100 Forest Rim CT S. at manhole 515 4th St NE 2500 Larkspur DR 403 5th St NE 1100 21st St SE 427 N MERIDIAN 1300 Terrace DR 803 4th St NE 1600 S. Meridian 103 17th St NW 1500 S. Meridian 426 17th Ave CT SW 414 9th St SW 518 9th St SW 516 S. MERIDIAN 1004 4th Ave SW 210 5th St SW 506 W PIONEER 410 5th Ave SW 601 7th Ave SW 419 13th St SW Table 10.2 Root Intrusion Locations ---PAGE BREAK--- Laterals Mains Table 10.2 Root Intrusion Locations 2205 7th Ave SW 1807 W PIONEER 1602 7th St SW 1519 7th St SW 2003 7th St SW 2008 7th St SW 1414 15th Ave SW 1502 11th Ave SE 1002 7th Ave SE 117 23rd St SE 1205 10th Ave SE 1509 5th Ave SE 1513 5th Ave SE 1008 21st St SE 1210 23rd Ave SE 2722 OLYMPIC BLVD 2614 35th Ave SE 445 to 451 10th Ave SE 1103 21st St SE 1804 6th St SW ---PAGE BREAK--- COPYRIGHT © 2015 BHC CONSULTANTS LLC. ALL RIGHTS RESERVED This map is a geographic representation based on information available. No warranty is made concerning the accuracy, currency, or completeness of data depicted on this map. 10.1 Figure Sanitary Sewer System Comprehensive Plan City of Puyallup, Washington August 2015 P:\Mapping\Maps_Generated\Puyallup\13-10323.00\013 - Assemble Draft Plan\maps\Fig 10.1 SS Root Spots - 8.5x11.mxd 8/21/2015 ctolentino Sanitary Sewer Root Spots Not To Scale ---PAGE BREAK--- COPYRIGHT © 2015 BHC CONSULTANTS LLC. ALL RIGHTS RESERVED This map is a geographic representation based on information available. No warranty is made concerning the accuracy, currency, or completeness of data depicted on this map. 10.2 Figure Sanitary Sewer System Comprehensive Plan City of Puyallup, Washington August 2015 P:\Mapping\Maps_Generated\Puyallup\13-10323.00\013 - Assemble Draft Plan\maps\Fig 10.2 SS Trouble Spots - 8.5x11.mxd 8/21/2015 ctolentino Sanitary Sewer Trouble Spots Not To Scale ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-8 10.2.2 WWTP Operations and Maintenance The program maintenance protocol currently being used at the consists of a system that tracks historical preventative maintenance measures for each piece of equipment. This system is the backbone of scheduling all preventative maintenance. All routine preventative maintenance like oil changes, lubrication and exercising of infrequently used equipment and corrective maintenance performed are chronicled on this record. The plant staff does most of the repairs and rebuilds with in-house personnel. More complex tasks such as motor rewinding, electrical or instrumentation modifications are outsourced to a third party. Critical equipment that could affect effluent quality has redundant and backup equipment ‘on- the-shelf’. This redundancy allows the City to respond to equipment failures without effluent violations. With the backup equipment available the City currently does not routinely replace old equipment until such time as the maintenance efforts become burdensome and replacement is the prudent decision. 10.3 Programs 10.3.1 Pretreatment Program The City, PMC 14.06, Article III, established pretreatment requirements for all non-residential dischargers into the City’s system (see Appendix These standards include a general prohibition that disallows any discharge that would result in a pass through or interference with the Public Owned Treatment Works (POTW). The intent of this ordinance is to: 1. Prevent the introduction of pollutants into the POTW which will pass through the POTW inadequately treated, into the receiving waters or otherwise be incompatible with the POTW 2. Ensure that the quality of the POTW sludge is maintained at a level which allows its use and disposal in compliance with the applicable statues and regulations. 3. Protect the POTW personnel who may be affected by wastewater and sludge in the course of their employment and to protect the general public 4. Improve the opportunity to recycle and reclaim wastewater and biosolids from the POTW 5. Promote strategies that reduce the amounts of pollution generated by users, thereby reducing the associated hazards to the POTW and receiving waters. The City’s pretreatment code also defines the requirements for sizing and maintaining the grease traps and/or interceptors. Failure to comply with the limitations and prohibitions presented above may result in the issuance of a Corrective Order and, if the directive of the corrective order is not followed, fines may be imposed on the violator. 10.3.2 Water Reclamation and Reuse The current plant uses UV disinfected effluent is used for wash down purposes within the plant. No offsite use is currently allowed. The plant does not meter wash down water, so the volume of reuse water is not precisely known. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-9 10.3.3 Biosolids Recycling All biosolids generated at the plant are currently sent to the belt filter press (but will be soon directed to a new screw press) and the Class B dewatered solids are hauled (by contract) off site to the Tenelco Beneficial Use Facility in the Wenatchee area. The hauled quantity of dry solids ranges from 650 to 700 dry tons per year. 10.3.4 Sewage Spill Response Plan Emergency response to reported sewage spills in the collection system are reported immediately to the Collections Division within Public Works. Sanitary Sewer Overflows (SSOs) caused by blockages or malfunction of the City-owned infrastructure and that results in a discharge to the waters of United States are reported to EPA within 24 hours and a written report is submitted to EPA, DOE and the Puyallup Tribe within five days. During non-business hours, the City has a rotating assignment among the staff to be on-call to respond to incidents 24 hours a day, 7 days per week (see Appendix 10.3.5 CMOM The EPA has issued draft regulations implementing the Capacity, Management, Operations, and Maintenance (CMOM) program. CMOM requires the development of facility maintenance plans, tracking of asset condition, establishing level of service and performance goals. Key requirements are outlined below: 1. Capacity Assurance Plan evaluate existing system; identify capacity deficiencies; establish short and long-term remedies to capacity deficiencies. 2. Management Program specify program goals; establish organizational structure legal authority (e.g. service agreements) to manage flow; establish program measures and ranking of O&M activities based on current capacity and structural deficiencies. audit documentation of changes in system condition and performance establish standards and requirements for new construction as well as rehabilitation and repair. 3. Overflow Response Plan (ORP) steps to respond to SSO’s and to implement response plan (see Appendix 4. Audit Operations and Maintenance performance initial assessment of O&M activities; establish performance goals, measures and priorities perform periodic audits to identify progress and required revisions to the program. The City actively uses Cartegraph Asset Management software to manage the sewer assets and maintenance activities. Cartegraph meets the goals of EPA’s CMOM program. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-10 10.3.6 Puget Sound Water Quality Management Plan The Federal Water Pollution Control Act established the requirement for a Water Quality Management Plan. Resultantly, RCW 90.71 established the need of a Puget Sound Water Quality Management Plan. The stated objectives of this governance are to recover Puget Sound waters by the year 2020. This Comprehensive Sewer Plan is consistent with the intended goals of the Water Quality Management Plan. 10.4 Management System / Record Keeping 10.4.1 Collection System The City maintains an ongoing record of existing and as-built sewer extensions. Previously these records were retained as AutoCAD files, though more recently, the City has developed GIS based drawings in an effort to have a more comprehensive and consolidated record of pipe age, size and material, invert and rim elevations, slopes and manhole identifiers. The O&M activities are tracked using Cartegraph Operations Management Systems (OMS) software which allows the O&M staff to chronicle maintenance measures, evaluate performance, and track real time tasks and data. Cartegraph is fully integrated with GIS. These activities should include the last time the pipe segments were internally televised, flushed and jetted. It could also include incident reports, backup events and surcharging manholes. 10.4.2 National Pollution Discharge Elimination System (NPDES) Permit The City’s NPDES permit requires that record keeping be maintained and that regular reporting be made to DOE. Any spills in the City’s collection system are reported as part of the NPDES Permit requirements. A copy of the City’s current NPDES Permit is included in Appendix K. 10.5 Performance Indicators 10.5.1 Wastewater Treatment Plant The treatment plant operates under the current NPDES Permit No. WA-0037168. This permit requires regular reporting of influent loading and effluent mass and concentrations discharged through the existing outfall. Performance of the plant is presented in Figure 8-2. From the period 2008 through 2013, the plant had no violations of the limits defined in the permits. The NPDES permits also defines the maximum allowable influent loadings and concentrations. None of the loading limitations were exceeded for the period 2008 through 2013 (see Table 8.1). 10.6 Condition Assessment 10.6.1 Collection System The City staff has an ongoing routine of performing internal inspection of the City’s lines. As described in section 10.2.1 the staff conducts CCTV inspections of 6% to 7% of the system each year, or approximately 50,000 linear feet of pipe each year. These records are retained and reviewed to judge the progression of the deterioration of those pipe segments. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 10-11 The staff also maintains a frequent flush list. The frequency and any particular observances are tracked to specifically address these chronic problem areas. 10.6.2 Lift Stations The City is currently undertaking an aggressive program of lift station rehabilitation. It is anticipated that this program will continue as presented in Table 9.1. 10.7 Sewer Collection Division Staffing Needs The City employs a total of 3.67 FTE in the Sewer Collection Division. To compare the pipeline and lift station staffing with other similar sized wastewater purveyors, the table below presents comparative manpower at the City of Lacey, Southwest Suburban Sewer District and Alderwood Water and Wastewater District. Agency Lift Stations Current Staff Length Pipe, LF Person / 100,000 LF City of Lacey, WA 47 6 898,000 0.67 11 6 1,219,000 0.49 AWWD 14 10 1,942,900 0.50 City of Puyallup 18 3.67 1,027,700 0.36 On a comparative basis, it appears that Puyallup is lower than other wastewater providers. With decreasing piping the economy of scale normally suggests that the smaller inventory agencies typically would expect higher personnel per 100,000 LF. Using this metric, the City’s Collection Division might be understaffed. The other variable is the number of lift stations which would cause the staffing to increase. It is recommended that the City conduct a staffing study prior to adding staff to determine if adding staff is warranted. 10.8 WWTP Staffing The WWTP is staffed 18 hours/day, 7 days/week. The City has a total WWTP Staff of 17.75 FTE. The EPA Estimating Costs and Manpower Requirements for Conventional Wastewater Treatment Facilities suggests that a WWTP the size and complexity of the Puyallup WWTP could support 23 FTE. However, it should be noted that this publication is several years old and tends to overestimate the manpower requirement. The City will soon be removing a belt filter press and installing a dewatering screw press which will allow 24-hour operation. If the City elects continuous staffing, there will be impact on the structure of plant employment. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-1 Chapter 11 Financial Chapter 11.1 Introduction Municipal utilities in Washington State are operated as enterprise funds, which are characterized by their reliance on user rates rather than taxes to cover the cost of providing service. The City of Puyallup operates water, sewer, and stormwater utilities, accounting for each of these utilities in a separate enterprise fund. This chapter assesses the ability of the City’s sewer utility to execute the capital improvement program (CIP) recommended in Chapter 9 while maintaining sewer rates at reasonable levels. It includes the following key elements: Assessing the historical financial performance of the City of Puyallup’s sewer utility over the past six years Discussing potential funding sources for the CIP and developing a strategy to fund the projected capital expenditures Forecasting future financial performance, considering impacts of the CIP on: Projected operation and maintenance (O&M) expenses Debt service Other legal / policy requirements Evaluating the affordability of the City’s current and proposed sewer rates in the context of industry standards Appendix B provides supporting details of the financial analysis. 11.2 Past Financial Performance This section includes a historical summary of the sewer utility’s financial performance, as reported by the City in its 2009 – 2014 Financial Statements. The ensuing subsections discuss the information used to assess the recent financial performance of the City’s sewer utility in further detail. 11.2.1 Assessment of Annual Financial Performance Table 11.1 summarizes the sewer utility’s 2009 – 2014 income statements, providing a basis for evaluating the utility’s annual financial performance over the past six years. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-2 The City did not increase its sewer rates from 2009 – 2012. In early 2013, the Council passed City Ordinance No. 3028 and established a policy of annual inflationary rate adjustments based on the Engineering News Record (ENR) Construction Cost Index. This policy resulted in rate increases of 2.6% in 2013 and 2.7% in 2014, increasing the sewer utility’s charges for services by about 5.4% over 2009 levels. Table 11.1 shows a total increase of about 6.6% in the sewer utility’s revenue from 2009 to 2014, suggesting a modest level of growth in the sewer customer base over the six-year period. While revenues remained relatively flat prior to the 2013 and 2014 increases, operating expenses increased every year – excluding depreciation, operating expenses increased by an average of 3.9% per year (a cumulative 2009 – 2014 increase of 20.8%). Total operating expenses (including depreciation) increased by 12.3% over the six-year period, corresponding to an average annual increase of 2.4%. Table 11.1 indicates that the City has consistently realized a positive change in net assets, due to positive net operating income and capital contributions. In this case, the term “capital contributions” includes both cash payments (connection charges) and in-kind contributions (value of developer-donated facilities). Table 11.1 Statement of Revenues, Expenses, and Changes in Net Assets 2009 2010 2011 2012 2013 2014 Operating revenues Charges for services 8,823,916 $ 9,005,716 $ 8,791,880 $ 9,014,641 $ 9,143,808 $ 9,408,002 $ Other operating revenues - 11,300 2,447 34,139 656 752 Total 8,823,916 $ 9,017,016 $ 8,794,327 $ 9,048,780 $ 9,144,464 $ 9,408,754 $ Operating expenses Operations & maintenance 3,277,132 $ 3,437,927 $ 3,684,043 $ 3,729,134 $ 3,813,137 $ 3,948,373 $ Administration & overhead 952,237 1,552,980 1,503,673 1,259,674 1,281,985 1,260,418 Taxes 899,996 962,235 956,239 967,738 954,544 985,686 Depreciation 2,279,215 2,277,147 2,310,040 2,391,122 2,511,492 2,124,769 Total 7,408,580 $ 8,230,289 $ 8,453,995 $ 8,347,668 $ 8,561,158 $ 8,319,246 $ Net operating income (loss) 1,415,336 $ 786,727 $ 340,332 $ 701,112 $ 583,306 $ 1,089,508 $ Non-operating revenues (expenses) Investment earnings 88,909 $ 35,679 $ 134,165 $ 127,149 $ 115,648 $ 99,075 $ Gain (loss) on sale of capital assets - 1,000 - - - - Other non-operating revenues - - (117,079) - - - Interest & fiscal charges (697,390) (618,201) (577,800) (519,260) (413,763) (314,556) Net non-operating revenues (expenses) (608,481) $ (581,522) $ (560,714) $ (392,111) $ (298,115) $ (215,481) $ Income before contributions & transfers 806,855 $ 205,205 $ (220,382) $ 309,001 $ 285,191 $ 874,027 $ Contributions & transfers: Capital contributions 983,608 $ 1,435,213 $ 1,459,112 $ 851,113 $ 692,276 $ 1,019,806 $ Transfers in - - - - - - Transfers out (2,651) - - - (62,963) (63,644) Total 980,957 $ 1,435,213 $ 1,459,112 $ 851,113 $ 629,313 $ 956,162 $ Change in net position 1,787,812 $ 1,640,418 $ 1,238,730 $ 1,160,114 $ 914,504 $ 1,830,189 $ Net position - beginning of year 46,902,593 $ 48,690,405 $ 50,330,823 $ 51,569,553 $ 52,729,667 $ 53,478,203 $ Prior-period adjustments - - - - (165,968) - Net position - end of year 48,690,405 $ 50,330,823 $ 51,569,553 $ 52,729,667 $ 53,478,203 $ 55,308,392 $ ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-3 11.2.2 Assessment of Cumulative Financial Position Table 11.2 summarizes the sewer utility’s 2009 – 2014 balance sheets, providing a basis for evaluating how the utility’s financial position has changed over the past six years. Table 11.2 Statement of Net Assets 2009 2010 2011 2012 2013 2014 ASSETS Current Assets Cash and cash equivalents 12,437,015 $ 9,409,441 $ 9,962,358 $ 11,220,452 $ 11,445,334 $ 11,842,929 $ Restricted cash and cash equivalents 1,240,665 1,276,258 1,541,251 1,602,622 1,654,589 1,663,897 Receivables: Customer accounts 1,577,840 1,757,365 1,634,192 1,799,791 1,856,512 1,706,981 Other receivables 2,535 448,833 1,340 5,934 2,107 2,270 Interfund loans receivable 1,281,659 1,940,000 1,537,025 398,345 859,145 620,336 Due from other governmental units - - - - 821 125,630 Inventories 77,419 84,762 96,366 63,957 98,983 98,978 Prepaid and other current assets - - 1,030 1,150 1,150 1,150 Total Current Assets 16,617,133 $ 14,916,659 $ 14,773,562 $ 15,092,251 $ 15,918,641 $ 16,062,171 $ Noncurrent Assets Restricted cash and cash equivalents 533,184 $ 500,325 $ 451,931 $ 398,611 $ 287,492 $ 242,236 $ Advances to other funds 2,003,341 3,000,000 3,212,975 4,063,733 2,804,587 2,184,251 Deferred charges 219,117 201,401 183,684 165,968 - - Capital assets (net) 49,582,327 50,386,141 50,127,173 48,151,463 48,027,241 47,986,966 Total Noncurrent Assets 52,337,969 $ 54,087,867 $ 53,975,763 $ 52,779,775 $ 51,119,320 $ 50,413,453 $ TOTAL ASSETS 68,955,102 $ 69,004,526 $ 68,749,325 $ 67,872,026 $ 67,037,961 $ 66,475,624 $ DEFERRED OUTFLOWS OF RESOURCES Deferred amounts on debt refunding - $ - $ - $ - $ 144,349 $ 120,930 $ TOTAL DEFERRED OUTFLOWS OF RESOURCES - $ - $ - $ - $ 144,349 $ 120,930 $ LIABILITIES Current Liabilities Current payables 284,455 $ 241,728 $ 343,641 $ 198,634 $ 501,707 $ 158,929 $ Other current liabilities 98,881 99,475 100,738 100,946 104,180 93,614 Due to other governmental units 324 29,129 17,264 22,499 18,806 19,989 Accrued interest payable 14,910 13,046 11,183 9,319 7,455 5,591 Other revenue debt 372,755 372,755 372,755 372,755 372,755 372,755 Liabilities payable from restricted assets: Revenue bonds payable 1,170,280 1,209,662 1,478,468 1,546,254 1,609,096 1,623,984 Accrued interest payable 70,385 66,596 62,783 56,368 45,493 39,913 Total Current Liabilities 2,011,990 $ 2,032,391 $ 2,386,832 $ 2,306,775 $ 2,659,492 $ 2,314,775 $ Long-Term Liabilities Accrued employee leave benefits 107,051 $ 105,930 $ 136,636 $ 126,145 $ 196,058 $ 171,715 $ Subtotal 107,051 $ 105,930 $ 136,636 $ 126,145 $ 196,058 $ 171,715 $ Bonds and loans payable Council-approved general obligation bonds - $ - $ - $ - $ - $ - $ Revenue bonds 15,536,368 14,298,850 12,792,527 11,218,417 9,692,436 8,024,615 Other revenue debt 2,609,288 2,236,532 1,863,777 1,491,022 1,118,266 745,511 Subtotal 18,145,656 $ 16,535,382 $ 14,656,304 $ 12,709,439 $ 10,810,702 $ 8,770,126 $ Total Long-Term Liabilities 18,252,707 $ 16,641,312 $ 14,792,940 $ 12,835,584 $ 11,006,760 $ 8,941,841 $ TOTAL LIABILITIES 20,264,697 $ 18,673,703 $ 17,179,772 $ 15,142,359 $ 13,666,252 $ 11,256,616 $ DEFERRED INFLOWS OF RESOURCES Deferred amounts on debt refunding - $ - $ - $ - $ 37,855 $ 31,546 $ TOTAL DEFERRED INFLOWS OF RESOURCES - $ - $ - $ - $ 37,855 $ 31,546 $ NET POSITION Net investment in capital assets 29,893,636 $ 35,274,943 $ 35,154,187 $ 34,991,294 $ 35,234,688 $ 37,309,485 $ Restricted for debt service 1,093,000 1,319,517 1,266,439 1,189,805 1,085,807 989,826 Restricted for future capital expenses - 3,006,601 1,534,541 1,468,279 - - Unrestricted 17,703,769 10,729,762 13,614,386 15,080,289 17,157,708 17,009,081 TOTAL NET POSITION 48,690,405 $ 50,330,823 $ 51,569,553 $ 52,729,667 $ 53,478,203 $ 55,308,392 $ ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-4 Table 11.2 suggests that the City has been maintaining a relatively high current ratio (ratio of current assets to current liabilities), with a minimum ratio of roughly 6:1 in 2013. As a general benchmark, a ratio of 2:1 or higher is considered to be very good in terms of healthy liquidity. The current ratio has fluctuated between 5.99 and 8.26 over the past six years, due in part to a decrease in interfund loans payable to the utility and an increase in revenue bonds payable by the utility. The sewer utility’s cash and cash-equivalent balances declined from 2009 – 2011, but increased from 2012 – 2014 due to the repayment of an interfund loan due to the sewer utility in 2012 and subsequent rate increases imposed by the City. Overall, Table 11.2 shows a consistent and steady increase in the sewer utility’s net position, primarily due to the City’s net investment in capital assets. 11.3 Current Financial Structure This section summarizes the financial structure used as the basis for the capital funding strategy and financial forecast developed as part of this CSP. 11.3.1 Financial Plan As an enterprise fund, the sewer utility is generally responsible for funding all of its costs. Its primary source of funding comes from ongoing charges for service, though the utility also derives some financial support from miscellaneous revenue such as late fees and interest earnings. Subject to the City Council’s authorization, the City can adjust sewer charges as needed to meet the utility’s financial objectives. In the context of this Plan, the purpose of the financial plan is to verify that the utility can fund the projects outlined in Chapter 9 while maintaining affordable rates. It consists of the following key elements: Capital Funding Plan: The capital funding plan defines a strategy for funding the CIP including an analysis of available resources from rate revenues, existing reserves, system development charges (SDCs), debt financing, and any special resources that may be readily available (e.g. grants, developer contributions, etc.). The capital funding plan impacts the financial plan through the use of debt financing (resulting in annual debt service) and the assumed rate revenue available for capital funding. Financial Forecast: The financial forecast identifies future annual (non-capital) costs associated with the operation, maintenance, and administration of the sewer system. Included in the financial plan is a reserve analysis that forecasts cash flow and fund balance activity along with testing for satisfaction of actual or recommended minimum fund balance policies. The financial plan ultimately evaluates the sufficiency of utility revenues in meeting all obligations, including cash uses such as operating expenses, debt service, capital outlays, and reserve contributions, as well as any coverage requirements associated with long-term debt. The plan also identifies the future adjustments required to fully fund all utility obligations in the projection period. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-5 11.3.2 Capital Funding Strategy Table 11.3 provides a summary of the CIP cost estimates developed for the Plan: The CIP shown in Table 11.3 identifies a total of roughly $81.2 million in project costs (in 2015 dollars) over the 20-year planning period, $60.8 million of which is planned to occur between 2015 and 2020 (with no deferral of the 6-year improvements). Assuming a construction cost inflation rate of 3% per year, the 20-year CIP increases to $94.6 million and the 6-year CIP increases to $66.1 million. 11.4 Available Funding Assistance and Financing Resources There are a variety of resources available for the City to use to fund the CIP, including both its internal resources as well as external resources. The following sections describe these funding sources in greater detail. 11.4.1 Internal Resources To fund capital needs, the City can commit its internal resources such as existing cash and investments, capital-related revenues, and rate revenue. Ongoing revenues from rates and capital-related charges are best suited to fund ongoing capital replacement and maintenance needs. System Development Charges (SDCs) Under the authority of Section 35.92.025 of the Revised Code of Washington (RCW), the City imposes SDCs on new customers as a condition of connecting to the public sewer system. The SDC promotes equity between new and existing customers while providing a source of revenue to fund capital projects. SDC revenue can be used to either pay for capital projects directly or to repay debt issued to fund those projects – however, it should not be used to fund operating costs. Derived in a 2004 study, the current charge is $4,520 per equivalent residential unit (ERU). Section 14.10.010 of the Puyallup Municipal Code defines a single-family home as 1 ERU; multi-family and commercial customers are assigned ERUs based on the number of dwelling units and fixture units, respectively. The financial analysis includes an update of the SDC to reflect the current cost of the sewer system as well as the CIP summarized in Table 11.3. A. Existing Facilities Cost Basis The existing cost basis is intended to recognize the current ratepayers’ net investment in the original cost of system assets. It reflects: Table 11.3 Capital Improvement Program ($000s) Costs Expressed In 2015 Dollars 2015 2016 2017 2018 2019 2020 6-Year Total CIP 2021 - 2034 20-Year Total CIP Conveyance System 1,410 $ 2,450 $ 3,870 $ 4,520 $ 4,290 $ 7,050 $ 23,590 $ 20,390 $ 43,980 $ Lift Stations 1,940 1,210 1,480 1,280 500 - 6,410 - 6,410 Wastewater Treatment Plant 4,164 4,213 3,260 11,621 1,750 5,822 30,830 - 30,830 Total (2015 Dollars) 7,514 $ 7,873 $ 8,610 $ 17,421 $ 6,540 $ 12,872 $ 60,830 $ 20,390 $ 81,220 $ Adjustment for Inflation Per Year) - 236 524 1,615 821 2,050 5,247 8,113 13,360 Total Projected Capital Expenditures 7,514 $ 8,109 $ 9,134 $ 19,036 $ 7,361 $ 14,922 $ 66,077 $ 28,503 $ 94,580 $ ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-6 Utility Plant-In-Service. The original cost of plant-in-service, as documented in the City’s 2014 fixed asset schedules, makes up most of the existing facilities cost basis. Less: Contributed Capital. Developer extensions identified in the City’s fixed asset schedule are excluded from the cost basis because the SDC should only recover costs actually incurred by the City. (This same logic would apply to grant-funded assets, but none were identified in City records.) Less: Provision for Capital Retirements. This adjustment recognizes that some capital projects will replace assets that are currently included in the City’s fixed asset schedule. This adjustment intends to avoid double charging customers for an asset and its replacement, while recognizing that assets are generally replaced at a cost that exceeds their original installation cost. Plus: Interest on Assets Included In Cost Basis. RCW 35.92.025 and subsequent legal interpretations suggest that connection charges can include up to 10 years of interest on an asset at the rate applicable when it was constructed or acquired (capped at 10%). Conceptually, this adjustment attempts to account for opportunity costs that the City’s customers incurred by supporting investments in infrastructure rather than having it available for investment or other uses. Less: Net Debt Principal Outstanding. This adjustment deducts the net liability of outstanding utility debt to recognize that new customers will bear a proportionate share of this debt (related to existing assets) through their utility rates. Since the utility typically has cash resources that are not included in the system cost basis, the net debt load is defined as total outstanding debt less cash and investments. B. Future Facilities Cost Basis The future cost basis includes utility capital projects identified in the City’s comprehensive system planning documents, expressed in current (uninflated) dollars. Each project in the capital improvement program was allocated between “upgrade / expansion” and “repair / replacement” functions. Repair and Replacement Projects. These projects are included in the future cost basis, with an adjustment to the existing cost basis to reflect the estimated original cost of the assets being replaced. Upgrade and Expansion Projects. Growth-driven projects that increase the capacity of the system are included in the future cost basis. Less: External Funding Sources. Projects funded by developers or grants are not included in the cost basis. C. Customer Base The customer base is defined in terms of equivalent residential units, and includes both existing and future (growth) components. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-7 Existing Customer Base. The existing customer base is defined based on current average daily flows at the City’s wastewater treatment plant. Based on an estimated average daily flow of 75 gallons per capita per day (gpcd) and an average household size of 2.49 people (per 2010 Census data), an ERU is defined as 187 gpd of flow. Table 6.6 of this Plan indicates that existing flows are about 4.08 mgd, which equates to 21,847 ERUs. Future Customer Base. The future customer base is defined in two ways. Treatment: The estimate of future ERUs is based on the treatment plant’s design capacity – assuming 187 gpd of flow per ERU, the plant’s 10.23 mgd of capacity would be able to serve 54,779 ERUs (32,932 ERUs of growth). Other (Conveyance / General): The future customer base is defined based on the projected flows at the end of the CSP planning period. Table 6.8 indicates a projected average daily flow of 5.46 mgd by 2034, corresponding to a 2034 ERU estimate of 29,237 ERUs (7,390 ERUs of growth). D. SDC Calculation The updated SDC uses an “average-cost” approach, in which the charge is calculated by dividing the existing and future facility costs by the total number of ERUs (existing ERUs plus growth). Table 11.4 shows the updated SDC calculation. Table 11.4 shows that the City could justify increasing its sewer SDC from $4,520 to $5,743 per ERU based on current system costs. Table 11.4 Sewer System Development Charge Calculation Treatment Other Total Existing Cost Basis Plant-In-Service as of 12/31/14 42,477,621 $ 52,026,013 $ 94,503,635 $ Less: Assets Funded By Developer Extensions - (1,948,304) (1,948,304) Less: Provision for Asset Retirements Due to R&R CIP Projects (16,704,168) (7,410,996) (24,115,163) Plus: Interest Accrued on Existing Assets Included In Cost Basis 26,899,338 30,291,262 57,190,600 Less: Outstanding Debt Principal Net of Available Cash - - - Total Existing Cost Basis 52,672,792 $ 72,957,976 $ 125,630,768 $ Future Cost Basis Capital Improvement Program 30,830,074 $ 50,390,000 $ 81,220,074 $ Total Future Cost Basis 30,830,074 $ 50,390,000 $ 81,220,074 $ Total Cost Basis (C = A + B) 83,502,866 $ 123,347,976 $ 206,850,842 $ Customer Base Existing ERUs 21,847 21,847 Growth ERUs 32,932 7,390 Total Customer Base 54,779 29,237 SDC Per ERU (C / D) $1,524 $4,219 $5,743 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-8 Local Facilities Charges The SDC recovers a proportionate share of the cost of facilities of general system benefit. A variation of the SDC, local facilities charges (LFCs) recover the cost related to facilities of localized benefit (e.g. service extension to local properties). Often called a front-footage charge and imposed on the basis of footage of the main “fronting” a particular property, it is usually implemented as a reimbursement mechanism to a City for the cost of a local facility that directly serves a property. It is a form of connection charge and thus can accumulate up to 10 years of interest. It typically applies in instances when no developer-installed facilities are needed through developer extension due to the prior existence of available mains already serving the developing property. The City could calculate an LFC that parallels the SDC that it charges for facilities of general system benefit. However, like the SDC, the LFC cost basis would generally not include facilities that the City didn’t pay for. The City would also have to take care to avoid overlaps in the LFC cost basis and the SDC cost basis. Similarly, the LFC could potentially include ULID-funded assets but the City would then need to exempt properties that have already paid for their share of those facilities via ULID assessments. RCW 35.92.025 would also allow the City to include up to 10 years of interest on assets included in the LFC cost basis. As for the basis for the charge, the City could either impose it based on front footage or ERUs. In general, this option would make the most sense for the City if it has invested (or plans to invest) in infrastructure of local system benefit. Developer Extensions / Latecomer Agreements The developer extension is a requirement that a developer install onsite and sometimes offsite improvements as a condition of extending service. These are in addition to any required SDC payments and must be built to City standards. Part of the agreement between the City and the developer planning to extend service might include a latecomer agreement, resulting in a latecomer charge to new connections to the developer extension. Latecomer charges are a variation of developer extensions whereby new customers connecting to a developer-installed improvement make a payment to the City based on their share of the developer’s cost. The City passes this charge on to the developer who installed the facilities. As part of the developer extension process, this defines the allocation of costs and records latecomer obligations on the title of affected properties. No interest is allowed, and the reimbursement agreement cannot exceed 20 years in duration. Local Improvement Districts / Utility Local Improvement Districts Local improvement districts (LIDs) and utility local improvement districts (ULIDs) represent another mechanism for funding infrastructure that assesses properties based on the special benefit received by the construction of specific facilities. Most often used for local facilities, some ULIDs also recover related general facilities costs that would otherwise be included in the SDC. Substantial legal and procedural requirements can make this a relatively expensive process, and there are mechanisms by which a ULID can be rejected. When using LIDs / ULIDs, it is important to adjust the cost basis for the SDC (and LFC, as applicable) to ensure that there is no overlap in the costs recovered through each charge. 11.4.2 External Resources This section outlines various grant, loan, and bond opportunities available to the City through federal and state agencies to fund the CIP. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-9 Grants & Low-Cost Loans While federal and state grant programs have historically been available to utilities for capital funding assistance, they have been mostly eliminated, reduced in scope and amount, or replaced by loan programs. Remaining programs are generally funded and heavily subscribed. Nonetheless, even the benefit of low-interest loans makes the effort of applying Grants and low-cost loans for Washington State utilities are available from the Department of Commerce including two assistance programs that the City may be eligible for. Public Works Trust Fund (PWTF): The PWTF offers low-interest loans for local governments to finance infrastructure construction and rehabilitation. Cities, counties, special-purpose districts, public utility districts, and quasi-municipal governments are eligible to receive PWTF loans for domestic water, sanitary sewer, stormwater, solid waste, road, and bridge projects. Eligible projects must improve public health and safety, respond to environmental issues, promote economic development, or upgrade system performance. PWTF loans are generally available for terms of up to 20 years. The interest rate on loans with a repayment period of 5 years or less is 1.28%; for longer repayment periods, the interest rate increases to 2.55%. Communities with utility bills that exceed 1.5% of median household income may qualify for reduced interest rates and / or extended repayment periods. All loan terms are subject to negotiation and Board approval. Currently no local match is required and the maximum loan amount is $7 million per jurisdiction per biennium. Due to legislative budget changes made on June 30, 2013, the 2014 Construction Loan cycle did not receive funding. The Legislature also passed a statute with the intent of redirecting tax revenue from the Public Works Assistance Account for six years to the state General Fund. Loan repayment revenues will continue to be available in future biennia. The effect of this diversion resulted in a decrease in funding available to local governments for high-priority infrastructure projects from the Public Works Trust Fund. For drinking water and sanitary wastewater projects not on the 2014 unfunded PWTF list, applicants must first apply to the Departments of Health or Ecology during their normal funding cycle – only projects that were not selected for funding and / or were partially funded by these agencies are eligible for the 2016 Construction Loan program. Information regarding the application process as well as rates and terms are posted on the PWTF website in early spring. Further detail is available at http://www.pwb.wa.gov. Department of Ecology: The Department of Ecology administers the following grants and loans for water quality projects: Centennial Grants: The Centennial program provides grants for water quality infrastructure and nonpoint source pollution projects that improve or protect water quality. Eligibility for Centennial Clean Water Grants is limited to financially distressed communities with sewer rates that exceed 2% of median household income; low-cost loans may be available either where grant funding is not available, or as part of a combined funding assistance package. Clean Water Act Section 319 Federal Grants: The Section 319 program provides grants to eligible nonpoint source pollution control projects similar to the Centennial ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-10 program. The federal Environmental Protection Agency (EPA) provides Section 319 grant funds to Washington State; the State has to provide a 40% match in funding. Clean Water State Revolving Fund Loans: Funded by an annual EPA capitalization grant, State matching funds, and repayments on past loans, this program provides low-interest and forgivable-principal loan funding for wastewater treatment construction projects, eligible nonpoint source pollution control projects, and eligible Green projects. More information is available at Though the 2016 Funding Cycle is now closed, the City would be able to apply for funding in subsequent years. Bonds Two types of municipal bonds are considered for financing the City’s capital costs: General Obligation Bonds: General Obligation bonds are bonds secured by the full faith and credit of the issuing agency, committing all available tax and revenue resources to debt repayment. With this high level of commitment, G.O. bonds have relatively low interest rates and few financial restrictions. However, the authority to issue G.O. bonds is restricted in terms of the amount and use of the funds, as defined by Washington constitution and statute. Specifically, the amount of debt that can be issued is linked to assessed valuation. RCW 39.36.020 states: “(ii) Counties, cities, and towns are limited to an indebtedness amount not exceeding one and one-half percent of the value of the taxable property in such counties, cities, or towns without the assent of three-fifths of the voters therein voting at an election held for that purpose. In cases requiring such assent counties, cities, towns, and public hospital districts are limited to a total indebtedness of two and one-half percent of the value of the taxable property therein.” While bonding capacity can limit availability of G.O. bonds for utility purposes, these can sometimes play a valuable role in project financing. A rate savings may be realized through two avenues: the lower interest rate and related bond costs; and the extension of repayment obligation to all tax-paying properties (not just developed properties) through the authorization of an ad valorem property tax levy. Revenue Bonds: Revenue bonds are commonly used to fund utility capital improvements, and are secured by utility revenues. With this limited commitment, revenue bonds typically bear higher interest rates than G.O. bonds and also require security conditions related to the maintenance of dedicated reserves (a bond reserve) and financial performance (added bond debt service coverage). The City agrees to satisfy these requirements by resolution as a condition of bond sale. Revenue bonds can be issued in Washington without a public vote. There is no bonding limit, except perhaps the practical limit of the utility’s ability to generate ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-11 sufficient revenue to repay the debt and provide coverage. In some cases, poor credit might make issuing bonds problematic. 11.5 Financial Forecast The financial forecast, or revenue requirement analysis, forecasts the amount of annual revenue that needs to be generated by user rates. The analysis evaluates the sufficiency of the sewer utility’s revenues to meet its financial obligations including operation and maintenance (O&M) expenses, debt repayment, rate-funded capital needs, and any other policy-based needs. The analysis determines the amount of revenue needed in a given year to meet that year’s expected financial obligations. For this analysis, two revenue sufficiency tests have been developed to reflect the financial goals and constraints of the City: Cash Flow Test: The cash flow test identifies all known cash requirements for the sewer utility including O&M expenses, debt service payments, rate-funded system reinvestment funding or directly funded capital outlays, and any additions to specified reserve balances. Coverage Test: The coverage test is based on a commitment made by the City when issuing revenue bonds and some other forms of long-term debt. The City’s existing revenue bond covenants require that the sewer utility maintains a coverage ratio of 1.20 as a legal minimum. In other words, the sewer utility’s revenue must be sufficient to pay O&M expenses, annual revenue bond debt service payments, plus an additional 20% of the revenue bond payments. The excess cash flow derived from the added coverage, if any, can be used for any purpose including funding capital projects. Targeting a higher coverage factor can help the City achieve a better credit rating and provide lower interest rates for future debt issues. In determining the annual revenue requirement, both the cash and coverage sufficiency test must be met; the test with the greatest deficiency drives the rate increase in any given year. 11.5.1 Current Financial Structure The City operates its sewer utility as a financially viable and fiscally responsible enterprise. The financial structure and policy framework used in this analysis is described in further detail below. 11.5.2 Fiscal Policies Key elements of the assumed policy framework include: A. Utility Reserves The sewer utility’s cash and investment balances are separated into three reserves / funds: Operating Fund: Operating reserves provide a “cushion” to accommodate fluctuations in cash balances resulting from differences in revenue and expense cycles, unanticipated cash expenses, or unanticipated revenue shortfalls. This analysis assumes that the sewer utility maintains a minimum Operating Fund balance equal to 60 days of O&M expenses – based on the 2015 Budget, this policy corresponds to a minimum balance of about $1.1 million. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-12 Capital Fund: The capital fund facilitates the segregation of resources restricted to capital purposes (e.g. SDC revenues, grants, debt proceeds) from other resources available for general utility purposes. It can also serve as a capital contingency reserve to accommodate capital cost overruns or unanticipated capital needs. A percentage of the cost of fixed assets is commonly used to set a minimum balance for the Capital Fund; other potential benchmarks include a rolling average of CIP expenditures or an amount based on the cost of the utility’s most expensive asset. The recommended policy maintains a minimum balance equal to 1% of the cost of assets, which would be around $945,000 based on the current inventory of fixed assets. Given the current financial status of the sewer utility and projected near-term needs, this analysis temporarily relaxes this policy to mitigate rate impacts. Bond Reserve: This reserve is required by the City’s bond covenants to provide security against default risk. The reserve requirement is defined as the least of three measures: maximum annual revenue bond debt service, 125% of average annual debt service, and 10% of the amount issued. Based on the utility’s current debt schedules, the reserve requirement is around $883,000. B. Capital Funding The City Council has established a policy to pay off existing debt and fund future capital needs on a “pay-as-you-go” basis (avoiding future debt issuance to the maximum extent possible). Consequently, this analysis does not assume any new debt issuance to fund the CIP. However, to promote a long-term strategy of stable and moderate rate increases, it may be for the City to consider issuing debt to fund major discrete capital projects. 11.5.3 Financial Forecast The financial forecast is developed from the 2015 Budget, along with other key factors and assumptions. The key revenue and expense assumptions used to develop the financial forecast are described below. Revenue: Rate revenue is projected to be about $9.8 million for 2015, based on actual 2014 rate revenue collections and expected growth. Other (non-rate) revenues are forecasted based on the 2015 Budget. Revenue from rates and customer-related fees is projected to increase with growth in the customer base. In the event of a forecasted annual shortfall, rate revenue can be increased to meet the annual revenue requirement. SDC Revenue: Based on the 2015 Budget, the current SDC of $4,520 per ERU is projected to generate $630,958 in 2015. To be conservative, this analysis assumes that the City retains the existing SDC rather than increasing the SDC to $5,727 per ERU as shown in Table 11.4. As a result, annual SDC revenues are projected to remain comparable to the 2015 estimate during the study period. Growth: The financial analysis assumes a growth rate of 1.0% per year in the customer base, which considers recent historical growth experienced by the City. Expenses: O&M expense projections are based on the 2015 Budget, and most are forecasted to increase with either general cost inflation (3.0% per year) or benefit cost inflation (5.0% per year). Beyond 2015, taxes are calculated based on projected ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-13 revenues and the applicable tax rates. Capital project costs are assumed to increase at 3.0% per year as well, based on recent inflation in the ENR Construction Cost Index. Debt: The sewer utility currently has one outstanding loan and three outstanding revenue bonds; its current annual payment on this debt is around $2.3 million. Debt service is expected to decrease to roughly $375,000 per year by the end of the study period, as the City pays off its loan and bonds. This analysis assumes that the City releases bond reserves to make the final payments on the 2004 Bond (2016), the 2009B Bond (2019), and the 2013 Bond (2020). As previously noted, the financial forecast does not assume any new debt issuance during the study period. Rate-Funded Capital: Without additional debt issuance, rates must fund capital needs in excess of existing balances, interest earnings, and SDC revenues. Based on the projections of capital costs (shown in Table 11.3) and these other revenues, rates will have to fund approximately $50.7 million in capital investment during the study period. Although the financial plan is completed for the 20-year time horizon of this Plan, the rate strategy focuses on the shorter-term planning period from 2015 through 2020. Table 11.5 summarizes the annual revenue requirements based on the forecast of revenues, expenditures, fund balances and fiscal policies. Table 11.5 indicates that while revenue at existing rates is sufficient to cover the sewer utility’s current operating expenses and debt service, revenue levels would have to increase considerably in order to support the planned capital projects on a “pay-as-you-go” (cash-funded) basis. Once the near-term capital projects have been funded, a rate decrease would likely be needed in order to manage a cash flow surplus. The City could potentially avoid this issue by either issuing debt (to spread the capital costs over a longer period) or deferring projects until funding is available. Table 11.5 Revenue Requirement Forecast ($000s) 2015 2016 2017 2018 2019 2020 Revenues Rate Revenue At Existing Rates 9,789 $ 9,886 $ 9,985 $ 10,085 $ 10,186 $ 10,288 $ Other Operating Revenues 155 161 193 201 160 177 Total 9,944 $ 10,048 $ 10,178 $ 10,287 $ 10,346 $ 10,465 $ Expenses Operating Expenses 6,795 $ 6,973 $ 7,181 $ 7,395 $ 7,617 $ 7,846 $ Debt Service 2,290 2,334 1,673 1,130 1,124 671 Less: Use of Bond Reserve for Final Payments - (333) - - (65) (292) Rate-Funded Capital - 2,860 8,491 18,386 6,704 14,259 Total 9,085 $ 11,834 $ 17,344 $ 26,911 $ 15,380 $ 22,484 $ Net Cash Flow 859 $ (1,787) $ (7,166) $ (16,625) $ (5,034) $ (12,019) $ Annual Rate Revenue Adjustment 0.00% 80.00% 1.72% 1.74% 1.76% 1.78% Cumulative Rate Revenue Adjustment 0.00% 80.00% 83.09% 86.27% 89.55% 92.93% Rate Revenue After Rate Adjustments 9,789 $ 17,796 $ 18,282 $ 18,786 $ 19,308 $ 19,848 $ Net Cash Flow 859 $ 5,347 $ 317 $ (8,777) $ 3,193 $ (3,396) $ Coverage Ratio Realized 2.01 6.71 8.58 10.08 10.97 31.42 Coverage Ratio Required 1.20 1.20 1.20 1.20 1.20 1.20 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-14 Table 11.6 summarizes a “phased” CIP scenario developed to manage the upfront rate increase required. Appendix B provides a more detailed forecast of capital costs by project. The phased CIP summarized in Table 11.6 reflects the deferral of $29.6 million in projects (in 2015 dollars) beyond the 6-year planning horizon. Of this amount, $14.6 million is attributable to conveyance system improvements, $13.5 million is associated with treatment plant improvements, and $1.5 million is related to lift station projects. With inflation at 3.0% per year, the deferral of projects shown in Table 11.6 would increase the total 20-year CIP expenditures by about $5.9 million – despite this increase, the City would be able to impose a more moderate set of rate increases as shown in Table 11.7. It is worth noting that the forecasts shown in Table 11.5 and Table 11.7 make the conservative assumption that the City retains its existing sewer SDC of $4,520 per ERU. The City could increase the SDC to $5,743 per ERU, which would generate an estimated $172,000 – $179,000 per year in additional SDC revenue. This revenue would potentially enable the City to reduce the cumulative rate revenue increase by around Table 11.6 Capital Improvement Program - Phased ($000s) Costs Expressed In 2015 Dollars 2015 2016 2017 2018 2019 2020 6-Year Total CIP 2021 - 2034 20-Year Total CIP Conveyance System 1,410 $ 2,215 $ 1,745 $ 910 $ 860 $ 1,805 $ 8,945 $ 35,035 $ 43,980 $ Lift Stations 1,940 - 200 1,480 1,280 - 4,900 1,510 6,410 Wastewater Treatment Plant 4,164 4,213 6,260 890 650 1,200 17,377 13,453 30,830 Total (2015 Dollars) 7,514 $ 6,428 $ 8,205 $ 3,280 $ 2,790 $ 3,005 $ 31,222 $ 49,998 $ 81,220 $ Adjustment for Inflation Per Year) - 193 500 304 350 479 1,825 17,422 19,248 Total Projected Capital Expenditures 7,514 $ 6,621 $ 8,705 $ 3,584 $ 3,140 $ 3,484 $ 33,048 $ 67,420 $ 100,468 $ Projected CIP Expenditures Per Table 11.3 7,514 $ 8,109 $ 9,134 $ 19,036 $ 7,361 $ 14,922 $ 66,077 $ 28,503 $ 94,580 $ Table 11.7 Revenue Requirement Forecast - Phased CIP Scenario ($000s) 2015 2016 2017 2018 2019 2020 Revenues Rate Revenue At Existing Rates 9,789 $ 9,886 $ 9,985 $ 10,085 $ 10,186 $ 10,288 $ Other Operating Revenues 155 161 174 158 168 180 Total 9,944 $ 10,048 $ 10,159 $ 10,243 $ 10,354 $ 10,467 $ Expenses Operating Expenses 6,795 $ 6,973 $ 7,181 $ 7,395 $ 7,617 $ 7,846 $ Debt Service 2,290 2,334 1,673 1,130 1,124 671 Less: Use of Bond Reserve for Final Payments - (333) - - (65) (292) Rate-Funded Capital - 1,372 8,061 2,934 2,484 2,820 Total 9,085 $ 10,346 $ 16,915 $ 11,459 $ 11,159 $ 11,045 $ Net Cash Flow 859 $ (298) $ (6,755) $ (1,215) $ (806) $ (578) $ Annual Rate Revenue Adjustment 0.00% 21.00% 3.00% 3.00% 3.00% 3.00% Cumulative Rate Revenue Adjustment 0.00% 21.00% 24.63% 28.37% 32.22% 36.19% Rate Revenue After Rate Adjustments 9,789 $ 11,963 $ 12,445 $ 12,946 $ 13,468 $ 14,011 $ Net Cash Flow 859 $ 1,574 $ (4,537) $ 1,365 $ 2,154 $ 2,780 $ Coverage Ratio Realized 2.01 3.46 4.50 5.38 6.00 17.53 Coverage Ratio Required 1.20 1.20 1.20 1.20 1.20 1.20 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-15 11.5.4 Sewer Utility Funds & Reserves Table 11.8 shows a summary of the projected fund activity based on the revenue requirement forecast shown in Table 11.7. Table 11.8 shows the sewer utility’s fund balance decreasing over the study period, beginning 2015 at $13.6 million and ending 2020 with roughly $8.8 million. As the City embarks on deferred capital projects in the early 2020s, the fund balance is projected to decrease further before reaching a minimum of $3.9 million in 2022. 11.6 Current and Projected Rates 11.6.1 Current Rates Summarized in Table 11.9 below, the City’s current rate structure consists of a fixed base charge and a variable charge per hundred cubic feet (ccf) of water use. Table 11.8 Summary of Projected Fund Activity ($000s) 2015 2016 2017 2018 2019 2020 Operating Fund Beginning Balance 1,117 $ 2,674 $ 5,296 $ 1,859 $ 3,460 $ 5,614 $ Net Cash Flow After Rate Adjustments (per Table 11.7) 859 1,574 (4,537) 1,365 2,154 2,780 Plus: Interfund Loan Repayment 698 1,047 1,100 236 - - Ending Balance 2,674 $ 5,296 $ 1,859 $ 3,460 $ 5,614 $ 8,394 $ Minimum Balance (60 Days of O&M) 1,117 $ 1,146 $ 1,180 $ 1,216 $ 1,252 $ 1,290 $ Capital Fund Beginning Balance 11,415 $ 4,589 $ - $ - $ - $ - $ Plus: Interest Earnings 57 23 - - - - Plus: SDC Revenue 631 637 644 650 657 663 Plus: Rate Funding for Capital (per Table 11.7) - 1,372 8,061 2,934 2,484 2,820 Less: Capital Project Expenditures (per Table 11.6) (7,514) (6,621) (8,705) (3,584) (3,140) (3,484) Ending Balance 4,589 $ - $ - $ - $ - $ - $ Bond Reserve Beginning Balance 1,086 $ 1,086 $ 753 $ 753 $ 753 $ 688 $ Plus: Interest Earnings 5 5 4 4 4 3 Less: Use of Interest Earnings for Debt Service Less: Release of Reserves for Final Payments (per Table 11.7) - (333) - - (65) (292) Ending Balance 1,086 $ 753 $ 753 $ 753 $ 688 $ 396 $ Minimum Balance 883 $ 753 $ 674 $ 600 $ 511 $ 378 $ Total Beginning Balance - All Funds 13,618 $ 8,349 $ 6,049 $ 2,612 $ 4,213 $ 6,302 $ Total Ending Balance - All Funds 8,349 $ 6,049 $ 2,612 $ 4,213 $ 6,302 $ 8,790 $ Net Change In Fund Position (5,269) $ (2,300) $ (3,437) $ 1,601 $ 2,090 $ 2,488 $ Minimum balance for the bond reserve is defined as the lowest of three measures: 125% of average annual bond debt service, maximum annual bond debt service, or 10% of the original amount issued. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-16 The base rate generally applies to all customers with a couple of exceptions. Low-income senior / disabled customers pay a discounted rate that is equal to roughly 43% of the standard rate; to recognize that multi-family living units generally use less water than a single-family home, multi-family customers pay 75% of the standard base rate per unit. The volume rates are strength-based, reflecting the higher demands for wastewater treatment that certain non-residential customers impose on the system. Per Section 14.01.030 of the Puyallup Municipal Code, customers are generally billed based on actual “winter” water usage from December 1 – May 3; bills from June 1 – November 30 are based on an average of winter water usage to avoid charging customers for irrigation usage that does not enter the sewer system. 11.6.2 Projected Rates Table 11.10 shows the near-term rate forecast: The rates shown in Table 11.10 reflect across-the-board increases to the existing rate structure, including the strength-based volume rates. Most recently reviewed as part of the City’s 2010 Sewer Rate Study, the strength-based rates were not directly updated as part of this analysis. It would be prudent for the City to revisit these charges as part of its next rate study and verify that they remain consistent with the cost of providing service. Table 11.9 Current Sewer Rate Structure 2014 2015 Base Rates: Service Charge $33.07 $33.96 Disability / Senior Discount $14.29 $14.68 Multi-Family Unit $24.80 $25.47 Volume Rates per ccf: Strength Category 1 $5.01 $5.15 Strength Category 2 $6.51 $6.65 Strength Category 3 $7.63 $7.77 Strength Category 3 (With Discount) $6.97 $7.11 Table 11.10 Sewer Rate Forecast 2015 2016 2017 2018 2019 2020 Annual Rate Adjustment (Per Table 11.7) 21.00% 3.00% 3.00% 3.00% 3.00% Base Rates: Service Charge $33.96 $41.09 $42.32 $43.59 $44.90 $46.25 Disability / Senior Discount $14.68 $17.76 $18.30 $18.84 $19.41 $19.99 Multi-Family Unit $25.47 $30.82 $31.74 $32.70 $33.68 $34.69 Volume Rates per ccf: Strength Category 1 $5.15 $6.23 $6.42 $6.61 $6.81 $7.01 Strength Category 2 $6.65 $8.05 $8.29 $8.54 $8.79 $9.06 Strength Category 3 $7.77 $9.40 $9.68 $9.97 $10.27 $10.58 Strength Category 3 (With Discount) $7.11 $8.60 $8.86 $9.13 $9.40 $9.68 ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 11-17 11.7 Affordability Evaluation As noted in Section 11.4.2.1, the Public Works Board and the Department of Ecology use an affordability index to prioritize awards of grants and low-cost loans. The PWTF loan program reduces interest rates and extends repayment terms for “distressed” communities, which it defines as communities with a utility bill that exceeds 1.5% of median household income. The Department of Ecology uses a higher threshold of 2.0% of median household income when evaluating eligibility for grants, forgivable-principal loans, and interest rate reductions for other loans. The most recent Census data (2009 – 2013 average) indicates that the median household income in Puyallup is $61,362. Table 11.11 summarizes the affordability evaluation: Table 11.11 indicates that the total residential sewer bill at 16 ccf would increase to about 1.34% of MHI, which falls within the range specified as “affordable” or “non-distressed” by the PWTF and Department of Ecology. 11.8 Conclusion The results of this analysis indicate that the City’s sewer utility will require rate increases to fund the CIP. The rates shown in Table 11.10 reflect the deferral of roughly $29.6 million in capital projects beyond 2020 (summarized in Table 11.6) – if the City wishes to further mitigate near- term sewer rate increases, it could potentially consider issuing debt and / or delaying additional CIP projects. It is important to note that this financial forecast is based on a number of assumptions that may vary from the City’s actual experience (e.g. growth, inflation rates). For this reason, it would be prudent for the City to revisit the forecast periodically and adjust the rate strategy as needed in order to ensure that the sewer utility is able to meet its obligations. Table 11.11 Affordability Evaluation 2015 2016 2017 2018 2019 2020 Residential Bill @ 16 ccf $116.36 $140.80 $145.02 $149.37 $153.85 $158.47 Annual Residential Bill @ 16 ccf $698.16 $844.77 $870.12 $896.22 $923.11 $950.80 Median Household Income (MHI) $61,362 $63,203 $65,099 $67,052 $69,063 $71,135 Assumed Inflation Rate 3.0% 3.0% 3.0% 3.0% 3.0% Annual Bill as % of MHI 1.14% 1.34% 1.34% 1.34% 1.34% 1.34% ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-1 Chapter 12 Sewer Policy Analysis 12.1 Purpose and Understanding The purpose of this Chapter is to analyze current and potential policy alternatives related to the administration and operation of the sanitary sewer utility. Policy analyses are organized into four identifiable policy goals or categories. A brief overview of the four general categories and/or goals is provided below: 1) Rate Discounting: The goal of utility rate discounts is to provide equitable and sustainable rate structures for City of Puyallup residents. Example discount populations are low-income, disabled and/or senior residents. 2) Sewer Expansion: Encouraging new sewer connections in the City accomplishes two goals. Water quality problems associated with septic systems in the Puget Sound region are well documented and even properly functioning septic systems discharge partially treated wastewater to the environment. Conversion from septic to the City sanitary system is generally considered beneficial to the environment. As a secondary benefit, new sewer connections mean more rate payers for the City. This often creates an “economy of scale benefit”, lowering the average cost to sewer rate payers. This allows the City to do more of the projects necessary to maintain and operate their system. 3) Inflow and Infiltration Chapter 7 identifies and concludes against a more aggressive capital improvement program to approach I/I problems. That said, low-cost I/I policies may still be beneficial. Storm/flow events are the basis for conveyance and WWTP planning and design. Reducing I/I during these events creates less strain on the system and creates potential to avoid future capital improvements as a result. A series of “low-hanging fruit” policies are discussed herein. 4) Sustainable Sewer Revenue and Growth: This policy goal aims to create a sustainable utility. First, forming a sustainable rate structure is discussed, whereas rate increases are set and cannot be changed by political figures. Second, the possibility of a growth moratorium is discussed when certain basins reach capacity. This would serve to direct growth to areas with the most capacity for potential sewer growth. 12.2 Current or Existing Known Policies Current policies are discussed in the four general categories identified above. 12.2.1 Rate Discounting Rate discounts are currently available for low-income senior and disabled persons. The City offers approximately a 12.5% discount for low-income seniors and disabled persons who use 1600 cubic feet of water on a basis. The criteria for low income, seniors and disabled persons is included in policy statements in this Chapter (see Policy 12.3.1.A – Elderly assistance and Policy 12.3.1.B – Disabled assistance). 12.2.2 Sewer Expansion Puyallup Municipal Code (PMC) Item 14.08.070 identifies requirements for connections and requires connections for new development or On-site Sewage Systems (OSS) failures within ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-2 300 feet of the municipal wastewater treatment system. The City might consider extending a low interest loan program to help offset the cost of connecting to the sewer system. Repayment of this loan could be financed through the sewer bills. 12.2.3 Inflow and Infiltration There are no known policies for inflow and infiltration reduction. 12.2.4 Sustainable Sewer Revenue and Growth There are no known policies for sewer revenue and growth. 12.3 Policies for Consideration The following policy options are discussed in Policy Option Tables on pages 12-3 to 12-15. 12.3.1 Rate Discounting Policy Options x 12.3.1a Elderly Assistance x 12.3.1b Disabled Assistance 12.3.2 Sewer Expansion Policy Options x 12.3.2a System Development Charges Waiver or Discount 12.3.3 Inflow and Infiltration Policy Options x 12.3.3a Inflow and Infiltration CIP x 12.3.3b Rain Harvesting x 12.3.3c CCTV Side Sewer Inspection 12.3.4 Future Financial Policy Options x 12.3.4a Sustainable Rate Formation ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-3 POLICY OPTION 12.3.1A – ELDERLY ASSISTANCE STATEMENT Should the City continuing the policy that offers a discount on sewer charges for qualifying elderly persons? CURRENT CITY OF PUYALLUP POLICY Utility Rate Discounts are available for either a) Citizens who are over 61, who earn less than $30,000 annually and who are currently receiving the senior discount on their property taxes or b) Disabled persons who earn less than $30,000 annually and who are currently receiving the disability discount on their property taxes The current rate discount is approximately 12.5% for residents who use approximately 1600 cubic feet of water on a basis. POLICY DISCUSSION The City’s existing policy offers a utility rate discount to fixed-income senior citizens. The number of senior accounts that applied for the discount in 2014 totaled 285. This number of applications includes both the senior and disabled populations. The value of the discounts is calculated as follows: The standard service charge in 2015: $33.96. The senior/disabled discounted rate: $14.68. The discount totals $33.96 - $ 14.68 = $19.28 per month per account. Total annual discount is 285 accounts x $19.28 x 12 months = 65,938 per year, or about 0.6% of total revenues. POLICIES OF OTHER SIMILAR CITIES x Anacortes: Elderly not addressed in 2013 utility billing rates x Bellingham: Elderly per se not addressed by BMC 15.04.070 Reduced Rates x Kirkland: Per KMC 15.24.100 low income citizens 62 or older charged 75% of single family residential rate x Monroe: Per MMC 13.08.430 citizen 55 or older with income 50% or less than OFM average for the area median income receive 30% discount x Sedro Woolley: SWMC Chapter 13.30 Sewer Rates does not address elderly assistance DISCUSSION Pro: 1. Reduced sewer rate for elderly persons may encourage settlement of retirees Con: 1. Reduced Elderly/Disabled sewer rate will decrease sewer utility revenue. The estimated annual value of the currently enrolled Elderly/Disabled discount totals approximately $65,938 or about 0.6% of total revenues. RECOMMENDATION Age alone is not considered justification for discounting sewer rates. No justification is seen to provide assistance to elderly citizens with median or above incomes. Current policy that couples age and income adequately addresses and provides for assistance to less fortunate senior citizens. No change to the current policy is recommended. The City might consider a graduated assistance rate for those on a fixed income. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-4 POLICY OPTION 12.3.1B – DISABLED ASSISTANCE STATEMENT Should the City continuing the policy that offers a discount on sewer charges for qualifying disabled persons? CURRENT CITY OF PUYALLUP POLICY Utility Rate Discounts are available for either a) Citizens who are over 61, who earn less than $30,000 annually and who are currently receiving the senior discount on their property taxes or b) Disabled persons who earn less than $30,000 annually and who are currently receiving the disability discount on their property taxes or The current rate discount is approximately 12.5% for residents who use approximately 1600 cubic feet of water on a basis. POLICY DISCUSSION The City’s existing policy offers a utility rate discount for the accounts of disabled citizens. The number of ‘senior’ accounts that applied for the discount in 2014 totaled 285. This number of applications includes both the senior and disabled populations. The value of the discounts is calculated as follows: The standard service charge in 2015: $33.96. The senior/disabled discounted rate: $14.68. The discount totals $33.96 - $ 14.68 = $19.28 per month per account. Total annual discount is 285 accounts x $19.28 x 12 months = 65,938 per year, or about 0.6% of total revenues. POLICIES OF OTHER SIMILAR CITIES x Anacortes: Disabled assistance not addressed in 2013 utility billing rates x Bellingham: Per BMC 15.04.070 disabled citizens sewer rate is reduced by 75% for income less than 50%, by 50% for income between 50 and 75%, and by 25% for income between 75 and 100% of qualified income per Whatcom County income eligibility limit. x Kirkland: Per KMC 15.24.100, citizen disabled or blind per social security criteria or on home dialysis is charged 75% of single family residential rate. x Monroe: Per MMC 13.08.430, qualified disabled person sewer rate is discounted 30 percent x Sedro Woolley: SWMC Chapter 13.30 Sewer Rates does not address disabled assistance. DISCUSSION Pro: 1. Provide greater assistance to less fortunate citizens. Con: 1. Modest reduction in Sewer Revenue. Reduced Elderly/Disabled sewer rate will decrease sewer utility revenue. The estimated annual value of the Elderly/Disabled discount totals approximately $65,938 or about 0.6% of total revenues. RECOMMENDATION Only disabled persons that are also low-income should be considered for utility rate discounts. Current policy is effective. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-5 POLICY OPTION 12.3.2A – SDC WAIVER OR DISCOUNT STATEMENT Should the City establish a policy that encourages or subsidizes sewer connections for properties with On- Site Sewage (OSS) systems but with reasonable access to the municipal wastewater treatment system? In other words, should the City temporarily waive or discount system development charges for connecting into the system? CURRENT CITY OF PUYALLUP POLICY Current City policy requires payment in full of all connection charges before permit to connect to the sewer is issued. System Development Charges (SDCs) are outlined in Puyallup Municipal Code (PMC) 14.10. PMC Item14.08.070 identifies requirements for connections and requires connections for new development or OSS failures within 300 feet of the municipal wastewater treatment system. POLICY FOR CONSIDERATION The City may consider offering a waiver or discount to System Development Charges (SDC). This expands the customer base and provides benefit to local environmental health. The policy process would follow: 1. Propose and receive approval from Council 2. Identify parcels on septic but within 300 feet of sanitary sewer system 3. Provide formal notification for sewer availability, offering a full or partial waiver to the system development charge (SDC). This waiver may also have a “window of opportunity” or after a brief period after which it is no longer offered. POLICIES OF OTHER SIMILAR CITIES Most Cities have a mandatory connection “trigger” when OSS systems fail or new development is proposed within a certain number of feet of the existing sanitary sewer system. The following are examples of City funded assistance for connection charges: Olympia: Olympia implemented a policy in February 2014 to encourage septic conversion for those properties on septic and within reasonable distance to the public sewer system. These properties received formal notification of sewer availability and were offered a waiver to the City’s Wastewater General Facility Charge. The offer was set to expire after 2-years following formal notification. DISCUSSION Pro: 1. Adds customers to the sewer utility to strengthen finances. 2. Improves environmental health by removing septic system discharge(s). 3. Property financed will gain value and property tax roll will be increased. Con: 1. “One-time” offer not given to all sewer customers at time of connection. Question on whether or not it is fair for new customers to receive waiver for former cost impacts. 2. City will incur upfront costs. RECOMMENDATION Adoption and implementation of a discount or total waiver of the System Development Charge is likely to be viewed as an unfair practice that would stir oppositional and argumentative feelings. For those reasons it is not recommended that a waiver or discount be adopted. However, in the interest of promoting conversion of septic systems, the City may want to investigate an option of a long-term incentive/loan program with low interest which would allow property owners to connect to the system and repaid through their utility bill. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-6 POLICY OPTION 12.3.3A – INFLOW AND INFILTRATION CIP STATEMENT Should the City establish a capital improvement program that takes a more pro-active approach to eliminating or reducing Inflow and Infiltration? In other words, should sewer projects be implemented to target overall inflow and infiltration in the system rather than react to necessary capacity increases? CURRENT CITY OF PUYALLUP POLICY No current City policy on taking pro-active approach to I/I reduction. POLICY FOR CONSIDERATION As part of the Comprehensive Sewer Plan Update, the City compared costs for a pro-active I/I CIP to a more typical CIP which increases capacity in the system as it becomes necessary. Due in large part to the future capacity at the WWTP the pro-active I/I removal approach is generally NOT cost effective. From a monetary perspective, it is considered more cost effective to make an increase in capacity as necessary to meet future development. However, the City’s design standards for new construction should be re-evaluated and improved to minimize future I/I from entering the system. POLICIES OF OTHER SIMILAR CITIES Many other Cities have CIPs with Cured-In-Place-Piping (CIPP) projects, aimed at reducing I/I. DISCUSSION Pro: 1. If the program is cost-effective, the City could avoid costly capacity upgrades at the WWTP. Con: 1. If the WWTP has ample capacity, it may be more cost-effective to upgrade or upsize the conveyance pipes and pump stations to meet large flow events. RECOMMENDATION No immediate I/I removal measures are proposed at this time. However, the City should periodically revisit this question of cost effectiveness if new sources of I/I are discovered. The City should also re- evaluate the design standards for new construction. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-7 POLICY OPTION 12.3.3B – RAIN HARVESTING STATEMENT Should the City encourage household rain harvesting by providing subsidies or rebates to properties practice rain harvesting? CURRENT CITY OF PUYALLUP POLICY The term Rain Harvesting for this policy includes rain barrels, rain gardens and permeable pavements. The City has an aggressive LID (Low Impact Development) cost sharing program that encourages rain water harvesting. POLICY FOR CONSIDERATION The City could encourage rain harvesting through a public rebate program. The rebate would be offered to those users who: 1. Demonstrate roof leaders are connected into the sanitary sewer system then: 2. Disconnect the roof leaders and install rain barrels or other rain harvesting techniques to minimize stormwater contribution during large flow events POLICIES OF OTHER SIMILAR CITIES City of Seattle has a similar program which offers rebates for qualifying households. DISCUSSION Pro: 1. Reduces or delays flow contribution during high flow events. Con: 1. Minimal reduction in water revenue due to rainwater re-use for gardening/lawn care. 2. City does not want to create flooding conditions as a result of the program. Overflows from the rain barrels should be directed to the stormwater system. RECOMMENDATION The existing LID cost sharing program should take the results from the recent smoke testing study and focus on the cross connections on private property. Where possible, the disposal of this intercepted stormwater should be directed to rain barrels, rain gardens and to porous pavement. If the Sewer Utility benefits from the interception of the stormwater, there should be a cost sharing structure between the Storm and Sewer Utilities. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-8 POLICY OPTION 12.3.3C – SIDE SEWER CCTV STATEMENT Should the City encourage/require side sewer video inspection upon ownership changes or at the time of building permit applications? CURRENT CITY OF PUYALLUP POLICY No current City policy for side sewer closed-circuit television (CCTV) inspections. POLICY FOR CONSIDERATION The City could require side sewer CCTV inspections when a property changes ownership. The City could either: 1. Offer side sewer CCTV inspections performed by maintenance staff. 2. Require side sewer CCTV inspections are performed or contracted by the seller or building permit holder. POLICIES OF OTHER SIMILAR CITIES / SEWER DISTRICTS Here are some measures that other sewering agencies have taken that address CCTV inspections at the time of title transfer or issuance of a building permit. It should be noted that there are very few policies in Washington, however, there are multiple cities throughout the country that require such inspections: City of Tacoma, WA – As of December 1, 2010, and in accordance with Tacoma Municipal Code, Chapter 12.08.720, the City of Tacoma provides a side sewer educational flyer to building permit applicants and prospective buyers and sellers recommending that the property owner locate and determine the condition of a side sewer before proceeding with the building improvements or title transfer. No inspections required. Clark Regional Wastewater District, WA – no policy requiring CCTV of private side sewers East Bay Municipal Utility District, CA – Their policy and ordinance requires inspection and certification of side sewers. A compliance certificate is needed for property title transfer, remodeling in excess of $100,000 or changing a water meter size. This program is in place for six cities and one district served by East Bay MUD Metropolitan Council Environmental Services, MN – This program is similar to East Bay MUD and also covers six cities. Southwest Suburban Sewer District, WA – no policy requiring CCTV inspections of the side sewer or stub. DISCUSSION Pro: 1. Better knowledge of I/I sources, including root infiltration and illegal cross connections. 2. City is more informed about the sanitary sewer system. Con: 1. Added cost or hurdle to new home transactions. 2. Additional cost for City Staff to track ownership transfers / issuance of building permits. RECOMMENDATION If politically feasible, we recommend this policy is adopted. ---PAGE BREAK--- City of Puyallup Comprehensive Sewer Plan February 2016 12-9 POLICY OPTION 12.3.4A – SUSTAINABLE RATE FORMATION STATEMENT Should the City require rate increases at an agreed upon rate to avoid shortfalls in future revenue? CURRENT CITY OF PUYALLUP POLICY The current City policy links annual adjustments to the sewer rates to the ENR Construction Cost Index. These adjustments keep pace with inflation for O&M costs and routine operational costs, but do not account for the costs associated with the CIP projects identified in Chapter 9. A Sustainable Rate structure needs to account for both inflationary adjustments and CIP projects. POLICY FOR CONSIDERATION The City could restrict council actions which substantially alter rate formation identified in rate studies and sanitary sewer comprehensive plan. This avoids political promises to reduce sewer rates, which significantly hamper the utility’s ability to operate and maintain the sanitary system. This policy makes the most sense as an alternative to not increasing rates for a number of years. If more substantial rate increases are needed, the most practical solution would be to try to phase them in to the degree possible. Phasing increases requires considering rates ahead of “crisis mode,” so that the increases can be put into place before the cash is needed, and actually following through and implementing the phased increases. An approach that could work moving forward would be to adopt multi-year rates based on a strategy of phased rate increases, and revisit them periodically (e.g. annually or every other year) to make sure that the rate strategy still holds. POLICIES OF OTHER SIMILAR CITIES The following cities have implemented a sustainable rate formation structure: x City of Fife has adopted a formula for automated adjustments that consider both the Consumer Price Index and the ENR Construction Cost Index. x City of Walla Walla, WA – similar formulaic structure x City of Vancouver, WA – similar formulaic structure DISCUSSION Pro: 1. City is better positioned to fund the long-term capital improvements necessary to maintain the sanitary sewer system. 2. This policy would provide regular adjustments to the rates without annual re-evaluation. Con: 1. May be undesirable to citizens who want to maintain stagnant or lower sanitary utility rates. 2. If not adopted, the utility could be in a reactionary, emergency mode. RECOMMENDATION This policy is recommended. The sanitary utility should set rate increases in accordance with that identified in Chapter 11. This will help avoid shortfalls and allow the City to properly implement the Capital Improvement Plan (CIP). ---PAGE BREAK--- APPENDICES A. ADS Flow Monitoring and RDII Analysis B. Financial Analysis C. Sanitary Sewer Standards D. SEPA Checklist and Determination of Significance E. Mini Basin Map Book F. Cost Estimates for CIP G. Sewer Service Agreements H. Pre-Treatment Policy I. East Valley Analysis Area J. Agency Review Comments and Responses K. NPDES Permit L. Letter from City Manager Bacon to Edgewood M. Sewage Spill Response Plan N. Smoke Testing Study ---PAGE BREAK--- ---PAGE BREAK--- APPENDIXA ADSFlowMonitoringandRDIIAnalysis ---PAGE BREAK--- ---PAGE BREAK--- CityofPuyallup,WA ADSFlowMonitoring&RDIIAnalysis November17,2011–March19,2012 FinalReportSubmitted May14,2012 ---PAGE BREAK--- 4455South134thPlacexTukwila,WA98168 Phone:[PHONE REDACTED]xFax:[PHONE REDACTED] www.adsenv.com May14,2012 Mr.MarvinCoxP.E. CityofPuyallup 160218thStreetN.W. Puyallup,WA,98371 P2538415499 E[EMAIL REDACTED] Re: CityofPuyallupFlowMonitoringandRainDependentInflow/Infiltration (RDII)Analysis DearMr.Cox, ThankyoufortheopportunitytocompletethisflowmonitoringandRDIIanalysisworkeffort for the City of Puyallup, WA. Please find attached the electronic report of results and conclusionsbasedonthedatacollectedfortheperiodNovember17,2011–March19,2012. Marvin,wecertainlylookforwardtootheropportunitiestoworkwiththeCityonwastewater andwaterprojectsastheyarise.Ifyouhaveanyquestionsregardingthecontentofthisreport, pleasedonothesitatetocallmeat(206)2556904. Sincerely, GillianWoodwardP.E.(WA) SeniorProjectEngineerPacificNorthwest [EMAIL REDACTED] ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 1 TABLEOFCONTENTS 1 BackgroundandSummary 2 1.1 ProjectObjectives 2 1.2 ProjectScopeofWork 2 1.3 ReportLayout 2 1.4 BasinFlowAnalysis 3 1.5 RDIIAnalysis 6 1.6 HydraulicAnalysis 8 1.7 ConclusionsandRecommendations 9 2 ProjectApproach 10 2.1 BasinIdentification 10 2.2 FlowMonitoringEquipment 12 2.3 Installation 12 2.4 RainGaugesandRainfallData 13 3 BasinDryWeatherFlowAnalysis 16 3.1 NetDryWeatherFlows 16 3.2 BaseInfiltration 16 4 WetWeatherFlows&RDIIAnalysis 20 4.1 NetRDIIAnalysis 21 4.2 Qvs.idiagrams 22 4.3 NormalizedRDIIAnalysis 24 5 MonitoringSiteHydraulicAnalysis 31 5.1 d/DRatioEvaluation 31 5.2 DepthversusVelocityScattergraphAnalysis 32 6 ConclusionsandRecommendations 36 6.1 Conclusions 37 6.2 Recommendations 38 APPENDIXAͲ FlowHydrographs,DryDayHydrographs, StormHydrographs,QvsiDiagramsandScattergraphs APPENDIXBͲ SiteReports ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 2 1 BACKGROUNDANDSUMMARY ADS Environmental Services was contracted by the City of Puyallup, WA (City) to perform an evaluationofsewerflowandrainfalldataobtainedduringthe2011/2012wetweatherseasonfor purposes of determining the degree of Rain Dependent Infiltration and Inflow (RDII) in the sanitarysewercollectionsystemcomprisingtheCitysewerservicearea.Theflowdatawasalso evaluatedtodiscernhydraulicperformanceateachoftheflowmonitoringlocationsduringthe studyperiodwhichextendedfromNovember17,2011untilMarch19,2012. 1.1 ProjectObjectives ThemainobjectiveofthisflowdataevaluationwastoidentifywhethertheisolatedsubͲdrainage basins (basins) within the City collection system experience excessive relative wet weather infiltration&infloworRDIIduringrainevents.ThisinformationisintendedtoassisttheCityin moreeffectivelyallocatingresourcestoaddresstheimpactsofRDIIwithinthecollectionsystem. Thereweretwentyfour(24)primarysanitarysewerdrainagebasinsstudied;eachidentifiedas Puyallup_1, Puyallup_02, etc. It is noted that some tables and figures in this report use alternativetruncatednames(e.g.Puy1,Puy2,etc.)toimproveformattingandreadability.Two(2) raingaugeswereinoperationduringthestudyperiodandwereusedtorecordrainfallassociated withthebasinswithintheCitysewersystem. 1.2 ProjectScopeofWork Thescopeofworkforthisstudyincludedthefollowingtasks: x Obtainflowandraindatafromthecollectionsystemareas; x ConductanRDIIanalysisoftherainfallandflowdatausingSli/icer™software; x Evaluate depth of flow and hydraulic performance at each flow monitoring site as applicable(i.e.identifythepresenceofbackwater); x Quantify RDII basin performance and site specific hydraulic performance and make recommendationsforfurtheractionbasedontheflowmonitoringdatacollected. 1.3 ReportLayout Thisreportpresentsthree(3)aspectsofsewerflowhydraulicperformanceinformationforeach oftheevaluatedsewerbasins: x GeneralnetflowinformationforeachsewerbasinincludingnonͲrainperiodestimatesof infiltration(orBaseInfiltrationͲBI); x Wetweatherflowinformationforeachbasinincludingquantificationofnetvolumeand peakflowsduringeachevaluatedstormeventthatwereinexcessofnormaldryperiod flows(i.e.RDII); x Pipe capacity information in terms of highest %full pipe based on evaluating ratios of observedpeakflowdepths(d)tothepipe’sdiameter(D)ord/D. Chapter1ofthisreportpresentsprojectbackgroundinformationandasummaryofthefindings of this study. Chapter 2 outlines the project approach, and the flow monitoring/rainfall proceduresobservedduringthedatacollectionphase.Chapter3presentsnetflowinformation foreachevaluatedbasinduringdryperiods,includingBaseInfiltration(BI)estimates.Chapter4 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 3 presentswetweatherdataandRDIIquantificationandresults.Chapter5presentsinformation regardinghydrauliccapacityofthelinesinwhichtheflowmonitorswereinstalledincludingd/D dataandotherrelatedpipehydraulicperformance(e.g.notablebackwaterconditions).Chapter6 presents summary conclusions and recommendations regarding future investigation and monitoringwork. 1.4 BasinFlowAnalysis TheevaluatedareasoftheCitycollectionsystemweredelineatedintotwentyfour(24)primary sewer shed areas or basins with sizes ranging from 10,679 lineal feet (lf) for basin Puy24 to 73,750lfforbasinPuy3.Figure1.1isanillustrationofthebasinsastheyweredelineatedforthe purposesofthisflowanalysis.Thebasinsareshownwitheachassociatedflowmonitoringsite depictedasadotatthebasineffluentmanhole. Whereabasinreceivedflowfromanupstreambasin,netflowswereobtainedbysubtractingthe gross flow at upstream meter sites from the gross flow at the meter measuring total flows discharged from the basin. For example, basin Puy3 was isolated by subtracting flows from upstreamsite/basinPuy8.BasinPuy14wasisolatedbysubtractingflowsfromupstreamsites Puy7,Puy9andPuy13. Basin Puy20 is the only basin requiring the addition of two flow sites (Puyallup_20Fifth Puyallup_20Meri) to determine gross flow from that basin, then subtraction of flow from upstreamsitePuyallup_10todeterminenetflow.Lessthan1%offlowfrombasinPuy20was measuredatthePuyallup_20Merilocation. Itisimportanttounderstandthattheevaluationofbasinflowscanprovideanindicationofthe general performance of all the sewer mains within the basin. However, follow up field investigationworkwouldbeneededtodeterminewhichisolatedzonesorsewerlinesegments withinthebasinareallowingthemajorityofRDIItoenterthesewersystem. The flow meters and rain gauges were installed and data was collected regularly from these devicesbyADSthroughoutthestudyperiod.ThenetAverageDryDayFlow(ADDF)attributable toeachstudybasinislistedinTable1.1.Sitescomprisinggrossflowfromeachbasinalongwith anyupstreamsitesareshowninTable1.1anddefinehownetflows(andnetassociatedpipe length)weredeterminedforeachbasin. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 4 Table1.1 BasinsSizesandADDF BasinID MH Number Pipe Diameter (in) MeterstoDetermineNet BasinFlow Net BasinArea (Acres) Net BasinPipe (Feet) GrossADDF Weekday (MGD) NetADDF Weekday (MGD) Puy1 5Ͳ037 8 +Puy1 182 25019 0.05 0.05 Puy2 6Ͳ077 10 +Puy2 190 25904 0.07 0.07 Puy3 80Ͳ027 36 +Puy3ͲPuy8 598 73750 0.49 0.34 Puy4 137Ͳ017 14 +Puy4ͲPuy1ͲPuy11 392 43246 0.30 0.10 Puy5 133Ͳ048 12 +Puy5ͲPuy12 234 32399 0.20 0.12 Puy6 84Ͳ005 18 +Puy6 423 20215 0.21 0.21 Puy7 102Ͳ003B 8 +Puy7 179 18057 0.23 0.23 Puy8 109Ͳ039 18 +Puy8 169 29256 0.16 0.16 Puy9 107Ͳ065 11 +Puy9 128 20559 0.13 0.13 Puy10 10Ͳ031 12 +Puy10 341 31048 0.23 0.23 Puy11 5Ͳ022 12 +Puy11ͲPuy2 147 22595 0.15 0.08 Puy12 140Ͳ038 8 +Puy12 181 24355 0.08 0.08 Puy13 108Ͳ008 15 +Puy13 234 27758 0.12 0.12 Puy14 111Ͳ120 24 +Puy14ͲPuy7ͲPuy9ͲPuy13 605 66442 1.03 0.55 Puy15 14Ͳ003 8 +Puy15 190 13609 0.03 0.03 Puy16 16Ͳ044 12 +Puy16 493 25604 0.20 0.20 Puy17 129Ͳ042 15 +Puy17ͲPuy15ͲPuy16 286 29778 0.23 <0.02 Puy18 134Ͳ049 8 +Puy18 174 18164 0.05 0.05 Puy19 129Ͳ034 11 +Puy19ͲPuyallup_20Meri 169 17725 0.18 0.18 Puy20 132Ͳ012 21 +Puyallup_20Fifth+ Puyallup_20MeriͲPuy10 565 56131 0.63 0.40 135Ͳ037 8 Puy21 116Ͳ070 13 +Puy21 242 18824 0.08 0.08 Puy22 116Ͳ024 12 +Puy22 170 26960 0.12 0.12 Puy23 116Ͳ010 8 +Puy23 115 16310 0.06 0.06 Puy24 130Ͳ007 10 +Puy24 162 10679 0.07 0.07 TOTAL 6,569 694,387 3.65 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 5 Figure1.1–PuyallupStudyBasins2011/2012 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 6 1.5 RDIIAnalysis An analysis was performed to quantify the Rain Dependent Inflow and Infiltration (RDII) producedbyeachbasininthestudy.Achartof“normalized”RDIIresultsmeasuredduringthe ten(10)studystormsissummarizedinFigure1.2.Theterm“normalized”meansthattheRDII (thevolumeofflowmeasuredtobeabovethenormalexpecteddryweatherflow)wasdivided byrainfallvolume(inches)andbasinsize(acresandalsofeetofpipe)toenableanapplesͲtoͲ applescomparisonofresultsamongbasins.ThenormalizedRDIIvaluesareintermsofPercent rainfall ingress (Figure 1.2) and also gallons of RDII per foot of pipe per inch of rain (presentedinChapter4). The twelve (12) (out of 24) highest Base Infiltration (BI) producing basins generate approximatelyatotalof1.05MillionGallonsperDay(MGD)ofBIwhichisabout76%ofthe totalsystemwideBIof1.39MGD.ThissystemwideBIaccountsforapproximately38%ofallthe ADDFmonitoredinthisstudy.ThebasinsproducingthehighestBIareconcentratedinthemidͲ sectionofthesystemandcomefrombasinsPuy5,Puy8,Puy9,Puy14,Puy21,Puy22,Puy23and Puy24(refertoFigure3.2).AdditionaldetailsregardingbaseinfiltrationareprovidedinChapter ThebasinsgeneratingthehighestrelativeRDIIarelocatedinthenorthernhalfofthesystem betweentheCrossValleyInterceptorandtheriver(refertoFigure4.5).Mostofthesebasins exhibit high relative normalized RDII as well as BI suggesting that inflow and infiltration pathwaysofRDIIlikelyexist.BasinPuy3exhibitsexcessive%rainingressandahighRDIIpeak factor,whichmayindicatethereisasignificantinflowcomponenttotheRDII. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 7 Figure1.2ͲNormalizedRDII(%RainfallIngress) 0 1 2 3 4 5 6 7 8 9 Rainfall Dependent Inflow/Infiltration NetIIVolumeEvent for Various Storms Volume(% Rainfall) Basin Puyallup_22 Puyallup_08 Puyallup_14 Puyallup_13 Puyallup_05 Puyallup_19 Puyallup_23 Puyallup_03 Puyallup_09 Puyallup_07 Puyallup_24 Puyallup_12 Puyallup_11 Puyallup_17 Puyallup_20 Puyallup_10 Puyallup_04 Puyallup_02 Puyallup_01 Puyallup_18 Puyallup_15 Puyallup_16 Puyallup_21 Puyallup_06 11/22/2011 02:30 am 12/27/2011 06:30 am 01/04/2012 10:00 am 01/20/2012 11:00 am 01/24/2012 08:00 am 01/29/2012 03:00 am 02/17/2012 02:00 pm 03/10/2012 09:30 am 03/12/2012 01:00 pm 03/15/2012 01:30 am ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 8 1.6 HydraulicAnalysis A hydraulic analysis was performed at each flow metering location to evaluate the pipeline hydraulicconditions.Thebasisofthisevaluationwastocomparethetypicalpeakdepthofflow (d)duringthestudytotheDiameter(D)ofthepipeduringnormal(dryday)conditionsversus themaximumhourlydepthversusDiameterobservedduringthestudyperiod. Ratiosofd/Dwerecalculatedateachsiteusing typicalpeakandmaximumpeakconditions. Figure1.3summarizesthed/Dratiosateachsite.d/Dratiosof1ormoreindicatesurcharged pipeflowconditions. Figure1.3ͲPipeFlowDepthPerformanceSummary ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 9 1.7 ConclusionsandRecommendations x Exceptionally high system wide meter data uptimes were achieved (100% raw, 98% finalized)withexcellentdataquality. x Theflowstudysuccessfullycapturedten(10)systemstressingrainevents,oneofwhich canbeconsidereda4Ͳyear,24Ͳhourevent(seeChapter2). x ThebasinsgeneratingthehighestrelativeRDIIarelocatedinthenorthernhalfofthe systembetweentheCrossValleyInterceptorandtheriver(seeFigure4.5).Theseven (7)basinsproducing5%ormorerainfallingressduringanystormincludePuy3,Puy5, Puy8,Puy13,Puy14,Puy22andPuy23.Thesebasinsrepresentabout32%ofthesystem area,yetproducenearly70%ofthetotalRDIIvolumesystemwide. x Selected zones within the tributary area associated with basin Puy3 (includes Puy8) whereinflowtypedefectsarelikelyacontributortoexcessivepeakRDIIflows,Sanitary Sewer Evaluation Surveys (SSES) including smoke testing and manhole inspections shouldbeconductedtoidentifyspecificsourcesofinflow.ThisSSESworkshouldalso include a compilation of any street/ area flooding records, proximity of manholes to streetstormflowlinesandtypesofmanholesinthoseareas(e.g.ventedorotherwise poorlysealedlids),astheseconditionscancreatesignificantinflowresponses. x IsolatedzoneswithinthebasinsidentifiedhereintobeyieldingexcessRDIIvolumesas wellasexcessBaseInfiltration(BI)shouldbeevaluatedusingnighttimeflowisolations andmanhole/lineinspections.ThisincludesbasinsPuy8,Puy14andPuy22.Manhole/ line inspections can be conducted using high resolution pipe cameras or CCTV to observemanholedefectsandlinedefects(preferablyfollowingastormeventsolive leaks can be observed). Any areas with elevated RDII and/or BI in conjunction with knownpipedefectscanthenbeprioritizedforupgradeorrehabilitation. x Install long term (semiͲpermanent) wireless telemetry flow monitoring stations to continue to monitor RDII responses from the collection system during future wet weatherseasons.OneobjectivewouldbetocaptureRDIIresponsesfromkeyzonesof the system during atypically heavy future storms. Candidate locations include flow monitoringlocationsusedforPuy3andPuy14sincethemajorityofsystemRDIIvolume (andnearlyhalfofallsystemBI)wasobservedtooriginatefromtheareaofthesystem tributarytotheseflowmonitoringlocations.Theseflowmonitorscouldbecoupledtoa realtimewebdisplayandalsoserveashighlevelalarmtriggersintheeventofexcessive system backup/surcharge. These monitors would also serve as excellent progress indicatorsoffutureRDIIreductionefforts. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 10 2 PROJECTAPPROACH RainDependentInflowandInfiltration(RDII)isdefinedasrainwaterthatentersasanitarysewer system during or just after a storm event. Inflow is defined as water that directly enters a systemthroughroofleaders,cleanͲouts,foundationdrains,sumppumps,andcellar,yard,and areadrains.Infiltrationisdefinedaswaterthatentersasewersystemfromthegroundthrough defectivepipes(includinglaterals),pipejoints,damagedlateralconnectionsormanholewalls. MostcollectionsystemshavebeendesignedtoconveysomequantityofRDII.Althoughitisnot practicaltoeliminateallRDIIfromenteringasewersystem,removingexcessiveamountsofRDII canpositivelyimpactacollectionsysteminthefollowingways: x Increaseavailablecollectionsystemcapacity; x Reducethepossibilityofsanitaryseweroverflows; x Reducetreatmentandtransportationcosts. The most cost effective means of identifying, quantifying, and prioritizing RDII entering a collection system is through a comprehensive RDII investigation program comprised of the followingmajorcomponents: 1. Collectionsystemreviewandbasinidentification; 2. Simultaneousflowmonitoringandraingauging; 3. Dataanalysisandrankingofbasinsagainstoneanotherbasedonnormalizedunitsoften referredtoasbasinprioritization; 4. SanitarySewerEvaluationSurveys(SSES)includingsmoketesting,manholeinspection, flowisolation,dyewaterflooding,closedcircuittelevision,etc. ADSconductedthefirstthreecomponentsoftheRDIIinvestigationprogram. 2.1 BasinIdentification TheevaluatedareasoftheCitycollectionsystemweredelineatedintotwentyfour(24)primary sewer shed areas or basins with sizes ranging from 10,679 lineal feet (lf) for basin Puy24 to 73,750 lffor basin Puy3. Each basin (and related gross flow monitoring site) is identified as Puyallup_1, Puyallup_02, etc. It is noted that some tables and figures in this report use alternative truncated names Puy1, Puy2, etc.) to improve formatting and readability. Figure1.1isanillustrationofthebasinsastheyweredelineatedforthepurposesofthisflow analysis.Thebasinsareshownwitheachassociatedgrossflowmonitoringsitedepictedasa dotatthebasineffluentmanhole. Whereabasinreceivedflowfromanupstreambasin,netflowswereobtainedbysubtracting thegrossflowatupstreammetersitesfromthegrossflowatthemetermeasuringtotalflows discharged from the basin. For example, basin Puy3 was isolated by subtracting flows from upstreamsite/basinPuy8.BasinPuy14wasisolatedbysubtractingflowsfromupstreamsites Puy7,Puy9andPuy13. Basin 20 is the only basin requiring the addition of two flow sites (Puyallup_20Fifth Puyallup_20Meri) to determine gross flow from that basin, then subtraction of flow from ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 11 upstreamsite/basinPuy10todeterminenetflow.Lessthan1%ofdryweatherflowandless than5%peakwetweatherflowfrombasin20camethroughsitePuyallup_20Meri(resulting fromanupstreamflowsplitatmanhole135Ͳ142thatcouldnotberedirectedduringthestudy). Although a small fraction of basin 20 flow was represented by flow measured at Puyallup_20Meri,itwasimportanttocapturethisflowtoassureaccurateRDIIvolumescouldbe measuredforbasin20. Table 2.1 provides a summary of each site/basin, the respective manhole in which it was installed,andthemetersusedtodeterminenetbasinflowandbasinsize. Table2.1 BasinSizesandAssociatedMeterSites BasinID MH Number Pipe Diameter (in) MeterstoDetermineNet BasinFlow Net BasinArea (Acres) Net BasinPipe (Feet) GrossADDF Weekday (MGD) NetADDF Weekday (MGD) Puy1 5Ͳ037 8 +Puy1 182 25019 0.05 0.05 Puy2 6Ͳ077 10 +Puy2 190 25904 0.07 0.07 Puy3 80Ͳ027 36 +Puy3ͲPuy8 598 73750 0.49 0.34 Puy4 137Ͳ017 14 +Puy4ͲPuy1ͲPuy11 392 43246 0.30 0.10 Puy5 133Ͳ048 12 +Puy5ͲPuy12 234 32399 0.20 0.12 Puy6 84Ͳ005 18 +Puy6 423 20215 0.21 0.21 Puy7 102Ͳ003B 8 +Puy7 179 18057 0.23 0.23 Puy8 109Ͳ039 18 +Puy8 169 29256 0.16 0.16 Puy9 107Ͳ065 11 +Puy9 128 20559 0.13 0.13 Puy10 10Ͳ031 12 +Puy10 341 31048 0.23 0.23 Puy11 5Ͳ022 12 +Puy11ͲPuy2 147 22595 0.15 0.08 Puy12 140Ͳ038 8 Puy12 181 24355 0.08 0.08 Puy13 108Ͳ008 15 Puy13 234 27758 0.12 0.12 Puy14 111Ͳ120 24 +Puy14ͲPuy7ͲPuy9ͲPuy13 605 66442 1.03 0.55 Puy15 14Ͳ003 8 +Puy15 190 13609 0.03 0.03 Puy16 16Ͳ044 12 +Puy16 493 25604 0.20 0.20 Puy17 129Ͳ042 15 +Puy17ͲPuy15ͲPuy16 286 29778 0.23 <0.02 Puy18 134Ͳ049 8 +Puy18 174 18164 0.05 0.05 Puy19 129Ͳ034 11 +Puy19ͲPuyallup_20Meri 169 17725 0.18 0.18 Puy20 132Ͳ012 21 +Puyallup_20Fifth+ Puyallup_20MeriͲPuy10 565 56131 0.63 0.40 135Ͳ037 8 Puy21 116Ͳ070 13 +Puy21 242 18824 0.08 0.08 Puy22 116Ͳ024 12 +Puy22 170 26960 0.12 0.12 Puy23 116Ͳ010 8 +Puy23 115 16310 0.06 0.06 Puy24 130Ͳ007 10 +Puy24 162 10679 0.07 0.07 Total 6,569 694,387 3.65 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 12 2.2 FlowMonitoringEquipment The equipment used for flow monitoring during this study period was ADS model 5000 (FlowShark)openͲchannelflowmonitor.Datawereretrievedorcollectedfromthemonitors, reviewedtwiceweekly,andfinalizedbyADSforuseinthisevaluationinaccordancewithADS’ documented procedures. The flow meters used in this study operated exclusively in Pacific Standard Time they were not reset on March 11 for Pacific Daylight Time). Therefore, comparingtypicaldrydaystoactualflowsduringthelasttwo(2)stormsofthestudyshowsa slightperceptibleoffset(onehour)duringminimumflowhours.Sincethisoffsetdidnotimpact theoverallaccuracyincomputingRDII(asdiscussedinChapter4),ADSchosetoleavethemeter data intact rather than shift the data series in late March to reflect the slight social shift in wastewatergenerationpatterns. 2.3 Installation Typicalopenchannelflowmeterinstallationincludesthefollowingsteps: x Siteinvestigation x InstallationofequipmentandstartͲup x Monitorconfirmationandcalibration AtypicalopenchannelflowmonitorinstallationisshowninFigure2.1. Figure2.1ͲTypicalOpenChannelFlowMeterInstallation ADSFlowMonitor PressureSensor VelocitySensor UltrasonicSensor ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 13 TheinstallationpresentedinFigure2.1istypicaloftheconfigurationusedinshorttermand longtermflowstudiesandiscustomarilyusedoncircularorovalpipesuptoapproximately42Ͳ inchesindiameterorheight.Inthistypeofinstallation,depthandvelocitysensorsaremounted onanexpandableringandinstalledupstreamofthepipe/manholeconnectionintheincoming sewerpipe.Theinstallationintotheincomingpipereducestheaffectsofturbulencecausedby themanhole. 2.4 RainGaugesandRainfallData AnimportantpartofanRDIIstudyisthecollectionandanalysisofrainfalldata(volumeand distribution as applicable). Two tipping bucket type rain gauges (RG01 and RG02) were temporarilysetup;oneattheCity’swastewatertreatmentplantinthevicinityofBuilding5and theotherinthePublicWorksCorporateYardat110039thAvenueSE.Theraingaugesused havearesolutionof0.01inofrain(perbuckettip)andrainaccumulationswereloggedon5 minuteintervalsthroughoutthestudyperiod.Therewereten(10)raineventsthatoccurred thatwereevaluatedduringthestudyperiod.EachoftheraineventsissummarizedinTable2.2 showingrainfallmeasuredateachraingauge.Thedurationshownreflectstheperiodduring whichthepredominantrainfallvolumeoccurredforthatevent(tothenearest6hourinterval). The storm events evaluated comprise up to fourteen (14) inches of the total study period rainfall. Table2.2 EvaluatedStormEventsSummary Storm Date Rainfall(in) Duration (hours) StormType Magnitude, Duration RG01 RG02 1 11/22/2011 3.07 2.85 48 4yr,24hour 2 12/27/2011 2.44 2.18 72 <2yr,24hour 3 1/4/2012 0.75 0.71 24 <2yr,24hour 4 1/20/2012 1.56 1.29 24 <2yr,24hour 5 1/24/2012 0.83 0.89 24 <2yr,24hour 6 1/29/2012 1.35 1.27 24 <2yr,24hour 7 2/17/2012 0.90 0.80 24 <2yr,24hour 8 3/10/2012 0.75 0.99 24 <2yr,24hour 9 3/12/2012 1.15 1.00 24 <2yr,24hour 10 3/15/2012 1.33 1.46 72 <2yr,24hour Arainfallaccumulationchartwasprepared(calledaDDFchart)basedonRG01andisdepicted inFigure2.2.Thischartwasusedtocomparecapturedrainfalltohistoricalrainfallstatisticsfor thearea(thedashedcurvesontheDDFchartarefortheTacomaarea).1Threeselectedstorms are plotted on the DDF chart (11/22/2012, 1/20/2012, and 3/15/2012) to show how they comparetostatisticalrecordsforthearea.Allofthestormscapturedinthisstudyrepresent 1HydraulicsManualM23Ͳ03.03,WashingtonStateDepartmentofTransportation,June2010. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 14 returnfrequenciesoflessthan2year(over24hours).Onlytheearlieststormon11/22/2011 producedahighenoughintensityandvolumeofrainfalltobeclassifiedasa4year,24hour event(basedonRG01). Each basin was assigned rainfall amounts in proportion to the distance each rain gauge was locatedfromtheapproximatecenterofeachbasin.TheInverseͲDistanceSquaredmethodwas usedtoassignweightingfactorsforeachraingaugetoeachbasin.Forexample,abasinthatis onemilefromRG01andtwomilesfromRG02wouldbeassignedarelativerainfallweightingof 1.0and¼(or100and25),respectivelyforrainrecordedatRG01andRG02.Table2.3shows therelativeweightingofrainfallfromeachofthetworaingaugesassignedtoeachofthestudy basins. Table2.3 RainGaugeRelativeWeightingperBasin BasinID RG01 RG02 Puy1 5 69 Puy2 6 159 Puy3 109 9 Puy4 6 22 Puy5 8 28 Puy6 92 6 Puy7 12 12 Puy8 43 12 Puy9 17 22 Puy10 6 917 Puy11 6 57 Puy12 8 59 Puy13 14 18 Puy14 32 16 Puy15 11 30 Puy16 8 75 Puy17 16 33 Puy18 12 49 Puy19 16 34 Puy20 9 114 Puy21 36 12 Puy22 99 10 Puy23 202 8 Puy24 28 18 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 15 Figure2.2–RainfallDepthDurationFrequencyChart 0 1 2 3 4 5 15 20 30 60 [PHONE REDACTED] [PHONE REDACTED] 2880 DDF Graph Rainfall (in) Duration (min) Puyallup_RG01-11/22/2011 2:30:00 AM Puyallup_RG01-1/20/2012 11:00:00 AM Puyallup_RG01-3/12/2012 1:00:00 PM 2-year 5-year 10-year 25-year 50-year 100-year ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 16 3 BASINDRYWEATHERFLOWANALYSIS 3.1 NetDryWeatherFlows Netbasinflowsarethoseassociatedonlywiththebasinasmonitoredbyitsmeterofthesame name.Forexample,forbasinPuy5,netflowswereobtainedbysubtractingflowscominginto theassociatedbasinfromupstreamsitePuyallup_12(RefertoTable2.1).Dryweatherdays weredefinedbasedonthefollowingsetofminimumcriteria: x Norainoccurringwithintheprevious3Ͳdayperiod; x Selected days must exhibit averageͲday flows within 85% Ͳ 115% of the averageͲday flowsofremainingdrydays; x In addition those dry days that exhibited unusual flow patterns were not used to generatenetdrydayflowvaluesforabasin. ThenetAverageDryDayFlow(ADDF)foreachbasinissummarizedinTable3.1. 3.2 BaseInfiltration BaseInfiltration(BI)istheflowthatremainsafterWastewaterProduction(WWP)issubtracted fromAverageDryDayFlow(ADDF)atametersiteasillustratedintheexampleinFigure3.1. WWPistheportionoftotalflowthatisconsideredtobesolelywastewater.LikeWWP,theBI valueisanestimate. 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 0 3 6 9 12 15 18 21 24 Estimated Base Infiltration Minimum Flow Avg Dry Day Flow Total WWP Time (hrs) Daily Dry Flow Figure3.1DryWeatherFlowComponents Equations3.1and3.2maybeusedtoestimateBaseInfiltration(BI): WWP=(ADDFͲMDF)/x BI=ADDFͲWWP Where: WWP =AverageWastewaterProduction(MGD); ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 17 BI =BaseInfiltration(MGD); ADDF =AverageDryDayFlow(MGD); MDF =MinimumDailyFlow(MGD);and =fractionofaveragedailyWWPthatisdomesticsewage. This approach estimates WWP based on the difference between average flow and minimum flow.AsBIvariesovertheyear,thedifferencebetweenaverageandminimumflow(andWWP) isexpectedtoremainconstant.Thismethodofestimatingisareasonablyreliablemeansto estimateBIforresidentialneighborhoodswithtotalsewermainlengthontheorderof20,000lf or less. The reliability of this method decreases as basins contain more mixed use or commercialoperationsand/orhavesignificantlymorethan20,000lfofpipe. Arefinementtothisempiricalmethod,theStevens/Schutzbachequation,usesacurvefitting techniquetoincreasethereliabilityoftheBIestimationatmeterswithhigherflowsandismore tolerant of basins with less stable/ measurable minimum flows. Equation 3.3 is the Stevens/Schutzbach equation and was used to estimate base infiltration in the basins in this study. 0.4*MDF Likeequations3.1and3.2,equation3.3isalsodependentonaverageandminimumflowsthat occurintraditionalresidentialflowpatterns.ReliabilityoftheBIcalculationdecreasesinnonͲ residentialbasinsandinbasinswheretheflowmetermeasuresflowfromcyclingpumpstations for both BI methods. Although there are limitations, Equation 3.3 is considered best for estimating BI using only flow data. Net BI (for a basin) can be determined by subtracting calculated total BI at upstream sites from the calculated total (gross) BI at the meter/basinlocation. Itisimportanttounderstandthatwhenonlyusingflowdata,BIcanonlybeestimatedandthat onlythroughmorerigorousmeansofflowisolations(e.g.assuringthereisnowastewaterflow ateachofthelateralconnectionsinisolatedsmallareasofthesystemandphysicallymeasuring continuedflowduringthepluggingperiod)canactualBIvaluesbedetermined.Becausethe abovemethodsyieldestimates,itisrecommendedthatusersnotexclusivelyrelyonBIorWWP estimatesforsewersystemdesignpurposes. Table3.1liststhevaluesforestimatednet(basin)BIaswellasnetBIasapercentageofADDF. BI is calculated based on weekday flows since there are more weekdays to evaluate in determiningMDFandADDFvalues.Thetwelve(12)highestBIproducingbasins(NetBI%values showninboldtypeinTable3.1)generateapproximately1.05MGDofBIwhichisabout76%of thetotalsystemwideBIof1.39MGD.ThissystemwideBIaccountsforapproximately38%ofall the ADDF monitored in this study. The basins producing the majority of system BI are concentratedinthemidͲsectionofthesystem(basinsPuy5,Puy8,Puy9,Puy14,Puy21,Puy22, Puy23andPuy24ͲseeFigure3.2). ValuesofnetBIforbasinsPuy4andPuy17wereconsideredindeterminatetoanyreasonable ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 18 degreeofconfidenceduetoahighdegreeofupstreamsubtractionofflowscausingthenet minimum(MDF)flowstobepoorlydefined.Therefore,grossvaluesofBIarereportedforthese basins(i.e.basedontotalflowsincludingallupstreambasins). Table3.1 DryDayFlowsandBaseInfiltrationEstimates Basin/ MeterID MH Number Upstream Subtractionsto DetermineNetBasin Flow Net BasinArea (Acres) Gross ADDF Weekday (MGD) GrossBI (MGD) NetADDF Weekday (MGD) NetBI (MGD) NetBI (%ADDF) Puy1 5Ͳ037 182 0.05 0.02 0.05 0.02 32% Puy2 6Ͳ077 190 0.07 0.02 0.07 0.02 21% Puy3 80Ͳ027 ͲPuy8 598 0.49 0.17 0.34 0.10 30% Puy4 137Ͳ017 ͲPuy1ͲPuy11 392 0.30 0.03 0.10 <0.01 *11% Puy5 133Ͳ048 ͲPuy12 234 0.20 0.08 0.12 0.06 53% Puy6 84Ͳ005 423 0.21 0.03 0.21 0.03 12% Puy7 102Ͳ003B 179 0.23 0.09 0.23 0.09 40% Puy8 109Ͳ039 169 0.16 0.07 0.16 0.07 46% Puy9 107Ͳ065 128 0.13 0.06 0.13 0.06 47% Puy10 10Ͳ031 341 0.23 0.08 0.23 0.08 35% Puy11 5Ͳ022 ͲPuy2 147 0.15 0.02 0.08 0.01 11% Puy12 140Ͳ038 181 0.08 0.02 0.08 0.02 20% Puy13 108Ͳ008 234 0.12 0.05 0.12 0.05 43% Puy14 111Ͳ120 ͲPuy7ͲPuy9ͲPuy13 605 1.03 0.48 0.55 0.27 50% Puy15 14Ͳ003 190 0.03 0.01 0.03 0.01 27% Puy16 16Ͳ044 493 0.20 0.06 0.20 0.06 28% Puy17 129Ͳ042 ͲPuy15ͲPuy16 286 0.23 0.05 <0.02 <0.01 *22% Puy18 134Ͳ049 174 0.05 0.02 0.05 0.02 35% Puy19 129Ͳ034 ͲPuyallup_20Meri 169 0.18 0.08 0.18 0.08 44% Puy20 132Ͳ012 ͲPuy10 565 0.63 0.25 0.40 0.17 42% 135Ͳ037 Puy21 116Ͳ070 242 0.08 0.05 0.08 0.05 60% Puy22 116Ͳ024 170 0.12 0.07 0.12 0.07 57% Puy23 116Ͳ010 115 0.06 0.03 0.06 0.03 49% Puy24 130Ͳ007 162 0.07 0.04 0.07 0.04 61% Total 6,569 3.65 1.39 38% *Ͳindicatesvalueisbasedongrossflowfromthebasinduetopoorlydefinednetminimumflow. ---PAGE BREAK--- Puy3 Puy20 Puy6 Puy14 Puy4 Puy16 Puy10 Puy8 Puy7 Puy5 Puy17 Puy1 Puy13 Puy2 Puy12 Puy21 Puy9 Puy15 Puy22 Puy18 Puy11 Puy19 Puy23 Puy24 9 8 7 5 4 6 3 2 1 24 23 22 21 20 20 19 18 17 16 15 14 13 12 11 10 0 3,900 7,800 1,950 Feet 4 Legend RG_Locations Sewer_Meters Sewer_Basins_BI NetBIPct 10 - 25 25 - 35 35 - 45 45 - 61 Figure 3.2 - Basin Base Infiltration Performance Color Rank Based on BI as a Percent of ADDF ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 20 4 WETWEATHERFLOWS&RDIIANALYSIS AnanalysiswasperformedtodeterminethequantityofRainDependentInflowandInfiltration (RDII)producedbyeachbasininthestudy.Theanalysisinvolvedsubtractingeachbasin’snet AverageDryDayFlow(ADDF)fromitsnetWetWeatherFlow(WWF)takingintoconsideration weekday or weekend flows and accounting for infiltration immediately prior to a storm. CompensationforanypreͲstormelevatedflowsistermed“precompensation”.Theprocessof breakingdownthehydraulicimpactonabasinassociatedwithrainfallistermeddecomposition. ThedecompositionhydrographforbasinPuy3duringtheNovember22,2011stormeventis depictedinFigure4.1. Figure4.1ͲBasinPuy3DecompositionHydrograph ThehydrographinFigure4.1showsthatbasinPuy3producedameasurablegrossRDIIresponse (shownas“GrossI/Iinthefigure).ThegrossRDIIincludesallupstreamflows(includingthose fromPuy8).ThenetRDII(shownas“NetI/I”inthefigure)depictsRDIIflowsattributedonlyto basinPuy3bysubtractingupstreamflowsfromPuy8. InFigure4.1,thegrayhighlightedtimeperiodpriortothestormperiodistheperiodduring whichprecompensationisdetermined.Thelightpurpleperiodisthestormperiod.Thetwo darkerpurpleperiodsfollowingthestormperiodaretherecoveryperiodsR1andR2.Theentire periodincludingstormandrecoveryperiodsiscalledtheeventperiod.Theentireeventperiod ofeachstormisusedexclusivelyforevaluationofRDIIinthisstudy.Eachoftheseperiodsisset at 24 hours in duration unless they are extended or reduced due to factors including longer stormperiod,shortdurationtosubsequentstorms,andshortdurationfrompreviousstorms (reducedprecompensationperiod). ADS notes that some practitioners attempt to assign RDII responses during early periods of 0.299 in/hr 06:20 Storm Event - 11/22/2011 2:30:00 AM Puyallup_03 Rainfall (in) Flow (MGD) Storms Date 21 Mon Nov 2011 22 Tue 23 Wed 24 Thu 25 Fri 26 Sat 27 Sun 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.0 0.5 1.0 1.5 2.0 2.5 0 1 Rainfall Gross Q Gross I/I Net I/I Precomp(-) Weekdays Weekends ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 21 stormsorevenassignpeakRDIIratesobservedexclusivelytotheinflowcomponentofRDII. However,ADShasobservedthatthiscanbeanerroneousassumption.Peakflowresponsesare oftenobservedaftermuchoftherainhasfallen.Furthermore,inflowsourcescanbedelayed (e.g.cloggedareadrainsthataredirectlyconnectedtothesewer)andinfiltrationsourcescan often materialize as very fast responses to rainfall flooded sewer trenches that quickly drainintothesewerpipe).Therefore,ADStreatsinfiltrationandinflowasRDIIthatcanbe characterizedasfastorslowresponding.Theactualsourcescanrequireextensiveadditional effort to uncover. The RDII hydrographs for each basin during the evaluated wet weather eventsareincludedinAppendixA. 4.1 NetRDIIAnalysis NetRDIIorrawvolumeofRDIIinmillionsofgallons(MG)fromeachbasinwasdeterminedand summarizedinTable4.1forthreesignificantstormeventperiodsrepresentingthebeginning, middleandendofthestudy.ThenetRDIIvolumesinmillionsofgallonsforeachbasinforeach storm event period (storm period plus recovery periods) are summarized in the table. In addition,thenetRDIIpeaksobservedfromeachbasin(peakrateinMGD)duringeachstorm event are summarized in the table. It is noted that the total of all peaks in the table is for informational purposes only* and will be higher than the total peak that would have been observedatanyonelocationinthesystemduetovaryingtimeoftravelandattenuationof peaksacrosstheentiresystem. Table4.1 SummaryofNetRDIIvolume(MG)andpeak(MGD)perStormEvent Basin 11/22/2011 1/20/2012 3/15/2012 RDII (MG) RDIIPeak (MGD) RDII (MG) RDIIPeak (MGD) RDII (MG) RDIIPeak (MGD) Puy1 0.09 0.39 0.09 0.09 0.07 0.11 Puy2 0.10 0.10 0.17 0.16 0.09 0.09 Puy3 1.12 1.45 1.54 1.12 0.56 0.82 Puy4 0.21 0.29 0.24 0.37 0.08 0.24 Puy5 0.53 0.32 0.55 0.43 0.20 0.14 Puy6 0.02 0.20 0.17 0.39 0.01 0.17 Puy7 0.24 0.19 0.25 0.44 0.08 0.13 Puy8 0.55 0.87 0.50 0.67 0.31 0.44 Puy9 0.18 0.12 0.23 0.16 0.13 0.10 Puy10 0.28 0.16 0.38 0.21 0.19 0.14 Puy11 0.15 0.18 0.21 0.18 0.05 0.12 Puy12 0.19 0.14 0.16 0.17 0.09 0.10 Puy13 0.62 0.33 0.67 0.40 0.36 0.18 Puy14 1.73 1.41 1.07 1.62 0.98 0.65 Puy15 0.06 0.07 0.08 0.08 0.04 0.07 Puy16 0.12 0.20 0.15 0.20 0.09 0.16 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 22 Basin 11/22/2011 1/20/2012 3/15/2012 RDII (MG) RDIIPeak (MGD) RDII (MG) RDIIPeak (MGD) RDII (MG) RDIIPeak (MGD) Puy17 0.30 0.32 0.23 0.26 0.08 0.20 Puy18 0.09 0.08 0.10 0.12 0.03 0.05 Puy19 0.38 0.35 0.24 0.22 0.23 0.17 Puy20 0.58 0.38 0.35 0.31 0.08 0.19 Puy21 0.06 0.08 0.06 0.06 0.06 0.06 Puy22 0.78 0.72 0.24 0.40 0.34 0.28 Puy23 0.26 0.20 0.24 0.18 0.18 0.14 Puy24 0.21 0.36 0.20 0.32 0.11 0.14 Total* 8.86 8.88 8.11 8.53 4.43 4.86 4.2 Qvs.idiagrams Thereisarelationshipbetweenrainfallvolume(in.)duringastormeventandnetRDIIvolume (MG)ineachbasin.ThiscorrelationbetweennetRDIIineachbasintorainfallcanbedepicted graphicallyandistermedaQvs.idiagram.TheQvsidiagramcanbedepictedtorepresent rainfallonlyduringthestormperiod(onlythelightpurplebandedperiodshowninFigure4.1)or forrainfallovertheentirestormevent(stormplusthetworecoveryperiods–typicallycovering atleast72hours).SincethelargerRDIIresponsesinthestudybasinsextendwellpastthestorm period,theentireeventperiodwasevaluated.TheQvs.idiagramforexcessvolumeresponse overtheentireeventperiodisdepictedinFigure4.2aforbasinPuy3. Figure4.2aͲQvs.iDiagramforBasinPuy3 (11/22/2011) (12/27/2011) (1/4/2012) (1/20/2012) (1/24/2012) (1/29/2012) (2/17/2012) (3/10/2012) (3/12/2012) (3/15/2012) 0.0 0.5 1.0 1.5 2.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Q vs i - Puyallup_03 Total Event Net RDII Volume vs. Rainfall Depth Total Event Net RDII Volume (mg) Total Event Rainfall Depth (in) AllStorms ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 23 Insomecases,therelationshipbetweenexcessRDIIvolumeandrainfallappearstobeloosely defined.However,inthecaseofbasinPuy3andseveralothersduringthisstudy,theprimary outlierdatapointisfromthestormeventofJanuary20,2012.Thisresponsevariabilitycan sometimes be explained by antecedent soil moisture conditions whether the rain event occurredshortlyafterapreviouseventoroccurredlaterinthewetseason).Inthecaseofthe January20,2012eventresponse,itisunderstoodthatthiseventoccurredafterseveraldaysof priorsnowfallaccumulationthroughoutmostoftheservicearea.FieldnotesfromCitystaff indicate between 8 and 10 inches of snow fell throughout the service area from January 16 through January 19, 2012. In the early morning hours of January 19, the light snowfall was mixedwithfreezingrain.TheimmediatesubsequentrainfallonJanuary20and21(about1.5 inches)wouldhavemeltedthesnowandcausedrunoffvolumesinthevariousbasins;reflecting amuchlargereffectiverainfallvolumeforthatstormevent(causingthehighresponseoutlier). These volumeͲbased Q vs. i data points above describe the relation between net event RDII volumeandrainfallandserveasanindicationoftheperformanceofthebasinregardingrainfall ingress(orRͲvalue)asdiscussedinSection4.3. ADSalsoevaluatednetpeakRDIIrates(inmgd)vs.rainfallintensitytodetermineifthisrate basedQvsirelationshipindicatesareasonablecorrelation,thereforesuggestingthepresence ofafastͲresponsecomponentofRDII(sometimesattributedtoinflow).BasinPuy3exhibiteda goodcorrelationasshownintherateͲbasedQvsidiagraminFigure4.2b.Thissuggeststhereis acomponentofRDIIthatisadirectpathway(inflow)forrainfalltoenterthesepartsofthe system.ThecomponentofRDIIthatisdirectlyresponsivetorainfallisvisuallyevidentinthe hydrograph shown in Figure 4.1 for basin Puy3. Although to a lesser extent, basins Puy8 (immediately upstream of Puy3), Puy22 and Puy23 showed moderately sharp RDII response componentsaswell. Figure4.2b–PeakQvs.iDiagramforBasinPuy3 (11/22/2011) (12/27/2011) (1/4/2012) (1/20/2012) (1/24/2012) (1/29/2012) (2/17/2012) (3/10/2012) (3/12/2012) (3/15/2012) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Q vs i - Puyallup_03 Peak Net I/I vs. Rolling Peak Rainfall Intensity Peak Net I/I (MGD) Rolling Peak Rainfall Intensity (in/hr) AllStorms ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 24 Q vs. i diagrams can be a useful tool for determining degree of success of RDII elimination efforts. Volume and rateͲbased Q vs. i diagrams for storm event periods are included in AppendixA. 4.3 NormalizedRDIIAnalysisͲ%RainfallIngress ToenableacomparisonofRDIIbetweenbasinsofdifferingsizes,thenetRDIIvolumesforeach basinwere“normalized”.ThismeansthatthevolumeofRDIIwasdividedbyrainfall(inches) andbybasinsize(inacresorlinealfeet(lf)ofpipe)toenableanapplesͲtoͲapplescomparisonof resultsamongbasins.ThenormalizedRDIIvalueisinunitsof%rainfallingress(orRͲvalue)or gallonsperfootofpipeperinchofraindependingontheuseofbasinsizeunitsofacresorlf, respectively.AsummaryofthenormalizednetRDIIintermsof%rainfallingressineachbasin duringeachstormeventisprovidedinFigure4.3(sortedfromworsttobestintermsofevent 11/22/2011performance).AsortedsummaryofnormalizednetRDIIinunitsofgallonsperfoot ofpipeperinchrainisprovidedinFigure4.4.Acolormapdepictingacategorizedviewofbasin RDIIperformance(intermsofmaximumobserved%rainfallingress)isdepictedasFigure4.5. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 25 Figure4.3ͲNormalizedRDII(%RainfallIngress) 0 1 2 3 4 5 6 7 8 9 Rainfall Dependent Inflow/Infiltration NetIIVolumeEvent for Various Storms Volume(% Rainfall) Basin Puyallup_22 Puyallup_08 Puyallup_14 Puyallup_13 Puyallup_05 Puyallup_19 Puyallup_23 Puyallup_03 Puyallup_09 Puyallup_07 Puyallup_24 Puyallup_12 Puyallup_11 Puyallup_17 Puyallup_20 Puyallup_10 Puyallup_04 Puyallup_02 Puyallup_01 Puyallup_18 Puyallup_15 Puyallup_16 Puyallup_21 Puyallup_06 11/22/2011 02:30 am 12/27/2011 06:30 am 01/04/2012 10:00 am 01/20/2012 11:00 am 01/24/2012 08:00 am 01/29/2012 03:00 am 02/17/2012 02:00 pm 03/10/2012 09:30 am 03/12/2012 01:00 pm 03/15/2012 01:30 am ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 26 Figure4.4ͲNormalizedRDII(Gal/ft/inrain) 0 2 4 6 8 10 12 14 16 18 Rainfall Dependent Inflow/Infiltration NetIIVolumeEvent for Various Storms Volume(Gal/ft/in-Rain) Basin Puyallup_22 Puyallup_14 Puyallup_13 Puyallup_19 Puyallup_24 Puyallup_08 Puyallup_05 Puyallup_23 Puyallup_03 Puyallup_07 Puyallup_20 Puyallup_17 Puyallup_10 Puyallup_09 Puyallup_12 Puyallup_11 Puyallup_04 Puyallup_16 Puyallup_18 Puyallup_15 Puyallup_02 Puyallup_01 Puyallup_21 Puyallup_06 11/22/2011 02:30 am 12/27/2011 06:30 am 01/04/2012 10:00 am 01/20/2012 11:00 am 01/24/2012 08:00 am 01/29/2012 03:00 am 02/17/2012 02:00 pm 03/10/2012 09:30 am 03/12/2012 01:00 pm 03/15/2012 01:30 am ---PAGE BREAK--- Puy3 Puy20 Puy6 Puy14 Puy4 Puy16 Puy10 Puy8 Puy7 Puy5 Puy17 Puy1 Puy13 Puy2 Puy12 Puy21 Puy9 Puy15 Puy22 Puy18 Puy11 Puy19 Puy23 Puy24 9 8 7 5 4 6 3 2 1 24 23 22 21 20 20 19 18 17 16 15 14 13 12 11 10 0 3,900 7,800 1,950 Feet 4 Legend RG_Locations Sewer_Meters Sewer_Basins_RValue RDIIRval 0.0 - 1.9 2.0 - 4.9 5.0 - 7.9 8.0 - 10.0 Figure 4.5 - Basin RDII Performance Color Rank Based on RDII as Max Percent Rainfall Ingress ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 28 Baseduponpublishedsewerrehabilitationresultsfrom99basinsworldwide2,sanitarysewer basinsaregenerallyconsideredtobeperformingadequatelyifconsistentlylessthan5%ofthe rainfallentersthesewerduringheavyrainevents.Basinscapturingbetween2%and5%rainfall ingress may warrant further investigation depending upon Agency specific economic or costͲ benefitanalyses.Forsystemsexhibitingprimarilyinflowresponses(i.e.shortlivedpeakexcess flowfollowingtherainfallclosely),valuesofrainfallcaptureaslowas1%cancreatesystemflow spikescausingcapacityissues;particularlyduringstormscontainingintenseperiodsofrainfall. Numericvaluesofpercentrainfallingresscanbeequateddirectlytonumericunitsofgallonsper footofpipeperinchofrain(gal/ft/inͲrainasalsonormalizedherein)inbasinswithtypicalratios of about 250lf of sewer pipe per developed acre. Also, a wastewater generation rate of 5 gallons per foot of pipe is considered a reasonable average for a typical medium density residentialarea.Therefore,excesswetweatherflow(RDII)thataddsmorethan5gal/ft/inrain to the system suggests the value, is a reasonable performance benchmark to use when evaluatingusingthesenormalizedmetrics. Sortingforbasinsproducing5%ormorerainfallingressduringanystormyieldsseven(7)basins. Theseseven(7)basinsincludePuy3,Puy5,Puy8,Puy13,Puy14,Puy22andPuy23.Thesebasins represent about 32% of the system area, yet produce nearly 70% of the total RDII volume systemwide. Thetopten(10)(worst)performingbasinsconsistentlyexhibitednormalizedRDIIinexcessof5 gal/ft/inrain;mostofwhichexceeded8gal/ft/inrainduringmorethanonestudystorm.From theperspectiveofthisnormalizationmetric,thetopten(10)basinsmaybeconsideredtobe generatingexcessiveRDII.Sortingforbasinsproducing10gal/ft/inrainorgreaterRDIIyields seven(7)basins;six(6)ofwhicharethesameastheabovelistofseven(7)basinsexceptthat Puy24replacesPuy23onthelist.Thesetopseven(7)basins(Puy3,Puy5,Puy8,Puy13,Puy14, Puy22andPuy24)representabout33%ofthesystemarea,andalsoproducenearly70%ofthe totalRDIIvolumesystemwide. Averysimilarlistoftopten(worst)performingbasinsisgeneratedbyusingthesorted%rainfall ingress and the gal/ft/in rain metrics. The largest difference among basins using the two normalizationmetricsisbasinPuy24whichgoesfrom11thhighestusing%rainfallingressto5th highestusingunitsgal/ft/inrain.Thislikelyindicatesthatasmallereffectivetributarylandarea isattributabletothisbasin(andlikelyseveralotherbasinsinthestudyarea)duetothelower valuesof%rainfallingresscomputedcomparedtogal/ft/inrainvalues.Thissuggeststhatmuch oftheareasofthesebasinsarenaturallydrainedorotherwisecollectedawayfromdeveloped areascontainingactivesanitarysewers.Thisisnotsurprisinggiventhemostlylowdensityrural natureofdevelopmentthroughoutmostofthesystem. 4.4 NormalizedRDIIAnalysis–NetRDIIPeakFactor AnotherbasinperformanceparameterevaluatedwasstormperiodnetRDIIflowpeakfactor. ThisisdefinedasthenetRDIIpeakrateplusnormalaveragedrydayflow(ADDF)dividedby ADDF.ThisevaluationcanbeusefulincircumstanceswhereRDIIvolumemayberelativelylow, 2Keefe,P.N.“TestBasinsforI/IReductionandSSOElimination”,1998,WEFWetWeatherSpecialty Conference,Cleveland,Ohio. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 29 butexcessiveshortͲtermpeaksofRDIIflowratesareevidentduringstormevents.Thisallows analternateprioritizationthatmayhighlightbasinsresponsibleforcreatingshortͲtermcapacity accountforrainfall(i.e.parameterisnotdividedbyrainfallamount).However,sincerainfall wasrelativelyuniformacrossthebasinsduringthestudy,thisaddscredencetotheRDIIpeak factorevaluationofrelativeperformancebetweenbasins.RDIIpeakfactorsthatare4(i.e.4 timeshigherthanatypicaldrydayof1)orgreatermaywarrantinvestigationforinflowdefects. RDIIpeakfactorsobservedduringthestudyperiodforeachbasinarelistedinFigure4.6sorted fromhighesttolowest.Thereareeight(8)basinsexhibitingRDIIpeakfactorsof4orgreater. These correlate generally well with those basins yielding the highest normalized RDII as discussedintheprevioussectionofthisreport.Specifically,basinsPuy3,Puy8,Puy13,Puy14, Puy22,Puy23andPuy24produceexcessiveRDIIpeakfactorsaswellasrainͲnormalizedRDII valuesdiscussedpreviously. Figure4.6–SortedMaximumRDIIPeakFactor Table4.2presentsasummaryofmaximumobservedvaluesofrainͲnormalizedRDII(as%rain ingressorRͲvalue),baseinfiltrationandRDIIpeakfactor.Valuesineachoftheseperformance categorieshavebeenboldͲhighlightedinthetablewhereconsideredexcessive.Generally,there appears to be a good correlation between these performance parameters among those highlighted. Basins Puy8, Puy13, Puy14, Puy22 and Puy23 exhibit excessive values in all categories suggesting that inflow and infiltration pathways of RDII likely exist. Basin Puy3 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 30 exhibits excessive rain ingress and a high RDII peak factor, which may indicate there is a significantinflowcomponentoftheRDIIpresent.Conversely,basinPuy5exhibitshighBIwitha longrecoverytimeafterraineventssuggestinginfiltrationistheprimarypathwayforRDIIinthis basin. ItisnotedthatthehighRDIIpeakfactorforPuy1occurredonNov28,manyhoursaftertherain during the immediately preceding storm event had ceased. The direct cause of this peak is unknown, but worthy of investigation given the high peak factor. The RDII peak factor associatedwithPuy17isbasedontotalgrossflowsincethereisverylittlenetflowremainingfor thisbasinaftersubtractingtheflowfromthetwoupstreambasinsPuy15andPuy16.Additional reviewofflowdatafromthese3meteringlocationsrevealednoreasontoalteroradjustthe dataforadditionalbias. Table4.2 SummaryofRDIIandBIPerformance Meter(Basin) MaxNetRͲvalue (%Rain) NetBase Infiltration (%ADDF) MaximumNetRDII PeakFactor Puy1 1.4 32% 9.1 Puy2 2.5 21% 3.2 Puy3 6.2 30% 5.3 Puy4 1.7 11% 4.8 Puy5 6.4 53% 3.1 Puy6 1.0 12% 2.8 Puy7 3.6 40% 2.9 Puy8 7.2 46% 6.5 Puy9 4.8 47% 2.2 Puy10 3.2 35% 1.9 Puy11 3.9 11% 3.3 Puy12 2.4 20% 3.2 Puy13 7.4 43% 4.9 Puy14 5.2 50% 4.0 Puy15 1.1 27% 3.4 Puy16 0.9 28% 2.0 Puy17 2.2 22% 2.9 Puy18 1.5 35% 3.6 Puy19 3.8 44% 3.0 Puy20 1.7 42% 2.0 Puy21 0.8 60% 2.0 Puy22 8.7 57% 6.9 Puy23 4.9 49% 4.6 Puy24 3.2 61% 6.1 ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 31 5 MONITORINGSITEHYDRAULICANALYSIS AhydraulicanalysiswasperformedateachflowͲmonitoringsiteusinggrossflowstoevaluate thepipelinehydraulicconditionsatthesite.Thebasisofthisevaluationwastocomparethe ratio of depthͲofͲflow to the diameter of the pipe throughout the study period and evaluate the pipes’ dynamic hydraulic performance based on depth velocity scattergraph analyses. 5.1 d/DRatioEvaluation Typically, sanitary sewers are conservatively designed to operate at no more than threeͲ quartersfullatpeakflow.3Pipes15inchesindiameterandsmallerareoftendesignedtoflow halffullorless.Whenad/Dratioexceeds1.0,thepipeisrunningfull(orisinsurcharge)and Figure5.1depictsachartoftypicaldrydayhourlypeakd/Dvs.maxhourlyd/Dvaluesrecorded duringthestudyperiod. Figure5.1–PeakFlowDepth(d)vs.PipeDiameter(D)Chart Thesignificantsurchargedconditions(peakhourlydepthof92inches)observedinthemanhole inwhichflowmonitoringwasconductedforbasinPuy6occurredduringdryweatherconditions 3GravitySanitarySewerDesignandConstruction,2ndEd.WEFManualofPracticeFDͲ5,2007. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 32 onFebruary4,2012between10:00amand3:30pm.Thiswaslikelytheresultofscheduled pumpstationmaintenance,butthisshouldbeverifiedbyCitystaff.Noneoftheothersites monitoredexperiencedsurchargedconditionsduringthestudy. 5.2 DepthversusVelocityScattergraphAnalysis The flow data for each basin monitor was reviewed for indications of possible hydraulically anomalousbehaviorcausedbyflowrestrictions.Thisincludedareviewofscattergraphplotsof velocityversusdepthdatapointsthatareinstructiveinidentifyinghydraulicanomaliessuchas Figure5.2–FlowDepthvs.VelocityScattergraphforSitePuy3 ThescattergraphforsitePuy3isdepictedasFigure5.2.Inthisdataplot,theredcurve(orpipe curve)depictsthepipe’stheoreticalflowdepthvs.velocityrelationshipinidealopenchannel flowconditionsbasedontheManningequationfittedtotheactualdatapointscollectedfrom themeter(shownastheLanfearͲCollorLCcurveinthefigure).TheLCcurveusesaHydraulic Coefficient(CͲLC)inplaceofpipeslopeandroughnesstermsintheManningequation.TheCͲLC term is then derived based on actual depth and velocity data points. The series of curves extendingtotherighthandyͲaxisindicatelinesofconstantflowrateorIsoͲQlines. InFigure5.2,thepipecurveindicatesthatthepipewouldtheoreticallyoperateatavelocity rangingfromabout0tojustover4ft/sfromemptytofullͲpipeataflowrateof0 toabout 18MGDoverthesamespanofflowdepths.Themeterdataplotindicatesflowinthispipetends tofollowthetheoreticalpipeperformancecurveandisthereforepresumedtobeinfreeflow conditions during most of the study no appreciable bottlenecks creating backwater 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 5 10 15 20 25 30 35 0.5 2 4 6 8 10 12 14 16 18 Scatter Graph Puyallup_03 VFINAL (ft/s) Iso Q (MGD) DFINAL (in) Lanfear-Coll (C-LC = 3.27) ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 33 conditions). Inbackwaterconditions,thedatawillgenerallyfollowparallelornearlyparalleltotheIsoͲQ™ lines (rather than continue to follow the pipe performance curve). This site shows signs of backwaterduringmostofthestudystormeventsduringwhichthisdepthvsvelocitypattern shiftedinthismanner.Thisisindicatedbythealternategroupingsofbluedatapoints(mostof which occur above 6in depth and follow the 1MGD IsoͲQ curve) to the right of the primary grouping along the pipe curve. This is indicative of a bottleneck (or flow restriction) theseevents,thuscausingstorageofwastewaterinthesystempipingproximatetotheplant. Table 5.1 includes a summary of pipe hydraulic performance based on d/D analysis and an examination of each site’s scattergraph. The scattergraphs for each of the basin monitoring sitesforthestudyperiodareincludedinAppendixA. The project recorded exceptionally high raw and finalized data uptime as listed in Table FinalizeddataarethedatathathavebeenQAQC’sandanyerroneousdataflaggedasinvalid. ThefinalizeddataareusedtoconducttheRDIIanalysis. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 34 Table5.1 HydraulicPerformanceSummary SiteID Pipe Diameter (in) Typical PeakDepth 1 (in) Maxhourly PeakDepth (in) Typicald/D 2 Maxhourly d/D2 PeakDepth3 Date/Time HydraulicComments basedonscattergraphandhydrographreview Puyallup_01 8 1.8 3.3 0.23 0.41 11/28/118:00AM Peakdepthduringpeakflowperiodofabout2hoursfrom7:00 to9:00amonNovember28,2011. Puyallup_02 10 1.9 2.3 0.19 0.23 1/21/1211:00AM Puyallup_03 36 5.5 12.7 0.15 0.35 11/22/114:00PM Backwaterduringstormeventsatdepthsabove6",duringwhich timeflowisrestrictedtoapproximately1to1.4MGD. Puyallup_04 14 3.0 3.6 0.21 0.26 1/21/1210:00AM Puyallup_05 12 5.0 8.5 0.42 0.71 1/21/126:00PM Puyallup_06 18 3.8 92.0 0.21 5.11 2/4/122:00PM Peakdepthaccompaniedbysignificantbackwater from10:00 amuntilabout3:30pmonFebruary4,2012.Likelyresulting fromapumpstationoperationalissue. Puyallup_07 8 4.5 5.0 0.56 0.63 3/29/124:00PM Puyallup_08 18 3.7 7.2 0.21 0.40 11/22/117:00AM Puyallup_09 11 3.6 4.6 0.33 0.42 1/22/1212:00PM Puyallup_10 12 5.5 6.7 0.46 0.56 3/19/1210:00AM Puyallup_11 12 3.7 4.6 0.31 0.38 1/21/1211:00AM Shiftingdepthvsvelocitypatternindicatesthepresenceofan inconsistenthydraulicjump.Dataqualityisgoodhowever. Puyallup_12 8 3.7 4.6 0.46 0.58 1/21/121:00PM Puyallup_13 15 3.0 5.7 0.20 0.38 1/30/1212:00AM Puyallup_14 24 11.5 21.3 0.48 0.89 1/21/121:00PM Puyallup_15 8 2.8 3.2 0.35 0.40 1/21/1211:00AM Puyallup_16 12 3.3 5.1 0.28 0.43 1/31/121:00PM Peakoccurredinbackwaterconditionsduringlast2daysof Puyallup_17 15 4.5 5.9 0.30 0.39 1/20/121:00PM ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 35 SiteID Pipe Diameter (in) Typical PeakDepth 1 (in) Maxhourly PeakDepth (in) Typicald/D 2 Maxhourly d/D2 PeakDepth3 Date/Time HydraulicComments basedonscattergraphandhydrographreview Puyallup_18 8 2.6 3.1 0.33 0.39 1/21/128:00PM Puyallup_19 11 4.5 6.6 0.41 0.60 11/22/112:00PM Puyallup_20Fifth 21 2.3 2.8 0.11 0.13 1/21/1212:00PM Puyallup_20Meri 8 0.5 1.0 0.06 0.13 1/21/123:00AM Puyallup_21 13 7.0 7.8 0.54 0.60 11/22/115:00PM Veryslowflowwithdepthalwaysgreaterthan5"(evenatzero invertatahigherelevationthentheincomingpipeinvert. Puyallup_22 12 3.7 8.7 0.31 0.73 11/22/113:00PM Backwaterwhendepthexceeds8"(duringNovember22,2011 stormevent). Puyallup_23 8 3.2 4.9 0.40 0.61 3/17/129:00AM Puyallup_24 10 2.4 3.7 0.24 0.37 11/22/114:00PM Notes: 1)Typicalpeakhourlydepthdatadeterminedfromapparentvaliddataduringdaysnotvisuallyaffectedbyrain. 2)Boldhighlightedvaluesintypicald/Dcolumnare>or=0.8.BoldhighlightedvaluesinMaxd/Dcolumnare>or=1.0 3)BoldhighlightedvaluesinPeakDepthDate/Timecolumnarethoseeventsoccurringduringrainevent. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 36 Table SitebySiteandSystemDatauptime RawUptime FinalUptime NotesforSites<=95%Uptime Puyallup_01\mp1\QFINAL 100% 82% Velocitydroppedoutto0ft/sfrequentlyatthis siteduetotheshallowdepthsandslowflow. Puyallup_02\mp1\QFINAL 100% 100% Puyallup_03\mp1\QFINAL 100% 100% Puyallup_04\mp1\QFINAL 100% 100% Puyallup_05\mp1\QFINAL 100% 100% Puyallup_06\mp1\QFINAL 100% 100% Puyallup_07\mp1\QFINAL 100% 100% Puyallup_09\mp1\QFINAL 100% 100% Puyallup_10\mp1\QFINAL 100% 100% Puyallup_11\mp1\QFINAL 100% 100% Puyallup_12\mp1\QFINAL 100% 100% Puyallup_13\mp1\QFINAL 100% 100% Puyallup_14\mp1\QFINAL 100% 100% Puyallup_15\mp1\QFINAL 100% 98% Puyallup_16\mp1\QFINAL 100% 100% Puyallup_17\mp1\QFINAL 100% 100% Puyallup_18\mp1\QFINAL 100% 89% Debrisonequipmentfrom1/28/2012Ͳ 2/9/2012. Puyallup_19\mp1\QFINAL 100% 100% Puyallup_20Fifth\mp1\QFINAL 100% 100% Puyallup_20Meri\mp1\QFINAL 100% 100% Thissitewaspredominantlydryandassucha numberof0ft/sreadingswereregistered. Thesewereflaggedinthedatasethoweverthe valueswerelikelyeither0orverycloseto0ft/s. Puyallup_21\mp1\QFINAL 100% 95% EquipmentjettedanddislodgedJanuary10Ͳ13, 2012.Invalidvelocitydropsto0ft/sthroughout period. Puyallup_22\mp1\QFINAL 100% 100% Puyallup_23\mp1\QFINAL 100% 97% Puyallup_24\mp1\QFINAL 100% 100% SystemAverage 100% 98% ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 37 6 CONCLUSIONSANDRECOMMENDATIONS 6.1 Conclusions Exceptionallyhighsystemwidemeterdatauptimeswereachieved(100%raw,98%finalized) withexcellentdataquality.Theflowstudysuccessfullycapturedten(10)systemstressingrain events,oneofwhichcanbeconsidereda4Ͳyear,24Ͳhourevent. ThebasinsgeneratingthehighestrelativeRDIIarelocatedinthenorthernhalfofthesystem between the Cross Valley Interceptor and the river (see Figure The seven basins producing5%ormorerainfallingressduringanystormincludePuy3,Puy5,Puy8,Puy13,Puy14, Puy22andPuy23.Thesebasinsrepresentabout32%ofthesystemarea,yetproducenearly 70%ofthetotalRDIIvolumesystemwide. The largest of the seven highest RDII producing basins, Puy3, indicates sharply defined RDII peakscorrespondingtotheperiodsofheaviestrainfall.ThisresultsinanexcellentpeakRDII rate vs. rainfall intensity relationship; all suggesting there is a significant fastͲresponse component to the RDII here indicating a probable high inflow component to the RDII. This phenomenon is also evident from neighboring basins Puy8, Puy22 and Puy23. Basin Puy5 exhibitshighrelativeRDII,butwithalessperceptibledirectconnectiontorainfallintensityanda longrecoverytimeafterraineventssuggestinginfiltrationistheprimarypathwayforRDIIinthis basin. The twelve (of 24 total) highest BI producing basins generate about 1.05MGD of BI which is about 76% of the total system wide BI of 1.39MGD. This system wide BI accounts for approximately38%ofalltheADDFmonitoredinthisstudy.ThebasinsproducingthehighestBI areconcentratedinthemidͲsectionofthesystemfrombasinsPuy5,Puy8,Puy9,Puy14,Puy21, Puy22,Puy23andPuy24(seeFigure3.2). Significantsurchargedconditionswereobservedinthemanholeinwhichflowmonitoringwas conductedforbasinPuy6.Thisoccurredonlyononeoccasionduringdryweatherconditionson February4,2012between10:00amand3:30pm.Thiswaslikelytheresultofscheduledpump station maintenance, but this should be verified by City staff. None of the other sites monitoredexperiencedsurchargedconditionsduringthestudy. ---PAGE BREAK--- CityofPuyallup,WA CollectionSystemInfiltration&InflowStudy2012 38 6.2 Recommendations Basedontheresultsofthisstudy,ADSrecommendsthefollowing: x For the tributary area associated with basin Puy3 (includes Puy8) where inflow type defectsarelikelyacontributortoexcessivepeakRDIIflows,SanitarySewerEvaluation Surveys(SSES)includingsmoketestingandmanholeinspectionsshouldbeconductedto identifyspecificsourcesofinflow.Thiscouldinitiallybelimitedtoisolatedzoneswithin thisbasinwherefieldcrewshavereasontobelievesuchdefectsaremostlikelypresent. ThisSSESworkshouldalsoincludeacompilationofanystreet/areafloodingrecords, proximityofmanholestostreetstormflowlinesandtypesofmanholesinthoseareas (e.g.ventedorotherwisepoorlysealedlids),astheseconditionscancreatesignificant inflowresponses. x IsolatedzoneswithinthebasinsidentifiedhereintobeyieldingexcessRDIIvolumesas well as excess Base Infiltration (BI) should be evaluated using flow isolations and manhole/lineinspections.ThisincludesbasinsPuy8,Puy14andPuy22.Flowisolations areconductedatnight(i.e.2:00amto5:00am)usingquickinsertweirsinisolated1,000 to2,000lfsectionsofidentifiedbasinstoconfirmandquantifycoldclear(infiltration) flows.Manhole/lineinspectionscanbeconductedtopsideusinghighresolutionpipe camerastoobservemanholedefectsandlinedefectswithinaboutten(10)diameters RDII and/or BI in conjunction with known pipe defects can then be prioritized for upgrade or rehabilitation. It is best to conduct such inspections shortly following significant seasonal storm events to increase the probability of observation and verificationoflivegroundwaterinfiltration. x Install long term (semiͲpermanent) wireless telemetry flow monitoring stations to continue to monitor RDII responses from the collection system during future wet weatherseasons.OneobjectivewouldbetocaptureRDIIresponsesfromkeyzonesof thesystemduringatypicallyheavyfuturestormstodetermineifsuchRDIIresponses become worse than would be expected based on extrapolating such responses from storm data and RDII responses studied herein. Candidate locations include flow monitoringlocationsusedforPuy3andPuy14sincethemajorityofsystemRDIIvolume (andnearlyhalfofallsystemBI)wasobservedtooriginatefromtheareaofthesystem tributary to these flow metering locations study basins Puy3, Puy7, Puy8, Puy9, Puy13andPuy14).Theseflowmonitorscouldbecoupledtoarealtimewebdisplayand also serve as a high level alarm triggers in the event of excessive system backup/surcharge.Thesemonitorswouldalsoserveasexcellentprogressindicatorsof futureRDIIreductionefforts.