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HomeMy WebLinkAboutResolution No. 4793 Pd~SOLUTION NO. 4793 A RESOLUTION ADOPTING THE 2004 MWMC FACILITIES PLAN AND 20-YEAR PROJECT LIST FOR THE EUGENE-SPRINGFIELD REGIONAL WASTEWATER TREATMENT FACILITIES. The City Council of the City of Eugene finds as follows: The 2004 MWMC Facilities Plan and 20-Year Project List for the Eugene-Springfield Regional Wastewater Treatment Facilities attached as Exhibit A is needed in order to identify facility enhancements and expansions that are needed to serve the community's wastewater needs and to implement solutions to ad&ess a full range of regional wastewater needs through 2025. NOW, THEREFORE, based upon the above findings, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF EUGENE, a Municipal Corporation of the State of Oregon, as follows: Section 1. The 2004 MWMC Facilities Plan and 20-Year Project List for the Eugene- Springfield Regional Wastewater Treatment Facilities attached as Exhibit A is adopted. Section 2. This Resolution shall become effective immediately upon its adoption. The foregoing Resolution adopted the 28th day of June, 2004. /s/Mary H. Feldman City Recorder Resolution DRAFT f~r the Eugene-Springfield Regional Wastewater Treatment Facilities Metropolitan Wastewater Managernen~ Commission DRAFT for the Eugene-Springfield Regional Wastewater Treatment Facilities Aprilt 2004 Metropolitan Wastewater Management Commission partners in wastewater management C~"~HILL Contents Section Page Executive Summary ............................................................................................................... ES-1 1.0 Introduction, Pmrpose and Need ...................................................................................... 1-1 1.1 IntroductSon ......................................................................................................... 1-1 1.2 Intergovernmental Agreements ........................................................................ 1-1 1.3 Background .......................................................................................................... 1-2 1.4 Previous Planning Efforts .................................................................................. 1-4 1.5 Industry ................................................................................................................ 1-5 1.6 Project Needs ....................................................................................................... 1-6 1.7 Project Goals and Objectives ............................................................................. 1-9 1.8 Public Outreach ................................................................................................. 1-10 1.9 Facilities Plan Organization and Content ...................................................... 2.0 Study Area Characteristics ................................................................................................ 2-1 2.1 Study Area ............................................................................................................ 2-1 2.2 Physical Environment ......................................................................................... 2-1 2.3 Socioeconom/c Env/ronment ........................................................................... 2-29 2.4 Land Use and Zoning ....................................................................................... 2-33 3.0 Existing Wastewater Facilities .......................................................................................... 3-1 3.1 Wastewater Conveyance System ...................................................................... 3-1 3.2 Wastewater Treatment Facility ......................................................................... 3-6 4.0 Wastewater Characteristics ............................................................................................... 4-1 4.1 Wastewater Flow CharacteristScs ...................................................................... 4-1 4.2 Wastewater Loading Characterist/cs ................................................................ 4-7 4.3 Selected Design Factors .................................................................................... 4-10 4.4 Projected Wastewater Flow and Load Characteristics ................................. 4-12 5.0 Basis of Planning ................................................................................................................. 5-1 5.1 Basis for Design ................................................................................................... 5-1 5.2 Basis for Cost Estimate ..................................................................................... 5-22 5.3 Water Qhaality Impact ....................................................................................... 5-23 5.4 Desigrt Capacity of Conveyance System and Wastewater Treatment Plant ........................................................................... 5-26 6.0 Development and Evaluation of Alternatives ............................................................... 6.1 Conveyance System Alternatives ...................................................................... 6-3 6.2 Wastewater Treatment Plant Liquid Stream Treatment Altemakives ......... 6-6 6.3 Disinfection Alternatives .................................................................................. 6-22 ~WMC_CONTENTS_REV5 DOC lit CONTENTS, CONTINUED 6.4 Effluen~ DisposaI Alternatives ........................................................................ 6-26 6.5 Biosolids Management ..................................................................................... 6-31 6.6 Development and Evaluation of System Alternatives ................................ 6-51 7.0 Recommended Plan ............................................................................................................ 7-1 7.1 Recommended Collection and Conveyance System Improvements ........... 7-1 7.2 Recommended Liquids Process Improvements ............................................. 7-2 7.3 Recommended Effluent Disposal and Biosolids Improvements ................. 7-7 7.4 Recommended System Improvements ............................................................ 7-9 7.5 Summary of Recommended Improvements ................................................. 7-10 7.6 Identification o£ Project Phasing ..................................................................... 7-13 7.7 Implementation ScheduIe ................................................................................ 7-13 8,0 Financial Strategy ............................................................................................................... 8-1 8,1 Introduction ........................................................................................................... 8-1 8.2 Current Financial Stab_~s and Policies ................................................................ 8-1 8.3 Future Costs and Revenues ................................................................................. 8-5 8.4 Evaluation of Local Funding Resources ............................................................ 8-7 8.5 Evaluation of Federal and State Funding Resources ....................................... 8-7 8,6 Recommended Fh~ancing Strategy .................................................................... 8-7 9,0 Environmental Report ....................................................................................................... 9-1 9.1 Intzoducfion ......................................................................................................... 9-1 9.2 Purpose and Need .............................................................................................. 94 9.3 System Attez~adve 1-No Action .................................................................... 9-5 9.4 System Alternative 5 - MWMC Preferred Alternative: Parallel Primary/Secondary Treatment ......................................................................... 9-8 9.5 System Alternative 4 - High-Rate Clarification ........................................... 9-19 10,0 References ........................................................................................................................ 10-1 Tables 1.8-2 Public Meeting Summm~ 2.2.1-2 Average Weather in Eugene, Oregon 2.2.1-2 Normal climate around Eugene, Oregon 2.2.3-2 I-{Lstorical Seismic Events That Have Occurred Within 60 tv~les of the MWMC Service ,Area 2.2.3-2 Modified NIercalti Scale 2.2.5-1 Energy Consumption During Fiscal Years 1994-2003 iV MWMC_CONTENTS_REV5 DOC CONTENTS, CONTINUED 2.2.7-1 Percent Vegetated Areas, Developed Areas, and Gravel Bars within 100 Feet of the Upper Willamette River (River Reaches 15-21), Eugene, Oregon 2.2.7-2 Species Classified as Endangered, Threatened, Sensitive, or Species of Concern Found in Wetland and/or Riparian Areas in the Greater Eugene Metropolitan Area 2.2.8-1 Estimated Emi._ssions from the WPCF 2.3.1-1 Oregon Total Non-Farm Employment and Personal Income Growth 2.3.2-1 Historical Population Data for the Eugene/Springfield Service Area, 1990-2002 2.3.3-1 Population Projection Data for Eugene/Springfield Metropolitan Area 3.1.3-1 Original Major Conveyance Pump Stations 3.1.3-2 Conveyance Pump Station Upgrades 3.1.4-1 West Eugene Pump Stations 3.2.1-1 Original Plant Construction Facilities 3.2.1-2 Plant Upgrades and Additional Facilities 3.2.2-1 WPCF Pretreatment Facilities Unit Processes and Equipment 3.2.2-2 WPCF Primary Clarification Unit Processes and Equipment 3.2.2-3 WPCF Secondary Treatment Unit Processes and Equipment 3.2.2-4 WPCF Disinfection Facility Equipment 3.2,2-5 WPCF Waste Activated Sludge Thickening Unit Processes and Equipment 3.2.2-6 WPCF Anaerobic Digestion Unit Processes and Equipment 3.2.2-7 Biosolids Dewatering Unit Processes and Equipment 3.2.2-8 WPCF Biosolids Dewatering Unit Processes and Equipment 3.2.4-1 Existing Liquids Unit Process Performance, Limiting Factors, and Deficiencies 3.2.4-2 Existing Solids Unit Process Performance, Limiting Factors, and Deficiencies 4.1.2-1 Historical Dry Weather Flow Statistics 4.1.2-2 Historical Wet Weather Flow Statistics 4.1.3-1 DEQ Methodology Flow Peaking Factors 4.2.2-1 Historical Dry Weather BOD Loading Statistics 4.2.2-2 Historical Wet Weather BOD Loading Statistics 4.2.2-3 Historical Dry Weather TSS Loading Statistics 4.2.2-4 Historical Wet Weather TSS Loading Statistics 4.3.1-1 Selected Flow'Per Capitas and Peaking Factors 4.3.2-1 Selected BOD Loading Per Capitas and Peaking Factors 4.3.2-2 Selected TSS Loading Per Capitas and Peaking Factors 4.4~1 Summary of Total Flow Projections (Residential, Commercial, and Industrial) 4.4-2 Summary of Total Load Projections (Residential, Commercial, and Industrial) 5.1.1-1 Existing NPDES Discharge Requirements and Limitations for the WPCF 5.1.4-1 Sampling Requirements for EPA 40 CFR, Part 503, Sludge Regulations 5.1.4-2 New Federal Regulation (40 CFR, Part 503) for Heavy Metals 5.1.4-3 DEQ Site Criteria for Biosolids Application 5.1.5-1 Treatment and Monitoring Requirements for Use of Reclaimed Water 5.1.5-2 General Treatment and Monitoring Requirements for Use of Reclaimed Water 5.1.6-1 Rehability Class I Requirements 5.1.6-2 Sludge Handling System Reliability MWMC_CONTENTS_REV5 DOC V CONTENT~, CONTINUED 5.4.2-1 Summary of Total Flow Projections for 2025 (Residential, Commercial, and Industrial) 5.4.2-2 Liquids Unit Process, Existing and 2025 Design Capacity 5.4.3-1 Summary of Total Load Projections for 2025 (Residential, Commercial, Industrial) 5.4.3-2 Biosolids Unit Process, Existing and 2025 Design Capacity 5.4.4-1 Seasonal Land Application 2025 Design Criteria 6.0-1 Project Matrix of Unit Process Alternatives 6.0-2 Example of Non-Monetary Evaluation 6.1.2-1 MWMC Wastewater Collection System Wet Weather Flow Management Plan (WWFMP) Selected Alternative 6.2.1-1 Design Criteria: Step-Feed Amoxic Selector Process 6o2.1-2 Facility Requirements for Alternative 1 at 2025 6.2.1-3 Design Criteria: Traditional Plug-Flow Aeration Basins 6.2.1-4 Facility Requirements for Alternative 2 at 2025 6.2.1-5 Comparison of Facility Requirements, Cost, and Non-monetary Evaluation 6.2.2-1 Summary of Secondary Clarifier Baffling and Mechanism Improvements - Alternatives Comparison 6.2.3-1 Summary of Primary Clarffier Enhancement Alternatives Comparison 6.2.4-1 Summary of Pretreatment Expansion Alternatives Comparison 6.2.5-1 Exhaust Flow Rates by Area 6.2.5-2 Design Removal Efficiencies 6.2.5-3 Summary of Odor Control Alternatives Comparison 6.3-1 Guidelines for Chlorine Disinfection Design 6.3-2 Design Criteria for LtV Disinfection 6.3-3 Summary of Disinfection Alternatives Order-of-Magnitude and Capital Cost Comparison 6.3-4 Summary of Disinfection Alternatives Present Value and Non-monetary Cost Comparison 6.5.2-1 Comparison of Digestion Treatment Processes 6.5.2-2 Digestion Alternatives Cost Comparison 6.5.4-1 Biocycte Farm Management Unit Acreage and Planting Schedule 6.5.4-2 Biocycle Farm Alternative I Capacity (dry tons) 6.5.4-3 Biocycle Farm Alternative I Cost Estimate 6.5.4-4 Biocycle Farm Alternative 2 Capacity (dry tons) 6.5.4-5 Biocycle Farm Alternative 2 Cost Estimate 6.5.5-1 Alternatives Cost Benefit Comparison 6.6.3-1 Summary of Peak Flow Management Alternatives Comparison 7.1.2-1 Recommended Conveyance System Improvements 7.1.2-2 Wastewater Conveyance System Design Criteria-Existing and 2025 Capacity Needs 7.2.1-1 Liquid Process Design Criteria, Existhng and 2025 Capacity Needs 7.3.1-1 Seasonal Land Application Desig~ Criteria - Existing and 2025 Capacity Needs 7.3.2-1 Solids Processes Design Criteria - Existkng and 2025 Capacity Needs 7.5-1 Summary of Recommended Improvements through Year 2025 7.7-1 Project Phasing Estimated Cost Summary MWMC_CONTENT$_REV5 DOC CONTENTS, GONTINUED 7.7-2 Recommended Project Phasing Plan with Capital Cost Estimates 8.2.1 MWMC Projected Personnel, Materials and Service Costs For Study Period 8.3.4-1 MWMC Sewer User Rate Data 8.3.4-2 Projected SDC Revenue for FY 2004 - 2005 8.6.1-2 Improvement Fee Allocation of Proiects to Facility Process Components and Project Type 8.6.1-2 Summary of 20-Year Project List Allocations for Improvement Fee 9.4.1-1 Parallel FrLmary and Secondary Treatment Flow Strategy 9.4.2-1 Comparison of WPCF NPDES Permit Conditions With Predicted Conditions Under System Alternative 5 (Parallel Primary/Secondary Treatment) 9.4.8-1 Specffications of Vehicles and Equipment Used During Typical Froject Construction Activities 9.5.2-1 Comparison of WPCF NPDES Permit Conditions With Predicted Conditions Under System Alternative 4 (High-Rate Clarification) Figures ES-3 Alternative 5 Project Phasing Diagram 2.1-1 City Map 2.1-2 MWMC Service Area Map 2.1-3 Facility Map 2.2.2-1 Soils of the MWMC Serv4ce Area 2,2.2-2 Soils in the Vicinity of the Biocycle Farm, Seasonal Industrial Waste S~te and Biosolids Management Facility 2.2.2-3 Soils in the Vicinity of the Eugene-Spr~gfield Water PoLlution Control Fadl~ty 2.2.3-1 Geology of the MWMC Service Area 2.2.3-2 Relative Earthquake Hazard Map of the Eugene-Springfield Metropolitan Area 2.2.7-1 Dominant Vegetation Along Rivers 2.2.7-2 Land Cover Map for the Eugene-Springfield Area 2.2.7-3 Wetlands Map for the Eugene-Springfield Area 2.2.9-1 Zoning Map of the Eugene-Springfield Area 2.3.2-1 Historical Population for MWMC Service Area 2.3.3-1 Population Projection Summary 2.4.2-1 Zoning Map of the Eugene-Springfield Metropolitan Area 2.4.2-2 Zoning Map of the Facility Area 3.1.4-1 IvlWMC Major Pump Stations 3.Z1-1 Existing FacEdties 4.1.1-1 Average and Maximum Monthly Dry Weather Flow 4.1.1-2 Average and Maximum Monthly Wet Weather Flow 4.2.1-1 Dry Weather Maximum Month Loads 4.2.1-2 Wet Weather Maximum Month Loads 5.1,3~1 Dry Weather Maximum Month Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows 5.1.3-2 Wet Weather Maximum Month Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows MWMC_CONTENT$_REV5 DOC 'Vii CONTENrS, CONTINUED 5.1.3-3 Dry Weather Maximum Week Effluent Concentration Reqrdrements Based on Ex~sting Mass Load Lhxdtations and Projected Flows 5.1.3-4 Wet Weather Maximum Week Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows 5.1.3-5 Dry Season Peak Week Excess Thermal Load Based on Existing Thermal Load Limitations and Projected Flows 6.1.2-1 Selected Alternative Elements 6.1.2-2 MWMC Wet Weather Flow Management Plan (WWFMP) 10-Year Implementation Schedule 6.2.1-1 WPCF Anox~c, Step-Feed Plug-Flow Process 6.2.6-1 CBOD and T~S Operating Performance 6.2.6-2 Filtration Required at Worst Case Maximum Month Wet Weather Flow 6.5.2-1 Digester Phasing 6.5.3-1 Facultafive Sludge Lagoon Phasing 6.5.3-2 Facultative Sludge Lagoon Solids Inventory 6.6.2-1 Process Flow Schematic for System Alternattve 3- Additional l~mary CIarffiers 6.6.2-2 Process Flow Schematic for System Alternative 4- HRC 6.6.2~3 Process Flow Diagram for System Alternative 5-ParalleI Primary and Secondary Treatment 6.6.3-1 Site Layout of System Alternative 2 Additional Primary and Secondary Clarifiers, Aeration Basin 6.6.3-2 Site Layout of System Alternative 3 Additional Primary Clarifiers 6.6.3-3 Site Layout of System Alternative 4 High-Rate Clarification 6.6.3-4 Site Layout of System Alternative 5 Parallel Primary and Secondary C-larifiers 6.6.4-1 Cost and Weekly TSS Loading 6.6.4-2 Cost and Weekly CBOD5 Loading 7.2.1-1 Recommended Aeration Basin Modifications to Step-Feed, Plug-Flow Activated Sludge with Selectors 7.2.2-1 Secondary Clarifier Enhancements 7.2.3-1 Recommended Primary Clarifier Enhancements 7.2.6-1 Proposed Effluent Stream Disinfection Operation 7.4.1-1 Recommended Process Flow Diagram for Peek Flow Management - Parallel Primary and Secondary Treatment 7.4.1-2 Site Layout of Recommended System Solution Parallel Primary/Secondary Treatment 7.4.2-1 General 2025 Liquids Process Flow Diagram and Liquids Balance 7.4.2-2 General 2025 Solids Balance 7.7-1 Alternative 5 Project Phasing Diagram 7.7-2 Alternative 4 Project Phasing Diagram 9.4.1-1 Proposed Layout for System Alternative 1-Parallel Primary and Secondary Treatment 9.5.1-1 Proposed Layout for System Alternative 2--High-Rate Clarification VI)t MWMC_CONTENT$_REVS, DOC Acronyms and Abbreviations 7Q10 seven-day, ten-year low flow AFD adjustable frequency drive AWT advanced wastewater treatment BFF belt filter press BMF Biosolids Management Facility BMP best management practices BOD biochemical oxygen demand BOD5 5-day biochemical oxygen demand BTU/hr British thermal units per hour CAC C~tizens Advisory Committee CBOD carbonaceous biochemical oxygen demand CBOD5 5-day carbonaceous biochemical oxygen demand CCI Construction Cost Index CFR Code of Federal Regulations c£s cubic feet per second CIP capital improvement project CO carbon monoxide CSZ Cascadia Subduction Zone DEQ Oregon Department of Environmental QuaLity DO dissolved oxygen DOGAMI Department of Geology and Mineral Industries [Oregon] DSL Oregon Division of State Lands DSMM dry season maximum month EBI East Bank Interceptor EDI energy-dismpating inlet ELA engineering, legal, and administrative ENR Engineering News-Record ESA Endangered Species Act EPA U.S. Environmental Protection Agency EQC Environmental Quality Commission ERU equivalent residential mt F Fahrenhei~ FEMA Federal Emergency Management Agency FRP fiberglass reinforced plastic FSL facultative sludge lagoon FTE bail-Nme equivalent frS/minute cubic feet per minute MWMC_CONTENTS_REV5 DOC Iii ABBREVIATIONS, CONTINUED ACRONYMS AND fpm £eet per minute GBT gravity belt thickener g/day grams per day GFOA Government Finance Officers Association GIS geographic information system gpcpd gallons per capita per day gpd gallons per day gpm gallons per minute GVW gross vehicular weight HAP hazardous air pollutant hp horsepower HR high-rate clarification ~&C instrumentation and control IDI infilco Degremont, inc. IGA intergovernmental agreement I&I infi_ltration and inflow 1-5 interstate 5 lb/ttr/m pounds per hour per meter LRAPA Lane Regional Air Pollution Authority NIECT Metropolitan Endangered Species Act Coordinating Team gg microgram ~g/L micrograms per liter ~tg/m3 micrograms per cubic meter MG million gallon rog/kg milligrams per kilogram rog/L milligrams per liter mgd million gallons per day mL milliliter mm millimeter MM Modified Mercalli MPN Mean Probable Number MU management unit MWMC Metropolitan Wastewater Management Commission N/A not applicable N/D not detected NGVD National Geodetic Vertical Datum NO2 nitrogen oxide NPDES National Pollutant Discharge Elimination System NTU nephelometric turbidity unit NWl National Wetlands Inventory IV MWMC_CONTENT$_REV5 DOC ACRONYMS AND ABBREVIATIONS, CONTINUED O2 oxide C)s ozone OAR Oregon Administrative Rule ODOT-ADU Oregon Department o£ Transportation - Accident Data Unit OEA Office of Economic Analysis [Oregon] O&M operations and maintenance OSHA Occupational Safety and Health Adrni~stration PDAF peak day average flow PE primary effluent PFRP process to further reduce pathogens PGA peak ground acceleration PHA process hazards analysis PM~0 particulate matter less than 10 micrometers in aerodynamic diameter POTW publicly owned treatment works ppcd pounds per capita per day ppd pounds per day ppm parts per million PP/ST parallel primary/secondary treatment PSM Process Safety Management [OSHA] PSRP process to significantly reduce pathogens PTE potential to emit PWWF peak wet weather flow RAS return activated sludge RDII rainfall-dependent infiltration and inflow RM river mile RMP Pdsk Management Program RMZ regulatory mixing zone RS raw sewage RSR rapid sludge removal RWP Regional Wastewater Program RWM reclaimed water main scfm standard cubic feet per minute SDC System development charge SE secondary effluent SIU significant industrial user SIWF Seasonal Industrial Waste Facility SOx sulfur dioxide SOR surface overflow rate SPCC spkll prevention, control, and countermeasures SRF State Revolving Loan Fund SRT solids retention time SSES Sewer System Evaluation Study SSO sardtary sewer overflow MWMC_CONTENTS_REV5 DOC V ACRONYMS AN D A~R£VI~TION~, CONT,NU~D TMDL total maximum daily load TPAD temperature-phased digestion ~y torts per year TSS total suspended solids UGB urban ~rrowth boundary USACE U.S. Army Corps of Engineers U.S.C. U.S. Code USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Survey UV ultraviolet VAR vector attraction reduction VSS volatile suspended solids WAS waste activated sludge WBI West Bank Interceptor WPCF Eugene-Springfield Wastewater Pollution Control Facility WSTP Westside Sewage Treatment Plant WWFMP Wet Weather Flow Management Plan WWTP wastewater treatment plant ZID zone of immediate dilution VI MWMC_CONTENTS_I~EV5 DOC Executive Summary This Facilities Plan, prepared for the Metropolitan Wastewater Management CommJssion (MWMC), is the result of a comprehensive evaluation of the regional wastewater treatment facilities serving the Eugene-Spr/ngfield metropol/tan area [Eugene-Springfield Water Pollution Control Facility (WPCF), major pump s~tions and interceptors, the Biosolids Management Facility (BMF), the Biocycle Farm, and the Seasonal Industrial Waste Facility (S1WF)]. This Facilities Plan is a comprehensive update to ~he crr~ginal "208 Plan," which was completed in 1977. The 208 Plan established the original pre~ect/ons, requirements, and projects needed to serve the Eugene-Springfield community through 2005. This Facilities Plan also builds on previous, targeted studies, including the 1997 Master Plan, 1997 Biosolids Management Plan, 2001 Wet Weather Flow Management Plan (WWFMP), and the 2003 Management Plan for a Dedicated Biosolids Land Application Site. Both Eugene and Springfield have separate sewer systems that come together into a regional system of pipes. Over 800 m/les of sewer pipes and 47 pump stations transport wastewater to the WPCF. Most of the conveyance pipelines of 24 baches in cl/ameter or greater and associated pumping facilities necessary to convey the region's wastewater to the regional facility were included in the facilities' original construction by regional and loca2 resources. This newly developed MWMC Facilities Plan is intended to identSf-y facility enhancements and expansions that are needed to serve the community's wastewater needs through 2025. Planning Criteria Regulatory requirements, existing MWMC polic/es, adopted citizen adv~sc~y, commi~e (CAC) recommendations, and direct Commission guidance provided the framework of objectives and planning criter/a for development of the Facilities Plan. In order for the Yacilit{es Plan to serve its intended purpose, implementation of the facilities improvements iden~/fied in the plan should enable MWMC and the partner agencies to have reasonable assurance that the following ol~ectives will be met: Compl/ance w/th appl/cable local, state, and federal laws and regulations Protection of the heo_Ith and safety of people and property from exposure to hazardous condit/ons such as exposure to untreated or inadequately t~eated wastewater Provision of adequate capacity to facffitate community growth/n the Eugene-Springfield metropolitan area consistent with adopted land use plans · Construction, operat/on, and rruanagement of MWMC facilit/es in a manner that is as cost-effective, efficient, and affordable to the community as possible in the short and long term · Implementation of Citizen Advisory Committee recommendations, which represent diverse community interest~s, values and involvement, and have been adopted by the Commission as MWMC plans and pohcies MWMC_EXE CSU M_RE-V4_2_ DOC ES~ MWIvlC FACILITIES PLAN Mitigation of potential negative impacts of MWMC facilities on adjacent uses and surrounding neighborhoods (ensuring that MWMC facilities are "good neighbors" as judged by the community) P annin§ Assumptions Listed below are the assumptions that were made regarding the future regulatory requirements for Eugene-Springfield, which are based on the current National Pollutant Discharge Elimination System (NPDES) wastewater discharge permit issued in May 2002. It should be noted that as water quality and fish concerns change over time, future discharge permits may contain different standards to protect the Willamette River's defined beneficial uses. However, the current permit conditions are anticipated to remain in effect through 2025. Dry season concentration limits will be set to the current Willamette River basi.~ standards of 10 mg/L for carbonaceous biochemical oxygen demand (CBOD) and total suspended solids (TSS) on a monthly average basis. Dry season mass limits for CBOD and TSS will remain the same as in the existing discharge permit and will be based on the dry season flow. Wet season concentration limits will remain the same as in the existing discharge permit. Wet season mass limits for CBOD a_nd TSS will remain the same as in the existing discharge permit and will be based on wet season flow. Dry and wet season monthly average percent removal for CBOD and TSS will remain at 85 percent, the same as the existing discharge permit. Wet season maximum day mass limits will be suspended when the plant flow is equal to or greater than twice the dry season design rating of the plant, the same as the existing discharge permit. The dry season ammonia concentration limits will remain the same as in the existing discharge permit. The excess thermal load limit in the dry season will remain the same as in the existing discharge permit. ~ The current limitation for effluent disinfection is based on E. Col£ It is assumed that the E. Coli limit will remain the same as in the existing discharge permit. · The effluent pH lirrtit will remain the same as in the existing discharge permit. Projected Wastewater Flows and Capacity Needs The Facilities Plan includes projections of wastewater flows and loads to the year 2025, at 5- year intervals, and for the build-out condition (estimated year 2050) for domestic and industrial sources. Average, maximum month, maximum week, and maximum day flow ranges and loads were determined for both dry and wet seasons. Domestic [residential and ES-2 MWMC_EXEC,SUM_REV4_ 2.~ DOC EXECL~rVE SUM~U~RY commercial, and infiltration/inflow (I/I)] projections were estimated based on population projections and selected per capita and peaking factors. Based on the method of projecting dry season flows, using actual historical data and statistical analysis, the projected flows during the wettest dry season month at 2025 is less than those projected using either the Oregon Department of Environrnental Quality (DEQ) guidelines or the lirwited data that was used in the 1997 Master Plan (Figure ES-I). Dry Season Haxirnurn Honth Flow Historical and Projected ~ 60~70-5 .................... ~ 40 20~ -- - ~ 2004 Facilities P]an~ DEq ~ethodo~ogy 10~ ~ 1997 ~aster P~an ~ Historical Data 1990 2000 2010 2020 Year F~URE F~ A 2003-04 collection system modeling effort indicated that wet weather peak hour (WWPH) flows generated in the collection system associated with the 5-year, 24-hour winter storm event were comparable to those projected in the WWFMP. This is the flow that must be treated under DEQ guidelines without resulting in sanitary sewer overflows (SSOs). The best current estimate of the 2025 WWPH flow at the WI~F is 277 mgd. Based on this projection, the WPCF faces a peak flow capacity deficit in a number of ~reatment process areas, which are summarized in Figure ES-2. Consistent with the WWFMP, the 2003-04 analysis showed that collection system capacity is limited primarily at the Willakenzie pump station and WPCF irffiuent screw pumps. Additional local (i.e. city) collection system upgrades will be needed at several of the other major local pump stations prior to 2025 to meet DEQ capacity requirements. The needs for these additional improvements have been identified as part of this Facilities Plan but are the responsibility of the individual cities. MWMC_EXECSUM_REV4~2_ DOC ES-3 MWMC FACILITIES PLAN FIGURE ES*2 Peak Flow Capacity Deficit MWMC Facilities Plan, Eugene-Springfield Current Capacity Additional Capacity Total Capacity Required Facility (mod) Through 2025 (mgd) in 2025 {mgd) A B C=A+B ~nfluent Pumping t 75 102 277 Pretreatment 175 102 277 Primary Treatment 90-110 50-70 160 Secondary Treatment 100-110 50-60 160 Disinfection 175 102 277 Outfall 175 102 277 Alternatives Evaluation As shown in Figure F,S-2, the treatment plant faces a significant peak flow capacity defidt. The WPCF currently has no additional peak flow capacity, and an additional 102 mgd of peak flow capacity is needed by 2025. The Facilities Plan analysis also concludes that in order to meet NPDES permit requirements for ammonia, thermal load and total mass removal, significant improvements to the treatment plant's unit processes are needed. To solve these projected capacity shortfalls, all available options known to staff and the consultants for resolving the regional treatment facilities capacity and performance constraints were identified. The regulatory requirements and other planning criteria discussed above were translated into a series of evaluation criteria. An evaluation matrix of treatment facility needs and potential solutions was developed and the criteria were applied, which resulted in a set of "preferred" and "acceptable" solutions. The solutions were further evaluated based on compatibility with existing treatment plant processes and on estimated costs, which resulted in the elimination of all but four systemwide alternative solutions. (DEQ requires that a "no action" option be presented, so a total of five options are summarized in the table below.) The final evaluation resulted in the alternatives summarized in Table ES-I, which are the least costly to implement in addition to meeting the stated planning requirements (with the exception of Alternative 1). EXECUTIVE SUM~RY TABLE ES-t AJtematives Selected for System Evaluation MWMC Facilities Plan, Eugene-$p#ng§eld Estimated Cost System Alternative (Millions of 2004 Dollars) Meets Planning Objectives 1 - No Action No 2 - Full Primary and Secondary $233 million Meets Most 3- FuJi P~ma~ $167 tuition Mee~ Mo~ 4- High Rate Cla~aon $157 tuition Meets All 5 - Parallel PHma~ Se~nda~ $144 million M~s Ail Recommended Plan Alternative 5 is the recommended set of facilities improvements to meet al~ of the 2025 planning criteria. It is the least cost set of facffities that can be constructed to meet the peak flow management and water quality requirements. The project phasing for the preferred system solution (Alternative 5)/s shown in Figure ES-3, and represents the thirteen initial project phases. Figure ES-3 does not show offsite projects, such as the hnprovements to conveyance pump stations, the $IV~,rF, the Biocycle Farm, and the BMF fac/l~ties. Alternative 5 meets all planning criteria a_nd requirements, and is the least-cost alternative, at $144 million in 2004 dollars. Because this option involves parallel use of the ex/sting primary and secondary treatment systems in peak wet weather events, it minimizes the need for new secondary treatment systems that would only be used in peak wet weather events (and thereby underu~l~zed for most of the year), but it is untested &om a regulatory standpoint. There remains uncertainty surrounding fi~ture blending policy and it ~s possible that the Oregon DEQ may not approve the proposed systemwide solution. Therefore, the next best systemwide alternative (Alternative 4), which includes the addition of High-Rate Clarification, may be implemented as a contingency plan. The alternative is identical to the preferred solution with the exception that High-Rate Clarification is provided ir~ addition to conventional primary clarification, and parallel primary secondary peak flow management is elflninated. If the High-Rate Clarification alternative is required by DEQ for regulatory purposes, an additional $13 million (2004 dollars) in project cost would be requ/~ed in phase 5. MWMC_EXECSUM_REV4_2_ DOC ES-5 MWMC FACIUTIE$ PLAN Financial Strategy The preferred Alternative 5 - Parallel Primary/Secondary work program results in a 20-year project list with a total cost of $144 million in 2004 dollars. If DEQ does not approve Alternative 5 - Parallel Primary/Secondary work program ($144 million), and Alternative 4 - High Rate Clarification work program ($157 million) is implemented instead, an additional $13 million will have to be spent on capital investments. Funding for the 20-year project list will be provided by a combination of user rates and system development charges (SDCs), with finan~g obtained tkrough issuance of revenue bonds. MWMC adopted an update to its Financial Plan in 2003. The MWMC Financial Plan contains an analysis and findings regarding MWMC's financial "fitness" to enable moving forward with a significant capital improvements program. It also includes an analysis of available financing and financial management tools. It provides policies and procedures that will position the utility well to manage the financial aspects of the Facility Plan in a manner that is fiscally responsible and cost-effective to the customers. ES-6 MWMC_EX£CSUM_REV4_2_ DOC; Introduction, Purpose and Need 1.1 Introduction This Facilities Plan, prepared for the Metropolitan Wastewater Management Commission (lvIWMC), is the result of a comprehensive evaluation of the regional wastewater treatment facilities serving the Eugene-Springfield metropolitan area. Regional wastewater facilities include the Eugene-Springfield Water Pollution Control Facility (WPCF), major pump stations and interceptors, the Biosolids Management Facility (BMF), the Biocycle Farm, and the Seasonal Industrial Waste Facility (SIWF). TI-ds Facilities Plan is a comprehensive update to the original "208 Plan," which was completed in 1977. The 208 Plan established the original projections, requirements, and projects needed to serve the Eugene-Springfield commurfity through 2005. The newly developed MWMC Facffities Plan is intended to identity facility enhancements and expansions that are needed to serve the community's wastewater needs through 2025. Current capacity cor~straints, new regulatory requ/rements and anticipated changes to these requirements, future capacity and performance requirements, new treatment technologies available to cost-effectively improve the capacity and performance of exist~g assets, and existing WPCF operational issues all provide the basis for evaluating and plan_v~g for the future of the regional wastewater ~eatment facilities. This evaluation reviews all of these areas and the resulting plan accounts for the most probable outcomes L~ the years ahead. The Facilities Plan builds on interim plmming efforts that were conducted from 1996 ffrrough 2001 to address specifically identified performance, capacity, and opera~onal deficiencies. For example, the models and analyses developed for the Wet Weather Flow Management Plan (CH2M HILL, 2001) and the Biosolids Management Plan (C/-I2M HILL, 1997) were leveraged fit order to develop solutions to both dry and wet weather treatment ~ssues. Also, those solutions are intended to provide for planned commun/ty growth that meets current regulations and anticipates f~ture environmental regulatory requirements. The selected alternatives should meet both short-term and long-term objectives and provide facilities that are acceptable to the public. This Facilities Plan provides solutions that address the full range of dry and wet weather liquids treatment and biosoIids issues, and operational health and safety concerns. The Plan also provides detailed descriptions and plans for recommer~ded project implementation. It is a comprehensive strategic road map for implementing the most cost-effective solutions to address a full range of regional wastewater needs over the next 20 years. 1.2 Intergovernmental Agreements MWMC is an/ntergovemmental entity that was created in 1977 by an ~tergovernmental agreement among Eugene, Springfield, and Lane County. MWMC owns and operates the Eugene-Sprirrgfield regional wastewater facili~es. In accordance with art intergovernmental agreement (IGA), the MWMC contracts with Eugene to operate and maintain these facilities, and with Springfield to provide administration services to the Commission. The MWMC is MWMC_I O_REV13 DOC ~-t MWMC FACILmES PLAN made up of seven Commissioners. The City of Eugene appoints three members, the City of Springfield two, and Lane County two members. One appointee from each jurisdiction is an elected official, the others are lay representatives. MWMC's purpose is to protect the publ/c health, safety, and environment by providing high-quality wastewater management services to the Eugene-Springfield metropolitan area in a n-tanner that is effective, efficient, and meets customer service expectations. Based on past surveys, M-WMC is looked upon by the community as a good neighbor and has developed a reputation for being environmental stewards in the communities they serve. 1.3 Background 1.3.1 Collection System Both Eugene and Springfield have separate sewer systems that come together into a regional system of lines. Over 800 miles of sewer lines and 48 pump stations transport wastewater to the plant. Most of the conveyance pipelines of 24 inches in diameter or greater and associated pumping facilities necessary to convey the region's wastewater to the regional facility were included in the facilities' original construction. 1.3.2 Eugene-Springfield Water Pollution Control Facility The WPCF, located at 410 River Avenue in Eugene, officially began operation in April 1984 and was constructed as part of a $105 million regional wastewater treatment system program. The regional facility replaced the separate plants previously owned and operated by Eugene and Springfield because studies concluded that neither cities' separate treatment plants could meet water quality standards or capacity. Planning, design, and construction for the regional facility occurred between 1979 and 1984 at the site of the original Eugene wastewater treatment facility. Existing facilities were either expanded and made a part of the new regional facility, or demolished. The Springfield sewage treatment plant was demolished. Since startup in 1984, the WPCF has been operating successfully, meeting all regional demands for increased sewerage service and complying with the facility's National Pollutant Discharge Elimination System (NPDES) permit issued by the State of Oregon Department of Environmental Quality (DEQ). At the time of construction the capacity of the plant was projected to serve the growing metropolitan area for 20 years. Slower than anticipated growth in the 1980s has slightly extended the design life of the plant. As a result of the slow growth and limited changes in regulatory policy, there has been limited capital investment in the facility over the past 20 years. 1.3.3 Biosolids Management Facility The regional BMF is located at 29689 Awbrey Lane and was constructed in 1985 to provide storage, further stabilization, and drying of digested biosolids received from the WPCF. A 5.5-mile-long pipeline from the WPCF to the BMF feeds anaerobic digested biosolids to four facultative sludge lagoons (FSLs). The FSLs provide the additional detention time for natural processes to further stabilize the biosolids and reduce pathogens. The original design provided for the stabilized biosolids to be dewatered for 6 to 10 weeks in thirteen sealed asphalt drying beds. However, lower than anticipated solids processing efficiency 1-2 t~WMC_I.O_REV13.DOC 1. INTRODUOTION, PURPOSE AND NEED (primarily because of variable summer weather conditions) prompted the development the Biosol/ds Management Plan, which was adopted by the MWMC in 1997. That plan evaluated available options for long-term, cost-effective management of biosolids, and called for the construct/on of belt filter presses (BFPs) at the BMF, which were completed in 2001. These facilities added solids processing (drying) capacity that closely matched the original (i.e., 1984-2005) design capacity of the treatment plant. Stabilized biosolids from the FSLs may be either mechanically dewatered with the use of the belt filter presses, or applied to drying beds for seasonal dewatering. Dewatered sludge cake is recycled through land application on cooperative farms and farmland owned by MWMC and leased to private farming operations. Supematant from the sludge lagoon/s returned to the WPCF. 1.3.4 Biocycle Farm Following the development of a feasibility study and development plan, MWMC purchased 596 acres of land near the BMF site in July 2000 to develop a Biocycle Farm. The Biocycle Farm provides MWMC with a dedicated land application site for biosoIids utilization. It enables cost-effective land application directly adjacent to the B/VIF, saving trucking and other costs associated with maintaining distribution of biosolids to cooperative farm sites. It also provides MWMC with long-term certainty as an available and permitted biosolids land application site. The site is located along Highway 99 between Awbrey Lane and Meadowview Road. The Biocycle Farm is scheduled to be constructed in three phases for completion by 2008. Phase 1 will consist of 160 acres of poplar trees and is scheduled to be complete and put into operation in summer 2004. Stabilized dewatered biosolids from the BMF lagoon w/Il be applied to the Biocycle Farm to provide the necessary nutrients for the poplar trees. The Biocycle Farm is anticipated to complement the current practice of hauling biosolids to cooperative farms. In addition, the Biocycle Farm will provide the flexibility to pump stabilized liquid biosolids directly from the BMF FSLs to the Biocycle Farm for lartd application. Ultimately, the three phases will occupy 595 acres, of which 400 acres contain poplar trees. 1.3.5 Seasonal Industrial Waste Facility The SIWF is located at 9199 Prairie Road. The SIWF-was originally constructed in 1984 to provide lagoon storage, and disposal of industrial cannery waste by irrigation. Seneca Foods (previously Agripac and then Chiquita) was the sole food processor to use the facility. Cannery waste from the industrial facility was piped directly to the lagoon for stabiliza~on. Irrigation is delivered to the grass crop at the site through a center pivot irrigation system. The cannery facility has permanently closed its operation and the facility is not currently receiving additional cannery waste. The SIWF continues to operate at a reduced level, /rrigating with the remaining stored cannery waste. This Facilities Plan evaluates the SIWF to determine how this facility can best be used to optimize the efficiency and cost- effectiveness of the residuals land application program, as well as the long-term asset value of the site. MWMC_I.0_REV13.DOG t-3 MVVMC FACILITIES PLAN 1,4 Previous Planning Efforts Prior to 1997, no comprehensive evaluation of the regional wastewater treatment facilities had been performed since/ts startup in 1984. In the mid 1990s MW-MC initiated a study to prepare a Master Plan in order to determine how the treatment processes and facilities were performing relative to the original capacity and performance expectations. The Master Plan (CH2M HILL, 1997) was completed in 1997 and recommended further evaluations to m_ssess the facilities' capacity to treat peak wet weather flows, and to adequately process biosolids. The Biosolids Management Plan (described above) was completed in 1997. In late 1997, lVlWMC initiated a project to develop a comprehensive Wet Weather Flow Management Plan (WWFMP), which was adopted by the MWMC and the two dries in 2001 (CH2M HILL, 2001). In 2000 MWMC initiated a project to develop a feasibility study and management plan for a dedicated biosolids land application site. This report was completed kn 2003 (CH2M HILL, 2003). 1.4.1 Master Plan The 1997 Master Plan provided an evaluation of the E-S WPCF based on historical flow, loads, and monitoring report data. Other selected facilities of the regional sewerage system were also evaluated. The purpose of the plan was intended to be Pe,,ofold: 1) identify low- cost capital improvements that could be implemented in the short term (3 to 5 years) to improve facility operations, and 2) identify faculty expansion improvements that would need to be implemented over a longer term to meet increasing regional demands for sewerage sen, ice or more stringent regulatory requirements, and to address specLfic priority issues affecting the WPCF. This plan did not include development of a comprehensive hydraulic and treatment process model. However, key evaluations included a limited flow and load analysis, general strategies to manage peak flows, an assessment of infiltration/inflow (I/I) programs, a preliminary peak flow assessment, a disinfection alternatives evaluation, a U.S. Environmental Protection Agency (EPA) risk management program evaluation, a preliminary biosolids management evaluation that led into the 1997 Biosolids Management Plan, and a plant effluent regulatory assessment. 1.4.2 Wet Weather Flow Management Plan The 2001 WWFMP was developed from reconunendarions in the 1997 Master Plan and results of preliminary analysis using a hydraulic model developed for the regional wastewater collection system. Developing the plan consisted of evaluating technologies for managing excess wet weather flow relative to performance, frequency of sanitary sewer overflows (SSOs), cost, and political and community acceptance. The overall objective of the plan was to determine the most cost-effecrive and politically feasible set of solutions for managing excessive wet weather wastewater flow rates both in the collection system and at the WPCF. The WWFMP was guided by a steering committee of approximately 20 Eugene and Springfield public works staff, and involved an extensive public involvement process. Staff from the cities forged a partnership to guide the project and to gather, review, analyze and interpret data as well as perform hydraulic modeling. A data subconurdttee to the steering committee performed much of the techrdcal analysis. A Citizens Advisory Committee (CAC) was charged with reflecting community values and concerns, assisting in evaluating 1-4 MWMC_I.O_REVl 3.DOC 1 ~NTRODUCTION, PU~OSE AND NEED desirabihty and priority of alternatives, providing recommendations on polio/issues, and assisting in communication and public awareness. Collectively, the groups' charge was to bring forward a plan to the MWMC for its adoption to manage wet weather flows in the separated sanitary sewer system. Key findings resulted in a "convey and treat" approach to managing peak flows, along with an aggressive yet feasible I/I removal program in the two cities. The collection system modeling effort showed that critical improvements in the collection system would provide adequate capacity to convey the peak flows to the WPCF, where the flows could be further managed and treated. 1.4.3 Bioso ids Management Plans The Biosolids Management Plan was adopted by the MWMC in 1997. Like the WWFMP, it involved a Eugene-Springfield steering committee and a citizen advisory committee. The Biosolids Management Plan included an evaluation of available options for long-term, cost- effective management of biosolids, and called for the construction of BFPs for mechanical dewatering at the BMF, a further study of alternatives for producing "Class A' biosolids, and the development of a dedicated biosolids land application site using poplar trees. The Class A Biosolids/Compost Evaluation was completed by Brown and Coldwell Engineers in January 1999; however, the MWMC determined that implementing the capital improvements to achieve a Class A product were not cost-effective at that time. In 1999 and 2000, the MWMC undertook a feasibility study and a reconnaissance study to determine whether to proceed with the purchase of land and development of a dedicated biosolids land application site. These preliminary studies indicated that the site meets the requirements for land application of biosolids as outlined in state and federal guidelines (OAR 340-50 and 40 CFR Part 503) and that it is a favorable site to be purchased for the dedicated land applicat/on site. The 2003 Management Plan for a Dedicated Biosohds Land Appl/cation Site was developed after the MWMC purchased the 596 acres on Awbrey Lane. This plan includes a conceptual plan and preliminary designs for the development, construction, and operation of a dedicated farm for biosolids land application. The plan outlines a fac/lity that can provide an economically viable agricultural operation that accommodates a significant portion (20 to 50 per cent) of the current MWMC Class B liqu/d biosolids production. The plan also stresses that the remainder of the biosolids recycling will be through continued use of cooperating agricultural producers, and that new cooperating producers will likely be required to meet future demands. The MWMC approved the plan to provide a dedicated Biocycle Farm to give MWMC dramatically increased flexibility in solids handling options, and to provide for economically and envirorm-mntally advantageous recycling of a significant portion of the biosolids produced at the WPCF. 1.5 industr There are 16 significant industrial users (SIUs) from Springfield and 22 from Eugene. Hynix Semiconductor in Eugene contributes over half of all significant industrial flow to the collection system. Historically, the total industrial flow contribution to the collection system has remained relatively constant at around 1.7 million gallons per day (mgd), or about three percent of the dry weather average flow. The Eugene and Springfield Industrial MWMC_I O_REV13.DOC ~-5 MWMC FACILITIES PLAN Pretreatment Programs require monitoring of historical biochemical oxygen demand (BOD), totat suspended solids (TSS), and ammonia contributions ~rom the industries. Indust~al flows are not anticipated to increase significantly over the next 20 years. 1.6 Project Needs ,6J Existing CondiUon Design of the original WPCF was based on demographic and population data established irt the mid-1970s. The facility was designed to provide adequate sewerage capacity through the year 2005 for a projected population of 277,100. This projection was made for the sewer service area that existed fin the 1970s. However, the growth rate during the 1980s was significantly less than projected. This trend in the growth rate was common throughout much of Oregon because of depressed economic conditions during the m/d- 1980s. The existing average dry weather design flow for the WPCF, as stated in the current NPDES permit, is 49 mgd. Tbds ~s defined as the average day flow calculated from May 1 through October 31. Although stated as an average dry weather capacity, the facility must meet the effluent requirements on a 30-day average flow (monthly) basis. Because any 30-day period, includfftg the maximum 30-day flow period (or maxLmum month flow) durLqg the dry season, must meet the NPDES effluent flow and load requirements stipulated for the average dry season flow, it is prudent to compare the actual dry season maxh~num month flow (DSMM) to the average dry weather design flow in order to assess treatment capacity. Tiffs method was reviewed with DEQ staff and verified as the appropriate method. There is available treatment capacity during certain periods of the year, very little during others, and in some cases there is a capacity deficit. This is because, in part, permit lin-fits change on discrete calendar dates, whereas the changes in influent wastewater flows and characteristics do not necessarily coincide with these permit dates. For example, dry season (May 1 through October 31) permit requirements are more stringent than wet season (November 1 through April 30) requirements, but wastewater temperature and flow in the month of May, and sometLmes into June, do not increase and decrease, respectively, to allow the WPCF to easily meet the more stringent dry season requirements. In addition to flow, temperature is important because the warmer the wastewater, the easier it is to treat. Measured DSMM flows from 1992 through 2003 range from 52 percent to 100 percent of the design capacity. It is anticipated that sufficient dry weather treatment capacity exists to meet short-term growth through 2005 for BOD and TSS, but modifications to the WPCF are needed to address ammonia; however, peak wet weather flows, not influent wastewater characteristics, currently constrain the life span of the plant's design capacity. This capacity constraint exists during winter wet season months as well as dttfing wet periods of the regulatory "dry" season. The plant has a wet weather peak design capacity of 175 mgd. High levels of wet weather flows are generated by I/I of stormwater into the sanitary sewer system. Infiltration is a process by which groundwater enters the system through cracks and joints Lrt sewer pipes. Inflow is the process by which stormwater enters the system through improper connections of roof drah~s and other storm drainage facilities to the sanitary sewers, and by surface runoff enter~g through manholes. The amount of I/I entering the system varies in different areas depending somewhat on the type, age, system 1-6 MWMC_'LO~REVI3,DOC 1. l~RODUC130~, PURPOSE AND NEED characteristics and groundwater table. It occurs throughout the system, and is attributable to newly developing areas as well as older developments. While some of the I/I cart be removed through repair and rehabilitation of pipes, and inspection and enforcement of plumbing code standards, water pollution control facilities must be designed to handle the remaining peak wet weather flows in the sanitary system with adequate treatment prior to discharge. 1.6.2 Regulatory Drivers Regulatory drivers include existing conditions contained in the NPDES wastewater discharge permit, and new regulations or c~anges in regulatory policy that affect the overall treatment capacity rating, treatment strategy, or effluent requirements. Regulatior~s that were newly incbaded in the 2002 reissuance by DEQ of the WPCF discharge permit include the requirement for a dry season effluent ammonia limitation, a thermal load limit, and implementation of the Temperature Management Plan and WWFMP, which were included as part of the NPDES permit renewal materials. New requirements, expected beginning in 2004 and 2005, include total maximum daffy loads (TMDLs) for effluent constituents, suC*h as temperature. Pending changes in federal regulatory policy also include the elimination of SSOs resulting from certain storm events, and changes to current effluent blending practices or new effluent blending policy currently under consideration. Dry Season Effluent Ammonia Limitation The current NPDES permit includes a requirement for dry weather nitrification. The permit requires a dry weather average month and maximum day effluent ammonia concentration limit of 12 milligrams per liter (rog/L) and 22 rog/L, respectively. Wintertime nitrification is not required. The treatment facility must partially or completely nitrify on a peak month basis in the dry season to meet permit. The addition of a nitrification requirement has the overall effect of reducing the design dry weather capacity of the facility because more wastewater treatment volume is required to achieve ammonia removal than is required solely for BOD removal. Additionally, a modification to the biological process is required to provide an environment suitable for nitrification while maintaining capacity. CBOD and TSS Limitations Dry season mass limitations for both carbonaceou~ biological oxygen demand (CBOD) and TSS as outlined irt the NPDES permit are based on the average dry season flow of 49 mgd. Concentration limits as well as percent removal requirements are also specified in the NPDES permit. The mass limit requirements must also be met for the highest 30-day flow period in the dry season (maximum month basis). Even if the constant concentration limits for CBOD and TSS are met, the mass limits imply a lower concentration requirement if the wastewater flows exceed the dry weather design capacity of 49 mgd. Because actual DSMM flows from 1992 through 2003 ranged from 52 percent to 100 percent of the design capacity rating, this indicates that the plant is at or near its dry weather capacity at certain critical dry periods. Additional secondary darifier capacity and tertiary filtration is anticipated as necessary to meet these more stringent effluent requirements. Similarly, wet season mass limitations for both CBOD and TSS, as outlined in the NPDES permit, are based on the average wet season flow of 75 mgd. Although sigr~icantly higher, concentration limits as well as percent removal requirements are a/~so specified in the MWMC_I O_REVt3 DOC 1-7 MW1MC FACILiTiES PLAN NPDES permit for wet weather. However, because peak wet weather flows are very dilute, it is the solids percentage removal requirement that limits effluent CBOD and TSS levels during critical wet weather flow periods and this is the most difficult to achieve. Peak wet weather flow, not wet weather influent wastewater characteristics, currently constra~ the WPCF's design capacity. The plant has a wet weather peak design capacity of 175 mgd. Current peak wet weather flows to the facility exceed 200 mgd, and only 200 mgd can hydraulically be moved ffrrough the WPCF because of a redundancy that yeas required by DEQ beyond the rated wet weather capacity. $S0 Limitations Collection system modeling efforts estimate the current peak wet weather flow in excess of 250 mgd, a situation that now results in SSOs. Current peak wet weather flows exceed 200 mgd, and are limited by both the collection system and plant capacity. An increase in both peak flow conveyance and treatment capacity is necessary to comply with the MWMC WWFMP objectives and policies to eliminate basement flooding and SSOs, as well as DEQ's requirement that the wet season flow associated with the 5-year, 24-hour ra~rffall event be accommodated by MWMC's fac~ties without resulting in SSOs. The MWMC WWFMP policies also direct that an increase in the level of full secondary treatment be provided through the expansion of the secondary treatment system. In addition, the treated peak flow must meet the secondary treatment standard. This federal regulatory requirement will take effect by January 2010 [OAR 340-41-0009 (6) and (7)]. Blending and WWFUP Secondary Treatment Policies Previous studies and collection system modeling efforts have concluded that peak wet weather flows resulting from the 5-year 24-hour storm could be conveyed by the collection system to the WPCF for treatment without SSOs. Under the 1997 Master Plan and 2001 WWFMP modeling, it was detemained that increased raw sewage pumping capability (among other improvements) needed to be completed by 2007 to avoid non-permitted overflows, and to conform to the objectives and policies of the ~P. However, current experience and system modeling indicate that current peak flow esl4_mate is in excess of 250 mgd. Recent modeling efforts and actual system performance ~dicate that plant expansions to avoid non-permitted overflows need to be constructed begixming in 2005. Current collection system modeling results estimate the 2025 projected peak hour flow to the WPCF to be 277 mgd. MWMC and the cities are continually collect~g pre- and post- rehabilitation/construction collection system flow data to assess the effectiveness of their I/I reduction efforts. It is anticipated that the peak flow values w~ll be periodically revised based on the more current data and collection model calibrations and o~tput. The current data and information form the basis for increasing the peak flow capacity of the facility to comply with DEQ's requirement to treat the 5-year, 24-hour rainfall event without resulting ~ SSOs. Blending is not addressed in the current NPDES permit; however, blending of pr/mary and secondary effluents is the current practice for treating the peak wet weather flows. Flows over 103 mgd (the secondary treatment capacity) receive primary treatment and are diverted around secondary treatment and blended with the secondary effluent. This blended effluent must meet current secondary treatment standards before it is discharged to the fiver. Increases in peak flows resulting from the elhnination of SSOs w~ll require that the MWMC_l,~_R~13.DOC t INTRODUCllON, PURPOSE AND NEED facility expand both its base secondary treatment capacity and its pr:anary treatment capacity for the plant to meet its NPDES permit. Regardless, the IViWMC adopted a WWFMP policy that facilities are to be constructed in order to increase the level of full secondary treatment from 103 mgd to 130 mgd. Current effluent blending policy is still evolving; however, blending now provides the most cost-effective approach to treating peak flows. A key underlying assumption in the preparation of this plan is that some level of effluent blending will continue to be an acceptable approach to treating the peak wet weather flows. If the DEQ does not accept this approach in reviewing this plan, contingency solutions that could be implemented are included and evaluated. However, the cost of these facilities would be significantly greater than those recommended in this plan. 1.6.3 Technology Drivers The original treatment facility was constructed in 1984, implementing the appropriate technologies of the era. New technologies have emerged since that time, and will continue to emerge to address both existing and future wastewater treatment needs. New technologies may have the advantage of providing better environmental results, providing more cost-effective treatment, lowering operational and maintenance requirements and costs, and other benefits. Technologies available for implementation today were evaluated as part of the planning process and are recommended where they meet cost-effectiveness, performance, and capacity criteria to meet the future regional wastewater treatment needs for MWMC's service area. 1.6.4 Existing WPGF ssues /% number of at the WPCF evaluated of the concerns were as part planning process to identify improvements to the existing facilities that would provide operational efficiencies, cost savings, reduced risks/liabilities, and improved worker and neighborhood safety. In some areas, the original capacity of equipment may now be limiting operations (influent pumping capacity is inadequate, screen trough sluice capacity is inadequate, etc.) Other needs are simply a result of aging or outdated equipment (i.e., pumps, valves, gates, communication systems, etc.). Process inefficiencies provide further bottlenecks to efficient operations (grease accumulation in influent screening conveyance, limited modes of operation in aeration basins, high operation and maintenance Lq the existing grit chambers, reduction in struvite scaling, etc.). Finally, the MWMC evaluated the current chlorine disinfection system and the available alternatives, and directed staff to include the conversion to a safer system using sodium hypochlorite. All of these needs must be addressed in order to provide the expansion capability necessary to meet future growth needs and to provide the most cost-effective and safe treatment facility operations. 1,7 Project Goa s and Objectives The goals of this Facilities Plan are to build on the previous planning efforts that have been ongoing since 1996 in order to develop a practical and cost-effective set of capital improvements necessary to meet community needs and minimum environmental standards for all MWMC facilities for the next 20 years. The Facilities Plan presents comprehensive and defensz~ble identification and evaluation of available capital improvement strategy alternatives, and recorrtrnendations that: MWMC_1.0_RE¥13 DOC MWMC FACILrrlES PLAN Accommodate projected growth in Eugene-Springfield through 2025 Provide the efficiency of solving multiple dry and wet weather issues Maximize the WPCF's exisQng investment in assets by incorpora~ng performance and capacity improving retrofits where possible instead of new facilities Meet minimum environmental standards for the Willamette River Provide regulatory certainty and protection from liabilities associated with non- compliance with requirements Mitigate negative neighborhood impacts such as odors and visual impacts of the treatment facilities The strategic plan will monitor and address future trends in the indush-y so that recommended facilities can be implemented with sufficient flexibility to meet anticipated future regulatory requirements. 1.8 PubLic Outreach Building and maintaining public trust and credibility requires dear and consistent communications. Recent national research has demonstrated that the public is deeply concerned about health risks, environmental protection, and the affordabilJty of services. MWMC recognizes that involving the public in decisions about service changes, public health, safety, environmental protection, and cost increases is essential to the success of its programs. In the past, M~VMC has provided proactive public education and participation programs to enhance understanding of the environmental services being provided. CACs have aided the MWMC in establishing the foundational polities and strategies that continue to guide the management of biosolids and wet weather flows, which are the two key areas of increased facilities needed over the next 20 years. Regular and spec2al meetings and workshops have been scheduled to brief MWMC Commissioners and the public on the sta~_s of evaluations and proposed alternatives that provide solutions to regional wastewater needs. Table 1.8-1 sttmmarizes the public meetings where the Facilities Plan development was discussed. In addition to public outreach programs, it will be essential to educate the public regarding the capital improvements and policies included in this Facilities Plan. A guidance document will be prepared to assist the MWMC in designing and implementing public information, education, and outreach programs that meet state and federal guidelines for major improvement projects. 1-10 MWMC_1 0_RE¥13.DOC t, [NTRODUCllON, PURPOSE AND NEED T~BLE 1 Public Meeting Summary MWMC Facilities Plan, Eugene-Springfield Date Discussion Topics November 24,2003 Briefing to the Commissioners and the genera~ public January 8, 2004 20-year project list presented to commissioners, obtained direction on effluent reuse (thermal loading) and odor control issues Mamh 3, 2004 Briefing to the general public 1.9 Facilities Plan Organization and Content The organizatior~ of [his report is based primarily on the facilities plan outl~e provided L~ AppendL~ C of the Guidelines for the Preparation of Facilities Plans and Environmental Reports for Community Wastewater Projects (DEQ, 1999). Some of the components reqrrLred by the DEQ facilities plan guidelir~es are addressed tn ~e previous planning documents entitled Metropolitan Wastewater Management Commission Master Plan for the Eugene-Springfield Water Pollution Control Facility (CI-I2M HILL, 1997), Wet Weather Flow Management Plar~ (CI-I2M HILL, 2001), and Biosolids Management Plan (CI-I2M HILL, 1997). DtLdng the facilities plarming effort, the project team wrote technical memoranda and/or developed summary tables to document and evaluate its f~d~gs. Form~g the foundation for this report, the follow~g memoranda arid/or tables provide barther [rfformat~on about specific topics: 1. Wet Weather Peak Flow Analysis Technical Memorandum 2. Preliminary Screening of Alternatives Technical Memorandum 3. Flow and Load Project~ons Technical Memorandum 4. Water Q~ality Analysis Techrdcal Memorandum 5. Pretrea~ent Alternatives Technical Memorandum 6. Primary Clar~er Capacity Analysis and Enhancements Technical Memorandum 7. Secondary Treatment Enhancements Technical Memorandum 8. Secondary ClarLfier Enhancements - Altemat~ve Analysis Tech~cal Memorandum 9. Peak Flow Management Alternatives Technical Memorar~dum 10. Disi~-rfecfion Alternatives Technical Memorandum ll. Odor Control AlternaQves Techrdcal Memorandum NIVt~C_i.O_REVI 3 DOC 141 MWMC FACII~IES PLAN 12. Plant Hydraulics Technical Memorandum 13. Reuse and Thermal Compliar~ce Technical Memorandum 14. Projected Flowstreams for Solids Processes and Capacity Analysis of Biosolids Treatment Processes and Facilities 15. Biosolids Management and Reuse Alternatives Analysis This Facilities Plan is organized as follows: Executive Summary: Summarizes the conclusions and recommendations of the ptarming team, including a description of the preferred alternatives. Chapter 1 Introduction, Purpose and Need: Discusses the purpose for this Facilities Plan and what the needs are at the current facilities, describes previous planning efforts, and includes the goals of the MWMC, particularly the public outreach component. Chapter 2 Study Area Characteristics: Locates the study area, describes the physical and socioeconomic environment, and discusses current land use regulations that apply to the MWMC service area. Chapter 3 Existing Wastewater Facilities: Describes the current facilities and their status, and further describes the WPCF, including its history, design, operations, and unit performance and deficiencies. Chapter 4 Wastewater Characteristics: Provides data on wastewater flows and loads to the plant, describes unit design £actors, and lists projected wastewater characteristics that will affect facilities planning. Chapter 5 Basis of Planning: Provides information on the basis for design and costing of the alternative(s), water quality impacts, and the design capacit~y and an analysis of Lhe current conveyance system and WPCF. Chapter 6 Development and Evaluation of Alternatives: Discusses the alternatives development process for the conveyance system, liquid stream treatment, disinfection, effluent disposal, and biosolids management. Synthesizes this information into three complete alternatives. Chapter 7 Recommended Plan: Discusses the recommended improvements, with a cost s,amma~ and implementation schedule. Chapter 8 Financial Strategy: Evaluates various options for funding sources, and includes a recommended rate structure and £mancing strategy for MWMC. Chapter 9 Environmental Report: Discusses the environmental ramifications for the various alternatives, and provides a preferred alternative for parallel primary/secondary treahnent. Chapter 10 References: Lists the references used to write this Facilities Plan. MWt~C_I,O_REVl 3 DOC 2.0 Study Area Characteristics Th/s chapter describes the location, physical environment, land uses and zoning, and other general characteristics of the study area that affect this facilities planning effort. 2.1 Study Area The Eugene-Springfield metropolitan area is located in the heart o£ Lane County, Oregon, and is situated in the southern Willamette Valley along the Willamette and McKenzie rivers. Eugene-Springfield makes up Oregon's second largest metropolitan area. Interstate 5 divides the metropolitan area; Eugene is located on the west side, and Springfield is located on the east side of Interstate 5. Figure 2.1-1 shows the location of Eugene-Springfield within Lane County. MWMC provides regional sewerage and wastewater services for the Eugene- Springfield metropolitan area. The current MWMC service area is shown in Figure 2.1-2 (the urban growth boundaries of Springfield and Eugene serve as the boundaries of service). Although not in the city 1Lmits, service is also provided to the Sa,nra Clara/R/ver Road area, north of the WPCF. MWMC will continue to provide regional services to a growing metropolitan area over the next 20 years. Figure 2.1-2 shows the anticipated urban growth boundary used for planning purposes through the design year 2025. The focus of this Facilities Plan is future expansion or modifications of M~WMC facilities and operat/ons. Impacted facilities include the WPCF, the BMF, the S1WF, and the Biocycle Farm. Study area characterist/cs for each of these sites and the general metropolitan area need to be well-defined so that any impact to the surrounding environment through facility modifications or operations may be easily quantified relative to the base characteristics. Figure 2.13 shows the location of each of the regional wastewater treatment facilities and their associated impact areas. The WPCF is located at 410 River Avenue, on 100 acres, township and range T17S R4W Section 13. The BMF is located at 29689 Awbrey Lane, township and range T16S R4W Section 33. The SIWF is located at 91199 Prairie Road, Junction City, township and range T16S R4W Sections 27, 35, and 34. 2.2 Physical Environment 2.2.1 Climate The average winter temperature at Eugene is approximately 42 degrees F with an average daily minimm temperature of 35 degrees, lmne lowest temperature occurred at Eugene on December 8, 1972, and registered -12 degrees F. In su_mmer, the average temperature is 64 degrees F. The average daily maximum temperature is about 76 degrees F (NRCS, 1977). Average annual raffffall is 43 inches, falling mostly bet~een September and June (City of E~ggene, 2004). The average seasonal snowfall is 5 inches at Eugene. The greatest snow depth at any one t/me during the period of record was 11 inches at Eugene. On an average, Eugene has 2 days with at least 1 inch of snow on the ground, but the number of such days varies greatly from year to year. MWMC_2.0_REV23 DOC MW'MC FACiLiTiES PLAN The average relative hurvddity in midaffemoon is about 60 percent. Humidity is higher at night, and the average at dawn is about 90 percent. The percentage of possible sunshine is 60 percent in summer and 25 percent in winter. The prevailing wind is from the west- northwest. Average windspeed is highest, 8 miles per hour, in winter. In most winters one or two storms over the whole area bring strong and somet;anes damaging winds, and in some years the accompanying heavy rains cause serious flooding. Every few years, in winter or stmuner, a large continental amass from the east causes abnormal temperatures. During winter, several consecutive days are well below freezing; in summer a week or longer is sweltering. Tables 2.2.1-1 and 2.2.1-2 summarize these data. TABLE 2.2.1-1 Average weather in Eugene, Oregon MWMC Facilities Plan, Eugene-Springfield Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average temp. (OF) 39.8 42.8 46.3 49.8 54 8 60.2 66.2 66.4 61,7 52.6 44.7 39.5 High temperature (°F) 45.0 48.4 50.1 55.2 59.7 64.7 69.9 69.3 66.6 56.8 50.3 44.9 Low temperature 31.2 35.5 41.3 44.7 50.9 55.8 62.1 62.2 57.4 47.9 37.2 32.6 (°F) Precipitation (in) 7.65 6.35 5.80 3.66 2.66 1.53 0.64 0.99 1.54 3.35 8.44 8.29 Days with precip. 17.1 15.8 17.3 14.2 10.8 7.4 3.2 4.1 5.9 10.9 17.7 17.3 Source: National Climatic Data Center, Asheville, North Carolina 28801, www.ncdc noaa.gov TABLE 2.2.1-2 Normal chmate around Eugene, Oregon MWMC Facilities Plan, Eugene-Springfield Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Wind speed 7.8 7.8 8.2 7.7 7.4 7.6 8.0 7.6 7.4 6.7 7.4 7,6 (mph) Morning humidity 92 92 91 90 91 90 87 88 89 93 93 92 (%) Afternoon 80 72 65 58 55 50 39 39 43 62 78 84 humidity (%) Sunshine (%) 28 38 48 52 57 56 69 66 62 44 28 23 Days clear of 2 3 3 4 6 8 16 14 12 5 2 1 clouds Padly cloudy 4 4 6 7 9 8 8 9 8 9 6 4 days Cloudy days 25 21 22 19 17 14 7 8 9 17 23 26 Snowfall (in) 1.5 1.4 0.1 O.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 1.8 Source; http://www.citv-data.cem/city/Euqene-Oregon.htm_l 2-2 MWtCIC_2.0_REVZ3.DOC STUDY AREA CHARACTERISTICS 2.2,2 Soils The Eugene-Spring,eld metropolitan area includes at least eight major soils sezdes (Figure 2.2.2-1) and numerous individual soft phasesI. Because of the large number of soils and corresponding descriptions, only a brief discussion of the nine soils located within the area hxtmediately underlying and surrounding major MWMC facilities (Le., SIWF, BMF, Biocycle Farm, and WPCF) is provided below. Soils are categorized according to the facility where they are located and are shown in detail on Figures 2.2.2-2 and 2.2.2-3. WPCF * Camas. The Camas series consists of very deep, excessively drained soils that formed in gravelly and very gravelly coarse textured alluvium of mixed mineralogy. Camas soils are on floodpla~s 50 to 3,000 feet in elevation and have slopes that range from 0 to 5 percent. They are excessively drained with slow runoff and very rapid permeability. They are subject to rare or occasional flooding, tr~ese soils are used for growing cultivated crops and for woodland. Camas soils are usually L~rigated. Na~aral vegetation is Oregon ash, Oregon white oak, red alder, rose, blackberries, annual weeds and grasses. Newbergfine sandy loam. This deep, somewhat excessively drained soil is on flood- plains and bottom lands at elevations of 290 to 850 feet. Slopes are 0 to 3 percent. This Newberg soil formed in recent alluvittm and has a moderately rapid permeability. Runoff is slow, and the hazard of water erosion is slight. The soil Js occasionally flooded for brief periods &om December to March. Ti-ds unit is used mainly for row crops, hay and pasture, small grain, and orchards. It is also used for urban development and recreation. The vegetation in areas not cultivated is mainly Douglas-fir, grand fir, Oregon white ual bigleaf maple, black cottonwood, shrubs, and grasses. Newberg-Urban [and complex. The Newberg-Urban land complex soils are on flood plains at elevation o£ 300 to 850 feet. Slopes are 0 to 3 percent. It formed in recent silty alluvium. The relatively undisturbed Newberg soil is deep and somewhat excessively drained with a moderately rapid permeability. Runoff is slow, and the hazard of water erosion is slight. The soft is occasionally flooded for brief periods from December to March. The native vegetation Js mainly Douglas fir, grand fir, Oregon white oak, bigleaf maple, black cottonwood, shrubs, forbs, and grasses. The disturbed Newberg soft has been covered by as much as 40 inches of fill material or has had as much as 30 inches of the original profile removed by cutfirtg or grading. The fill material commonly is from adjacent areas of Newberg, Chehalis, Cloquato, Camas, and McBee softs that have been cut or graded. The characteristics of the d~turbed areas are highly variable. Urban land consists of areas where the soils are largely covered by concrete, asphalt, buildings, or other impervious surfaces that obscure or alter the soils 1 Soils that have profiles that ate almost alike make up a soil series. Except for differences in texture of the surface layer or of the underlying layers, all of the soils in a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer or of the underlying layers. They can also differ in slope, stoniness, salinity, wetness, degree of erosion, and other characteristics that affect their use. On the basis 0l~ such differences, a soil series is divided into soil phases (NRCS, 1977). MWIv~_2.0_REV23.DOC 2-3 MWMC FACILITIES PLAI~ so that identification is not feasible. This unit is used mainly for urban development. It is also used for yards, parks, and open areas around and between buildings. Ma[abon. Malabon soils are of moderate extent in the Willamette Valley and occur dominantly on stream terraces, but are also recogrfized on high floodpla'ms in some areas. Elevation is 100 to 1,100 feet. Slopes are 0 to 3 percent. The soils formed in silty and clayey alluvium from mixed materials. Areas of Malabon soils on high floodplains are subject to rare to occasional flooding for brief periods from December to March. The soil series is well-drained with slow runoff to moderately slow permeability. These soils have wide use for growing orchard, berry, vegetable, small grain, hay, pasture, and grass seed crops. Natural vegetation is Douglas fir, Oregon white oak, blackberry, Pacific poison oak, other shrubs, and grasses. Coburg. COburg soils are on stream terraces of the Willamette Valley at elevations of 100 to 1,100 feet. Slope gradients are dominantly 0 to 7 percent. The soils formed in silty and clayey alluvium fi:om mixed materials. They are moderately well-drained with slow nmoff and moderately slow permeability. Some areas of Coburg soils are subject to rare or occasional flooding for brief periods from December to March. An apparent water table is at its uppermost limit from December to March. These soils are used for production of small grain, hay, pasture, and grass seed crops. Natural vegetation is Douglas fir, Oregon white oak, blackberries, Pacific poison oak, other shrubs, and grasses. Awbrig. Awbrig soils are in drainageways and nearly level to slightly concave or depressed parts of stream terraces at elevations of 200 to 600 feet. Slope gradients are 0 to 2 percent. The soils formed in stratitied silty and clayey mixed alluvium and weathered from volcanic and sedimentary bedrock. They are poorly drained, ponded or with very slow runoff, and have a very slow permeability. Awbrig soils are subject to rare flooding. A perched water table is at its uppermost limit from November to April and is ponded from December to April. This soil also has an apparent water table. These soils are used for grass seed, hay, pasture, and spring grain crops. Native vegetation is mainly grasses, sedges, rushes, and scattered hawLhom, rose, and Oregon ash. Biocycle Farm blotcomb. The YIolcomb series consists of very deep, somewhat poorly drained soils in nearly level to slightly convex areas on broad valley terraces at elevations are 125 to 650 feet. They have slopes of 0 to 3 percent and formed in stratified silty and clayey mixed alluvium. They are somewhat poorly drained with slow runoff and very slow permeability. A perched water table is at its uppermost limit from November to April. This soil also has an apparent water table. Holcomb soils are under cultivation with small grains, hay, pasture, and grass seed as the principal crops. The vegetation is largely annual and perennial grasses, wild blackberry, wild rose, and oak. Coburg, Awbrig and Malabon soils also occur at the Biocycle Farm. 2-4 MWMC_20_REV23.DOC 2. STUDY AREA CHARACTERISTICS SiWF ~, Salem. The Salem series consists of very deep, well-drained so/Is that formed gravelly medium and moderately fine-textured mixed alluvium over very gravelly coarse ~ textured alluvium. They are on valley terraces at elevat/ons of 100 to 800 feet. Slope gradients range from 0 to 12 percent. They are well-drained with slow runoff and moderately slow permeability over very rapid permeability. Salem softs are used for production of cereal grain, corn, pole beans, berries, orchards, pasture and hay. The native vegetat/on ks ponderosa pine, Douglas fir, Oregon white oak, bigleaf maple, wild rose, and annual and perennial grasses. e Coburg, Matabon and Awbrig soils also occur at the SIWF. 2.2.3 Geologic Hazards Geologic hazards that reasonably could be expected to occur in the MWMC service area include seismic hazards (earthquakes), volcanic eruptions, and landslides. The following sections include a brief discussion of the geology and geologic hazards in fire MWMC service area and a description of historical seisrrdcity and the probabilib;~ of a seismic event occurring within 60 miles of the Eugene-Springfield metropolitan area. It should be noted that the following discussion on geology wa~s adapted from a geologic description originally publ/shed in the Aquatic and Riparian Habitat Assessment for the Eugene-Springfield Area, September 2002, Final Report, by the Eugene-Springfield Metropolitan Endangered Species Act Coordinating Team (MECT). Geology The landforms of the study area were created over m/llions to thousanct.~ of years ago by a combination of influences including ice ages, volcanism, and cataclysmic hydrologic events. The area is comprised of numerous geologic units that fall within three major geologic formations comprised of basaltic rock, Missoula flood deposits, and river alluvium. Basaltic units are found below the steeper slopes and their rock outcroppings form the southern boundary of the study area. Specifically, these h/Ils were formed from andesitic basaltic or pyroclastic bedrock formed 10-25 million years ago (Th/eman, 2000; U.S. Army Corps of Engineers, 1953). The Missoula flood deposits consist of that part of the main valley floor buried with silts deposited primarily during the Bretz Floods that filled the Willamette Valley with sediment 12,000-600,000 years ago (Allen et al., 1986). The th/rd geologic formation is the river alluvium. This is the area within and near the rivers that has been scoured of silts left over from the Bretz Floods and is characterized by coarse sediments and gravel deposited by rivers originating in the Cascade Mountains (Figure 2.2.3-1). Prior to the geologically recent series of ice ages (40-50 million years ago), the Willamette Valley was submerged under the Pacific Ocean. Fossil remains of marine mollusks, crabs, and sharks indicate that the climate was tropical (Thieman, 2000). From 25-40 million years ago, the Willamette Valley dried as the Coast Range rose from the ocean floor, blocking marine inundation. Two to three million years ago, a series of ice ages sent glaciers stretching south of Seattle (Kettler ,1995). Glacial melt water flooded [he WLllamette Valley, leaving behind till and debris (Thieman, 2000). During the Wisconsin ~ce age, for which there is the best geologic record, sea levels were significa~_tly lower thart they are currently MWMC_20_REV23, DOC 2-5 MWMC FACILITIES PL~,N because most water was held on land in the form of ice. As the ice started to melt, however, both coastal and inland areas were inundated (Thieman, 2000; Allen et al., 1986). The most recent significant geologic events that have shaped the Wigamette Valley as we see it today are the Lake Missoula Floods, which occurred from 12,000-15,000 years ago. The most recent of these flood events is the Bretz Flood (Allen et al., 1986). Prior to the Bretz Flood, the Willamette Valley was likely much as it is now, although the valley was likely deeper and the Willamette and McKenzie Rivers larger, roaring with glacial melt from the ice-capped Cascades. Flooding from the Bretz Flood began far up the Columbia River Watershed in Montana and Idaho at Lake Missoula. Lake Missoula was mn enormous lake formed behind large ice dams created by a glacial finger of the continental ice sheet that extended into northern Idaho. The ice dams broke suddenly and rapidly, allowing 500 cubic miles of lake water to rush out at 60 miles per hour in volumes greater than ten times the crtrrent volume of all the rivers on earth (Parfit, 1995). This flooding may have occurred a number of times starting 600,000 years ago. The most recent flood event, the Bretz Floods, occurred 12,000 years ago (Allen et al., 1986). Flood water roared through Idaho and down the Columbia River, carrying boulders, icebergs, glacial wash, loess, and other materials from as far away as Idaho and eastern Washington down through the Columbia River Valley and into the Willamette Valley. Water was directed through two gaps at Lake Oswego and Oregon City when a hydraulic dam was created between Kalama Gap and Crown Point. Approximately a third of the flow in the Bretz Flood sluiced down the Willamette Valley. h-t effect, the Willamette Valley was a backwater alcove for the floods. Each flood inundated the Willamette Valley from the Columbia River as far south as Eugene under nearly 400 feet of water. This lake, named Lake Allison, was one of the four temporary major lakes formed by flooding, glacial melt, and impoundment, and extended as far south as Eugene..As water flowed farther down the valley, it slowed, leaving larger bedload materials lower in the valley and depositing silts and smaller materials farther south. The Eugene area, at the far end of Lake All/son's reach, experienced the finest deposition of silts and clays. Most of these depositions reach to the west of Eugene. These Mits form the lower parts of the Willamette Silt soil type (Alien et al., 1986). Seismic Hazards The seismic hazards in the region result from three seismic sources: interplate (subduction) events, intraslab events, and crustal events. Each of these events has different causes, and therefore produces earthquakes with different characteristics (that is, peak ground accelerations, response spectra, and duration of strong shaking). All three types of earthquakes threaten the Eugene-Springfield area. However, because the strength of shaking decreases with increasing distance from the earthquake source, the most severe shaking will result from either shallow crustal earthquakes or great subducfion zone earthquakes (Mabey and others, 1993). Two of the potential seismic sources, subduction and intraslab events, are related to the subduction of the Juan de Fuca plate beneath the North American plate. Subduction events occur as a result of movement at the interface of these two tectonic plates. Lntraslab events originate in the subducting tectonic plate, away from its edges, when built-up stresses in the sUbducting plate are released. These source mechardsms are referred to as the Cascadia 2-.6 MWMC_ZO_REV23 DOC Subduction Zone (CSZ) source mechanism. The CSZ originates off the coast of Oregon and Washington and subducts beneath both states. The two source mechan~ms associated with the CSZ currently are thought to be capable of producing moment mag~tudes of approximately 9.0 and 7.5, respectively (GeomatrLx, 1995). Earthquakes caused by movements along shallow crustal faults, generally in the upper 10 to 15 miles, result in the third source meclxanism. In Oregon, these movements occur on the crust of the North American tectonic plate when built-up stresses near the surface are released. According to the Oregon Department of Geology and Mineral Industr/es (DOGAMI), the two largest earthquakes Ln recent years in Oregon, Scotts Mills, (magrfitude 5.6) and Klamath Falls main shocks (magnitude 5.9 and magnitude 6.0) of 1993 were crustal earthquakes (DOGAMI, 2004). Historical Seismicity and Earthquake Risk and Probability Two earthquake databases managed by the U.S. Geological Survey (USGS) National Earthquake Information Center were searched to identify magnitude and location of historical seismic events that have occurred within 60 miles of the Project site (USGS, 200la). The databases searched were, 'USGS/NEIC 1973-Present,' and "Significant U.S. Earthquakes (1568-1989)." These searches identified 31 seismic events of all magnitudes and intensities that occurred between 1592 and 2004 (the records are more complete for the time period from 1987 to present). Table 2.2.3-1 identifies only those seLsmic events that meet rite following criteria: Magnitude and/or intensity data are available. The magnitude of the event is 3.0 or h~gher. The intensity of the event using the Modified Mercalii (MM) Intensity Scale (Table 2.2.3- 2) is III or h_~gher, or the event was actually "felt." For reference, an intensity of MM III is associated with shaking that is "felt quite noticeably by persons indoors, especially on upper floors of btdldings. Many people do not recognize it as an earthquake" (USGS, 2002). In comparison, an event with an intensity of MM VII would produce the following effects: "Damage negligible in buildings of good design a_nd construction; slight to moderate in well-built ordinary structures; considerable damage in poorly bu]tt or badly designed structures; some chimneys broken. Noticed by persons driving motor cars'(USGS, 2002). The seismic event was not an affershock associated with a larger quake at the same location. MWMC_2.D_REV23 DOC 2-7 MWMC FACiLITiES PLAN TABLE 2.2.3-1 Historical Seismic Events That Have Occurred Within 6¢ Miles of the MWMC Service Ama2 MWMC Facilities Plan, Eugene-Springfield Latitude Longitude Distance Year Month Day (° North) (° West) Magnitude3 Intensity4 (miles) 1892 2 4 45.50 122.70 5~0 VF 35.4 1896 4 2 45,20 123.20 5,0 VF 12.4 1953 12 16 45.50 122~70 5.0 VIF 35.4 1957 11 17 45.30 123.80 4.0 VIF 40.4 1959 8 4 45.68 122,27 4.7 VF 57.8 1961 8 19 44.70 122.50 4,5 WF 36.0 1961 11 7 45.70 122,40 4.5 VIF 54.7 1962 1 t 6 45.64 122,59 5.2 VI ~F 46.6 1963 3 7 44.88 122.74 4.6 VF 19.3 1963 12 27 45.70 123,40 4.5 VlF 47.8 1987 10 2 45.63 122.65 3.0 IVF 44.1 1989 8 1 45.61 122.46 3.9 VF 47.8 1990 4 6 45.47 123.55 3.2 I~IF 37.3 1991 3 5 45.79 122.68 3,1 IVF 53.4 1991 7 22 45.64 122.87 3.5 IVF 41.0 1991 10 18 45.63 122.90 3.1 F 40.4 1991 10 21 45,63 122.89 3.0 IIIF 40.4 1993 3 25 45.03 122,61 5.7 VHC 21.1 1993 3 25 45.03 122.60 3.0 F 21.7 1993 3 25 45,03 122.61 3 2 IVF 21.7 1993 3 26 45.04 t22.62 3,0 -- 21.1 1993 3 26 45.05 122.63 3.1 IVF t9.9 1993 6 8 45,03 122.60 3.7 IVF 21.7 1995 2 8 45.13 122,71 3.7 VF 17.4 1995 6 13 45.92 122.98 3,0 IVF 59.7 1996 8 2 44.98 122.65 3.3 F t9.9 1999 7 16 45.65 122.77 3.2 F 42.9 1999 11 25 45.12 122.78 3.4 VF 13.7 2003 4 24 45.64 122.75 3.9 lllF 42.9 2003 7 25 45.64 122.74 3.0 IIIF 43.5 2-8 MWMC_2 O_REV23,DOC Z STUDY AREA CP~RACTER~S~CS TABLE 2.2.3-1 Historical Seismic Events That Have Occurred Within 60t Miles 0f the MWMC Service Area2 MWMC Facilities Plan, Eugene-Springfield Latitude Longitude Distance Year Month Day (° North) (o West) Magnitude3 Intensity4 (miles) 2004 2 26 45.65 122.75 3.0 IIIF 43.5 1The approximate center of the MWMC service area is located at latitude 45° 05' 00" N, longitude 123° 07' 00" W. 2 Source: USGS Earthquake Hazards Program (see http://neic.usgs.Qov/neis/epic/epic circ.htmlL The database search included Significant U.S. Earthquakes 1568 to 1989 and USGS/NEIC (PDE) 1973-Present. The only earthquakes in the database recorded prior to 1953 include two events, in 1892 and 1896. 3 Magnitude values are calculated by the USGS. Magnitude values are Local Magnitudes (LM) and Coda Duration Magnitude (MD). ML magnitude is generally referred to as the true "Richter magnitude." The values are computed for distances less than 600 km w~th depths less than 70 kin. MD estimates are derived from the duration or coda length of earthquake vibrations. Duration or coda magnitude scales are normally adjusted to agree with ML(see http'//neic.usgs.gov/neis/epic/code_magnitude.htmt). 4 Modified Mercalli intensity scale. Dashed line equals no data for that event. Based on J_rfformation from the USGS database, numerous small earthquakes with magnitudes between 3 and 5 have occurred with 60 m/les of the M-WMC service area during historical times. The closest earthquakes were magnitude 5.0 and 3.4 events that occ~arred 12.4 and 13.7 miles from the approximate center of the service area. The largest h/storicat event was an estimated magnitude 5.7 earthquake that occurred in 1993, approximately 21 miles from the center of the service area. As noted above, the two largest earthquakes in recent years in Oregon include the Scotts Mills, (magnitude 5.6) and Kdamath Fails quakes (magnitude 5.9 and magnitude 6.0) of 1993 (both_ earthquakes were beyond the 60-mile radius noted in Table 2.2.3-1) According to the Uniform Building Code Seismic Risk Map of the United States, the Eugene-Springfield metropolitan area (and most counties west of the crest of the Cascades, including the Willamette Valley and the Portland Metro area) are located in Seismic Zone 3 (UBC, 1997). This seismic zone corresponds to an intensity VIII earthquake cm the MM Scale. An intensity VIII earthquake can produce slight damage in specially designed structures to considerable damage in ordinary substantial buildings, with partial collapse(see Table 2.2.3.2). An earthquake magrdtude of 9.0 was selected as being the controlling event at the Project site (USGS, 2003). The earthquake magnitude selected for the Project site was based on USGS deaggregation seismic hazard mapping for the Eugene-Springfield metropolitan area. The latitude and longitude of the approximate center of the site was entered into the USGS database to obtain seismic magnitude probability for the Project location. The USGS seismic hazard maps present the average magnitude of all potential sources at a given locat/on, and provide the percent contribution at discrete locatfons of the overall seismic hazard. This magnitude event (9.0) corresponds to a 475-year mean return interval. Seismic ground acceleration for the Project site was determ/ned according to the National Earthquake Hazards Reduction Program (NEHRP) maps for probabil/st/c ground motion MWMC_2.0_REV23 DOC 2-9 MWMC FACILITIES PLAN (FEMA, 1997), and the USGS National Seismic Hazard Mapping Project database. One of the values generally used to determine an earthquake's relation to building damage is peak ground acceleration (PGA). According to USGS, a PGA of 0.10 g (g equats the acceleration as a result of gravity) maybe the approxLmate threshold of damage to older (pre-1965) dwellings or dwellings not made to resist earthquakes. In comparison, some posh1985 dwellings, built to California earthquake standards, have experienced severe shaking (0.60 g) with only chimney damage and damage to dwelling contents. The PGA at the site corresponding to a 10 percent probability of exceedance in 50 years (approximately 475-year mean return period) is approximately 0.18 to 0.19 g at the bedrock surface. This value of PGA on rock is an average representation of the acceleration most likely to occur at the site for all seismic events (crustal, intraplate, or subduction) for the 475- year return period. TABLE 2.2.3-2 Modified lVlercalli Scale MWMC Facilities Plan, Eugene-Springfield M~& Accel Description of intensity Level intensity %g I 0.1 Not felt except by a very few under especially favorable circumstances. Felt only by a few persons at rest, especially on upper floors of buildings. Delicately II 0.2 suspended objects may swing. Fait quite noticeably by persons indoors, especially on upper floors of buildings. Many ~ll 0.3 people do not recognize it as an earthquake. Standing motor cars may rock s~ightly. Vibration similar to the passing of a truck. Duration estimated. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, IV 0.7 windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects V 1.5 overturned. Pendulum c~ocks may stop. VI 3 Felt by all; many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight. Damage negligible in building of good design and construction; slight to moderate in well- Vii 7 built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving motor cars. Damage slight in specially designed structures; considerable in ordinary substantial VIII 15 buildings, with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Damage considerable in specially designed structures; well-designed frame structures iX 32 thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations, Some welbbuiit wooden structures destroyed; most masonry and frame structures with X 7O foundations destroyed. Rails bent. Xt Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bent greatly. Xll Damage total. Lines of sight and level distorted. Objects thrown into the air. Note: The approximate values of acceleration shown are not part of the definition of MM intensity. The values are from Richter, C., Elementary Seismology, W.H. Freeman, 1958. 2-10 MWMC_2 0_REV23 DOC STUDY AREA CHARACTERISTICS Liquefaction Liquefaction is a phenomenon in which shaking of a saturated so/~ causes its material properties to change so that it behaves as a liquid. Lateral spreading ks a liquefaction- induced hazard that involves the displacement of essentially intact blocks of soil either downslope or toward a free face, such as a river channel. In the Eugene-Springfield area the lateral spread hazard ranges from none to moderate, with a moderate lateral-spread hazard within the Holocene meander belts of the Willamette and McKenzie Rivers. Soils that liquefy tend to be young, unconsolidated, water-saturated silts and sands with low clay content. Older (Pleistocene) gravels with a thin veneer of silt (outside the meander belt) or young (Holocene) sand and gravel (~rtside the meander belt) underlie that part of the Eugene-Springfield area potentially subject to liquefaction. Gravel will liquefy only under exceptional conditions. Within the modem meander belts of the Willamette and McKenzie Rivers, shear wave velocity measurements indicate that the youngest sands and gravels may liquefy. This urdt averages about 5 meters (approximately 16 feet) in thickness with a range of 0-8 meters (approximately 0-26 feet) (DOGAMI, 2000). A seismic vulnerability evaluation was performed in 1996 to provide a preliminary opinion on major seksrrdc weaknesses and deficiencies at the WPCF. The report revealed that the potential for liquefaction or other permanent ground deformation is low for all structures except the plant ouffall (see Section 2.2.4). Landslides tn the Eugene-Springfield area, slope instability from strong shaking could be a significant threat. However, the movement and characteristics of existing landslides are highly variable, ranging from active movement to stable. Although most earthquake-induced landslides occur in materials not previously involved in sliding (Keefer, 1984), it would require numerous site-specific studies to analyze landslide hazards in the area and to understand the nature of each of the landslides that currently exist in the Eugene- Springfield area. However, hazard characterizations for the area are provided on the Relative Earthquake Hazard Map of the Eugene-Springfield Metropolitan Area (Figure 2.2.3-2). Seismic Hazard I~ap Areas prone to seism_~c hazards in the Eugene-Springfield area are identified on the Relative Earthquake Hazard Map of the Eugene-Springfield Metropolitan Areaa (Figure 2.2.3-2) (DOGAMI, 2000). The map depicts the relative risk of earthquake damage that results from local geologic conditions. The composite hazard map was developed by combining single hazard maps for ground motion amplification, and slope instability. The single component maps were developed to show geographic patterns of stronger earthquake effects for two likely sources. Zones that are expected to have the most pronounced damage in any moderate or larger earthquake are shown on the map as having the greatest hazard. 2 The map depicts earthquake hazard zones that are based on limited geologic and geophysical data. The map is not a substitute for site-specific investigations by qualified practitioners. At any point in the map area, site-specific investigations may give results that differ from those shown on the map. For a complete understanding of the earthquake hazard, consultation of the following DOGAMI publication is also recommended: Madin, I.P., and Mabey, M.A., 1996, Earthquake Hazard Maps for Oregon: Oregon Department of Geology and Mtneral Industries Geological Map Series GMSIO0. MWMC_2.0_REV23 DOC 2d ~ MWMC FACILITIES PLAN 2,2,4 Public Health Hazards Four types of potential public health hazards were evaluated for the WPCF: Air pollution restrlting from chlorine or sulfur dioxide releases at the facility Air pollution from other facility sources (e.g., wind-blown dust or combustion engine exhaust) · Worker or public exposure to chlorine or sulthar dioxide, or physical collapse of onsite buildings due to seksmic instability · Potential biohazard from spill of biosolids during offsite transport The first potential public health hazard (chlorine or sulfur dioxide release) ks addressed under EPA's Risk Management Program (RMP) Rule. This rule, developed in 1996 following guidance under the Clean Air Act Amendments of 1990, requires companies using more than threshold quantifies of certain flammable and toxic substances to develop a Risk Management Plan (RIvIP). Risk Management Plans include the following features (EPA, 2002): Hazard assessment detailing potential effects of an accidental release, an acddent history over the last 5 years, and an evaluation of worst-case and alternative accidental releases · Prevention program describing safety precautions and maintenance, monitoring, and employee training measures Emergency response program detailing emergency health care, employee training measures, and procedures for informing the public and response agencies if an accident occurs Chlorine and Sulfur Dioxide Usage at Existing Facilities Currently, the WPCF uses chlorine gas for disinfection of effluent prior to wastewater discharge into the W/llamette River. Cl'dorine has been an effective disinfectant at the WPCF. No chemical release accidents resulting in injury to facility workers or the public 1-~ave occurred in facility history. Disinfected wastewater has met permit requirements consistently since plant startup in 1984. Sulfttr dioxide gas ks used to dechlorinate WPCF effluent prior to discharge into the Willamette River. Sulktr diox/de is transported to the WPCF in pressurized 1-ton containers. It is metered by one to two sulfonators to the effluent channel just upstream of the pipe. The sttlfur dioxide system has proven effective in controlling chlorine residual to meet effluent requirements. A 2-ton capacity emergency scrubber is located in the chemical buddding. The neutralizing chemical in the scrubber used during a chlorine or sulfur dioxide leak is sodium hydroxide. The scrubber has been operational since plant startup. Z STUDY AREA CHARACTERISTICS Accident History for Chlorine and Sulfur Dioxide No accidents chlorine sulfur dioxide releases have occurred on Oregon roads involving or since 1980, according to the Oregon Department of Transportation - Accident Data Unit (ODOT-ADU; Date). No reportable leaks of sulfur dioxide have occurred since plant startup in 1984. No reportable chlorine leaks occurred at the plant between 1984 and August 14, 1993. On August 15, 1993, the plant experienced a major chlorine leak totaling 1,300 pounds. The leak was fully contained within the cherrdcal storage building and contarrdnated air was neutralized by emergency scrubbers prior to release. No plant personnel were injured, and the leak posed no public health hazard. Between August 16, 1993 and July 15, 1996, four minor chlorine leaks of less than one pound each occurred at the fac/lity. Since July 1996, nine additional minor leaks occurred. These minor leaks were fully contained, and the air was scrubbed prior to release. EPA Risk k~anagem.ent Program Regulation Chlorine (threshold quantity > 2,500 pounds) and sulfur dioxide (threshold quantity > 5,000 pounds) are regulated under RMP guidelines. WPCF plant operations exceed these threshold quantities; therefore, the EPA RMP rule applies to the WPCF. Under the RMP rule, the WPCF was required to prepare an RMP by June 21,1999. The WPCF is operating under an RMP and will update the Plan (following the RMP rule for 5-year updates) in 2004. Hazard Assessment Under the RMP r_de, the hazard assessment focused on the offsite environment and neighbors around the facility. The assessment included an evaluation using an EPA air dispersion computer models. The results of the assessment were based on a range of releases, including worst-case and alternative release scenarios, an analysis of potential offsite consequences, and a 5-year accident bSstory at the facility. The worsbcase scenario involves 100 percent release of a 1-ton container of chlorine or sulfiar d/oxide. The model calculates the concentration of the chemical in a dispersion pattern of 360 degrees until an endpoint of three parts per million (ppm) is reached (City of Eugene, 2001). The aitemative scenarios were determined by facility staff in accordance with typical accidents, such as leaks during container exchanges. In all release scenarios, the regulated substance concentrations at the nearest public and/or environmental receptor were estimated based on either air dispersion models or other available data. For the worst-case scenario, the computer model indicated that an endpoint concentration of three ppm chlorine would reach a distance of 0.9 from the sottrce. However, an important feature of the facility is the fact that both chlorine and sulfur dioxide are stored within a containment bu/lding constructed specifically for the purpose. The structure is constructed of concrete and steel, so the risk from fire is negligible. The containment building is designed with tight-fitting doors and normally closed inlet louvers to contain a potent~l leak and to facilitate the use of a chemical scrubber system. In addition, air dispersion models are intentionally conservative in nature. This means the endpoint concentration of three ppm would not likely reach a distance of 0.9 mile as suggested by the model. 3 The scenano was modeled using RMP*Como version 1 06, which is available via the Intemet from EPA's CEPPO Web site. Only passive mitigahon is allowed in this scenario, so the containment building was factored in at 55 percent according to guidance documents. The containment building at the facitity would exceed the passive mr~igation factor of 55 percent. MWMC_2,0_REV23 DOC 2-13 MWMC FACILITIES PLAN For the alternative scenario4, the endpoint concentration was reached at a distance of less than 0.1 mile. The radius does cross the fenceline of the facility on the east side, but no dwellings exist in this area. The only offsite consequences under th/s scenario are a bike path, and a recreational vehicle dump site on the north side. Both chlorine and sulRu' dioxide were analyzed under the alternative release scenario and similar endpoints were determined. Prevention Program The EPA prevention program is a substantial element of the l~2vIP rule. This program focuses on employees at the facility and includes a list of ten components of compliance. These components can be satisfied by complying with similar requirements of the Occupational Safety and Health Association (OSHA) Process Safety Management (PSM) program. The WPCF met the final OSHA PSM compliance deadline of May 1997. Risk Management P~an The risk management component of the RMP consists of completing general paperwork and submitting it to responsible agencies and to the public. The risk management section completed for the WPCF includes the following sections: Description of major hazards, such as equipment failure, human error, and nabaral phenomena, that could lead to a significant accidental release Description of the consequences of failing to control for major hazards Summary of all actions taken or planned to address these hazards, including starting states · Methods for prevention or mitigation of significant accidental releases Public Health Risk from Chlorine and Suffur Dioxide Chlorine and sulfur dioxide are extremely hazardous substances. Increasing concerns about security and the potential severity of life safety consequences of an uncontrolled major release resulted in a review of alternative disinfection technologies. The M~IC is interested in replacing gaseous chemical disinfection with a safer alternative disinfection technology such as hypochlorite and bisulfite solutions. Until then, the risks associated with the use of chlorine and sulfur dioxide will continue to be managed through controls such as regular maintenance, engineering features to contain and treat contaminated air, training and work rules at the facility, and operational safety procedures. Air Toxics and Regulatory Assessment Based on regulatory review, there are no significant, outstanding air quality compliance issues for the WPCF. The facility is in compliance with all federal regulations and with 4 The alternative release scenario allows the use of active mitigation such as the scrubber system. The scrubber system was assumed to be 99 percent efficient and the endpoint concentration was reached at a distance of ~ess than 0.1 mi~es, he scenario itself was based on a break in a one-inch pipeline used to transport liquid chlorine or suffur dioxide from the cylinder to the evaporator. A pipeline break was chosen for the analysis not because it represents the most likely scenario, but it does represent a more conservative estimate. The release rate from the broken pipeline in pounds per minute was determined using tables furnished in the guidance documents from EPA for wastewater treatment facilities. 2-14 ~MC_z0_REV23 DOC STUDY AREA CHARAC3ERISTICS requirements of the Lane Regional Air Pollution Authority (LRAPA), the pr/mary agency working with WPCF Regional Wastewater Program on quahty staff issues. An emissions inventory was conducted in 1997 to identify and describe all possible sources of air emissions found at the WPCF. Calculatiorts based on EPA-approved/reviewed methodologies were performed for the significant emissions sources identified at the WPCF. The results indicate that the IArPCF is not a major source of cr/teria pollutants or hazardous air pollutants (HAPs) (see Section 2.2.8). Given the chlorine and sulbar dioxide storage capacities at the WPCF, the facility is required under federal rule to implement an RMP. The WPCF currently is operatkng under an RMP and wffi update this Plan in 2004. Future issues that could prompt compliance-related discussions with LRAPA include: Public nuisance issues - Dust blowing off site Emissions from internal combustion engines on site Proactive air quality measures currently are in place at the facility to achieve the following: · Identification of the next project activity that is likely to require an LRAPA permit and activities necessary to meet the permit/construction schedule · Review of the air emission inventory list on file with LKAPA, and identification of any additional emissions units or emissions activities that could be updated or expanded · Tracking emerging regulatory of issues Public Health Risk from Air Emissions The WPCF currently is in compliance with federal air quality regulations and with LRAPA guidelines (see Section 2.2.8). Public health risks from WPCF-related air quality issues are tow. Seismic Vulnerability A seismic vulnerability evaluation was performed in 1996 to provide a preliminary opinion on major seismic weaknesses and deficiencies at the WPCF. The evaluation indicated that the existing fac~ty is in good repair, -with no signs of damage from past wind storms or seismic events. Potential for liquefaction or other permanent ground deformation is low for all structures except the plant outfall. Forty-two seismic deficiencies for individual elements at the plant were discovered, and short-term improvements were recommended for 16 of the 42. Structural improvements were completed in 1998 for the following facilities: Sludge transfer pump station building e Gas mixing building No. 2 Pretreatment facility building Secondary control complex building Maintenance building Final treatment complex NlWt/IC_2.0_REV2$ DOC 2-15 bIWMC FACILtTIE~ PLAN The upgrade qualified all nine buildings to meet the current building code requirements for seismic loading. Public Health Risk from Catastrophic Release of Chlorine and Sulfur Dioxide Structural deficiencies at the plant could pose health risks if a seismJc event resulted in structural damage to facil/ties and building collapse (risk to plant workers), or cherrfical release (risk to plant workers and the public). However, the recommended seismic upgrades have been completed and, therefore, potential public health risks from seismic activity near the WPCF are low. Additional information on the RMP for chlorine and suifiar dioxide is presented above. Biosolids Transpor~ Biosolids are transported £rom the WPCF via pipeline to the BMF at a separate site. There, they are put into a sludge lagoon and subsequently processed (dewatered). The dewatered cake is transported via trucks to cooperative farms for land application. These are Class B biosolids, highly regulated, and not fit for land application on crops for humm-t consumption. Alternatively, biosolids will be pumped in liquid form to the Biocycle Farm for liquid land application, or dewatered cake will be transported via truck for land application. Because biosolids are transported offsite, via pumping or by truck, and spread for land application, there is potential for a spill. However, a cleanup and response protocol for biosolids spills is in place, and the potential for pUblic health hazards res~xlting from a biosolids spills is low. Public Hea~th Risks from Biosolids Transport As noted above, biosolids are transported to onsite application areas through an enclosed biosolids distribution system, and dewatered cake is transported via trucks to cooperative farms for land application. If additional neighboring land is required for disposal, biosolids will be transported off site by truck. MWMC has developed a spill response plan that details act/ohs to take in the event of a biosolids spill. The plan includes over-the-road spill response and clean-up proceduress. 2.2.5 Energy Management and Consumption During development of the 1997 Master Plan (CH2M HILL, 1997), a condition assessment of the WPCF was performed. This evaluation confirmed that the facility's energy consumption is extremely low ha comparison to other similar treatment facilities. The plant operating staff has been very cognizant of energy consumption in the operation of the fac4~ty, and has been aggressive in both implementing improvements to reduce energy consumption and in obtaining grant funding to implement those improvements. Staff also have further managed continuous improvement of energy consumption through development and implementation of a Environmental Management System. The WPCF is ISO 14001 certified and includes an ongoing objective to reduce energy consumption. Numerous work programs have been implemented that indude targets and measures to manage its continuous improvement strategy. 5 MWMC's bioso~ids spill response and cleanup procedures are adapted from the Biosolids Hau~er Spill Response Procedure--CWEA Manual of Good Practice for Agricultural Land Application of IBiosohds, 1998. MWMC_2.0_REV23 DOC Z STUDY AREA CHARACTERISTICS Table 2.2.5-1 shows the annual energy consumption on a per million gallon treated basis for 10 Also shown is the of consumption for an activated sludge typical years. range energy secondary treatment plant. Energy consumption in 1997 was unusually low because it was a particularly wet year. RaLnfall for the year totaled 42 inches, measured at the Eugene Airport, as opposed to 26 inches, which is typical for the Eugene-Springfield area from January to Jmne (1995-96 Weathemet, Inc., data from 1961-90). As a result, although more wastewater was treated, additional energy was required simply for pumping the wastewater, not necessarily additional pollutant removal which is the more energy- intensive portion of the process, TABLE 2.2.5-1 Energy Consumption During Rscal Years 1994-2003 MWMC Facih'ties Plan, Eugene-Springfield Unit Energy Consumption Year (kWh/~G) FY 1994 1,386 FY 1995 1,221 FY 1996 1014 FY 1997 914 FY 1998 1094 FY 1999 1085 FY 2000 1059 FY 2001 t075 FY 2002 1006 FY 2003 1105 Typical range for activated sludge plant 1,300 to 2,300 Additionally, the energy audit determined that management of peak demands (i.e., the instantaneous power requirement) is excellent at the facility. The WPCF's load factor (the ratio of average energy use -to peak energy use) is approximately 77 percent, a number significantly above typical treatment plants and nearing the 80 percent load factors of such highly managed fadlities as hospitals. High peak demand requirements (i.e., low load factors) are typically a major contributor to the overall cost of energy in a treatment plant. To reduce energy demand at the WPCF, MWMC employs management practices such as control schemes Lhat in,bit the simultaneous operation of large horsepower motors during equipment staging, and operator awareness training aimed at eliminating overlapping operation of large energy users during startup and shutdown procedures. 2.2.6 Water Resources The following discussion focuses on water quality parameters including max/mum water temperature, bacteria, heavy metals and nutrients. Each represents a class of pollutants that MWMC_2.0_REV23.DOC 2-17 MW'MC FACILITIES PLAN have the potential to influence fish and other aquatic organisms. In the discussion regarding bacteria, nutrients, and heavy metals, data obtained from ambient monitoring program, s in rivers and streams have been separated from data obtained by sampling stormwater discharges dur;mg wet weather events. Typically, pollutant concentrations of bacteria, nutrients, and heavy metals are higher in wet weather stormwater discharges than in rivers and streams. The water quality monitoring programs that generate data used for this study do not include analysis for pesticides. Because the mainstem of the Willamette River is the water body that would be most directly affected by potential expansion of major MWMC facilities, this section only examines selected characteristics for water quality in the mainstem. For a more detailed description and comparison of treated wastewater discharge and water quality in the Willamette River in the vicinity of the WPCF ouffall, see section 5.3, Water Quality Impact. It should be noted that the following discussion on water quality was adapted from a description on water quality originally published in the Aquatic and Riparian Habitat Assessment for the Eugene-Springfield Area, September 2002, Final Report, by the Eugene- Springfield MECT (MECT, 2002). Natural influences on Water Quality Streams in the IVIWMC study area (e.g., Amazon Creek, Willow Creek) are influenced primarily by the geology of the fiat valley floor, a landscape that does not promote infiltration of water or delayed release of winter precipitation into the dry season. These water bodies tend to warm quickly in the suma~er and are relatively high in sediment and nutrients at other times of the year. Water quality in the maiustem of the Willamette River is directly affected by underlying surface geology. Creeks and rivers that flow into the Willamette mainstem upstream of the MWMC service area (Le., McKenzie River and Middle Fork Willamette River) originate in the Cascade Mour~tains in porous rock that is young in geologic age and favors deep infiltration and delayed transfer of-water to channels, where there are few opportunities for warming and incorporation of nutrients or other substances. Further downstream, these two rivers flow through rock of older geologic age consisting of porous, fractured basalt that also promote deep infiltration of runoff and delayed transfer of water to the rivers, although the effect is not as significant as further upstream. Upon reaching the flat valley bottoms, groundwater influx to the rivers is low, warming accelerates, fine-grained sUbstrates that line the stream banks are readily incorporated, and nutrient-rich lenses of water within the Missoula flood deposits leach into the rivers. Human ~nfluences on Water Quality In addition to structural modifications to water bodies irt the area such as charmelization and dredging, human influence on the river includes non-point source discharges from stormwater runoff and permitted point source discharges. Permitted discharges include discharge of treated sanitary wastewater into the Coast Fork downstream of Cottage Grove, and into the Willamette River downstream of Eugene. In addition, cooling water is discharged from power generation facilities at the University of Oregon into the Eugene Mill Race (an artificial side channel of the Willamette River), and from both treated and non- contact process water from numerous industries in both Eugene and Springfield that 2-~ 8 MANMC_2.0_REV23.DOC STUDY AREA CHARACTERISTICS discharge to the McKenzie and Willamette rivers. Other activities upstream of the study area may result in water quality changes. These activities and possible altered parameters include forestry (sediment, herbicides, temperature), agriculture (sediment, herbicides, nutrients, pesticides, bacteria, temperature), rural residences (sediment, bacteria, nutrients, temperature), and old m~nes (heavy metals). Water Temperature In Oregon the water temperature standard in a basin for which salmon and steelhead spawning is a designated beneficial use is 55.4° F from October 15 through May 15 (OAR 340-04t-0028(4)(a)). The Oregon water temperature standard in a basin for which salmonid fish rearing and migration is a designated beneficial use is 55.4° F from October 15 through May 15 (OAR 340-041-0028(4)(c)). Although the natural temperab~re regime of many water bodies will exceed 64° F at various times of the year, the aim of the standard/s to protect beneficial uses most sensitive to water temperature--in this instance, fish and aquatic life. The mainstem Willamette River exceeds the numeric criteria and, therefore, the river has been identified as water quality-lirrfited for temperature. In order to determ/ne the magnitude of the temperature change on the Wffiamette River, the WPCF wastewater staff collected in-stream temperature data in 2003 at locations upstream and downstream of the diffuser ouffall, and of WPCF effluent~. The sections below discuss results of the in-stream temperature monitoring program. Management staff at the WPCF believe the temperature effects of the effluent from the facility are insignificant because: Temperature-monitoring results for the period of April to November 2003 show that river temperatures downstream of the ouffall are less than those measured upstream. These results are consistent with those reported to the DEQ for river temperature monitoring done in 2002. e Under conditSons of 7Q10 river flow? and maximum measured effluent temperature, the calculated temperature increase of the Willamette River downstream of the WPCF ouffall at the edge of the mixing zone is 0.3 F°, less than the 0.5 F° human use allowance specified under OAR 340-41-0028(12)(b)(A). Daily regulatory mixing zone (RMZ) calculated temperatures using upstream temperature and plant effluent data, and a mixing ratio of Willamette River flow to effluent flow of 12:1, indicate no exceedance of the 0.5 F° human use allowance over the monitoring period. Similarly, no exceedance was obser~'ed for maximum 7-day average temperatures. 6 In addition, probes were deployed throughout the plant to evaluate the relative temperature change over each treatment stage. Monitoring locations included the influent waste stream, preliminary treatment, pnmary clarification, activated sludge return, aeration, and secondary cladticat,on. These data were used to assess waste stream thermal loads due to trea~nent processes, and to aid E-S wastewater management staff in assessing options for process temperature management 7 The 7Q10 refers to the lowest consecutive 7 day streamflow that is likely to occur in a ten year period. ~t is used by many states and the federa~ government in setting discharge Iim~s in NPDES water quality permits. A permit will only be granted the proposed amount of pollutant that will be discharged into a river will not significantly impair the designated uses, such as drinking or swimming, when the streamflow falls to the 7Q10 level. MWMC_20_REV23.DOC 2-19 MWMC FACILmE$ PLAN In adclition, management staff anticipate that the WPCF will not be a sigrdficant thermal load source under the biologically based numeric criteria of 55.4 °F (13 °C) £or salmon and steelhead spawning from October 15 tlxrough May 15, and a human use allowance temperature increase of 0.5 F° (0.3 C~). To put the water temperature data in perspective, in general, the coo~ess of water at night has some bearing on the ability of cool-water fish to withstand ma×imva-n water temperatures dur~g the day. Because fish are cold-blooded, their energy needs increase with increasing water temperature. Trout usually leave water that regularly exceeds 70° F during the day. Rivers and streams with Iow water temperature at rdght enable fish to rejuvenate and be better prepared for the next day's increased water temperatures. Bacteria Monitor~mg for E. coli in the Willamette River in the MWMC service are has occurred over a number of years and for a large number of sites. The mainstem o£ the Willamette River had no exceedances of the state water quality standard. Currently, Escherichia coli (abbreviated as E. colO is widely used to evaluate the level o£ harmbal bacterial contamination in water. In Oregon, the water quality standard £or E. cdi ~s 406 orga~dsms/100 m~ll~liter (mL) to protect swimming and aquatic life; the drinking water standard is <1 orgardsms/100 mL. These organisms, along with other, more harmful types, have their origin in the intestinal tracts of humans and some ardmals. While E. co[i counts alone do not measure contamination risk for humans, they are indicative of stormwater quality entering rivers and streams. Perhaps more importantly, they are indicators of potentially more significant water quality issues that are generally associated with land development. Although naturally occurring bacteria in streams generally have no affect or~ fish, other aquatic orgardsms, or wildlife, certain types of bacteria or high concentrations may pose a health risk to people through recreational contact with the water. In addition to bacteria, other water-borne protozoa and d~sease-causing microorganisms can adversely affect human and animal health. Because of the number of various organisms with the potential to affect health, mordtor~g commonly focuses on easily-detected but relatively harmless bacterium that frequently occur with the other, more harmful varieties. Heavy Uetals Heavy metal concentrations in Oregon streams and rivers are generally well below water quality standards. Where concentrations above water quality standards are found, it is usually a result of contamination from human sources, such as industrial sites, paved surfaces, mining operations, galvanized metal siding and roofs on buildLngs, and water trea~ent plants. Aquatic insects and algae are organ~sm_s most affected by high concentrations of heavy metals, ~y of which readily adhere to sediment particles so they may not appear in the water column except at short distances downstream from their SOurCe. With few exceptions, heavy metal concentrations in the Willamette River are, on average, less than the water quality criteria specified by DEQ. In many instances, the concentrations are several orders of magnitude less than the criteria. Water quality data in the IVIWMC 2-20 MWNtC_20_REV23 DOC service area are available for a number of heavy metals that are harmful to aquatic life, such as zinc, cadmium, chromium, copper, lead, mercury, and nickel. Above a certain concentration, these metals have been determined to be toxic to aquatic life; thus, the Oregon DEQ has established a set of water quality standards for their protection. These are specified in OAR 340-41. When applicable, the standards consider water hardness (a measure of mineral salts dissolved in the water). A discussion of the heavy metals found in the Willamette River within the MWMC service area is presented below. Mercury has been found in some species of fish caught in the Willamette River and its major tributaries. The mercury in the fish is believed to come from natural volcanic and mineral sources and mining wastes in the headwaters of the Willamette River, and from human sources along the r~ver. Fish with high levels of mercury are resident fish that eat other fish, such as largemouth bass and northern pike mirmow. Anadromous fish that spend most of their adult life in the ocean do not have high mercury levels in their bodies. Potential sources of human-derived mercury include household products, food products, dental waste, wrecking yards (mercury-based automobile switches), fluorescent and compact lamps, and deposition of air-borne particles. In Lane County, perhaps one of the largest single sources of mercury in the Coast Fork Willamette River is rtmoff from the Black Butte rrdne, which was once the second largest mercury mine in Oregon until operations ceased in 1968. It is estimated that mine tailings on the site contain about 90,000 pounds of mercury, and that between 180 and 1,800 pounds of mercury is potentially mobilized into the environment each year (Weiss and Wright, 2001). The Oregon DEQ is currently conducting a TDML study of mercury in the W~amette basin. The Health Division has issued health for in fish for the Oregon advisory a mercury Willamette River. Ambient water quality monitoring of the Willamette River at four stations above, within, and below the Eugene-Springfield urban growth boundary suggests mg2Jmal mercury discharges from urban stormwater runoff and permitted point-source discharges. The average total mercury concentration upstream of the urban growth boundary is 0.00217/zg/L, while the average downstream of the urban growth boundary is 0.00232 gg/L. Effluent from the Eugene-Springfield wastewater treatment plant averages 0.00553 gg/L of mercury. These values are lower than the state chronic criteria standard of 0.012 #g/L. Flow-weighted averages for those days on which samples were collected are 60 grams per day (g/day) of mercury in the Willamette River, and 0.71 g/day of mercttry in effluent from the treatment plant. The City of Eugene reported no statistically significant difference between mercury concentrations detected upgradient and downgradient of the urban growth boundary. An evaluation of the long-term concentration trends for metals by the City of Eugene found that arsenic was decreasing over time. This was the only analyte demonstrating a statistically significant trend. Arsenic, a metalloid, is included in this discussion because it is toxic to aquatic organisms. Its chronic criterion is 48 #g/L and it is hardness- dependent. The decreasing trend is significant at I percent; that is, there is a 1 percent probability that the observed trend is caused by random sample variability. The cause for the decreasing trend is unknown, although changes in land use or practices within the drainage basin could lead to this phenomenon. MWMC_20_REV23 DOC 2-2~ FACILITIES PLAN Nutrients The productivity of fish and their food base hinges on the amour~t of bioavaitable nitrogen and phosphorus in the water. In natural waters of the Pacific Northwest, phosphorus is usually the nutrient that limits primary productivity, which includes algae and zooplankton. This means that, unless extra phosphorus becomes available, there will still be spare bioavailable nitrogen in the water column. Phosphorous The bioavailable form of phosphorus is referred to as soluble reactive phosphorus. There is another portion that is attached to sediment particles that is not immediately available for uptake by aquatic organisms, but has the potential to be released into the water column if dissolved oxygen levels become low. Shallow reservoirs, such as Fern Ridge Reservoir, can have low dissolved oxygen levels and release phosphorus from sediments, especially at night and during early fall when plant material begins dying off. Median values for total phosphorus concentrations are relatively low in the Willamette River upstream of the urban growth boundary at 0.03mg/L, and rise slightly to 0.06 mg/L downstream of the urban growth boundary near the Beltline Road bridge. Nitrogen Nitrogen has three bioavailable forms that include nitrate (NO3-), nitrite (NO2-), and ammonia. The term ammonia refers to two chemical species that are in equilibrium in water: un-ionized (NH3), and ionized (NH4+). Tests for ammonia usually measu~re total ammonia; that is, NH3 plus NH4+. The toxicity of ammonia is primarily attributable to the u~n-ionized NI-I3, as opposed to the ionized form NH4+. Irt general, the toxicity of NH3 to fish is a function of pH and water temperature. In the presence of NH3, an increase in either pH or temperature can be harmhd to aquatic organisms. Nitrate (NO3-) and ammonium (NH4+) are rarely found in Pacific Northwest streams and rivers except immediately downstream of point sources of pollution because chemical and biochemical processes in a river quickly transform them into nitrate. Consequently, most bioavailable nitrogen irt the Pacific Northwest is in the form of nitrate for streams, rivers, and groundwater. Nitrate and nitrite data evaluated below are reported as nitrate plus nitrite as nitrogen. This is abbreviated to the form NO3+NO2 (as N). Median values for combined nitrate+nitrite as nitrogen (NO3+NO2 as N) are 0.03 mg/L in the Willamette River upstream of the urban growth boundary, and rise slightly to 0.10 mg/L downstream of the Beltline Road bridge. Median values for combined nitrate+nitrite as nitrogen (NO3+NO2 as N) are 0.03 mg/L in the Willamette River upstream of the urban growth boundary, and rise slightly to 0.10 mg/L downstream of the Beltline Road bridge. A review of the long-term trend of NO3+NO2 data downstream of the urban growth boundary shows that concentrations are increasing with time. This is likely the result of continued development of land immediately upstream of the monitoring location. Stormwater The median value for total phosphorus at all composite stormwater-monitoring sites in Eugene is 0.25 mg/L, with values ranging from 0.09 to 11 mg/L. Concentrations of NO3+NO2 (as N) in Eugene stormwater samples ranged from not detected to 3.7 rog/L; the median was 0.06 mg/L. Sources for NO3+NO2 (as lq) are similar to those for phosphorus. 2-22 MWMC_ZO_RE¥23 DOC STUDY AREA CHARACTERISTICS Phosphorus in stormwater drains is ILkely a combination of runoff containing fertilizers, soaps, animal feces, soil erosion, atmospheric deposition, and potential leakage of hookups from adjacent sewage pipes or industrial sources. Conclusion As the Willamette River flows through the study area, it expe~ences increases irt pollutants that can be tied to human activities, but concentrations are far below state water quality standards (E. coil and total zinc) or levels of concern (nitrogen and phosphorus). Nevertheless, nitrogen concentrations have been increasing in recent years. Arsenic, copper, lead, zinc, E. co[i, nitrogen, and phosphorus are, on average, statistically lower in the WLllamette River upstream of the Eugene-Springfield urban growth area than at downstream locations. 2.2.7 Rora and Fauna This section provides a general description of wildlife species and habitat conditions in the vicinity of the ]VIWMC BMF, SIWF, Biocycle Farm,' and WPCF. Because of the potential for expansion of these facilities, this section focuses on habitat in and along the stretch of the Willamette River in the immediate vicinity of the above mentioned facilities (Figure 2.2.7-1). Habitat Types in the Eugene ~letropolitan Area According to the Aquatic and Riparian Habitat Assessment for the Eugene-Springfield Area (MECT, 2002), greater than 85 percent of the land area immediately (within 100 feet) surrounding the Upper Willamette River in Eugene (River Reaches 15-21) is vegetated. Of vegetated land, approximately percent supports trees, percent supports the 75 hardwood 13 shrubs, and 13 percent is pastureland, fields, or grass. Approximately 14 percent of land along the Upper Willamette River is not vegetated, with 5 percent of total riverside land covered by gravel bars and greater than 9 percent of the land developed (Table 2.2.7-1; Figure 2.2.7-2). TABLE 2.2.7-1 Percent Vegetated Areas, Developed Areas, and Graver Bars Within 100 Feet of the Upper Willamette River (River Reaches 15-21), Eugene, Oregon1 MWMG Facilities Plan, Eugene-Sp#ngfield Area Description Percent (%) of Total Area Hardwood trees 64.t Shrubs (including Willow) 10.8 Grass, pasture, fields 10.7 Total Vegetated 85.6% Gravel Bars 4.8 Developed Areas 9.5 Total Nonvegetated 14.3% Total 100% 1Adapted from METe, 2002. MW~C_2 0_REV23.DOC 2-23 MWMC FACILITIES PLAN Wildlife habitat along or near the W~amette River and its tributaries includes riparian habitat and wetland areas. Riparian Habitat Riparian areas are transitional between aquatic and upland habitat and, as such, support elements of both aquatic and terrestrial ecosystems (Lev, 1990). A 198%1988 survey by Lev (Lev, 1990) describes vegetation and wildlife species common in riparian habitat in the Eugene-Springfield metropolitan area. Riparian vegetation within the metropolitan area is characterized by herbaceous ground cover, understory shrubs, and deciduous (hardwood) trees. Plant species common in riparian habitat in the Eugene-Springfield area include black cottonwood (Populus trichocarpa), willow (SaIix spp.), Oregon white ash, creek dogwood (Comus stolinifera), snowberry ( Symphoricarpos albus), Himalayan blackberry (Rubus discolor), rush species (Juncus spp.), sedge species (Carex spp.), and reed canarygrass (Phalaris arundinaceae). Other plant species found in area riparian habitat include English hawthorne (Crataegus monogyna) and cattail (Typha latifoIia). Riparian areas in the Eugene metropolitan area provide habitat for a variety of wildlife. Mammals common in the these riparian areas include raccoon (Procyon lotor), beaver (Castor canadensis), nutria (Myocastor coypus), and bats. W~amette Pdver habitat supports as marly as 173 species of birds (Roesler, 2004), including wading birds (e.g., great blue heron [Ardea herodias], waterfowl (e.g., mallard ducks [Arias platyrhynchos]), shorebirds, raptors (e.g., osprey [Pandion haliaetus], red-tailed hawks [Buteo jamaicensis], a_nd bald eagles [Hatiaeetus teucocephalus]), kingfishers (Ceryle alcyon), and a variety of passerine birds (e.g., warblers and swallows) (Lev, 1990; CH2M HILL, 2001). In addition to birds and marranaL% as many as 14 species of amphibians and reptiles, such as the western pond turtle (CIemmys marmorata) use Willamette I~Sver riparian habitat (Roesler, year). The riparian corridors serve as travel routes for wildlife between wetland and upland areas and as stopover sites for migrating birds (Lev, 1990). The Willamette River and its tributaries are the primary riparian features in the vicinity of the WPCF. Following primary treatment (scum and solid removal), secondary treatment (bacterial digestion), and final processing (chlorination followed by addition of sulfur dioxide to dechlorinate), effluent is discharged into the Willamette River (City of Eugene Public Works Department, 2003). Wetland Habitat The U.S. Fish and Wildlife Service (USFWS) defines wetlands as follows (USFWS, 2004): Lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. Additionally, wetlands have one or more of the following attributes: - At least periodically, the land supports predominantly hydrophytes - The substrate ~s predominantly undrained hydric soil - The substrate is nonsoil and is saturated with water or covered by shallow water at some time during the growfftg season of each year Wetlands in the Eugene-Springfield metropolitan area are characterized by plant species such as willow, Douglas spirea (Spirea douglasiO, least spikerush (Eleocharis acicularis), reed 2-24 MWMC_ZO_REV23 DOC STUDY AREA CHARACTERiSTiCS canarygrass, rushes, sedges, cattail, and introduced species such as grasses (Poa spp., Fescue spp., Canthonia californica), hawthorne, and Himalayan These blackberry. rnetropolitan wetlands support a variety of wildlife, including reptiles (e.g., Western pond turtle[Clemmys marmorata]), amphibians (Clouded salamander [Aneidesferreus], birds (e.g., great blue heron, mallard, red-winged blackbird [Agelaius phoeniceus]), and mammals (e.g., nutria, raccoon, beaver, red fox [Vutpes vulpes]) (Lev, 1990). The location of wetland areas at or near the WPCF, as well as in the vicinity of the Biosolids Waste Management Facility and Seasonal Industrial Waste Facility are shown on Figure 2.2.7-3. Threatened, Endangered, and Sensitive Species Riparian and wetland habitat in the Eugene Metropolitan area supports several species listed under the Endangered Species Act (ESA) as Federally or State Endangered or Threatened, or as Federal Species of Concern or State Sensitive Species. Such designated species observed or likely to occur in Willamette River riparian and/or wetland habitat include two plants, one bird, one reptile, two bats, and two fish species (Table 2.2.7-2). TABLE 2.2.7-2 Species Classified as Endangered, Threatened, Sensitive, or Species of Concern Found in Wetland and/or Riparian Areas in the Greater Eugene Metropolitan Area MWMC Fac/lit/es Plan. Eugene-Springfield Species Type Species Name Common Name Federa~ Status State Status Plant White-topped aster Aster curtus Species of Concern Threatened Plant Willamette daisy Erigeron decumbens Endangered Endangered Bird Bald eagle Haliaeetus leucocephalus Threatened Threatened Reptile Western pond turtle Clemmys marmorata Species of Concern Sensihve Mammals Long-eared bat Myotis evotis Species of Concern Sensitive Mammals Yuma bat Myotis yumanensis Species of Concern None Fish Spring chinook Oncorhynchus Threatened None tshawytscha Fish Cutthroat trout Oncorhynchus clarki None Stock of Concern~ ~ Oregon Department of Fish and Wildlife stock of concern status for cutthroat trout is an Agency designation (i.e., not a state listing). This designation applies to cutthroat trout in the entire Willamette Valley and is based on a lack of information on population abundance and distribution for this species, Facility Upgrades and Habitat Potentially sensitive habitat in the vicinity of the major MWMC facilities (including the Biocycle Farm, SIWF, BMF, and WPCF) include wetland and riparian areas. Wetland Habitat Wetland types/n the Eugene metropolitan area include open water/riparian wetlands, wet prairie grasslands, scrub-shrub wetlands, forested wetlands, agricultural wetlands, and pasture/old field wetlands (City of Eugene, 2003). Wetlands in the Eugene area, and the Willamette Valley generally, have largely been lost to agriculture and urban development l~3t~rMC_2 0_REV23 DOC 2-25 MW'MC FACILfTIES PLAN (e.g., dragged and/or filled in). For example, native prairie wetlands in the Wilamette Valley currently occ~apy less than 1 percent of their former area, and the remafi~ng remnants are highly fragmented. The West Eugene area supports the greatest concentration of native prairie remrmnts and associated rare species in the Willamette Valley (Nelson and Beall, 1995). Wetland habitat ~s located within the boundaries of the major MWMC facilities, as shown in Figure 2.2.7-3. These wetland areas are limited in extent as a result of agricultural activity and commercial and municipal land use. Riparian Habitat The Willamette River, the ma~n riparian feature in the vicinity of the %rPCF, totals 187 main- stem miles and 16,000 total stream miles in the Willamette River Basin (Wilamette American Heritage River Partnership, 2004). The nearly 200-mile reac/-t of the Willamette River between Springfield and Portland has been designated an American Heritage Pdver under the American Heritage River Initiative (Executive Order 13061; EPA, 2004). This stretch of the river flows through the three largest cities in the state: Eugene-Springfield, Salem, and Portland. More than two million people live in the Willamette basin, the fastest- growing region in Oregon (EPA, 2004). The WPCF has been discharging treated wastewater into the Willamette Privet from the facility at 410 River Avenue in North Eugene since beg4nning operation in 1984. Discharged effluent has undergone primary treatment (scum and solids removal), secondary treatment (bacterial digestion), and final processing (chlorination followed by addition of sulfur dioxide to dechlohnate) (City of Eugene Public Works Department, 2003). The facility uses an activated sludge process that consistently removes more than 95 percent of pollutants from the waste stream before wastewater is discharged into the Willamette River (City of Eugene Public Works Department, 2003). 2.2.8 Air Quality and Noise Air Quality Based on a 1997 regulatory review (CI-L?.M HILL, 1997), "there are no significant, outstanding air quality compliance issues for the WPCF and the facility is in compliance with all Lane Regional Air Pollution Authority (LRAPA) and federal regulations.' An emissions inventory was conducted to identify and describe all possible sources of air emissions found at t_he WPCF. Operations at the fac~ty were reviewed, and a list of potential emission sources was developed. Calculations, prepared following EPA- approved/reviewed methodologies, were performed for the sigrdficant sources identified at the WPCF. The results indicate that the WPCF is not a major source under Title V regulations, including criteria pollutants and hazardous air pollutants (HAPs). Facilities are considered major sources if they emit more than 100 tons per year (tpy) of a criteria pollutant, and/or greater than 25 tpy of total HAPs or 10 tpy of an individual HAP. Because the facility is considered a minor source, a Title V operating permit is not required. However, EPA and LRAPA may impose additional record keeping and monitoring requirements in the future because actual annual carbon monoxide (CO) and nitrogen oxides (NO×) emissions at the W"PCF exceed the 50 percent major source threshold and the potential to emit (PTE) is very close to a major source trigger level. However, under EPA 2-26 MWMC_2 0_REV23.DOC STUDY AREA CP, ARAC~RISTICS guidance, true natural minor sources (the WPCF) are exempted from meeting these additional compliance requirements because both their actual and PTE emissions below major souxce triggers for criteria pollutants and HAPs. The most likely issues that could create compliance-related actions concern nuisance issues. Other activities at the WPCF that may impact air quality include fiagitive dust blowing offsite, or visible emissions from the internal combustion engines or other combustion sources. However, WPCF staff have been proactive in implementing favorable air quality activities and have been mitigating these factors with actions such as conducting odor evaluations and planning; implementing proper boiler, flare, and internal combustion engine maintenance programs; watering dirt roads and construction sites; and dealing with public concerns in an effective and timely manner. Table 2.2.8-1 presents the results of the emissions estimates. TABLE 22.8-1 Estimated Emissions ~rom the WPCF MWMC Facilities Plan, Eugeno-$pringfield Pollutant PTE (tpy) Actual (tpy) CO 86.1 57.8 NOx 89.9 55,2 SOx 7.1 5.7 PM-10 1.0 0.3 Total VOCs 23.9 16,5 Total HAPs 8.4 6.0 It should be noted that 65 percent of the residents in the vicinity of the WPCF rate the WPCF as a good or excellent neighbor, according to results of the Wastewater Facilities Good Neighbor Survey performed by the Oregon Survey Research Laboratory at the University of Oregon as part of the master planning effort. Furthermore, an additional 16 percent rate the WPCF as a fair neighbor. The overall good-neighbor rating of the WPCF considers the residents' attitudes about the facility's appearance, odors, traffic, noise, and use of chemicals. Process Hazards Analysis of Chlorine and Sulfur Dioxide Systems A comprehensive process hazards analysis (PI-LA) evaluation was performed at the WPCF in August 1996. The PHA is a requirement for regulated substances as stipulated by the Occupational Safety and Health Administration (OSHA) and the Oregon Process Safety Management (PSM) program. More than 100 "what if" ~enarios were evaluated, including determining the scenario's consequences and existing protections, and developing and implementing recommendations for improvements, new procedures and policies, and additional maintenance or monitoring of key process and safety equipment to address each scenario, when needed. The PHAs and release scenarios in the PSM manual adequately cover all regulated substance usage, storage, and handling scenarios to meet PSM requirements. MWi~C_Z0_REV23.DOC 2-Z7 MWMC FACILmES PLAN Noise Noise from the exist~g £ac~ties does not appear to be a significant ~ssue in the areas surrounding the WPCF. According to results of the Wastewater Facffities Good Neighbor Survey, performed by the Oregon Survey Research Laboratory at the University of Oregon as noted above, 65 percent of the residents in the vicinity of the WPCF rate the W?CF as a good or excellent neighbor. An additional 16 percent rate the WPCF as a fair neighbor. (The overall good-neighbor rating o£ the WPCF considers the residents' attitudes about the facffity's appearance, odors, traffic, noise, and use of chemicals.) 2.2.9 Land Use and Zoning The MWMC savJtary system and major ~reabx~ent facilities are located throughout the Eugene-Springfield metropolitan area. These facffities are situated in numerous zoning designations within the urban growth boundary (UGB) and on adjacent lands Lmmediately outside the boundary. However, to describe all of the various zoning designations occupied by MWMC infrasb~uc~ure would be overly complex and beyond the scope of ff~s discussion. Therefore, to simplify the description, the discussion is ILrnited to the following major facilities that would be subject to potential expansion: Eugene-Springfield Water Pollution Control Facility Biosolids Management Facility-Exclusive Farm Use Seasonal Industrial Waste Site-Exclusive Farm Use Biocycle Farm-Exclusive Farm Use; Industrial All four of the facilities are located in central Lane County in the northwest section of the City of Eugene (Figure 2.2.9-1). The area surrounding the WPCF is urban, with high to medium population density. The areas around the other facilities are more rural with low population density. The following ~ect~or~s srrmmar~e land use and zorL~g de$ignatio~ for areas adjacent to each of the four facLl~ties: , The WPCF is located within the UGB of Eugene-Springfield near Beltline Highway and along the Willamette River. The facffity is zoned as Public Land, the areas to the south are zoned Agricultural with an Urbanizable Land overlay zone and Low-Density Residential with an Urbanizable Land overlay zone, the area to the west is zoned Medium-Density Residential, the areas to the north are zoned Community Corrrmercial and Light-Medium Industrial with Urbar~abte Land overlay zone, and the area to the East is zoned as Medium-Density Residential with a Planned Unit Development overlay zone. The Biosolids Management FacLlity is located outside but adjacent to the UGB of Eugene-Springfield. The facility is zoned as Exclusive Farm Use 40 Acre Minimum. Adjacent land use is designated as Rural Residential 5 Acre ~um and Exclusive Farm Use 40 Acre MInimum to the west, Rural Industrial and Exclusive Farm Use 30 Acre Minimum to the east, and Light-Medium Industrial with UrbanLzable Land and Commercial ALrport Safety overlay zones inside the UGB to the south. 2-28 MWMC._20_REV23.DOC STUDY AREA CHARACTER~SllCS The Seasonal Industrial Waste Site is also located outside of the Eugene-Springfield UGB to the north on the northwestem-most portion of Eugene. The site and surrolJxlding are zoned as Exclusive Farm Use 30 Acre Minimum, with a portion of the area to the south zone Rural Industrial. The Biocycle Farm is bounded on the west by Highway 99. The facil/ty is approximately one-th/rd inside and two-thirds outside of the Eugene-Springfield UGB. The area of the site inside the UGB ks zoned Heavy Industrial with Site Review, Urbanizable Land and Commercial Airport Safety overlay zones while the area of the site outside the UGB is zoned Rural Industrial. The area to the west of the facility across Highway 99 is the Eugene Airport zoned for Airport Operations; the area to the north includes zoning for Rural Residential 5 Acre Minimum, Rural Industrial and Exclusive Farm Use 40 Acre Minimum; the area to the east includes Rural Residential 5 Acre MAnimum and Exclusive Farm Use 40 Acre Minimum zoning, and the area to the south is inside the UGB and zoned for Heavy Industrial with Urbanizable Land and Commercial Airport Safety overlay zones. 2.3 Socioeconomic Environment 2.3.1 Economic Conditions and Trends The Oregon economy experienced a "jobless recovery" through 2003. As the U.S. economy builds strength in 2004, Oregon should follow the same path. According to the Oregon Office of Economic Analysis (OEA), the jobless recovery will slowly become a job generating recovery, with jobs regaining their pre-recession levels in early 2005. OEA forecasts employment to grow 1.6 percent in 2004 and 2.2 percent in 2005. Table 2.3.1-1 is a summary of the forecast outlook. The table compares OEA's forecast to other published forecasts. Economy.corn has the most pessimistic outlook for 2004 and 2005. OEA's forecast follows more closely the direction of the Global Insightsa forecast, but believes the recovery will be stronger although still milder compared to other recovery periods. The outer years continue to add jobs. TABLE 2.3.1-1 Oregon Total Non-Farm Employment and Personal income Growth MWMC Facilities Plan, Eugene-Springfield Employment Growth Personal income Growth Date of Forecaster Forecast 2004 2005 2006 2004 2005 2006 Economy.corn Dec. 2003 0.6 2.0 1.9 4.3 4.2 4.6 Global Insight Winter 2003-04 1.2 2.1 1.7 5.2 5.4 5.3 Wells Fargo & Co. Dec. 2003 2.2 NA NA 5.5 NA NA U.S. Bank Dec. 2003 2.5 NA NA 5.5 NA NA 8 Global Insights is a consulting firm that business and economic provides forecasts, industry strategic COflSU~in§, financial data and software. MWMC_2.0_REV23.DOC 2-2~ MWMC FAC~UTJES PLAN TABLE 2.3.1-1 Oregon Total Non-Farm Employment and Personal Income Growth MWMC Facilities Plan, Eugene-Springfield Employment Growth Persona~ ~ncome Growth Date of Forecaster Forecast 2004 2005 2006 2004 2005 2006 Conerly Consulting Feb. 2004 2.4 3.8 NA 5.9 5.1 NA OEA Jan./Feb. 2004 1.6 2.2 1.9 5.0 5.0 5.9 Source: Oregon Economic and Revenue Forecast, March 2004. Looking back at 2002 economic data for Large County, the County showed a total employment rate of 6.8 percent, with total employment numbers at 157, 267 for 2002 (OEA, 2004). More recently, during the first quarter of 2004, Lane County's unemployment rate decreased to 7.8 percent in February compared with a revised 8.1 percent in January. In March 2004, it was below the state's seasonally unadjusted rate of 8.4 percent, but above the nation's seasonally unadjusted rate of 6.0 percent. Non-farm payroll employment increased in February due mostly to seasonal gains in education. There typically is little change in the unemployment rate between January and February. The rate this February is 0.5 percentage points lower than the 8.3 percent rate recorded in February of 2003. The number of unemployed people decreased by 505 from January and is now 762 lower than February of last year, to 13,443. In February, total non-farm payroll employment increased by 1,100 to 141,100. The gain was due largely to seasonal increases in state and local education. Total non-farm employment is up by 100 compared to February of last year, for an annualized gain of .07 percent (Oregon Employment Department, 2004). 2.3.2 Historical Population Populations from the City of Eugene, the City of Springfield, and the Santa Clara/River Road area contribute to the WPCF. Historical population data obtained from the Lane Council of Governments for both Eugene and Springfield were collected for years 1990 and 1995 through 2002 (Figure 2.3.2-1). Begiru-~g in 1991, fifteen percent of the Santa Clara/River Road area population was connected to the WPCF collection system each year. The total Santa Clara River Road population, of 21,400, was completely connected as of 1997. Historical population data have been summarized and presented in Table 2.3.2-1. The total MWMC service area population equals the sum of the Eugene, Springfield, and Santa Clara/River Road populations. 2-30 MWIC~C_Z0._REV23.DOC 2 STUDYAREA CHARACTEDSTtCS TABLE 2.3,2-1 Historical Population Data for the Eugene-Springfield Service Area, 1990-2002 Santa Clara/ Total Eugene Springfield River Road Population Year Population Population Population Served 1990 112,669 44,683 0 157,352 1995 121,905 49,005 16,050 186,960 1996 126,325 50,140 19,260 195,725 1997 129,300 50,670 21,400 201,370 1998 133,460 51,700 21,400 206,560 1999 136,490 52,945 21,400 210,835 2000 137,914 53,005 21,400 212,319 2001 140,571 53,483 21,400 215,454 2002 142,391 53,946 21,400 217,737 FIGURE 2.3,2-1 Historical Populab0n for MWMC Service Area MWMC Facilities Plan, Eugene-Springfield 22S,000 ~ ........................ 200,000 1 150,000 I ..................... 100,000 I- - - - ..... 75,000 i 50,000 1-- 25,000 ~ - 1990 199l 1992 [993 1~94 1995 1996 1997 1998 1999 2000 200[ 2002 2.3.3 Population Growth Projections Historical population data were used to forecast the future MWMC service area population through the buildout year of 2050. Assuming that population growth will continue at a similar rate as it did between 1990 and 2002, the growth rate was projected forward to the year 2050 providing an estimate of future populations within Eugene-Springfield. Figure 2.3.3-1 illustrates the projected population for the service area. The build-out service area MWMC_20_REV23 DOC D31 MWMC FACiLiTIES PLAN population is assumed to occur in year 2050, resulting in a population density of 18.1 persons per acre. Table 2.3.3-1 summarizes the population projections for Eugene-Springfield, Santa Clara/River Road, and the combined MWMC service area at 5-year intervals over the study period. TABLE 2.3.3-1 Population Projection Data for Eugene-Springfield Metropolitan Area MWMC Facilities Plan, Eugene-Springfield Eugene-Springfield Estimated MWMC Service Population Santa Clara/River Road Area Population Year Projections Population Pr~ections 2005 207,745 21,400 229,145 2010 224,855 21,400 246,255 2015 241,965 21,400 263,365 2020 259,075 21,400 280,475 2025 276,185 21,400 297,585 2050 361,735 21,400 383,135 FIGURE 2.3,3-1 Population Project~on Summary MWMC Facilities Plan, Eugene-Springfield 400,000 T 350,000 ~ ~oo, ooo 100,~0 50,000 0 2005 20i0 2015 2Q20 202S 2030 2035 2040 2045 2050 2-32 MWMC_20_REV23 DOC STUDY AREA CHARACTERISTIC.~ 2,4 Land Use and Zoning 2.4.1 Relation to the Eugene-Springfield Uetropolitan Area General Plan Modifications to the MWMC sanitary system and major treatment facilities would be consistent w~th the overall policy framework and planning and land use designations set forth in the Eugene-Springfield Metropolitan Area General Plan 2004 Update (Metro Plan; 2004). The Metro Plan is the official long-range comprehensive plan (public policy document) of meh:opolitan Lane County and the cities of Eugene and Spr~_ngfietd. The Metro Plan sets forth general planning policies and land use allocatiorrs and serves as the basis for the coordinated development of programs concerning the use and conservation of physical resources, furtherance of assets, and development or redevelopment of the metropolitan area. The Public Facilities and Services element of the Metro Plan provides direction for the future provision of MWMC infrastructure and services to planned land uses within the Metro Plan, Plan Boundary. MWUC Facilities Located Within the Urban Growth Boundary For planning and coordination of services within the urban growth boundary (UGB), the Public Facilities and Services Plan identifies jm~dictional responsibility for the provision of wastewater services, describes respective service areas and existing and planned wastewater facilities, and contains planned facilities maps for these services9. MWMC facility development will remain consistent with Metro Plan policies by using planned facilities maps of the Public Facilities and Services Plan to guide the general location of water, wastewater, stormwater and electrical projects in the metropolitan area. In ad&tion, MWMC will use local facilit~j- master plans, refinement plans, and ordinances as the guide for detailed planning and project implementation. MWMC Facilities Outside the Urban Growth Boundary In accordance with statewide planning goals and administrative rules, MWMC facilities may be located on agricultural land and forest land outside the UGB when the facilities exclusively serve land within the UGBm. Furthermore, in accordance with statewide planning goals and administrative roles, MWMC facilities are allowed in the public fight-of- way of public roads and highways. The ultimate construction of planned public facilities outside the UGB and Plan Boundary will require close coordination with and permitting by Lane County, and possible Lane County Rural Comprehensive Plan amendments. MWMC will remain consistent with local regulations by locating new urban wastewater facilities on farm land and forest land outside the UGB only when the facilities exclusively serve land inside the UGB and there is no reasonable alternative. In addition, MW'MC will locate urban water and wastewater facilities in the public right-of-way of public roads and highways outside the UGB, as needed to serve land within the UGB. These provisions are made in accordance with Oregon Department of Land Conservation and Development Statewide Planning Goal 11 and Oregon Administrative Rule (OAR) 660. 10 Pursuant to OAR 660-006 and 660-033 MWMC_Z0_REV23.DOC 2~33 MWMC FACILiTiES PLAN 2.4.2 MW IC Facility Zoning Designations The WMC sanitary system and major treatment fac~ties are located throughout the Eugene~Spr~gfield metropolitart area. These facilities are situated in numerous zordng designations within the UGB and on adjacent lands immediately outside the boundary. However, to describe all of the various zoning designations occupied by NI%tMC in~astructure would be overly complex and beyond the scope of th~ discussion. Therefore, to s~nplity the descrip~on, the discussion is limited to the following major facilities that would be subject to potential expansion: Eugene-Springfield Water Pollution Control Facility Biosolids Management Facility (BMF) Seasonal Industrial Waste Facility (S1WF) Biocycle Farm All four of the facilities are located in central Lane County in the northwest section of the City of Eugene (Figures 2.4.2-1 aa~d 2.4.2-2). The population density surround~g the facilities ranges from high to medium. The following sections summarize land use and zoning designations for areas adjacent to each of the four facilities: The WPCF is located within the UGB of Eugene-Springfield near Beltline Highway and along the Willamette River. The facSlity is zoned as Public Land. The areas to the south of the WPCF are zoned Agricultural with an Urbanizable Land overlay zone and Low- Density Residential with art Urbanizable Land overlay zone. The area to the west of the facility is zoned Medium-Density Residential. The areas to the north of the facility are zoned Commurdty Commercial and Light-Medium Industrial with Urbanizable Land overlay zone, and the area to the East is zoned as Medium-Density Residential with a Planned Unit Development overlay zone. The BMF is located outside but adjacent to the UGB of Eugene-Sprh~gfield. The facility is zoned as Exclusive Farm Use 40-Acre Mirtimum. Adjacent land use is designated as Rural Residential 5-Acre Minimum and Exclusive Farm Use 40-Acre MinLrnum to the west, Rural Industrial and Exclusive Farm Use 30-Acre Minimum to the east, and Light- Medium Industrial with Urbanizable Land and Commercial Airport Safety overlay zones inside the UGB to the south. · The SIWF Ls also located outside of the Eugene-Springfield UGB to the north on the northwestern-most portion of Eugene. The site and sttrrotmding area are zoned as Exclusive Farm Use 30-Acre Minimum, with a portion of the area to the south zoned Rural Industrial. The Biocycle Farm is bounded on the west by Highway 99. The facility is approx/mately half ~n and half outside of the Eugene-Springfield UGB. The area of the site inside the UGB is zoned Heavy Industrial with Site Review, Urbardzable Land, and Commercial Airport Safety overlay zones, while the area of the site outside the UGB is zoned Rural Industrial. The area to the west of the Biocycle Farm across Highway 99 is the Eugene Ah'port, zoned for Airport Operations; the area to the north includes zoning for Rural Residential 5-Acre Minim~, Rural Industrial and Exclusive Farm Use 40-Acre Minimum; the area to the east includes Rural Residential 5-Acre Minimum and Exclusive Farm Use 40-Acre Minimum zoning, and the area to the south is inside the 2-34 MWMC_2.0_REV23 OOC 2. SllJD¥ A~EA CHARACTER~S33CS UGB and zoned for Heavy Industrial with Urbanizable Land and Commercial Airport Safety overlay zones. M'C~C_2.0_REV23 DOC 2-35 3,0 Existing Wastewater Facilities 3.1 Wastewater Conveyance System The collection system that conveys wastewater to the WPCF inch_~des the sewerage facilities that serve Eugene and Springfield. The two cities formerly maintained sewerage facilities independently, including collection and treatment. Beginning in 1984, all wastewater flows were treated at the newly upgraded regional treatment facility at the former Eugene treatment plant site. Springfield flows were conveyed to the regional treatment facility through the then newly constructed East Bank Interceptor (EBI) that follows the east bank of the Willamette River to the Willakertzie Pump Station just across the river from the WPCF. 3.1.1 Springfield Wastewater Collection System The Springfield collection system includes approximately 240 miles o~ pipeline. The major trunk systems in Springfield are Gateway, Thurston, Main Street, East Springfield Interceptor, South Springfield Interceptor, Central, and Downtown. The original downtown basin is the oldest portion of the Springfield collection system. Constructed before World War I, it was designed to carry and dkscharge both stormwater and sanitary flows to the Willamette River. Irt the 1950s, the City constructed a wastewater treatment plant. Wastewater flows remained in the existing conduits, but new conveyance facilities were built to transport stormwater to the Willamette River. The remainder of the system was developed around the downtown core as the city expanded. The or~gh~al East Springfield interceptor was constructed in 1962 and t_he South Springfield Interceptor in 1997. The City of Springfield Sanitary Sewer Master Plan dated July 1980 contains additional information describing the Springfield portion of the collection system. 3.1.2 Eugene Wastewater Collection System The Eugene collection system includes approximately 770 miles of pipelLne. Construction of Eugene's system began between 1900 and 1910. The original system was constructed to carry both stormwater and sanitary flows to the Willamette River. Around 1950, the first Eugene wastewater treatment plant was constructed; the plant provided pri_mar-y treatment. After World War II, the Eugene system expanded rapidly to provide service to development in newly annexed areas. Expansion was also rapid in areas outside the City that were formerly served by septic systems. Additional major expansion occurred between 1960 and 1970, at which time the combined sewers in the older portion of the Eugene system were separated. The 1992 City of Eugene Public Works/Engineering Urban Sanitary Sewer Master Plan describes the City of Eugene portion of the collection system in more detail. MWMC_3.0_REV11 DOC 3-1 MWMC FACILITIES PLAN 3.1,3 Conveyance Pump Station History For the regional fadlity to begin operation in 1984, wastewater flows from the Eugene- Springfield metropolitan area needed to be consolidated. New sewers were also constructed throughout the unincorporated River Road/Santa Clara area. This resulted in a number of newly constructed regional and local conveyance pump stations. In addition, upgrades to selected existing pump stations that once served the separate Eugene and Springfield treatment facilities were required so they could continue to operate and serve the new regional facility. Most of the o~ginal planning and design for these conveyance pump stations took place &om 1979 to 1983. The majority of f. he construction for the major conveyance pump sta~on facilities took place between 1983 and 1987. Table 3.1.3-1 summarizes the construction of new conveyance pump stations and the modificahons to existing pump stations required as part of the original construction that would serve the new regional facility. TABLE 3.1.3-1 0riginaI Major Conveyance Pump Stations MWMC Facilities Plan, Eugene-Springfield Construction Project Year Description of Construction or Modification West irwin Pump Station 1983 Regionally owned station serving the Bethel section of Eugene. West Irwin pump station ownership should change to the City of Eugene in 2005. Original pump station constructed in 1965. Expanded in 1983 as part of the regional facility. Added force main to pump raw sewage from 2525 West irwin Street to the WPCF Wiilakenzie Pump Station 1984 Regionally owned station serving the area east of the W~llamette River. Expanded m 1984 as part of the regional facility. Pumps raw sewage from 3050 Goodpasture Lakes Loop, east of the Willamette River, via force main directly to the WPCF Terry Street Pump Station t985 Regionally owned station serving the southwestern area of Eugene. Terry Street pump station ownership should change to the City of Eugene in 2005. Pumps raw sewage from 5190 Barger Drive via force mare to West Irwin Pump Station Division Pump Station 1985 Locally owned station serving the Santa Clara Square and area north of the Beltline Highway. Pumps raw sewage from 203 Division Avenue and d~scharges into either the Terry Street or West Irwin force mains Skipper Pump Station 1986 Locally owned station serving the area south of the Beitline Highway. Pumps raw sewage from 1 t95 Skipper Avenue and discharges into the TerryANest/Irwin/Irvington Valve Array Vault Greenwich Pump Station 1987 Locally owned station serving the area west of River Road to Northwest Expressway. Pumps raw sewage from 811 Greenwich Avenue and discharges into the Irvmgton force main Irvington Pump Station 1987 Regionally owned station serving the Santa Clara area and the Biosolids Management Facility. Pumps raw sewage from 1248 Irvmgton Drive to the TerryANest/Irwin/irvington Valve Array Vault via force main. 3-2 MWMC_30_REVlt DOC 3 EXIS-flNG WASTEWATER FAC~LmES Subsequent upgrades to the original facilities and the addition of new facilities have been completed since the initial facilities were put into operation. Table 3.1.3-2 surmmarizes the major construction contracts associated with facility upgrades and additions. The end result of these construction projects is the facility as it stands today. TAI~LE 3.1.3-2 Conveyance Pump Station Upgrades MWMC Facilities Plan, Eugene-Springfield Construction Project Year Description Fillmore Pump Station improvements 1996 Serves area west of central downtown Eugene. Updated station with bye submersible pumps and variabfe speed controls West Irwin Pump Station 1998 Updated pump station with new pumps and drives Improvements Barger-Greenhill Pump Station 1999 Serves southwestern Eugene, along with the Terry Street pump station. Pumps raw sewage from 1725 Legacy Street to the Terry Street force main. Division Street Pump Station 2001 Upgraded and replaced control panel Oakway Pump Station 2002 Constructed new pump station with three pumps and variable speed controls Division Street Pump Station 2001 Upgraded and replaced control panel 3.1.4 Conveyance System Pump Stations In all there are 47 pump stations throughout Eugene and SpringfieJd that contribute flow to the WPCF. Figure 3.1.4-1 shows the locations of the major wastewater collection system pipelines and pump stations. Inflows to the WPCF consist of three components. The first is the West Bank Interceptor (WBI), a 72-inch-diameter gravity pipeline (herein called tZLe Gravity System). This component-is capable of delivering a flow of 100 mgd to the screw pumps at the WPCF. The second component is a pump station/force main system from the east side of the Willamette River (East Side Pump Station System). This system consists of the Willakenzie pump station and force mains. The final inflow component is a system of pump stations and force mains conveying flows to the WPCF from the west (West Eugene Pump Stations System). k~rl/MC_3 0_REV11 DOC 3-3 MWMC FACILITIES PLAN ~WNIC Major Pump Stations FIGURE 3,1.44 MWMC Facilities Plan, Eugene-Springfield West Bank Gravity System and WPCF Screw Pumps The existing 72-inch WBI gravity sewer conveys up to 100 mgd to the WPCF directly to the existing screw pumps. Flows are controlled by the upstream gravity conveyance system and the Fillmore pump station. At the WPCF, four existing screw pumps lift the flow into a common channel that flows into the influent screens and aerated grit removal process. These existing screw pumps have a capacity of 21 mgd per pump, or 63 mgd with one pump out of service. The capacity is 84 mgd with all of the screw pumps rrtm~dng. East Side Pump Station and Force Nlain System The East Side pump station and force main system consists of the Willakenzie pump station and force main trader the Willamette River. The existing Willakenzie pump station consists of two pump stations linked together to convey wastewater flows from the 78-inch East Bank Interceptor (the in fluent gravity sewer). The existing variable speed pumps have a capacity of 17.5 mgd per pump, or 70 mgd with one ptuT~p out of service. The capacity is 80 mgd with all of the pumps rtumLng. West Eugene Pump Station and Force Main System The West Eugene Pump Station System consists of seven pump stations cozmected by a series of parallel force mains. Force main sizes range from 14 inches to 48 inches in diameter, rtmning generally west to east from the Barger-Greenhill pump station to the WPCF. All of the pump stations connecting to the force mains have been included in this evaluation 3-4 MWMC_3 o_REVll DOC 3 EX~STING WASTEWATER FACILmES without respect to ownership, because all stations will need to be upgraded prior to 2025. Table 3.1.4-1 lists the major stations and their existing pump capacities. TABLE 3.1 West Eugene Pump Stations MWMC Facilities P/an, Eugene-Springfield Pump Station Number of Capacity With One Capacity With All Pumps Pump Out (mgd) Pumps Operating (mgd) Division Street 2 0.7 1.4 Skipper 2 3.0 5.0 Greenwich 2 1.0 1 5 Irvmgton (updated in 2003) 3 13.5 18.0 West Irwin 3 18.0 21.0 Terry Street 3 10.0 14.0 Barger-Greenhill 2 3.7 7.5 3.1.5 Status of Conveyance System The conveyance system was evaluated during development of the MWMC Wet Weather Flow Management Plan (WWFMP) (CH2M HILL, 2001). This included: Performing flow monitoring to characterize wet weather flows in basins Estimating peak flows for the 5-year, 24-hour storm Identifying pipeline and pump station deficiencies for existing and bufldout land use conditions Identifying pipe and pump station upgrades necessary to convey peak flows to the WPCF ~ Developing and analyzing wet weather flow management options for producing the most cost-effective flow management in all basins Analyzing the potential effecbveness of reducing peak flows through reduction of rainfall-dependent infiltration and inflow (RDII) in basins with high RDIL Since the adoption of the WWFMP, both Eugene and Springfield have initiated positive management practices for the wastewater collection system as outlined in Section 7.15 of the WWFMP. Both cities have aggressively pursued RDII source detection and reduction projects, executing RDII projects recommended in the WWFMP 10-year implementation plan on schedule. The results of the conveyance system evaluation described in the WWFMP were updated as part of this facilities planning effort. MWMC_3,0_REV11 DOC 3-5 MWMC FACILmE$ PLAN 3A.6 Summary of Previous Collection System Modeling The WWFMP provided the MWMC, Eugene, and Springfield with a plmu to identify the immediate rehabilitative needs of the wastewater conveyance system, and recommended a proactive approach to future wastewater management. The basis of these recommendations is the DHI MOUSE hydraulic model, which simulates unsteady flows in pipe networks. To meet the objectives of the WWFMP, it was not necessary to include every pipe of the service area in the model. Because flows were analyzed at a subbasin level, the model network needed only to be similarly detailed. In general, pipes 12 inches in diameter and larger were included in the model, as well as major pump stations and force mains. However, where necessary to maintain continuity in a series of pipes within a conveyance reach, pipes with smaller diameters were included. Figure 3.1.4-1 shows the modeled portions of the wastewater collection system. As part of the WWFMP, the hydraulic model was calibrated to flow data from extensive flow monitoring conducted between 1997 and 1999 throughout the wastewater collection system and from the WPCF. In accordance with DEQ guidelines, the 10-year summer and the 5-year winter rainfall events were compared to determine which storm produced the defining (i.e., worst-case) flow condition in the wastewater collection system. The 10-year summer rainfall event is typically of shorter sustamed duration and higher intensity compared to the 5-year winter event. The 2000 WWFMP modding effort concluded that the 5-year winter event was more critical and the buildout flow rate for the WPCF was estimated at 290 mgd. The collection system mode1 would be subsequently updated for ti'ds Facility Plan to define the 2025 peak flow rate. That analysis is presented in section 5.4.1. 3.2 Wastewater Treatment Facility 3.2.1 Facility History The WPCF officially began operation in April 1984. Most of the planning and design of the original facility took place in 1979. The majority of the construction for the major treatment facilities took place between 1983 and 1985. Table 3.2.1-1 summarizes the construction of the original major treatment facilities, notes the year that construction took place, and briefly describes the facilities constructed. TABLE 3.Z1-1 0rigmal Plant Construction and Facilities MWMC Facilities plan, Eugene-Springfield Construction Project Year Descriptio~ Pretreatment 19~ Influent pump station, five screening channels with comminutors, four aerated grit chambers, four preaeration chambem, and two ca.on odor control ~mbbers Pdma~ Treatment 1984 Four prima~ cladhers and pdmaw sludge pump station Aeration Basins 1984 Eight aeration basins w~th course bubble diffuser aeration Secondaw Cladfiers 1984 Eight secondaw cladliers 3-6 MWMC_3 0_REV11 DOC 3 E×~STING WAS'fEWATER FACILITIES TABLE Odgina~ Plant Construction and Facilities MWMC Facilities plan, Eugene-Springfield Construction Project Year Description Final Treatment 1984 Four effluent Pamhall flumes, four chlorine contact basins, sulfonation chamber, chemical building, plant water pump station, outfall structure, diffuser outfall, and bankside outlall Secondary Control Complex 1984 Blower building, return activated sludge pump station Solids Processing 1984 Add one new gas mixed prima~¥ digester, add gas mixing building for existing two primary digesters, new boiler building, modify floating covers on existing two b~osolids storage tanks, add polymer feed for flotation thickener Seasonal Industrial Waste Site, Pump 1984 Industnal pump station, irrigation control building, aeration Station, and Site Work basin, lagoon, and center pivot irrigation system Phase 1 Biosolids Facilities 1985 Onsite dewatering facility using centrifuges, b~osolids storage tank, polymer Operations Building 1984 Operations building and laboratory Maintenance Building 1984 Maintenance building, covered storage build~ng, storage buildings and steam cleamng building Subsequent upgrades t:o the original facilities and the add/don of new facilities have been completed since the initial plant came on line. Table 3.2.1-2 summarizes the major construction contracts associated with facility upgrades and additions. The end result of these construct/on proiects is the fac/lity as it stands today (Figure 3.2.1-1). TABLE 3.2.1-2 Plant Upgrades and Add~ti0nal Facilities MWMC Facilities Plan, Eugene-Springfield Construction Project Year Description North Aeration Basin Upgrades 1996 Converted three o1 four north aeration basins from coarse bubble a~r diffusers to fine bubble membrane diffusers North Aeration Basin Upgrades 2002 Replaced membrane diffusers in aeration basin No. 3 North Aeration Basin Upgrades 2003 Replaced membrane diffusers in aeration basin Nos. 1 and 2 Pretreatment Upgrades 1995 Replaced comminutors with five vertical coarse screens and screening sluice system, new grit and solids dewatering equipment, and biofiiter Biosohds/Biocycle Farm Reclaim water 2004 Constructed 3.2-mgd plant effluent water I~ne to BMF for line non-potable water use and tree farm irrigation MWMC_3 O_REV 11 DOC MWI~C FACILITIES PLAN TABLE 3,2.1-2 Plant Upgrades and Additional Facilities MWMC Facilities Plan, Eugene-SprinCeld Construction Project 'Year Description Solids Handling 1988 Constructed 4 facultative sludge lagoons and 13 drying beds at the offsite Biosolids Management Facility. Constructed new biosolids pump station (operational in 1989) SIWF ~dification 1995 Installed new center p~vot ~rdgation system Gravity Belt Thickener Building 1993 Added new gravity belt thickener buiMing and ~o 3-meter gravity belt thickeners w~lh polymer system BMF Dewatering Facill~ 2001 Dewatenng building with three 2-meter belt presses, added two belt filter press mix tanks, polymer system, three biosolids presses, solids Ioadout system Biocycle Fa~ 2004 Anticipate planting t57 acres in poplar trees, constructed biosohds irrigation p~petine, and b~osolids pump stahon at the BMF Maintenance Facility Modifications 1990 Expansion o~ ex, sting maintenance [ac[l~ty to ~nc]ude men's room, locke~ ~ooms, storage room, and miscellaneous locker rooms Laborato~ Braiding Addition 2003 New laboratop/buildm9 replaces the existing labo~ato~ 3.2.2 Facility Design Pretreatment The pretreatment facility at the WPCF is comprised of irrfluent screw pumps, coarse bar screens, aerated grit removal and preaeration. Screenings and grit are processed in a separate building through screenings washer/compactors and grit separation. Table 3.2.2-1 sttmmarizes the pretreatment facility umt processes and equipment. TABLE 3o2.2-1 WPCF Pretreatment Faci)ity Unit Processes and Equipment MWMC Facilities Plan, Eugene-Springfield Capacity, (eacWtotal Equipment Type Quantity ~tma/totaib) Raw Sewage Pumps Helical Screw (capacity at peak flow) 4 2t/63/84 mgd Bar Screens Mechamcalty raked, 1/2-inch opening bar 6 35/175/210 mgd screen MW~C_3 0_REVi 1.DOC 3 E×ISTING WASTEWA~ER FACIUT)ES TABLE 32.2-1 WPCF Pretreatment Facility Unit Processes and Equipment MWMG Facilities Plan, Eugene-Springfield Capacity, (each~otal Equipment Type Quantity flrm~/totalb) Screenings Grinder Inhne (rated at 150 cubic feet of screenings 2 1,000/1,000/2,000 gpm per hour) Grit Removal Aerated Grit Chambers (101,000 galtons 4 58.3/1751233 mgd each; design cdteda of 2.5 minutes detention time at peak flow) Grit Slumj Pumps Recessed impeller 4 300/900/1,200 gpm Preaeration Chambers (152,000 gallons each; design 4 14.6/43.8/58.4 mgd criteda of 15 minutes detention time at average flow) Screenings Impeller Washer 2 2,000/2,000/4,000 gpm WashedOompactor Shafted Screw Conveyor and Compactor Compacted Shaftless, Dual-Drive, Reversing Screenings/Gdt Grit 2 900/900/1,800 lb/hr Conveyor Screenings 2 1,400/1,400/2,800 lb/hr Solids Loadout Conveyor Shaftless Screw Gnt 2 900/900/1,800 Ih/hr Screenings 2 1,400/1,400/2,600 lb/hr Gnt Separation Cyclones 4 300/900/1,200 gpm Classifiers 2 600/600/1,200 gpm Notes: a Total firm capacity is with largest unit out-of-service. b Total capacity is with all unas in service. Primary Treatment The MWMC WPCF currently uses a total of four primary clarifiers to treat screened and degritted raw sewage. The existing primary clarifiers are circular, have outboard launders, and are 135 feet in diameter. Each clarifier receives effluent from the plant's existing headworks through a dedicated 60-inch-diameter pipe. Primary sludge is accumulated at the bottom of the clarffier and thickened through compaction. Primary sludge solids are drawn off with intermittent sludge pumping and a thin sludge blanket is maintained within the clarifier. Table 3.2.2-2 summarizes the prin-mry treatment processes and equipment. MWMC_3 0_REV11 DOC 3-9 MWMC FACILITIES PLAN TABLE 3.2.2-2 WPCF Primary Clardication Unit Processes and Equipment MWMC Facilities Plan, Eugene-Springfield Capacity, (each/total Equipment Type Quantity firma/total~b) Primary Clarifier 135-foot-diameter, 12-foot side water depth, 4 2t/64/86 with standard scraper mechanism, 44-inch influent column Primary Sludge Pumps 4-inch a~r-operated diaphragm pumps 4 110/330/440 gpm Primary Scum Pumps 4-inch a~r-operated diaphragm pumps 2 110tl 10/220 gpm Notes: ~ Total firm capacity is with largest unit out -of service. b Total capacity is with ali units in service. Secondary Treatment The MWMC WPCF currently has a total of eight activated sludge basins to provide biological secondary treatment. The original design was intended to operate in complete mix, plug flow, or contact stabilization mode. The original aeration system consisted of six centrifugal blowers and coarse bubble aeration. In 1996 three of the eight aeration basins were modified and the coarse bubble aeration systems were replaced wi~h fine bubble membrane diffusers. The secondary treatment average dry weather capacity was estimated at 49 mgd prior to the issuance of the new 2002 NPDES permit. This capacity was based on an adequate solids retent/on time (SRT) to remove 5-day carbonaceous biological oxygen demand (CBODs) only and does not account for any nitrification. At the same time, the peak hour wet weather treatment capacity was estimated at 103 mgd, limited by secondary clarification capacity. The hatroduction of nitrification in the 2002 NPDES permit stresses the facility's operatior~ during dry weather as a result of the high solids concentrations maintained/n [he aeration basins to provide the SRT required for nitrification and the secondary clarifier's inabil/ty to handle those additional solids. Historically for wet weather peak flows, primary effluents in excess of 103 mgd are diverted around secondary treatment and blended with secondary effluent and disinfected prior to disposal. Secondary clarification takes place using the original eight secondary clarifiers constructed in 1984. Mixed liquor is split to each secondary clarifier using sluice gates. Each secondary clarifier is 130 feet in diameter, uses inboard launders, and contains a rapid sludge removal (RSR) mechanism that draws return sludge from the clarifier floor with [he use of PVC suction tubes. Secondary scum is removed from the surface of the clarffier and flows by gravity to the secondary scum pump station located in the secondary control complex. Recent data indicate the wet weather peak hour capacity of the secondary clarifers to be 111 mgd, somewhat more than the 103 mgd estimated originally. OperatSons staff have been able to pass these higher peak flows; however, flow management techniques are required for the facility to stay within permit t/mits. Reharn sludge is removed from each clarifier through the RSR mechanism. The return sludge flow can be adjusted from each clarifier using electrically operated and controlled 3~10 MWMC_30_REV1'I DOC 3 EXISTINGWASTEWATER FACILITIES weir gates. Return sludge flows by gravity to the retum activated sludge (P~kS) pump station. Four vertical turbine pumps lift the activated sludge to a control structure where the IL4S is distributed back to the aeration basins through four parallel pipes. Activated sludge is then subsequently distributed to each aeration basin through a submerged diffuser header. The waste activated sludge (WAS) flow rate is controlled using flow meters and control valves. The WAS flows by gravity to the gravity belt thickener (GBT) and receives subsequent digestion. Table 3.2.2-3 summarizes the secondary treatment unit processes and equipment at the WPCF. TABLE 3.2.2-3 WPCF Secondary Treatment Unit Processes and Equipmenl MWMC Facilities Plan, Eugene-Springfield Capacity, (each/total Equipment Type Quantity firmaAotalb) Aeration Basins Complete mix or plug flow activated sludge 2 (8 ceils) MMDW 24.5/43/49 MGDc cells, 135 ftx 135' × 16 ft mdewater depth, MMWW 21/63/75 mgd Volume = 2.2 MG each, Total Volume = PWWF 111 mgd 17.6 MG Fine Bubble Aeration 7-inch membrane disc d~ffusers, 0.28 sq in 3 10,353/20,706132,538 scfm each, d~ffusers, Basin t = 4017, Basin 2 = 4014, Basin 3: 4490. Coarse Bubble Coarse bubble stainless stee~ air diffusers, 5 15,000/60,000/75,000 scfm Aeration 24-inch Aeration Blowers Centrifugal multi-stage b~owers, 1000 hp 6 17,000/85,000/102,000 scfm Secondary Clarlfiers 130-foot-diameter, 14-foot side water depth, 8 WWMM 9/66/75 mgd inboard launder, rapid sludge withdrawal DWMM 6/43/49 mgd mechanism, 44-inch influent column PWWF 111 mgd RAS Pump Station Vertical Turbine Pumps - 30-inch 2 23(12)/58/70 mgd Vertical Turbine Pumps - 24-inch 2 Waste Activated One 8-tach gravity wasting, with 6-inch 2 MMDW = 0.41 mgd Sludge magnetic flow meter and 6-tach flow control MMWW = 0.44 mgd valve PWWF = 0.78 mgd Secondary Scum Vertical centrifugal 2 1,200/1,200/2,700 gpm Pumps Notes: "Total hrm capacity ~s with iargest unit out -of service. t~ Total capacity is with al~ units in service. c Capacity noted is current rated capacity in NPDES permit. Disinfection Chlorine is delivered to the plant in 1-ton cylinders. Chlorinators dL~pense chlorine in the desired quantities to each application point. The primary use of chlorine at the WPCF is effluent disinfection. Chlorine is occasionally used to control filamentous bulking organisms through addition to the R~S line. MWMC_3 0_REV11 DOC 3-I ! FACILITIES PLAN The existing WPCF disinfection system uses liquid chlorine for disinfection and sulfur dioxide for dech.lorinafion of the disinfected effluent. Chlorine solution is delivered to secondary effluent or blended primary and secondary effluent flow streams through a diffuser at the influent box to each chlorine contact basin. Following chlorine addition, flow passes through a chlorine contact basin to gain the desired detention time. The current disinfection capacity is estimated at 175 mgd, although higher peak wet weather flows in excess of 200 mgd have been disinfected effectively because of their dilute nature. The addition of sulfur dioxide for dechlorination takes place before the finat effluent flows to the ouffall box. Sulfur dioxide is delivered to the plant in 1-ton cylinders. Sulfonators dispense the sulfur dioxide in the desired quantifies. Sulfur dioxide injectors operate in a manner similar to the chlorine injectors. The sulfur dioxide solution is added to the effluent downstream of the chlorine contact basins as the effluent flows through a mixing orifice. Table 3.2.2-4 presents a sunmzary of the existing equipment associated with the disirdection system. The existing chlorine and sulfur dioxide systems have a sodium hydroxide wet scrubber system that is automatically started if a chemical leak is detected in the chlorine building. The wet scrubber has a 2-ton capacity, contains a 4,100-gallon tank of 12 percent NaOH, and is rated at 10,000 cfm. TABLE 3.2.2-4 WPCF Disinfection Facihty Equipment MWMC Facilities Plan, Eugene-Springfield Capacity, (each/total Equipment Type Quantity firm~Jtotalb) Chlorine Contact Four contact basins each 585 ftx 15 ftx 4 58/185/230 MGD Basins 13 fi, volume = 0.85 MG, (3.8 MG total volume, capamty at 20 minutes for instantaneous peak Evaporators (chlonne) Wallace and Tiernan, Series 50-202 2 8,000/8,000/16,000 lb/day Chlorinators Portacel, AVP2, 2000 lb/day units 5 1,000/4,000/5,000 lb/day running with 1000 lb/day telemeters Evaporators (sulfur Wallace and Tiernan, Series 50-202 2 8,000/8,000/16,000 lb/day dioxide) Sulfonator Wallace and Tiernan, V2020 1 45014501450 iblday Sul/onator Podacel, AVP2, 2000 lb/day units 1 1,000/1,000/1,000 lb/day running with a 1000 lb/day telemeter Chlorine Scrubber I 10,000 cfm- a~rttow t2% NaOH solution Chtorine Scrubber Currently under construction i 5,000 cfm - aidlow 20% NaOH solution Notes: ~ Total f~rm capacity' ~s with largest unit out of service. b Total capacIty ~s with alt units in service. I~WMC_30_REV1 f DOC 3 EXISTING WASTEWATER FACILmES Effluent Disposal Current effluent disposal practices consist of discharging plant effluent L~to the Willamette River. The WPCF has historically met all regulatory requirements for secondary effluent disposal with one exception. On May 17, 1991 the dally mass lflxfit was exceeded for TSS and BOD. Effluent is preferentially d~sposed of through a submerged dffkzser h~ the Willamette River. The NPDES perm/t requires the use of the submerged dfffi, zser from May 22 through October 31. Peak wet weather flows over 103 mgd consist of blended primary and secondary disinfected effluent. The wet weather hydraulic capacity of the WPCF is estimated at 175 mgd, although higher flow rates approaching 215 mgd have been achieved. The current prac~ce for discharging peak wet weather flows in excess of the submerged diffuser ouffall capacity is to overflow into a bankside outfalL These overflows occur at a weir located at the ouffall control structure. The current NPDES peru-fit allows the bankside ouffall to be used from November 1 through May 21 to accormmodate peak wet weather flows. Thickening WAS is currently thickened at the WPCF with the use of GBTs. The GBT facility houses 3-meter gravity belts, a polymer distribution system, and the thickened WAS pumps. WAS flows either by gravity or pumped flow from the RAS control structure to the GBT facility, The WAS flow rate is metered and controlled with flow control valves at the PAS and/or GBT control structure. Prior to tbJckening, the WAS is conditioned with a cationic polymer. Thickened WAS is bfpically around 5 percent solids and is pumped directly to the digester for anaerobic digest/on. Table 3.2.2-5 summarizes the waste activated sludge unit process and associated equipment. TABLE 3.2.2-5 WPCF Waste Activated Sludge Thickening Unit Processes and Equipment MWMC Facilities P~an, Eugene-Springfield Capacity, (each/t~ta~ Equipment Type Quantity fi~ma/tota~~) Gravity Belt Thickeners 3-meter, 95% solids capture, 5% so/ids, 2 45,250148,250/96,500 lb/day MWWW SLR= 2010 lb/hr, MWWW HLR = 120 gpm/m WAS feed pumps Screw centrifugal with adjustable frequency 2 800/800/1,600 gpm dr'rye (AFD), 15 hp Thickened Waste P regressive cawty w~th AFD, 20 hp. 2 120/120/240 gpm Achvated Sludge Pumps Polymer System Liquid tote polymer system, 17 lb/ton 2 17/17/34 lb/ton capacity Notes: a Total firm capacity is with largest unit out of service. bTotal capacity is with all un~ts in service. Anaerobic Digestion Three primary anaerobic digesters located at the WPCF stabilgze primary, sludge and secondary WAS. Each digester is 85 £eet/n diameter and contains a fixed cover. Table 3.2,2-6 summarizes the anaerobic digestion unit processes and associated equipment. MWMC_3.0_flEVH DOC MWMC FACILITIES PLAN TABLE 3.2.2-8 WPCF Anaerobic Digestion Unit Processes and Equipment MWMC Facilities Plan, Eugene-Springfield Capacity~ (each/total Equipment Type Quantity firmaAotalb) Digesters Anaerobic, fixed cover, 85-foot-diameter, 3 19,432/38,864/58,295 lb VSS/day 27.6 foot SWD, active volume = 1.14 MG each, DWMM SLR = 0.15, DWMM SRT =15 days Biosolids Storage Fixed cover, 60-foot-d~ameter 2 360,000/360,000/720,000 gal Tanks Digested Sludge Progressive cavity with AFD, 75 hp 2 430/430/860 gpm Pumps Notes: a Total firm capacity is w~th largest unit out -of service, bTotal capacity is with all units in serwce Facu~tative Sludge Lagoons and Drying Beds The FSLs are located at the BMF facility offsite ot~ the WPCF. The lagoons were constructed to provide storage and further stabilizat/on of digested biosolids received from the WPCF. Anaerobically digested biosloids are pumped from the sludge holding tanks at the WPCF through a 5.5-mile-long pipeline, to the four facultative lagoons at the BMF Facility. The lagoons provide the additional detent/on time for natural processes to further stabilize the biosolids and reduce pathogens. Sealed asphalt drying beds provide for the stabilized biosolids to be dewatered for 6 to 10 weeks in the dry season. Dewatered biosolids are recycled through land application on cooperative farms. Supematant from the lagoon is returned to the WPCF. Table 3.2.2-7 summarizes the biosolids stabdizat/on unit processes and associated equipment. TABLE 3.2.2-7 WPCF Biosol~s Stabilizahon Unit Processes and Equipment MWMC Facilities Plan, Eugene-Spnnfefd Capacity, (each/total Equipment Type Quantity firma/totalb) Biosolids Stabilization Facultative lagoons, 6.25 acres 4 6,806/20,419/27,225 lb VSS/day Lagoons each, 13.5 ft depth Drying Beds Asphalt {ined, 1.85 acres each, 0.48 ~3 1,393 CY ft depth, 67 ~b/cf density Notes: aTotal firm capacity is w~th largest unit out -of service. b Total capacity is with all units in service. Biosolids Dewatering The original design provided for the stabil/zed biosolids to be dewatered for 6 to 10 weeks in thirteen sealed asphalt drying beds. However, lower than anticipated solids processing efficiency (primarily because of variable summer weather conditions) required the addition 3-14 MWMC_30. REV'H DOC 3 EXISTING WASTEWATER FACIUTIES of belt filter presses at the BMF facility. In 2002 the addition of three 2-meter belt filter added solids processing capacity that closely matched the design capacity of the presses treatment plant. Stabilized biosolids from the lagoons may be either mechanically dewatered using the belt filter presses, applied to drying beds for seasonal dewatering, or pumped directly to the Biocycle Farm for land application. Dewatered biosolids are recycled through land appJacation on cooperative farms. Filtrate from the belt filter presses and FSLs is returned to the WPCF. Table 3.2.2-8 summarizes the biosolids dewatering unit processes and associated equipment. TABLE 3.Z2-8 WPCF Biosolids Dewatering Unit Processes and Eqmpment MWMC Facilities Plan, Eugene-Springfield Capacity, (each/total Equipment Type Quantity flrma/totalb) BFP Feed Tank Screw centrifugal, 25 hp 2 1,80011,800/3,600 gpm Mixing Pump BFP Feed Tank Open top concrete, 48 ft d~ameter, 26 2 360,000/360,000/720,000 gal ft SWD, volume each = 360,000 gal Belt Filter Presses 2-meter belt filter presses, 98% 3 29,770/59,530/89,304 lb/day capture BFP Feed Pumps Progressing cavity with AFD, 15 hp 3 200/400/600 gpm BFP Filtrate Pumps Submersible with AFD, 15 hp 3 575/115/1,725 gpm Cake Conveyance Auger screw 1 30/0/30 wet tons/hr B,osohds Strainers Biosolids Strainers 3 200/400/600 gpm Notes: ~ Total firm capacity ~s with largest unit out ---of service. ~ Total capacity is w~th al~ units in service. 3,2.3 Plant Operation and FaciJities MWMC WPCF operations full-time staff consists of art operations supervisor, a ct'del operator, and 14 operators. Plant operations staff respond to all alarms on a 24/7 basis for the WPCF, 47 pump stations, the BMF and the SIWF. Safety of personnel and the public is the staff's highest priority. The second highest priority is maintaining WPCF operations within NPDES permit parameters. Decisions regarding cost-saving measures are a balance between environmental performance and environmental impact, with selected decisions being positive for both criteria. The computerized system documents and summar2es plant operations. Administration and operational facilities (non-process) include administration offices,; the plant laboratory,; operations rooms,; records management offices,; personnel support areas such as locker room. s, conference areas, and lunch rooms; and the operations console. All are located in the existh~g administrative building, of which 8,749 square feet ks dedicated to admirdstration, 944 square feet is dedicated to operations personnel, and 4,515 square feet is dedicated to laboratory operations. MV~MC_3.0_REV1 I.DOC 3~15 MWMC FACILITIES PLAN The WPCF maintenance facilities consist of the maintenance shop, welding shop, steam cleaning bay, stores area, and field maintenance shop. The maintenance shop, welding shop, and steam room comprise approximately 11,770 square feet, stores occupies 2,290 square feet, and the facility maintenance shop comprises approximately 2,000 square feet. 3.2.4 Unit Performance and Deficiencies Unit processes at boff~ the WPCF and the BMF have been evaluated for capacity and performance so that current and future needs can be addressed without a lapse in treatment capability. Table 3.2.O1 sttmmarize the liquids unit processes, process limitations, and process deficiencies identified through the analysis. Table 3.2.4-2 summarize the solids unit processes, process limitations, and process deficiencies. MWMC_3 0_REV11~DOC 4.0 Wastewater Characteristics Tlxis chapter presents the ex/sting wastewater characteristics at the WPCF and consists of an evaluation of historical flows and loads, as well as historical per capita and peaking factor calculations. It also presents an analys/s that correlates current plant wastewater flows with current rainfall data in an independent effort to produce flow peaking £actors. PWWFs have been determined using an extensive collection system modeling approach. Th/s historical data analysis, in conjunction with the rairffall data analysis and the collection system modeling, provide the bas/s for future flow and load projections. The "Flow and Load Projections" technical memorandum presented a historical flow and load analysis, rainfall flow analysis, population projections, and projections for future flows and loads based on lwo independent methodologies. The "Wet Weather Peak Flow Analys~s' tec]mical memora~qdum presented the collection system modeling methodology to develop the peak wet weather flows. The following is a summary of the information presented in those technical memorandums. 4.1 Wastewater Flow Characteristics Two separate analyses of historical flow data were conducted. The first analysis/ndudes assessment of 12 years of historical plant data. The second analys/s follows the Guidelines for Maldng Wet-Weather and Peak Flow Projections for Sewage Treatment in Western Oregon: MMDWF, MMWWF, PDAF, and ?IF, from the Oregon DEQ (DEQ, 1996). 4,1.1 Historical Seasonal Flow Analysis YIistorical flow data ~rom May 1990 through May 2002 were evaluated to determine average, maximum month, maximum week, and maximmn day flows. The data analys/s was broken up h~to dx~f and wet weather seasons. The two seasons align with the effluent requdrements as specified in the WPCF's NPDES permit. Flows at the WPCF are measured at the irutluent Parshall flume. Dry weather includes flows occurring between May 1 and October 31. Historical dry weather average and maximum month flows are depicted in Figure 4.1.1-1. Wet weather includes flows occurring between November 1 and April 30. Historical wet weather average and maximum month flows are depicted in Figure 4.1.1-2. MWMC_40_REV9 DOC 4-~ MWMC FACILITIES PLAN FIGURE 4,1.1-1 Average and Maximum Month Dry Weather Flow MWMC Facilities Plan, Eugene-Springfield 35.o- -- /\ -- -- 25 0 15 0 '~ lOgO lggl 1902 1903 lgg4 lgg~ IDg6 1997 1908 lggg 2000 2~1 2002 FIGURE 4.1 Average and Maximum Month Wet Weather Flow MWMC Facilities Plan, Eugene-Spnngfleld 600 ! 30 0 OO 19~ ~991 1992 1993 1994 1995 ~996 1997 1998 1999 2000 -~ Wet Weather Maximum Month F(ow ~ Wet Weather Average ~ 4-2 MWMC_40_REV9 DOC 4 WASTEWATER CHARACTE R~'TICS 4,1,2 Historica Fi0w Statistics Peaking factors are commonly used to estimate future peak flow condgdons and are ~requently based on analyses of historical average and peak flow data. The methods used for estimating peaking factors involved analysis of historical peaking factors for the years 1990 tlxrough 2002 for both dry and wet weather conditions and the DEQ methodology. Peakirtg factors for flow and load events (maximum month, maximum week, maximum day and peak hour) are ratios of the particular seasonal events to the corresponding seasonal averages. Tables 4.1.2-1 and 4.1.2-2 present the historical dry and wet weather flow per capita and peaking factor statistics, respectively. 'tABLE 4.1.2-1 Historical Dry Weather Flow Statistics MWMC Facilities Plan, Eugene-Springfield Maximum Flow Per Capita Month Peaking Maximum Week Maximum Day Peak Hour (gpcd) Factor Peaking Factor Peaking Factor Peaking Factor Minimum 105 1.1 1,2 1,5 2.3 Average 128 1.3 1.7 2.3 2.8 Maximum 147 1.5 2.8 3.9 4.0 TABLE 4.1.2-2 Historical Wet Weather Flow Statistics MWMC Facilities Plan, Eugene-Spnngfiold Maximum Flow Per Capita Month Peaking Maximum Week Maximum Day Peak Hour (gpcd) Factor Peaking Factor Peaking Factor Peaking Factor Minimum 139 1.2 1,5 2.3 (a) Average 227 1.6 2.5 3.4 (a) Maximum 275 1.4 I 9 2.8 (a) (a) Determined by collections system modeling, see Wet Weather Peak Flow Technical Memorandum. 4.1.3 DEQ Methodology Peaking Factor Analysis The Guidelines for Making Wet-Weather and Peak Flow Projections for Sewage Treatment in Western Oregon: MMDWF, MMWWF, PDAF, and PIF (DEQ, 1996) present i~st-tucdons on calculating current flow rates. A statistical analysis of l~dsto~tical data &om 2000 arid 2002 was used to predict current peak flow rates. The maximum month flows for dry weather and wet weather are predicted using rainfall recurrence data obtained &om the National Oceanic and Atmospheric Administration, National Climatic Data Center, CJimatography of the United States No. 20, 1971-2000, Eugene Mahlon Sweet A~rport Stador~ (~IOAA, February MWMC_40_REV8 DOC 4-3 UWMC FACILmES PLAN 2004). The peak day average flow (PDAF) was predicted using daily precipitation and flow data for January through.May, the months that groundwater affects I/I rates irt the system. Using a probability distribution, the peak week and peak instantaneous flow rates were predicted. Table 4.1.3-1 presents the peaking factors derived from the DEQ predicted flows. TABLE 4.1 DEQ Methodology Flow Peaking Factors MWMC Facilities Plan, Eugene-Springfield Dry Weather Wet Weather Wet Weather Peak [~aximum Month Maximum Month Max~murn Week Peak Day Instantaneous 2.0 1.4 1.7 2 6 6.1 4.1,4 Infiltration and Inflow Many commtmJties typically experience higher flow rates in their wastewater collection systems during rain events. These flow responses to rainfall (and sometimes snowmelt) will usually vary according to storm volume and intensity, as well as the mount and duration of antecedent rainfall (rainfall in the days preceding the particular rain event). The flow response to rainfall/snowmelt can generally be referred to as RDII (rainfall dependent infiltration and inflow). It corresponds with that portion of a wastewater collection system hydrograph that/s above the normal base flow. The ratio of RDII (volume or peak flow rate) to precipitation is generally referred to as the RDII "return rate." Infiltration and inflow are two distinct contributors to a wet weather hydrograph, but there is no clear demarcation between them. Inflow enters sewers through direct stormwater connections such as roof leaders, illegal drain connections, and leaky manhole covers in depressed or sump areas. Infiltration is produced by fair, all and/or snowmelt that has been sustained long enough to soak into the soil and produce temporary saturated soil conditions. Infiltration enters sewers directly through cracks and faulty deteriorated joints, and indirectly through basement sump pumps. RDII can be reduced through rehabilitation of the wastewater collection system. Rehabilitation can include repair or replacement of facilities, relining of fadlit/es, and disconnection of inflow sources. Previous Infiltration and Inflow Studies During the mid 1970s, a Sewer System Evaluation Study (SSES) was performed for the Eugene and Springfield sewer system study areas to assess the amount of RDII entering the collection systems. The study estimated that in 1978 the peak flow to the plarmed regional WPCF would be 264 mgd. The SSES also predicted quantifies of RDII that could be cost- effectively removed. These removal estimates formed the basis for the 175-mgd design flow rate of the WPCF. Subsequent studies for Eugene (City of Eugene Public Works/Engineering Urban Sanitary Sewer Master Plan, 1992) and Springfield (City of Springfield Sanitary Sewer Master Plan, July 1980), documented RDII as significant contributors to systemwide wastewater peak 44 MWIVIC_4.0_REVS. DOC 4. WASTEWATER CHARACTERISTICS flow rates. The studies recommended continued and additional funding to rehabilitate the respective systems to correct structural deficiendes and reduce RDII contributions. Comprehensive RDII reduction programs in both dries fulfill NPDES waste discharge permit requirements. Both cities' programs include varying degrees of flow monitoring, TV inspection, smoke testing, and manhole inspections as appropriate. Unforttmately, the programs have not been as effective in controlling excessive peak flows as estimated in the 1978 SSES study. Limited success with RDII reduction programs has also been the case for many other communities around the state and country. The inability of RDII rehabilitation programs to achieve desired targets formed the impe~_s for the September 2000 Wet Weather Flow Management Plan (WWFMP; CH2M HILL, 2001), which evaluated and recommended individual technologies or combinations of technologies to manage wet weather flows. The WWFMP estimated more up-to-date and realistic rates of RDII reduction that could be expected as a result of collection system rehabilitation projects. For the purposes of the WWFMP study, two groups of system rehabilitation were evaluated: (1) rehabilitation of main lines and laterals within the public right-of-way (lower lateral), and (2) rehabilitation of the same but including portions of the laterals that are outside the public right-of-way (upper lateral). The two types of rehabilitation are referred to as "public only" and "public and private." Public only includes the entire collection system within the right-of-way limits, independent of ownership. The cities of Eugene and Springfield have collected a large amount of data in the last 5 to 10 years to measure the effectiveness of their system rehabilitation programs. The data comprise flow records taken before and after implementation of rehabilitation in specific areas. These data were used for estimating the operational and economic benefits of further system rehabilitation activity. All local data from both dries represented system rehabilitation within the public fights-of-way. Neither city has performed comprehensive system rehabilitation of the private laterals outside of rights-of-way; consequently, all local data used in the WWFMP analyses represent the public-only condition. CH2M HILL performed a three-phase analysis of the data. The first phase involved a preliminary review of the raw data that resulted in a general assessment of system rehabilitation benefit. The second involved a quantitative comparison of basin-spedfic data. This examination reviewed pre- and post-rehabilitarion RDII quantifies relative to type and amount of system rehabilitation per sub-basin. Both local and other agency data were reviewed. The third phase identified performance measures to be used in later analyses of wet weather flow management strategies. Along with performance measures, the economic costs of system rehabilitation were reviewed. Rehabilitation PracIices and History Most of the data used in estimating RDII reduction as a result of public-only system rehabilitation are from City of Eugene projects and monitoring. The data are relatively recent and considered appropriate as a basis for RDII reduction estimates. The City of Springfield has also performed public-only system rehabilitation, but their data are not as current and often represent unique system conditions. Post-rehabilitation monitoring was not typically performed in Springfield. Therefore, the description of rehabilitation practices on performed by City of Eugene. It was assumed that RDiI section is based work the ~WMC_4.0_REVS.DOC MWMC FACILmES PLAN reduction conclusions developed using City of Eugene data would also apply to the Springfield system. The City of Eugene has foc~ased its wastewater rehabilitation efforts on sUb-basins with high wet weather to dry weather flow ratios. The City has extensive video inspection data showing collection system defects. These data have been evaluated by staff who have assigned deficiency ratings to pipe reaches. These deficiency ra~-~gs, along with flow monitoring, have been the basis for prioritizing and implementing City of Eugene public- only system rehabilitation. The majority of the lines rehabilitated to date were 8 inches in diameter. For the most part, the main line was 5 to 10 feet deep and the average depth of the service lines was about 4 feet deep at the edge of the right-of-way. Eugene's comprehensive public system rehabilitation approacA includes rehabilitating the majority of the main line, building services and connections, and manholes with_in the right- of-way. City staff have most often selected trenchless liner as the rehabilitation method. Replacing building service cormections at the main and sections of service lines located within the public fight-of-way has also been a major component of the City's rehabilitation effort. For building service lines within the public right-of-way, the City has installed, through open excavation, new PVC pipe with rubber-gasketed joints and taps at the main line. An additional component of the rehabilitation program involves mod/b/Lng manholes to reduce the surface inflow potential, and sealing the interior barrel sections and bases (where needed) with internal cement-based material to reduce or elLminate iruCiltration. In a few cases, the City performed, a spot repair on a segment of pipe instead of lifting the whole pipe. For these cases, the whole segment and its associated length were cour~ted as being rehabilitated. With regard to RDII reductions attributable to system rehabilitation, Eugene-Springfield's experience was compared with that of other agencies within and outside of Oregon. As in Eugene and Springfield, monitoring data from other agencies were ~j/3ically obtained within a few years of completing system rehabilitation projects, so the data were not necessarily representative of RDII reduction over the long-term. Data representing RDII reduction over the long-term were not identified. In general, agencies were found to address system rehabilitation in one of three ways: 1. Rehabilitation of main lines only (no portion of the lateral). 2. Rehabilitation of main lines and lower laterals (that portion of the lateral in the public right-of-way). 3. Rehabilitation of main lines as well as upper and lower laterals (the entire lateral, both in the public right-of-way and on private property to the struch~e served). Hydraulic Modeling A hydraulic model was developed to depict existing and future flows in the wastewater collection system, and the expected RDII reduction benefits in the system for both public- only and public and private rehabilitation efforts based on the estimated RDII reductions attributable to system rehabilitation. MW~C_40_REV8 DOC 4. WASTEWATER CHARAC'rERISTiCS The response of the sewer system to immediate and antecedent rainfall during the wet weather events of the 1997-1998 monitor~g period was analyzed as part of the WWFMP. As a first Step in analyzing the monitoring data, the diurnal base flow hydrograph for selected storms was subtracted to obtain the RDII hydrograph. For the WWFMP study, flow inputs were developed from regression equations, and were modified to reflect the experience of MWMC operations personnel and the observations of return ratio at monitor locations. The regression equations provided a method to generate the RDII component of the flow input hydrograph for each monitoring location for any storm of interest. Although the method is a good one, it can be deficient if the equation is applied to storms that differ signfficantly in character (inten~sity, pattern, and volume) from the storm for which the equation was created. As part of the task of updating the MWMC MOUSE hydraulic model for 2003-2004, the model was recalibrated using the latest flow monitor data from six permanent MGD Technologies monitor installations (herein referred to as MGD monitors) within the collection system and one at the WPCF. Changes to the collection system pipes and pump stations were also incorporated into the updated model. The methodologies used to generate model flow inputs were different than those used for the WWFMP, although the relative distribution of flows within the collection system and the peak flow at the WPCF were consistent with the WWFMP. The MOUSE dry weather flow module was used to create the diurnal sanitary flow based on population, and the MOUSE RDII module was used to generate system RDII flows from rainfall. This change in methodology allowed all of the flow inputs to be generated within the hydraulic model rather than as separate computations external to the MOUSE model More detailed 5~fformafion on the subject of the wastewater collection system hydraulic modeling analysis is given in the March 2004 "MWMC Wastewater Facility Plan--Wet Weather Peak Flow Analysis" technical memorandum (see appendix). Assumptions for system rehabilitation identified under the ~ were incorporated in the future conditions model runs (2025 and bttfldout). The W~ZFMP used a peak rainfall dependent inf~tration and inflow (RI)H) rate of 2,000 gallons per additional future developed acre per day for the 5-year storm event. The updated MOUSE rnodel also uses the 2,000 gallons per acre per day peak RDII rate for all future developed areas. This value was derived as part of the WWFMP and was based on measured data in areas considered to represent future system conditions. System rehabilitation recommendations included in the WWFMP for exLsting and future conditions were assumed to have been implemented for the 2025 peak flow estimates. These rehabilitation projects were included in the plan as a result of the cost-effectiveness analysis that identified proiects to reduce peak flows in the collection system. 4,2 Wastewater Loading Characteristics BOD and TSS concentrations at the WPCF are measured using 24-hour composite samples collected and analyzed by plant personnel. MW~C_4.0_REVS. DOC 4-7 MW'MC FACILITIES PLAN 4.2.1 Historical Seasonal Loading Analysis Historical loading data from May 1990 through May 2002 were evaluated, with corresponding flow data, to determine average, maximum month, maximum week, and maximum day BOD and TSS loads. The data analysis was broken up into dry and wet weather seasons. The two seasons aligner with the effluent requirements as specified in the WPCF's NPDES permit. Dry weather includes flows occurring between May 1 and October 31. Historical dry weather average and maximum month loads are depicted in Figure 4.2.1-1. Wet weather includes flows occurring between November i and April 30. Historical wet weather average and maximum month loads are depicted in Figure 4.2.1-2. FIGURE 4,2,1-1 Dry Weather Maximum Month Loads MWMC Facilities Plan, Eugene-Springfield lo, ooo 0 L 1990 lg91 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 ~ Dry W~at~er Ma~murt3 Mont~l BOO Lo~dm~J -~--Ory We~ttte~t Maximum Month T$.~ Loading 4-8 MWMC_40_REV900C 4 WASTEWATER CHARACTERISTICS FIGURE 4.2,1-2 Wet Weather Maximum Month Loads MWMC Facilities Plan, Eugene-Springfield 10,000 -- 0 lgDO lggl lgg2 1993 lgg4 lgg$ lgg6 lgg7 1998 Iggg 2000 200I 2002 Year --~--Wet Weather Maxl~u~m ~o~[h ~0 LoaEmg ~We~ther ~axlmum Nonth TSS Loadmg 4.2,2 Historical Loading Statistics Per capita loads are commonly used to estimate future loading conditions and are frequently based on analyses of historical seasonal average data. To calculate the average seasonal per capita domestic wastewater loads, it is necessary to correlate historical population h'~formation with the historical seasonal average domestic wastewater loading data. These per capita values are then used in conjunction with projected populations to estimate future domestic seasonal wastewater loads to the WPCF. In addition, peaking factors for maximum month, maximum week, and maximum day were developed from the seasonal historical data. Tables 4.2.2-1 and 4.2.2-2 present the historical dry and wet weather BOD per capita and peaking factor statistics, respectively. TABLE 4.2.2-1 Historical DP/Weather BOD Loading Statistics MWMC Facilities Plan, Eugene-Springfield BOD Loading Per Maximum Month Maximum Week Maximum Day Year Capita (ppcd) Peaking Factor Peaking Factor Peaking Factor Mimmum 0.12 1.1 1,2 1.4 Average 0 15 1 2 1,4 1.7 Maximum 0.19 1 3 1.7 2 4 MWMC 4 0 REV9 DOC 4-9 ~lW~C FACILrr]ES PLAN TABLE 4.2.2-2 Historical Wet Weather BOD Loading Statistics MWMC Facilities Plan, Eugene-Springfield BOD Loading Per Maximum Month Maximum Week Maximum Day Year Capita (ppcd) Peaking Factor Peaking Factor Peaking Factor Minimum 0.11 1.1 1.3 1.5 Average 0.15 1.2 1.5 1.9 Maximum 0.23 1.6 1.9 2.4 Tables 4.2.2-3 and 4.2.2-4 present the historical dry and wet weather TSS per capita and peaking factor statistics, respectively. TABLE 4.2.2-3 Historical Dry Weather TSS Loading Statistics MWMC Facilities Plan, Eugene-Springfield TSS Loading Per Maximum Month Maximum Week Maximum Day Year Capita (ppcd) Peaking Factor Peaking Factor Peaking Factor Minimum 0.17 1.1 1.2 1.6 Average 0,19 1.2 1.4 2.3 Maximum 0.20 1.4 1.8 4.0 TABLE 4.2.2.4 Historical Wet Weather TSS Loading Sta~stics MWMC Facilities Plan, Eugene-Springfield TSS Loading Per Maximum Month Maximum Week Maximum Day Year Capita (ppcd) Peaking Factor Peaking Factor Peaking Factor Minimum 0.18 1.1 1.3 2.0 Average 0.23 1.2 1.5 2.9 Maximum 0.26 1.6 2.0 4.3 4.3 Selected Design Factors The selected design factors were chosen based on compari.~on of the results from the historical data analysLs, the DEQ methodology, and best engineering judgment. MW~iC_4,0_PEVB, DOC 4. WASTEWATER CHARACTERISTICS 4.3.1 Wastewater Flows Table 4.3.1-1 presents the selected design factors for flow. TABLE 4.3.1-1 Selected Flow Per Capitas and Peaking Factors MWMC Facilities Plan, Eugene-Springfield Seasonal Average Per Capita Values Parameter Dry Weather Value Wet Weather Value Flow (gpcd) 129 229 Peaking Factor Values Flow Condition Dry Weather Value Wet Weather Value Average 1.0 1,0 Maximum Month 1.5 1,6 Maximum Week 2.2 2.4 Maximum Day 3.2 3.3 Peak Hour 4.0 ~ll 4.3.2 Wastewater Loads Tables 4.3.2-1 and 4.3.2-2 present the selected design factors for BOD and TSS loading, respectively. TABLE 4.3.2-1 Selected BCD Loading Per Capitas and Peaking Factors MWMC Facilities Plan, Eugene-Springfield Seasonal Average Per Capita Values Parameter Dry Weather Value Wet Weather Value CBOD (ppcd) 0.185 0,185 Peaking Factor Values Condition Dry Weather Value Wet Weather Value Average 1.0 '~ .0 Maximum Month 1,3 1,3 Maximum Week 1.5 1,6 Maximum Day 2.0 2.3 MW~C_40_REVB. DOC 4-11 MWI~C FACIL~ES pLAN TABLE 4.3.2-2 Selected TSS Loading Per Capitas and Peaking Faclors MWMC Facilities Plan, Eugene-Springfield Seasonal Average Per Capita Values Parameter Dry Weather Value Wet Weather Value TSS (ppcd) 0.205 0~26 Peaking Factor Values Condition Dry Weather Value Wet Weather Value Average 1.0 1.0 Maximum Month 1.4 1.3 Maximum Week 1.8 2.0 Maximum Day 2.5 3 0 4.4 Projected Wastewater Flow and Load Characteristics Wastewater flows and loads were projected to the year 2025, at 5-year intervals, and ~or the build-out condition (estimated year 2050) for domestic and h~dustr~al sources. Sim~ar to the h~storica] analysLs, average, maximum month, maximum week, and maximum day flow rar~ges and loads were determined for both dry and wet seasons. Domestic (residential and commercial, and I/I) projections were estimated based on the population projections and the selected per capita and peaking factors ~den~ed above. The methods for dete~g average, maximum month, maximum week, maximum day, and peak hour values are listed below and refer to both flows and loadings: Average Dry Weather--Determined by multiply~g the selected per capita value by the projected population for 2005, 2010, 20:I5, 2020, 2025, and brdldozat. Average Wet Weather--Determined by mult~plyin§ the selected per capita value by the projected population for 2005, 2010, 2015, 2020, 2025, and buildouL Maximum Month---Determined by multiplying the future dry or wet weather averages for a given year by the selected maximum month peaking factor. Maximum Week~Detez~dned by multiplying the future dry or wet weather averages for a given year by ff~e selected maximum week peaking factor. ~ Maximum Day~De[errrdned by multiplying the future dry or wet weather averages ~or a given year by the selected maximum day peaking factor. Dry Weather Peak Hour F/ow---Determined by multiply~g the dry weather: average for a given year by the selected peak hour peaking factor. 4-12 MWMC_4,0_flEVS,DOC 4 WASTEWATER CHARACTERISTICS Wet Weather Peak Hour Flow--Detemfined by modeling the collection system at a 5-year, 24-hour storm recurrence. The result of the modeling efforts is presented L~ the "Wet Weather Peak Flow" technical memorandum. Tables 4.4-1 and 4.4-2 summarize the average and maximum month ba~re projected flows and loads for both dry and wet seasons. These are the total flow and total load projectior~ consisting of the residential, commercial, industrial, and I/I components. Peaking factors are not applied to the industrial portion of the overall flows and loads. TABLE Summary of Total Flow Projections (Residential, Commercial, and industrial) MWMC Facilities Plan, Eugene-Springfleld 2050 Year 2005 201 o 2015 2020 2025 (build-out) Estimated Population 229,145 246,255 263,365 280,475 297,585 383,135 Wastewater Flow Projections (mgd) Average Dry Weather 29.6 31.8 34.0 36.2 38.4 49.4 Max. Month Dry Weather 46.0 49.4 52.7 56.0 59.3 75.8 Average Wet Weather 52.5 56.4 60.3 64.3 68.2 87.8 Max. Month Wet Weather 85.7 92.0 98.2 104.5 110.8 142.1 Peak Hour Wet Weather (Modeling)* 266 268.5 271 274 277 294 · The 'modeling" values for wet weather peak hour flows are based on actual modeling results for 2005 and 2025. For the purpose of planning at the WPCF, the intermediate peak flow values are interpolated. See "Wet Weather Peak Flow" technical memorandum for additional discussion. TABLE 4.4-2 Summary of Tota~ Load Projections (Residential, Commercial, and Industrial) MWMC Facilities Plan, Eugene-Springfield 2050 Year 2005 2010 2015 2020 2025 (build-out) Estimated Population 229,145 246,255 263,365 280,475 297,585 383,135 BOD Loading Projections (lb/day) Average Dry Weather 42,400 45,600 48,700 51,900 55,000 70,900 Max. Month Dry Weather 57,500 61,600 65,700 69,900 74,000 94,500 Average Wet Weather 42,400 45,600 48,700 51,900 55,000 70,900 Max. Month Wet Weather 57,500 61,600 65,700 69,900 74,000 94,500 TSS Loadi~9 Projections (lb/day) Average Dry Weather 47,000 50,500 54,000 57,500 61,0(30 78,500 Max. Month Dry Weather 68,000 73,000 77,800 82,800 87.800 112,200 Average Wet Weather 59,600 64,000 68,500 72,900 77,400 99,600 Max. Month Wet Weather 79,700 85,500 91,200 97,000 102,800 131,700 Mw~c_40_REV9 DOC 4-13 5.0 Basis of Planning 5.1 Basts for Design 5,1.1 Existing Regulator] Requirements The WPCF discharges to the Willamette River at river mile 178. The discharge is permitted under an NPDES permit issued by the DEQ. DEQ issued a renewed NPDES permit for the WPCF in May 2002. The previous permit expired in 1997, and the current NPDES perrrdt (No. 102486) expires December 31, 2006. The discharge limitat/ons and requirements for the WPCF's current NI~DES permit are summarized in Table 5.1.1-1. These discharge l'mxitations and requffements are defined for three categories of wastewater sources: Treated effluent: ouffall 001 [diffuser and Ouffal100lA (ban~k ouffall)] 2.Recla/med water: ouffall 101 (Level II) and ouffall 102 (Level III) 3.Emergency SSOs: ouffalls 002 to 014 TABLE 5.1.1-1 Existing NPDES D~scharge Requirements and bmitations for the WPCF MWMC Facilities Plan, Eugene-Springfield (1) Treated Effluent Outfall 001 and 001A (No discharge from Out[all 001A from May 22 through October 31 unless approved by the DEQ) May t - October 31: Average Effluent Monthly1 Weekly~ Daily~ Concentrations Average Average Maximum Parameter Monthly Weekly (lb/day) (~b/day) (lbs) CBOD5 10 mg/L 15 m~L 4,100 6,100 8,200 TSS 10 mg/L 15 mg/L 4,100 6,100 8,200 November 1 - April 30: Average Effluent I~onthly~ Weekly~ Daily1 Concentrations Average Average Maximum Parameter Monthly Weekly (lb/day) (lb/day) (lbs) CBODs 25 mg/L 40 mg/L 16,000 24,000 32,000 TSS 30 mg/L 45 mg/L 19,000 28,000 38,000 Year Round: Parameter Limitations E. co# Bacteda Shall not exceed 126 organisms per 100 mL monthly geometric mean. No single sample sha~l exceed 406 organisms per 100 mL. pH Shall be within the range of 6.0 - 9.0 MWMCF~IL1TIESP~N TABLE 5.1.1-1 Existing NPDES Discharge Requirements and Limitations for the WPCF MWMC Facilities Plan, Eugene-Springfield CBODs and TSS Removal Shall not be less than 85% monthly average for CBOD5 and Efficiency 85% monthly for TSS. Total Residual Chlorine Shall not exceed a monthly average concentration of 0.05 mg/L or a daily average concentration of 0.12 mg/L Excess Thermal Loading: May Shall not exceed a weekly average of 3.1 billion BTUs per day 1 - Oct 31 (Summer) Ammonia: May 1 - Oct 31 Shall not exceed 22 mg/L daily (Summer) Ma~Jmum and 12 mgJL monthly average, (Not speclhed in permit, but should be expressed as Ammonia-N) (1) The permit also defines the m~xing zone as follows: The allowable mixing zone is that portion of the Willamette River from 20 feet upstream of the diffuser to 200 feet downstream of the diffuser. In addition, the zone of immediate dilution (ZID) shall include that portion of the Willamette River within 50 feet downstream of the diffuser. (1) The permit also contains the following language regarding effluent limitations: This permit contains either technology or water quality based effluent limits for those parameters discharged by the perm~ttee that the Department has determined require effluent limitations to comply with the water quality standards found in OAR 340-41-445 outside the above mixing zones. The limits were established on the basis of the information provided by the permittee and following the Department's rules, including OAR 340-41-026. Other parameters also were identified m the perm/tree's application for which the Department did not establish effluent limitations. The Department has determined that those parameters do not present a reasonable potential to violate applicable water quality standards. The perm/tree is required to notify the Department if changes occur in Its processes or influent stream which could significantly change the effluent stream for any of these parameters. (2) Reclaimed wastewater outfal1101 and 102 No d~scharge to state waters is permitted. Alt reclaimed water reuse shall prevent: a. Prolonged pending of treated reclaimed water on the ground surface b. Surface runoff or subsurface drainage through drainage tile The creation of odors, fly and mosqu~to breeding, or other nuisance conditions d. The overloading of land w~th nutrients, organics, or other pollutar~t parameters e. Impairment of existing or reasonably probable beneficial uses of groundwater Out/all 101: Pdor to reuse of the reclaimed water, it shall receive at least Level ii treatment as defined in OAR 340-55 to: Reduce total coliform to 240 organisms per 100 mL in two consecutive samples, and a 7-day median of 23 organisms per 100 mL. Outfal~ 102: Prior to reuse of the reclaimed water, it shall receive at least Level iii treatment as defined in OAR 340-55 to: Reduce total coliform to 7-day median of 2.2 organisms per 100 mL and maximum of 23 organisms per 100 mL. irrigation shall conform to the irrigation management p/an approved by the Department ~n accordance w~th OAR 340-55 for agricultural, commemial, or industrial use. (3) Emergency Overflow Outfalls 002 through 014 5 BASIS OF PLANNING TABLE 5.1.1-1 Existing NPDES Discharge Requirements and Limitations for the WPCF MWMC Facilities Plan, Eugene-Springfield (1) No wastes shall be d~scharged from these out-falls and no activities shall be conducted which violate water quality standards as adopted in OAF{ 340-41-0445, unless the cause of the discharge is due to storm events as allowed under OAR 340-41-120 (13) or (14) as follows: (2) Raw sewage discharges are prohibited to waters of the state from November 1 through May 21, except during a storm event greater than the one-in-five-year, 24-hour duration storm, and from May 22 through October 31, except during a storm event greater than the one-in-ten-year, 24-hour duration storm. ii' an overflow occurs between May 22 and June 1, and if the permittee demonstrates to the Department's satisfaction that no increase in risk to beneficial uses occurred because of the overflow, no violation shall be triggered cf the storm associated with the overflow was greater than the one-in-hve-year, 24-hour duration storm. ~ Average dry weather design flow to the facility equals 49 mgd. Summer mass load ~imits based on average dry weather design flow to the facility, Winter mass load limits based on average wet weather design flow to the faclJity equaling 75 mgd. The da~ly mass load limit is suspended on any day in which the flow to the treatment facility exceeds 98 mgd (~wce the design average dry weather flow). The treated effluent discharge has mass load and concentration limitations for CBODs and TSS established for the dry season (May 1 - October 31) and the wet season (November 1 - April 30). These current mass load limitations are the same as for the previous NPDES permit, and these are based on the standards for the Willamette Basin. The permit requires 85 percent removal of BODs and TSS, and the permit also allows for the daily mass toad limitations to be suspended on any day that the influent flow exceeds 98 mgd (or twice the design average dry weather flow). The permit does not address effluent blending or selective treatment operation methods that are used by the VVPCF when plant flows exceed the maximum day hydraulic capacity. Under these conditions, a portion of the primary effluent flow is directed to the chlorine contact basins and blended with secondary effluent prior to d/sinfection. Treated effluent also includes limitatiol~s for ammonia, bacteria (E. colt), pi-I, total residual chlorine, and excess thermal loading (during May 1 - Oct. 31). The ammonia and excess thermal load limitations are new to the 2002 permit. The untreated emergency SSOs have specific limits on the seasonal fim~_ng and storm event conditions that create circumstances such that these discharges are unavoidable and allowable under state law [OAR 340-41-120 (13) or (14)]. The third category of discharge that is addressed in the NFDES permit is reclaimed wastewater. MWMC is constructing a reclaimed water pipeline from the WPCF to the BMF to provide water to the planned poplar plantation and the BMF's beit filter presses. No reuse ' is permitted without meeting specific permit conditions and providing a spedfic plan for its use. The permit specifies that prior to any use of reclaimed water it must receive at least Level II or Level III treatment as defined in OAR 340-55, and must meet specific bacteria limitations. ~WMC_5.0_.REVS_VKS DOC 5-3 MWI~IC FACILITIES PLAN 5,1.2 Regulatory Basis of Planning To plan for future regional wastewater fadlities for the Eugene-Springfield metropolitan area, the following assumptions were made regarding the future regulatory requirements for Eugene-Sprkngfield with respect to the current NPDES pern~it: Dry season concentration limits willbe set to the current W~llamette Pdver basin standards of 10 rng/L for carbonaceous biochemical oxygen demand (CBOD) and TSS on a monthly average basis. Dry season mass 1Lmits for CBOD and TSS will remain the same as ~n the existing discharge permit and will be based on the dry season flow. · Wet season concentration limits will remain the same as in the existing discharge permit ,, Wet season mass lirrdts for CBOD and TSS will remain the same as ~n the existing discharge permit and will be based on wet season flow. Dry and wet season monthly average percent removal for CBOD and TSS will remain at 85 percent, the same as the existing discharge permit. - Wet season maximum day mass limits will be suspended when the plant flow is equal to or greater than twice the dry season design ~'ating of the plant, the same as the existing discharge permit. The dry season ammonia concentration limits will remain the same as in the ex~sting discharge permit. The excess thermal load limit in the dry season will remain the same as in the existing discharge permit. · The current lh~tation for effluent disinfection is based on E. Coll. It ks assumed that the E. Coli limit w~l remain the same as in the existing discharge permit. ,, The effluent pH limit will remain the same as in the existing discharge permit. 5.1.3 Effluent Quality CBOD and TSS Dry season mass limitations for both CBOD and TSS as outlined in the NPDES permit are based on the current average dry season flow of 49 mgd. The mass limit requirements must also be met for the highest 30-day flow period in the dry season (maximum month basis). Even if the constant concentration limits for CBOD and TSS.are met, the mass limits imply a lower concentration requirement if the wastewater flows exceed the cu~rrent dry weather design capacity or if the future dry weather design capacity of the facility is increased. Concentration limits as well as percent removal requirements are also specified in the NPDES permit. Figure 5.1.91 illustrates the anticipated maximum month CBOD and TSS concentrations that result from projected flows and tmchanged mass limitatmns as specified in the existing NPDES permit. These are shown relative to the anticipated concentration limits. Percent removal lircdts apply; however, they are not a factor during the dry season because the mass and concentration limits are significantly more stringent. 5-4 MW~C_50_REVS~S.DOC BASIS OF PLANNING RGL~RE ,5,1 Dry Weather Maximum Month Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows MWMC Facilities Plan, Eugene-Springfield 12.0 -- - - -- 85.0 75,8 10.0 ju./~ ~-~..~.~._ _ _ Current ECfluent Concentrabon '9.9 ~-'.~.. 6.0 J ......... . .................... Z __ 55.0 4.0 --4,.0 ......................... 45.0 0.0 ~3 25.0 2005 20~0 20~5 2020 2025 2030 2035 2040 2045 2050 ~r ~ CBOD a~d ~S Concentration + DW Weather Max Month Flow ~ Average D~ Weather Flow Similarly, wet season maximum month mass limitations for both CBOD and TSS as outlined in the NPDES permit are based on the average wet season flow of 75 mgd. Although significantly higher, concentration limits are also specified in the NPDES permit for wet weather. Percent removal requirements also apply. Figure 5.1.3-2 illustrates the anticipated maximum month CBOD and TSS concentrations that restdt from projected flows and unchanged mass limitations as specified in the existing NPDES permit. These are shown relative to the anticipated concentration and percent removal requirement. However, because peak wet weather flows are very dilute, it is the percent removal requirement that limits effluent CBOD and TSS during critical wet weather flow periods and this is the most difficult to achieve. MWMC_5 o_REV8 DOC 5-5 MWMC FACILITIES PLAN FIGURE 5.1 Wet Weather Maximum Month Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows MWMC Facilities Plan, Eugene-Springfield 35.0 l ..... 150 142.1 Current TSS Effluent 30.0 ....... Z30 Concentration t~mJt 110.8 25.0 '- 24.7 __ Current CBOD Effluent _ _. 110 23 2 lO~,." Concentration L;mit 22 4 9B 2 19.5 20.0 ~3S ~3 _/~ 90 Bg~s 85% TSS Removal ~'~ ConcentraUon ~~ ........... ~ ?/~ ......... ~5.0 ~ - - - - ~6~ ~-- ~ 70 : 5~-'~ ~3.~ 10.0 - 50 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 Year ~ CBOO Concentration ~-TSS Concentration ~ Max Nonth Wet Weati~er Flow --X--Average we~ Weather FJow Dry weather maximum week mass limitations for both CBOD and TSS as outlined in the NPDES permit are based on the average dry season flow of 49 mgd. Concentration limits are also specified in the NPDES permit. Figure 5.1.3-3 illustrates the anticipated maximum week CBOD and TSS concentrations that result from projected flows and tmchanged mass limitations as specified in the existing NPDES permit. These are shown relative to the anticipated concentration limits. Percent removal limits do not apply on a maximum week basis. 5-6 MWMC_5 o_REV8 DOC 5 BASIS OF PLANNING FIGURE 5.1 Dry Weather Maximum Week Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows MWMC Facilities Plan, Eugene-Springfield 16.0 t ..... r 125 Current E~uent 15,0 Concentration L{m~t 14,0 9.0 7.0 -  3~ s -'~ 6.0 ~- 25 2005 20~0 20~5 2020 2025 2030 2035 2040 2045 2050 Yea ~CBOD and TSS Concentrat;on ~ Max Week D~Wea~er Flow + Average D~ Weather Flow Wet season maximum week mass limitations for both CBOD and %SS as outlined in the NPDES permit are based on the average wet season flow of 75 mgd. Concentration limits are also specified in the NFDES permit. Figure 5A.3-4 illustrates the anticipated maximum week CBOD and TSS concentrations that result from proiected flows and m-tchanged mass limitations as specified in the existing NPDES permit. These are shown relative to the anticipated concentration limits. Daily maximum mass limits also apply but are suspended when the average flow exceeds twice the dry weather capacity rating of the facility (currently 98 mgd). MWMC_5,0_REV8 DOC 5-7 MWMC FACILITIES PLAN FIGURE 5.1.3-4 Wet Weather Maximum Week Effluent Concentration Requirements Based on Existing Mass Load Limitations and Projected Flows MWMC Facilities Plan, Eugene-Springfield 50,0 I 190 45.0 Current TS$ Effluent Concentrahon Limit -- -- 175 40.0 Current CBOD Effluent Concentrabon L~mlt _ 1.6 s 160 35.0 l- ~ -145 ~00 ~~ -~ 130 26 3 25.0 ~2g 115 8~ ~ 21.5 20.3 20,0 - 2z.o 19,6 ~ 17,4 18,4 15,0 ~ - ' 85 10,0 .... 66.0 -- __~ 70 620 - 58.1 54 2 ~ 5.0~ ......... ~ 55 2005 2010 2015 2020 2025 ~ear -~ CSOD Concentra~n~ TSS Concen~Jt~ Max Week Wet Weather Flow ~Average Wet Wea~he~ Ammonia The current NPDES permit (issued in 2002) includes a requirement for dry weather nitrification. Current Oregon water quality criteria drove previous reasonable potential findings amd the justification for a dry weather average month and maximum day effluent ammonia concentration limit of 12 milligrams per liter (mg/L) and 22 rog/L, respectively. If Oregon were to adopt EPA's 1999 update of water quality criteria, as recommended by the Triennial Review Policy Advisory Committee, there may be a relaxation of the acute and chronic criteria. However, in the absence of adoption of that criterion, aa~d based on the premise that it will be difficult to relax the current effluent ammonia requirernents, it is assttmed that the current ammonia effluent limitations will be implemented in future permits. The result is that the biological process at Eugene-Springfield will need to be modified to accommodate more sustainable nitrification, and thus de-nitrification will be reqttired to address the alkalinity deficit currently experienced during nitrification. Excess Thermal Load Under the 1996 Oregon Temperature Standard (Oregon Admh-fistrative Rule 34041-0026), the WPCF was required to prepare and implement an approved Temperature Management Platt for the following reasons: 5-8 MWMC_50_REV8 DOC BASIS OF PLANNING Discharge from the facility is to a stream that is water quality-li~rdted; Heat.is.con~buted to the stream above a water quality-lhnited stream segment; Reasonable potential exists for the discharge to have a measurable impact outside of the assigned n~xing zone; and · Temperature-sensitive endangered fish may be present The Temperature Management Plan for the facility was developed and approved by the DEQ prior to permit renewal. The current NPDES permit was issued with a thermal load limitation that was based on the dry weather design average flow. The NPDES permit specifies that the fac~ty must meet this thermal load limit for the maximum week during the dry season. Because of the way that the excess thermal load limit is calculated, the facLlity has the potential to surpass the permitted excess thermal load limit of 3.1 billion BTUs during peak week flows. Since the Temperature Management Plan was approved by DEQ, Oregon's water quality standard for determining thermal load limitations has been somewhat in flux. After a period of uncertainty, the regulatory envkonment for temperature d~charges has become dearer. In June 2003 DEQ published guidance that specifies that the maximum weekly design flow should be used to calculate the excess thermal load. In early March 2004, EPA approved Oregon's new water quality standards for temperature. The DEQ is developing a temperature TMDL for the Willamette River based on the new Oregon standard. The details of the T~DL are s~-~ll to be worked out, but could result in a revised thermal load limJtation for the facility once the permit is up for renewal. In the absence of the new TIv[DL standards, the WPCF will continue planning for facilities using the current thermal load limitation and will continue to implement the approved Temperature Management Plan. A detailed thermal load analysis was performed for this facilities plan to estimate the projected dry season thermal load through 2025. Thermal loads discharged to the river are the product of wastewater flows and their corresponding temperatures. The analysis evaluated 12 years of historical flow and temperature data to develop average and peak week dry season thermal loads From this data, a peak week thermal load peaking factor was calculated and applied to fiature average thermal loads developed from projected flows and historical average temperatures. The resulting projected peak week thermal load is Shown in Figure 5.1.3-5. This figure also shows the flow rate that would be required to be removed from the river to meet the current peak week thermal load l~rdt specified in the NPDES permit. Sanitary Sewer Ovedlows (SSOs) Perhaps the most significant impact to potential future treatment tedmologies lies in the changing regulations for SSO requirements. Currently, untreated emergency SSOs have specific limits on the seasonal t/ming and storm event conditions that create circumstances such that these discharges are unavoidable and allowable under Oregon state law. Oregon's current SSO rules are embedded in the bacteria water quality standard, wtdch prohibits overflows from less than a 5-year 24-hour winter storm, and from a less than lO-year 24-hour summer storm. Proposed federal rule changes for SSO requirements are currently on hold for MWMC_50_R£VB_VKS DOC 5-9 M~C FACILITIES PLAN further review. More restrictive future federal rules on SSOs will override the Oregon regulations. SSO requirements are a major driver for significant future wet weather improvements. Recommended future treatment tecl'mologies should include alternatives for various combinations of SSO possibilities and blending techniques. F~GURE 5.1.3-5 Dry Season Peak Week Excess Thermal Load Based on Existing Thermal Load Limitations and Projected Flows MWMC Facilities P/an, Eugene-Springfield 30 0 30 0 25 0 L~ /~'~ 25 0 Required Reuse Ftow to Meet Excess Thermal Loading  20 0 20,0 ~5o ....... ~5o~ ~ 100 ~~ ............. 100 50 - -50 Permit Excess Thermal Load Limit O0 - 2005 2010 2015 2020 2025 Year Previous studies and collection system modeling efforts have concluded that peak wet weather flows (PWWFs) resulting from the projected 2025 5-year 24-hour storm (which equates to 3.9 inches of rain for the Eugene/Springfield area, derived from statistical evaluation of precipitation data recorded at the Mahlon Sweet Airport) could be conveyed by the collection system to the WPCF for treatment without SSOs. Collection system models estimate the current PWWF in excess of 250 mgd, a situation that now results in SSOs. Current PWWFs entering the treatment facility exceed 200 mgd, and are limited by the influent pump station's ability to get flow into the plant. An increase in both peak flow conveyance and treatment capacity is necessary to comply with DEQ's future requirement that the wet season flow associated with the 5-year, 24-hour rainfall event be accommodated by MWMC's facilities without resulting in SSOs. 5d 0 MWMC_50_REV8 DOC 5. BASIS OF Blending Policy Blending or split flow refers to the practice of diverting flow around a treatment component (usually secondary treatment) during high flows; specifically, PWWFs. The WI>CF was designed to operate using blending when flow exceeds the secondary system capacity, currently estimated at 103 mgd. The practice is not acknowledged in the current NPDES permit and is currently under review by EPA. In late 2003 EPA issued for public comment a p~:oposed policy on blending that if adopted would clarify that blending is a legal practice, subject to the six principles outlined in the proposal. The proposal requires that all re-routed flows be combined before discharge. It is anticipated that the practice of blending will continue to be an acceptable approach for treating PWWFs. For the purposes of evaluating treatment technologies, it is recommended that the WPCF look at solutions that are flexible enough to implement either conventional primary effluent blending or equivalent secondary effluent blending. With the elimination of SSOs, blending will provide the most cost-effective opportunity for the WPCF to provide a treated effluent that meets secondary treatment standards in the most cost- effective manner. Using blended treatment would eliminate large capital investments for facilities that would be used very infrequently. In addition, treatment alternatives should attempt to maximize the capacity of the existing facility's primary and secondary treatment facilities, minimizing the frequency of blended treatment, and taking full advantage of MWMC's existing investment. Even under the best circumstances, significant investments and modifications to the facility will be required to convey and ~eat the projected I>WWF. Bacteria It is anticipated that the current bacteria limitations specified in the NPDES permit, which require a monthly geometric mean of 126 E. Colt per 100 mL and a maximum sample containing 406 E. Colt per 100 mL, will continue to be implemented in future NPDES permits. Although not required to meet anticipated bacterial limitations, alternative disinfection technologies should be evaluated to address operator and community safety issues associated with the current disinfection practice that uses gaseous chlorine and sttlfur dioxide. Turbidity The current turbidity standard is based on the Oregon State Water Quality Standard, which stipulates that the wastewater cannot increase the river turbidity by more than 10 percent at the edge of the mixing zone. This standard is currently under review by the state and it is possible that a more stringent numerical limit could be imposed in future NPDES permits. Treatment alternatives that include improved secondary treated effluent water quality and effluent filtration should be considered. Dissolved Oxygen The Willamette River in the Eugene area is not included in the 303(d) list for dissolved oxygen (DO). The current DO standard is based on the Oregon State Water Quality Standard; however, there is no current numerical limit in the NPDES permit. It is possible that a more stringent numerical limit could be imposed in future NFDES permits. The implementation MWI¢~C_50_REVS_¥KS.[)OC 5:11 MWMC FACiLiTiES PLAN of a future DO nttmericat limit may require future treatment facilities. However, for purposes of this facility plan, no facility accommodations for DO are being considered. Uercury A TMDL for mercury is currently being developed for the Willamette River~ The requirements resulting from the TMDL are tmcertain at this time. Arsenic The Willamette River was listed in the 2002 303(d) list for exceedances of the arsenic huJnan health criterion for "water and fish ingestion." This 1/shng could eventually lead to development of a TMDL for arsenic. Any numerical arsenic limit is unlikely to affect future recommended treatment technologies at the WPCF and will likely be implemented as source control reductions. Cyanide Cyanide discharges into the treatment facility are currently below the calculated maximum headworks loading. Analytical laboratory results for final effluent indicate detectable levels of total cyanide, while analysis of secondary effluent before chlorination has consistently resulted in non-detectable amounts. The current disinfect/on process generates compounds that analyze as cyan/de. These analytical results for total cyanide concentrations are not high enough to cause an exceedance of a water quality standard in the Willamette River and wdll not affect future recommended treatment technologies. lVletals Current effluent and biosotids metals concentrations are well below any regulatory thresholds. Some changes to the Oregon criteria for metals are expected as a result of triennial review. New criteria are expected to be adopted by the Envh:onmental Qual/ty Commission (EQC) in April 2004, including metals criteria expressed as d/ssolved. This will reduce the likelihood of water quality-based effluent limitations for metals becoming a permit issue. Any numerical limits for metals are unlikely to affect future recommended treatment technologies at the WPCF and wilt likely be implemented as source control reductions. Toxicity There are no current problems complying with the acute and chronic toxicity requirements in the permit. If a situation were to arise whereby effluent toxicity was identified as a potential problem, a Toxicity Identification Process would be implemented that would likely result in a source control reduction program. Phosphorus Phosphorus has not been identified as an effluent quahty issue for the Willamette River and there is currently no TMDL for phosphorus planned in the immediate future. However, phosphorus is quickly becoming targeted for biological nutrient removal in the wastewater treatment industry. FlexJbility for phosphorus removal should be considered when evaluating alternative treatment technologies. 5-12 MWMC_5.0_REV8_VKS DOC 5 BASIS OF PLANNING Total Dissolved Solids (TDS) The TDS standard ht the Willamette l~Jver is 100 mg/L There are currently no compliance issues with respect to effluent quality and TDS. Any numerical 1Lmit Ls urdikely to affect future recommended treatment technologies at the WPCF. However, alternative disinfection practices such as the addition of sodium hypochlorite can significantly increase TDS discharges. Dioxins and Furans A toxic eqttivalency factor approach for the human health criteria for dioxins and b~rans was considered by the DEQ for ~clusion in the proposed changes for Oregor~ water quality standards, but at the time of writing it appears that this wilt not be included in the standards revision package to be considered by the EQC, cttrrently planned for May 2004. Any limits for dio×irLS and furans are unlikely to affect future recommended treatment technologies at the WPCF and will likely be implemented as source control reductions. 5.1.4 Biosolids Quality Both federal and state regulations apply to land application of biosolids from wastewater treatment plants (WWTPs). Federal regulations include 40 CFR 257 and approved 40 CFR, Part 503. State of Oregon regulations include OAR 340-50. Since the passing of the federal 503 regulations, the state has prepared and passed amendments to OAR 340-50 that adopt provisions outlined tn the 503 regulation. For disposal of biosolids as interrm cover or as fill at a solid waste landfill, federal regulations 40 CFR, Part 258, apply. If the biosolids is incorporated in the final cover for the landfill, the 503 regulations would st~ apply. State regulations take precedence over federal regulations, where applicable. In some instances, state regulations may impose more stringent requirements than federal regulations. However, federal regulations apply if no state regulations are declared. Regulations Current federal regulations for land treatment of biosolids are listed in the Federal Register under 40 CFR, Part 257, "Criteria for Classification of SoLid Waste Disposal Fac~ities and Practices," dated September 13, 1979. Lr~ the past, Part 257.3-5 has regulated solid waste application to food crops; however, these regulations have been corrsidered too general. Therefore, new regulations under 40 CFR, Part 503, were required by Section 405 (d) of the Clean Water Act of 1977 (as amended by the Water Quality Act of 1987). The new regulations under 40 CFR, Part 503, have gone through several scientific community and public reviews and were released as final in late 1992. In December 1984, DEQ defined rules for the land application a~d dLsposal of sewage treatment plant biosolids and biosolids-derived products, including septage (OAR 340-50). These regulations are currently in the process o£ being updated to conform to the adopted federal regula~ons. MWMC_5 0._REVS_VKS.DOC 5- ~ 3 MWMC FAC1Lff~E$ PLAN Biosolids Quality According to current state and new federal regulations (40 CFR, Part 503), biosotids samples should be analyzed for the parameters listed in Table 5.1.4-1. TABLE 5.1.4-1 Sampling Requirements for EPA 40 CFR, Part 503, Sludge Regulationsa MWMC Facility Plan, Eugene-Springfield Parameter Units Arsenic mg/kg dry weight Beryllium mB/kg dry weight Cadmium mB/kg dry weight Copper mB/kg dry weight Lead mB/kg dry weight Mercury mB/kg dry weight Molybdenum mcj/kg dry weight Nickel rog/kg dry weight Selenium mB/kg dry weight Zinc mB/kg dry weight Total Nitrogen % dry weight Nitrate nitrogen % dry weight Ammonia nitrogen % dry weight Phosphorus % dry weight Potassium % dry weight pH standard units Total sofids % dry weight Volatile solids % dry weight PCBsb ,ug/kg a From 40 CFR, Part 503 (December 1992). b PCBs indude PCB-lO16,-1221 ,-1232,-1242,-1248,-1254, and -1260. The nitrogen, phosphorus, and potassium content of the bio,solids are important when applying biosolids at agronomic rates. Nitrogen content can vary significantly in the biosohds depending on its source, age, and history. The concentration levels of these nutrients should be determined from samples taken immediately prior to biosolids application because stored biosolids can lose nitrogen rapidly. Therefore, it is important that the real nitrogen content of the biosotids is known to avoid under- or over-application. The available nitrogen in the biosolids was determined assumh~g the following: 15-20 percent of the organic nitrogen will be available ( Cogger, Sul~van, et. al. indicate lagoon stored biosolids typically mineralize organic nitrogen in 15 to 20 percent range) e 50 percent oX the ammorda nitrogen will be available ~ 100 percent of the nitrate-nitrite nitrogen will be available MWMC_5.0_REVB_VKS DOC 5 BAS4S OF PLANNING Under the new federal regulations 40 CFR, Part 503, max/mum concentrations, cumulative pollutant loading rates, average pollutant limits or "clean biosolids; and armual pollutant loadflng rates have been established for nine heavy metals. Table 5.1.4-2 shows the acceptable levels for land application. These rates are rrsed to determine site life, which is the number of years that biosolids with a uniform metal content could be applied to a specific site. However, MWMC has adopted a policy that pollutant concentratiorts in biosoLids be half of the federally required standards. TABLE 5.1.4-2 New Federal Regulations (40 CFR, Part 503) for Heavy Metalsa MWMC Facility Plan, Eugene-Springfield Average Maximum Cumulative Average Concentration Concentration Loading Concentration Loading Rate Parameter (mc/kg) (kg/ha) (mc/kg) (kg/h~yr) Arsenic 75 41 41 2.0 Cadmium 85 39 39 1.9 Copper 4,300 1,500 1,500 75 Lead 840 300 300 15 Mercury 57 17 t7 0.85 Molybdenum 75 18 0.90 Nickel 420 420 420 21 Selenium 100 100 100 5.0 Zinc 7,500 2,800 2,800 140 a From 40 CFR, Part 503 (December 1992). Site Identification and Approval Prior to approving any potentially sensitive application site (with respect to residential housing, runoff potential, or groundwater threat), DEQ may require an opportunity for public comment and public hearing. A statement of land use compat/bflity from the responsible planrfing jurisdiction should accompany requests for approval of biosolids land application sites. New sites or expansion of existing sites must be proposed to DEQ prior to use. Newly approved sites become part of the biosolids management plan. Site criteria for land-applying biosolids include physical geographical features (geological formation, flood plain proximity, and groundwater and surface water proximity, topography, and soils), and method of application. DEQ's specific criteria are outlined in Table 5.1.4-3. Special Management Considerations Land receiving bulk Class B biosolids for agricultural use requires special management considerations. These relate to access to the site, types of crops grown, plant nutrient ra~es, MWMC_50_REVS_VKS.DOC 5-15 MWMC FACIUTIES PLAN timing and duration of biosolids land application (site life and seasonal constraints), and g.razing restrictions. Access Controlled access to bulk Class B domestic biosolids and domestic septage land appl/cation sites is required for a rnirdmmn of 12 months following surface application of solids. Controlled access means that public entry or traffic is tmlikely. Rural private land is assumed to have controlled access while parks or other public lands may require fencing to ensure control. TABLE 5.1.4-3 DEQ Site Criteria for Biosolids Applicationa MWMC Facility Plan, Eugene-Springfield Parameter Criteria Geology o Must have a stable formation. Floodplain o Restricted period of application end incorporate biosolids if in a floodplain. Groundwater , At time of application, the minimum depth to permanent groundwater is 4 feet; the minimum depth to temporary groundwater ,s 1 foot. Topography · Liquid biosolids application with appropriate management to eliminate sudace runoff. Slope less than or equal to 12% · Surface application of dewatered or dded biosolids. Slopes up to 30% , Direct incorporation of liquid biosolids into the soil. Soils · Minimum rooting depth of 24 inches. ,, No rapid leaching. · Avoid saline or alkaline soil. Method of application and · Buffer stnps may' be required to protect water bodies. Size depends on proximity to water bodies method of application and proximity to sensitive area (variable with local conditions and left to discretion of DEQ), as described below. , Direct injection: no limit required. · Truck spreading: less than 200-foot buffer stdp. · Spray irrigation: 350- to 500-loot buffer strip. · Near ditch, pond, channel, or waterway; greater than 50-foot buffer strip · Near domestic water source or well: greater than 200-foot buffer strip. a From OAR Chapter 340, Division 50, as amended. Crops As a general rule, crops grown for human consumption should not be planted for at least 14 months after bulk Class B biosolids or domestic septage application. If the edible parts will not be in contact with the biosolids-amended soil, or if the crop is to be treated or processed prior to marketing such that pathogen contamination is not a concern, this requirement may be waived. No restrictions on planting time are required where Class A biosolids-derived products are land-applied to sites used for the cultivation of fresh market vegetables. 5-16 MWMC_5.0_REVS_VKS DOC 5 B/~)S OF PLANNING Nutrient Loading Biosolids application to agricultural land should not exceed the annual nitrogen loading required for maximum crop yield and is, therefore, managed according to its fertilizer value. Biosolids may be applied to approved sites above agronorrdc rates on a one-time basis or less than once per year as long as rtmoff, nuisance conditions, or groundwater contamination do not occur. Nitrogen accumulation from higher than agronomic rates and annual nitrogen use w/Il determine the acceptable loading rate and frequency. Site Life Site life is important in planning because sites generally have a t/mAted application life based on the chemistry of the soil and the metals loading from the biosolids. Site life is calculated by dividing lifetime biosolids loading limits based on the most limiting constituent by the annual application rate. Seasonal Constraints In western Oregon, where soil damage may occur from applicatSon equipment traffic in the wet season, biosolids application should be restricted to the dry season. The main consideration in land-applying on sloping ground is avoiding surface runoff and soft erosion. Grazing Restrictions Grazing animals should not be allowed on pasture or forage nor should Livestock feed be harvested for 30 days after application of bulk Class B biosolids or domestic septage. The current biosolids management practices are discussed in section 6.5 in Chapter 6.0. 5.1.5 Reuse Effluent Quality An alternative to direct river discharge of treated effluent during dry weather is to apply treated effluent to meet irrigation demands at agricultural lands, golf courses, and parks. Effluent can also be reused as reclaimed water for specific nonagricultural industrial trses, such as cooling water. The standards for effluent reuse in Oregon are established by the DEQ through OAR Chapter 340 Division 55 (340-55). Treatment and Monitoring Requirements for Effluent Reuse Through OAR 340-55, DEQ has established treatment and monitoring requirements for potential agricultural and nonagricultural uses of the treated effluent. DEQ has classified reclaimed water into four categories and assigned a minimum degree of treatment required: Level I: Less than biological treatment or biological treatment without disinfection Level II: Biological treatment plus disinfection - Level III: Biological treatment plus disinfection (stricter coliform 1Lrrdt) Level IV: Biological treatment, darification, coag~ation, and filtration treatment plus disinfection Limits for total coliform (organisms/100 mL) and turbidity [nephelometric turbidity units (NTUs) have been established for the four categories. These standards serve as a general gu/deline for defining the anticipated water quality required for the various uses. In M~C_5.0_REVs_VKS.DOC 5-17 MWMC FACIUTIES PLAN addition to the water quality limits, DEQ has provided standards for the minimum monitoring required for total coliform and turbidity based on the four categories. Table 5.1.5-1 summaries the treatment and mordtoring requirements for the four reuse categories. DEQ may include additional permit effluent 1/mitations and/or other perrrdt conditions other than those shown in Table 5.1.5-1 if they have reason to believe that the reclaimed water may contain physical or chemical contaminants that would impose potential hazards to the public or environment. TABLE 5.1.5-1 Treatment and Monitoring Requirements for Use of Reclaimed Water MWMC Facilities Plan, Eugene-Springfield Category Level ! Level Ii Level iii Level IV Biological Treatment X X X X Disinfection X X X Clarification X Coagulation X Filtration X Total Coliform (orgamsms/100 mL): Two Consecutive Samples N/L 240 N/L NIL 7-Day Median NiL 23 2.2 2.2 Maximum NIL NIL 23 23 Sampling Frequency N/R 1 per week 3 per week 1 per day Turbidity (NTU): 24-Hour Mean N/L N/L N/L 2 5% of Time During a 24-Hour Period N/L NIL NIL 5 Samphng Frequency Hourly General Public Access Prevented Controlled Controlled No direct (fences (signs, (signs, public gates, rura~ or rurai or contact locks) nonpublic nonpublic during lands) lands) ~rrigation cycle General Requirements A number of general requirements have been outlined in DEQ's Chapter 340 Division 55 rule. These requirements address agrioaltural and nonagricultural uses that are acceptable based on the effluent water quality level, irrigation system, public access requirements, and buffer zones for irrigation. Table 5.1.5-2 summar/zes these general requirements based on the different levels of reclaimed water quality. 5-18 MWMC_5.0_REV~_VKS DOC BASIS OF PLANNING 'fABLE 5.1 General Treatment and Monitoring Requirements for Use of Reclaimed Water* (Numbers in the Table refer to Footnotes) MWMC FaclTities Plan, Eugene-Springfield Category Level I Level Ii Level Ill Level IV Buffers for irrigation: Surface: Surface: 10 ft, None 'jO ft. 'JO ft. required Spray: Spray: site-specific 70 ft. Agricultural: Food Crops N/A N/A N/A Unrestricted Processed Foods Crops N/A 1 Unrestricted Orchards and Vineyards N/A 2 2 Unrestricted Fodder, Fiber, and Seed Crops not for 3 1 1 human consumption Unrestricted Human ingestion Pasture for Animals N/A 4 4 Unrestricted Sod N/A 1 1 Unrestricted Ornamental Nursery Stock N/A 1 1 Unrestricted Christmas Trees N/A I 1 Unrestricted Firewood NJA I 1 Unrestricted Commercial Timber 3 I 1 Unrestricted Parks, Playgrounds, Schoolyards, Golf N/A N/A NIA 5, 6 Courses with Contiguous Residences Golf Courses without Contiguous Residences N/A 5,7 5,7 5,6 Cemeteries, Highway Medians, Landscapes N/A 5,7 5,7 w~thout Frequent Public Access 5,6 industrial or Commercial Use N/A 9,10,11,12 9,10,11,12 9,10,12 Construction Use N/A 9,10,t 1 9,10,11 9,10, 12,13 t2,13 12,13 impoundments: Unrestricted N/A N/A N/A 8,10 Restricted tWA N/A 8, I 0,14 8,10 Landscape impoundments N/A 8,10,14 8,10,14 8,10 *DEFINITIONS: Surface: Surface irrigation where application of reclaimed water is by means other than spraying such that contact between the edible portion of any food crop and reclaimed water Is prevented. Spray: Spray irrigation where application of reclaimed water to crops is by spraying it from orifices in piping. Processed Food Crops: Those which undergo thermoprocessing sufficient to kill spores of CIostrid~um botuJinum. Washing, pickling, fermenting, milling or chemical treatments are not sufficient. MWMC_5.O~REV6_V KS. DOC MWMC F^CILfflE$ PLAN TABLE 5.1.5-2 General Treatment and Monitonng Requirements for Use of Reclaimed Water* (Numbers in the Table refer to Footnotes) MWMC Facilities Plan, Eugene-Springfield Category Level ~ Level ii Level ~li Level iV N/A: This level of reclaimed water not allowed for this use. N/L: No limiL X: Required treatment for this treatment level. N/R: Not required. FOOTNOTES: 1 Advisory Notice Only: The Oregon State Health Division recommends that there should be no irrigation of this level of effluent for 3 days prior to harvesting. 2 Surface irrigation where edible portion of crop does not contact the ground, and fruit or nuts shall not be harvested off the ground. 3 The Department may permIt spraying if it can be demonstrated that public health and the environment will be adequately protected from aerosols. Advisor,/Notice Only: The Oregon State Health Division recommends that there should be no irrigation of this level of effluent for 30 days pdor to harvesting. 4 Surface or spray irrigation: No animals shall be on the pasture during irrigation. 5 Signs shall be posted around the perimeter of the facility's perimeter and other locations indicating that reclaimed water is used for irrigation and is not sale for drinking, and in the case of effluent quality Levels II and I11 for body contact (e.g., for Level IV, ATTENTION: RECLAIMED WATER USED FOR IRRIGATION DO NOT DRINK. ATENCION: RECLAMADO DESPERDICIO DE AGUA USADO PARA LA IRRIGACION NO BEBA EL AGUA; for Levels II and III, ATTENTION: RECLAIMED WATER USED FOR iRRIGATION AVOID CONTACT DO NOT DRINK. ATENCION: RECLAMADO DESPERDICIO DE AGUA USADO PARA LA IRRIGACION EVlTE EL CONTACTO NO BEBA EL AGUA). 6 Reclaimed water shall be applied in a manner so that it is not sprayed onto areas where food is prepared or served, or onto drinking fountains. 7 Reclaimed water shall be applied in a manner so that it is not sprayed w~thin 100 feet from areas where food is prepared or served, or where drinking fountains are located. 8 Signs shall be posted around the perimeter and other locations indicating that reclaimed water is used and is not safe for drinking, and in the case of effluent quality Levels II and III for body contact (e.g., for Level IV, ATTENTION: RECLAIMED WATER DO NOT DRINK. ATENCION: RECLAMADO DESPERDICIO DE AGUA NO BEBA EL AGUA; for Levels II and III, Aq-rENTION: RECLAIMED WATER AVOID CONTACT DO NOT DRINK. ATENCION: REOLAMADO DESPERDICIO DE AGUA EVITE EL CONTACTO NO BEBA EL AGUA). 9 The Depadment may impose more stringent limits on the use of reclaimed water ~f it believes it is necessary to protect public health and the environment. 10 There shall be no disposal of reclaimed waters into surface or groundwaters without authorization by an NPDES or WPCF permit. 11 Use of reclaimed water in evaporative cooling systems shall be approved only if the user can demonstrate that aerosols will not present a hazard to public health. 12 Members of the public and employed personnel at the site of the use of reclaimed water shall be notified that the water is reclaimed water. Provisions for how this notificahon will be provided shall be specified in the reclaimed water use plan. 13 Unless decontaminated in a manner approved in writing by the Oregon Health Division, tanker trucks or trailers that transport and/or use reclaimed water shall not be used to transport potable water intended for use as domestic water. A tanker truck or trailer used to transport and/or use reclaimed water shall have the words "NONPOTABLE WATER~ written in 6-inch high letters on each side and the rear of the truck. The words "NONPOTABLE WATER" shall not be removed until decontamination as approved by the Health Division has occurred, 14 Aerators or decoratIve fixtures which may generate aerosols shall not be used unless approved in writing by the Department, Approval will be considered if it can be demonstrated that aerosols will be confined to the area of the impoundment or a restricted area around the impoundment, ADVISORY NOTICE ONLY: The Oregon State Health Division ~ecommends that persons who must handle irrigation or other equipment for reclaimed wastewater or who are exposed to reclaimed water should be fully advised of any hazards associated with such exposure and should be provided with necessary protective clothing. ~b~C_5.0_REVSZVKS DOC 5 BASIS OF PLANNING 5.1,6 Plant Reliability and Redundancy Criteria New or .expanding treatment works are required to meet min~um standards for mechanical, electrical, fluid systems, and component reliability in accordance with EPA's policy. This is to ensure that the treatment facilities will operate effectively on a day-to-day basis and that capabilities are provided for satisfactory operation during power fmlures, flooding, peak load's, equipment failures, and maintenance shutdowns. These reliability and redundancy standards are important to ensure that unacceptable degradation of the receiving water will not occur as a result of the interrupted operation of specific treatment operations or processes. In that regard, standards have been established for three classes of wastewater treatment works. The Reliability Class I definition is applicable for the WPCF. Thi~ reliability designation is based on the possible beneficial uses that may be negatively affected by a WPCF failure. The Reliability Class I definition consists of the following: "Works which discharge into navigable waters that could be permanently or unacceptably damaged by effluent which was degraded in quality for only a few hours. Examples of Reliability Class I works might be those discharging near drinking water reservoirs, into shellfish waters, or ~n close proxhnity to areas used for water contact sports." Table 5.1.6-t lists the mJnLmum backup requirements for plant components that may be provided at the WPCF facility in accordance with EPA's Works Design Criteria, Reliability Class I, for sewage treatment plants. In addition to the standards listed in the table, with the exception of prLmary clarification, unit operations will be designed to pass the peak hydraulic flow with one unit out of service. Also, mechanical components in the facility will be designed to enable repair or replacement without violating the effluent limitati~ or control diversion. causing 3'ABLE 5.1.6-1 Reliability C~ass I Requirements MWMC Facility Plan, Eugene-Springfield Plant Component Requirement Raw Sewage Pumps Peak flow with largest unit out of service. Peak flow is defined as the maximum wastewater flow expected during the design pedod of the treatment works. Mechanical Bar One backup with either manual or mechanical cleaning (manual cleaning r~ only two Screens screens). Gnt Removal Minimum of two units. Primary Sedimentation 50% of design flow capaci'~ with largest unit out of sep,~ice. Design flow is defined as the flow used as the design basis of the component. Activated Sludge A minimum of two equal volume basins; no backup basin required. Process Aeration Blowers Supply the design air capacity with the largest umt out of service; provide a minimum of two umts. Air Diffusers Isolation of largest section of d~ffusers (w~thin a basin) without measurably impairing oxygen transfer. Secondary 75% of design flow capacity wIth largest unit out of service. Design flow is defined as Sedimentation the flow used as the design basis of the component. Disinfectant Contact 50% of the design flow with largest unit out of sen/ice. Design flow is defined as the Basin flow used as the design basis of the component. MWMC_5 0_REVS_V~(S.DOC MWMC FACILITIES PLAN Reliabil~ Class I Requirements MWMC Facility Plan, Eugene-Springfield Plant Component Requirement Filtration 75% of design flow capacity with largest unit out of service. Design flow is defined as the flow used as the design basis of the component. Ef/luent Pumps Peak flow with largest umt out of service. Peak flow is defined as the maximum wastewater flow expected during the design pedod of the treatment works. Electrical Power Two separate and independent soumes of electrical power shall be provided, e~ther from two separate utihty substations or from a single substation and a works-based generator. Designated backup source shall have sufficient capacih/to operate all vital components, critical lighting, and ventilation during peak flow conditions The reliability criteria for sludge processes presented in Table 5.1.6-2 are also based on the guidance offered in EPA's Works Design Criteria. TABLE 5.1.6-2 Studge Handling System Reliability MWMC Faciltty Plan, Eugene. Springlfeld System Component Requirement Sludge Holding The volume of the holding tank shall be based on the expected time necessary to Tanks perform maintenance and repair of the component in question. Anaerobic Sludge At least two digestion tanks shall be provided. At least two of the digestion tanks Digestion provided shall be designed to permit processing of all types of sludges normally digested. Sludge Pumping Pumps sized to pump peak sludge quantity and maintain velocities above 2 fps. Prowde a minimum of 2 pumps. 5.2 Basis for Cost Estimate Unit process and system alternative cost comparisons are to be based on total project or relative project costs. Project costs are calculated to include legal costs, administrative costs, contingency costs, and engineering costs in addition to the construction and axmual operation and maintenance costs. End-of-life salvage value will not be considered in the cost evaluations. Relative cost estimates are typically used to compare alternatives in which rmany of the facilities in each alternative are identical. Only those costs that are unique to each alternative are estimated and used for comparison purposes. This approach is useful when considering systemwide alternatives in which many of the facilities are the same and the relative costs of each alternative can be narrowed down to selected facilities. Costs for the selected 5-22 k~WMC_5.O_REVS_VKS,DOC BASIS OF PLANNING systemwide alternative, used to develop the 20-year project list, are to be comprehensive costs that/nclude all costs associated with the facilities in that alternative. 5.2.1 Capital Costs Order-of-magnitude capital costs for alternatives will be estimated ba.~sed on a combination of pubJLkshed cost literature, past vendor quotes, and past experience with similar-sized structures, equipment, and systems. The accuracy of this type of cost estimate typically ranges from -30 percent to +50 percent. The capital costs will be indexed to the January 2004 Engineering News-Record (ENR) Construction Cost Index (CCI) for the City of Seattle (7864). All capital costs include contingency, eng~eering, legal, and administrative costs. 5.2.2 Operations and tvlaintenance Costs O&M costs will be based on cu_rrent cost information for chemicals, power, and labor. Chemical costs are obtained from local distributors. Power costs are based on the current WPCF rate of $0.05 per kilowatt-hour. Labor costs for O&M are based on $68,000/FTE (Full Time Equivalent employee including fringe benefits). For many of the unit process and system alternative cost evaluation~s, the 20-year O&M costs will be insignificant relative to the capital cost. In other cases the O&M costs will be equal for the alternatives being considered. In these situations, the O&M costs are not required to be considered in the cost evaluation. 5.2.3 Present Worth Costs W-here a present worth cost was calculated £or alternatives, a present worth factor is to be applied to the O&M costs to convert the armual expenditures to present dollars. The present worth and annualized costs are to be based on an interest rate of 3 percent over the 20-year design life of the fac/lit-y, resulting in a series factor of 14.88. The total present worth cost of each alternative is then determined by adding the capital cost to the O&M present -worth cost. 5.2.4 Contingency Costs For all cost evaluations a 25 percent contingency is to be applied to the capital cost to account for unknowns and unidentified items. 5.2.5 Engineering, Legal, and Administrative Costs For all cost evaluations a 25 percent allowance for legal, adr~_inistrative, and engineer~g is to be applied to the capital and contingency costs to cover the project design and Ckvner legal and project administration. 5.3 Water Quality Impact 5.3.1 Background Data on Receiving Stream The WPCF discharges treated wastewater to the Willamette River at river mile 178 through a multi-port diffuser. The beneficial uses for this area of the Willamette River are listed in the OAKs and include public and private domestic water supply, industrial water supply, MWMC_5.~._REVS_VKS OOC 5-23 MWMC FACIL~ES PLAN irrigation, livestock watering, anadromous fish passage, salmordd fish rearing and spawning, resident fish and aqualSc life, w~ldlife and hunting, fishing, boating, water contact recreat/on, aesthet/c quality, and hydro power. Applicable water quality standards for the Willamette River that protect these uses are found in OAR 340 Division 41. In general the water quality of the Willamette River in Eugene-Springfield meets applicable standards, with a few exceptions. DEQ's "2002 List of Water Quality L/mired Waterbodies' (DEQ, 2002) indicates that the beneficial uses of the Willamette River are not entirely supported in the area of the discharge. The list indicates the WillameRe River violates [he in- stream standards for temperature in summer, mercury in fish tissue year-round, and also violates the human health criteria for arsenic. Temperature New revised Oregon water quality standards for temperature were recently approved by EPA. Included in the standards package are a series of maps that delineate the fish uses for water bodies in the state. According to these maps, [he Willamette River in the area of the WPCF discharge is listed as salmon and trout rearing and migration, and also as salmon and steelhead spawning from October 15 through June 15. This assignment of a spawning use to the Willamette River in Eugene-Springfield does not match other findings, including the recent Habitat AssessmentI. It may be a reflection of thinking that the area is a potential spawning area. Temperature criteria ha the new standards are expressed as 7-day-average maximum temperatures. The new criterion for salmon and trout rearing and rrdgration areas is 18 degrees Celsius (64.4 degrees Fahrenheit). The October 15 to June 15 spawrdng use has an associated temperature criterion of 13 degrees Celsius (55.4 degrees Fahrenheit), and this may be a future issue for fur[her noncompliance with standards, particularly in October during warm, dry fall periods. The temperature standard is violated in the Willamette River during the summer. Typical summer wastewater temperatures are in the low 70s Fahrenheit. The new Oregon temperature standard provides for a human use allowance along a specified reach of 0.3 degrees Celsius, and ut/lizing 25 percent of the 7Q10 stream flow assuming the stream temperature is above the numerical standard ~ercury The Willamette River in Eugene is included in the 2002 303(d) li~qt as not meeting water quality criteria for mercury in fish tissue. This listing is based on exceedances of the reference fish tissue value of 0.35 parts per million (ppm). The EQC is expected to act on DEQ's recommendations for changes to water quality criteria for toxic substances in the near future, and is expected to adopt EPA's recommended fish tissue criterion for methyl mercury of 0.30 ppm. Currently, DEQ is developing a mercury TMDL for the Willamette River. This TMDL is not expected to initially result in waste load alloca6ons for point sources, but rather to impose requirements for monitoring a~td implementation of mercury reduction plans. 1MECT, 2002. Aquatic and Riparian Habitat Assessment for the Eugene-Springfield Area, September 2002. 5-24 MWMO~5 0_REVS_VKS.[~ 5 BASIS OF PLANNING The mercury in the Willamette River system is believed to originate from natural volcanic and mineral sources and legacy mining wastes and atmospheric deposition in the river headwaters. The MWMC has monitored its influent and effluent for mercury for many years. The facility does not use, store, treat or discharge mercury in significant amou_nts and should not impact the water quality stahas for that pollutant. Arsenic Based on data from the regional wastewater program's ambient water quality monitoring program, DEQ has included the Willamette River in Eugene-Springfield as water quality limited for arsenic, based on exceedances of the current human health criterion of 0.002 ~tg/L. As mentioned above, DEQ is expected to adopt new criteria for toxic substances in the near future, and this criterion is expected to be revised upwards to 0.014 gg/L. The ambient monitoring datae ind/cate that the river would continue to be listed if the criterion is revised upwards. This arsenic in the river is believed to be from natural sources. Arsenic is present in rock formations in Lane County, and in some areas arsenic is commonly found in groundwater. A TMDL for arsenic will be developed but is not on DEQ's current TMDL schedule. Other Parameters Data from the Eugene-Springfield ambient monitoring program indicate no exceedances of other water quality criteria at any of the Willamette River monitoring sites, including e. coli and metals2. Nutrient concentrations do not approach levels of concern. Ammonia-nitrogen is typically less than 0.1 mg/L. Nitrate+nitrite nitrogen and total phosphorus concentrations do show a measurable increase downstream of the WPCF discharge. For example, average nitrate+nitrite - N concentrations increase from 0.02 mg/L to 0.11 rog/L, and total phosphorus from 0.04 mg/L to 0.09 mg/L2. Dissolved oxygen (DO) concentrations in the Eugene-Springfield area and downstream of the WPCF discharge meet apphcable criteria for cold water uses. If the designation of the Willamette River ~ Eugene-Springfield as a salmon and steelhead spawning area from October 15 to June 15 remain~s in effect, the corresponding DO criterion would be 11.0 mg/L. Monitoring data indicate that the DO concentrations are frequently below this criterion. Summary Willamette R/vet water quality in the Eugene-Springfield area generally exceeds applicable water quality criteria, with the principle exception of temperature. ~II-te background water quality does not create any significant issues related to the treated wastewater discharge, both at current and future planned flows. 2 City of Eugene, 2003. City of Eugene Stormwater Annual Report May 2003. MWMC_5.0_REVE[_VKS DOC 5-25 IvIWMC FACILITIES PLAN 5.4 Design Capacity of Conveyance System and Wastewater Treatment Plant 5.4.1 Conveyance System Conveyance system alternatives were developed and evaluated in the WWFMP (CH2M HILL, 2000). The current facilities planning effort foc~ased on the analysis of wastewater treatment alternatives regarding influent pumping, preliminary and primary treatment, secondary treatment, disinfection, and biosolids management. As part of the current facility planning effort, collection system modeling was performed by updating the MWIvIC MOUSE hydraulic model developed for the W~WFMP to provide an estimate of WWPH flows to be used in the analysis of wastewater treatment alternatives and pumping capacity. A detailed report of the wastewater collection system hydraulic modeling analysis is given in the March 2004 "MWMC Wastewater Facility Plan--Wet Weather Peak Flow Analysis" technical memorandum (see appendix). The most significant tasks in the modeling update process were the following: 1. Conversion of the wet weather flow estimating method from a spreadsheet-based regression analysis to the new RDII modeling module that is a part of the MOUSE model 2. Calibration of the model based on more recent system flow monitoring data 3. Use of a new planning time frame (2025) not addressed in the WWFMP The WWFMP did not explicitly evaluate peak flows for 2025, although it did evaluate buildout flows. Current modeling efforts were also undertaken, using the limited additional flow monitoring data (from six permanent monitoring locations), to assess the effectiveness of ongoing RDII reductSon efforts. Lrt addition, the current modeling effort has incorporated system network configuratSon modifications, such as physical upgrades to pump stations and/or pipelines. In accordance with DEQ guidelines, the 10-year summer and the 5-year winter rainfall events were compared to determine which storm produced the defining (worst case) flow condition in the wastewater collection system. The 10-year, 24-hour storm event produced an unadjusted peak flow at the *vVPCF of 181 mgd for the 2025 condition, far less than the 277 mgd for the 5-year event. Therefore, the 5-year rainfall event was used as the design rainfall event. The 2003-04 modeling effort indicated that WWPH flows generated in the collection system were comparable to those projected in the WWFMP. The best current estimate of 2025 WWPH flow at the WI>CF is 277 mgd. The buildout flow rate at the WPCF is 294 mgd. Based on these values and the 290 mgd peak buildout flow rate predicted in the WWFMP, a value of 300 mgd as the 2025 peak flow rate was used in evaluating peak flow management alternatives under the overall facility plarming effort, to account for the uncertainty associated with projecting flows 20 years into the future. The peak flow irt 2025 (based on the 5-year, 24-hour storm) that MWMC will control and manage for, however, is 277 mgd. 5-26 NIWMC_5 5 BASIS OF PLANNING 5,4.2 Liquids Treatment Facilities Design The 2025 design criteria for flow at the WPCF are summarized in Table 5.4.2-1. These flows . provide the basis for future hquids unit process design. TABLE 5.4.2-1 Summary of Total Flow Projections For 2025 (Residential, Commercial, and Industrial) MWMC Facilities Plan, Eugene-Springfield Year 2025 Estimated Population 297,585 Wastewater Flow Projections (mgd) Max. Month Dry Weather 59.3 Max. Month Wet Weather 110.8 Peak Day Wet Weather 227 Peak Hour Wet Weather 277 Table 5.4.2-2 summarizes the anticipated 2025 facility needs, design basis, and condition requirements for each 1/quids unit process based on reliability and redundancy requirements. TABLE 5.4.2-2 L~quids Unit Process, Existing and 2025 Design Capacity MW/ftC Factlities Plan, Eugene-Springfield Existing Total 2025 Capacity Design Capacity Need Unit Process Basis (mgd) (mgd) 2{:)25 Condition of Need Infiuent Pumping PWWF 215 277 Firm capacity without largest unit out of service Influent Screening PWWF 175 277 Firm Capacity with one unit out of service Grit Remova~ PWWF 175 277 Firm Capacity with one unit out of service Preaeration AWWF 58.4 No Additional None Capacity Need Primary Clarification PWWF 86 277 or 160 with 50% of design flow capacity w~th flow management largest out of service Aeration Basins ADWF 49 59 Total Capacity AWWF 75 111 Total Capacity Secondary ADWF 49 59 75% of design flow capacity with Clanfication largest out of service AWWF 75 111 MWMC_5.0_REVS._VKS,DOC 5-27 MW~C FACIUTIES PLAN TABLE 5.,~2-2 Liquids Unit Process, Existing and 2025 Design Capacity MWMC Facilities Plan, Eugene-Spring,eld Existir~g Total 2025 Capacity Design Capacity Need Unit Process Basis (mgd) (mgd) 2025 Condition of Need Dis~nfectien ADW F 80 59 PDWWF 175 227 PWWF 175 277 50% of design flow capacity with largest out of service Filtration ADWF 0 30 75% of design flow capacity with largest out of service Plant Hydraulics PWWF 175 277 5,4.3 Biosolids Treatment Facilities Design The 2025 design criteria for CBOD and TSS loads at the WPCF are summarized in Table 5.4.3-1. These loads, in conjunction with the 2025 flows, provide the basis for bamre solids unit process design. TABLE Summary of'fotal Load Projections lot 2025 {Residential, Commercial, and industrial) MWMC Facilities Plan, Eugene-Sprindeld Year 2025 DOD Loading Projec~ions (lb/day) Average Dry Weather 55,000 Max. Month Dry Weather 74,000 Average Wet Weather 55,000 Max. Month Wet Weather 74,000 TSS Loading Projections (Ih/day) Average Dry Weather 61,000 Max. Month Dry Weather 87,600 Average Wet Weather 77,400 Max. Month Wet Weather 102,800 Table 5.4.3-2 summarizes the anticipated 2025 facility needs, design basis, and condition requirements for each sohds urdt process based on reliabihty and redundancy requirements. MWI~C_5.0_REVS_VKS BASIS OF PLANNING TABLE 5.4.3-2 Biosolids Unit Process, Existing and 2025 Design Capacity MWMC Facilities Plan, Eugene-Springfield Process Design Existing Total 2025 CapacRy 2025 Condition Unit Process Description Basis Capacity Need of Need Waste Activated Gravity Belt WWMW 96,500 lb/day 144,720 lb/day Tota~ capacity Sludge Thickening Thickeners Sohds Stabilization Anaerobic Digestion AA 145,350 gpd 200,000 gpd Total capacity with minimum of two tanks Solids Stabilization Facultative Sludge SLR 27,225 lbs 27,225 lbs VSS Total capacity Lagoons VSS/day Biosohds Dewatedng WWMVV 307,440 gpd 307,440 gpd Total capacity Biosol~ds Storage Facultative Sludge NA 41 MG 41 MG Total capac~y Lagoons Biosotids Storage Air Drying Beds NA 3130 d~ tons 3130 dry tons Totat capacity 5.4.4 Seasonal Land Irrigation Table 5.4.4-1 summarizes the anticipated 2025 fac~ty needs for seasonal land Lrrigation. TABLE 5.4.4-1 Seasonal Land Applicatio~ 2025 Design Criteria MWMC Facilities Plan, Eugene-Springfield Unit Process Existing CritedafCondiflons Year 2025 SITE CHARACTERiSTiCS Site Delineation Poplar Trees (non-buffers) 165 acres 425 acres Grass (buffers) 20 acres 132 acres Roads 23 acres 23 acres Feed Store Lot 16 acres 16 acres Site Capacity (based on non-irrigated loading) Poplar Trees (liquid biosolids) 1,444 dry tons 2,128 dry tons Grass (dewatered bioso~ids) 549 dry tons 612 dry tons Poplar Harvest Rotation 10 years t 0 years Percent Dry Solids in Applied Liquid Biosolids 1-4% 1 MW~tC_50_RL=VS_V~ DOC 5-29 MWI~C FACILITIES PI. AN TABLE 5.4.~-1 Seasonal Land Application 2025 Design Criteria MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 S~te Loading Criteria Nitrogen Loading Poplar Trees (liquid biosolids) 220 lbs N/acre 220 tbs N/acre Grass (dewatered biosolids) 120 lbs N/acre 120 tbs N/acre Biosolids Loading Poplar Trees (liquid biosolids) 3.4 dry tons/acre 5.4 dry tons/acre Grass (dewatered b~osolids) 4.2 dry tons/acre 4.2 dry tons/acre SiTE CHARACTERISTICS Available Land, total 7500 acres Unknown E)ewatered B~osolids Capacity, total 31,200 dry tons/year Unknown ~WMC_5 ~)_REVS_VKS.DOC 5-3O 6.0 Development and Evaluation of Alternatives This chapter documents the identification and screening of viable system ~nprovement alternatives for addressing the various projected requirements of the planning period. It outlines a range of potential trait process solutions and documents the methodology for a preliminary screerdng evaluation process that advances certain unit process alternatives for further consideration. It further describes a more rigorous unit process alternative selection process. Those selected processes are used in the development of three systemwide alternatives that are evaluated for permit compliance and cost-effectiveness. Identification of Alternative [init Process Solutions Regulatory drivers, ex/sting WPCF drivers, and technology drivers can all be combined to form a matrix of treatment facility needs and potential solutions. Table 6.0-1 summarizes the project matrix for the WPCF. The matrix identifies potential unit process solutions for all of the various issues identified at the WPCF. Preliminary Screening Process Each of the unit process solutions identified in the project rnatrix were screened to determine their suitability for further consideration. They were evaluated against important criteria developed by MWMC and Eugene-Springfield staff at a c~harter~ng workshop. Developed criteria fall into three categories: ,, Process Performance Process O&M - Process Implementation Process performance criteria included the following: · Reliabi~ty to meet current requirements · , Capability to meet future requirements · Multiple applications or benefits - Impact to offter processes , Sttstainability ( chemical, power, other resource a_se) ,~ Minimal odor, noise, and other impacts O&M criteria included the following: O&M ease and simplicity - O&M flexibility O&M envircmment and safety Process implementation criteria included the following. Capital cost Annual O&M cost 20-year present worth MWMC_60_REV11 DOC 6-1 N~WMC FACiLiTIES PLAN Site impact Ease/impact of construction Flexibility for phased implementation For each identified unit process a fact sheet was developed that rated each unit process alternative against these criteria. A numerical score was assigned for each criteria and t,he total score for each unit process was added up. The unit processes with the highest scores were identified as preferred solutions, alternatives with intermediate scores were identified as acceptable solutions, and some alternatives with the lowest scores were etim2nated from consideration. A subsequent discussion and screening process narrowed the scope of unit processes further. Although the identified preferred and acceptable solutions scored high in meeting the staff's criteria, some of the solutions were not easily implemented, did not work well with the existing infrastructure to meet future needs, or were simply cost-prohibitive. Unit process solutions in these categories were eliminated from further consideration. A final short list of unit process solutions to be considered for a more comprehensive analysis was developed. Technical memorandums provide a detailed discussion of each evaluation, and alternative comparisons. The remainder of this chapter summarizes those alternatives analyses and provides insight into the selection of a systemwide alternative that addresses all the facility needs. Each alternative analysis includes a monetary and identical non-monetary evaluation. Non-monetary evaluations are based on the criteria shown in Table 6.0-2. For each criterion, the alternative was given a score of I to 5, I being negative or difficult, and 5 being beneficial. A total maximum score of 30 points is possible and a minimum score of 6 points is possible. TABLE 6.0-2 Example of Non-Monetary Evaluation MWMC Facilities Plan, Eugene-Springfield Alternative I Alternative 2 Siting 5 I Constructability 5 Performance 5 1 Effect on Performance of Downstream Equipment 5 Operational Flexibility 5 1 Maintenance 5 t Total Score (30 points maximum) 30 Scoring: 1 = Negative/Difficult 5 = Beneficial 6-2 MWMC_6.0_REV11 DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES 6.1 Conveyance System Alternatives A rigorous analysis was made of potential wastewater collection system flow management alternatives as part of the September 2000 MWMC Wet Weather Flow Management Plan (WWFMP) [CH2M HILL, 2000]. The results of that analysis are summarLzed below. 6.1.1 Basic A tematives The W-W~P considered several technologies £or managing wet weather flow ~-~ the wastewater collection system: system rehabilitation to reduce RDII; storage; conveyance; and wet weather ~reatment. This section summarizes the analysis, evaluates the four technologies and combinations oJ~ the four, and develops solutions for most cost-effectively managing wet weather flow. The analysis included many iterations of hydraulic model simulations, as well as economic optimization coupling hydraulic modeling results (flow management effectiveness) and cost estimates. The WWFMP analysis primarily- addressed ~vo objectives: - Object~ve 1: Manage flows and water surface elevations in ma,_holes in the collection system to eliminate overflows and basement flooding. Objective 2: Provide the most cost-effective means to manage excess flow rates at the WPCF. The alternatives analysis/system optimization proceeded in two phases directed at these two objectives. In the first phase, sub-area alternatives and solutions were developed and evaluated to elm~nate basement flooding and overflows in the collection system. With implementation oJ~ successful sub-area solutions, the flow arriving at the WPCF was estimated to still exceed the maximum primary treatment capacity. Therefore, the second phase dealt with additional effort beyond the sub-area solutions to manage the excess peak flow arriving at the WPCF. To meet Objective 1 (described above) city staff used the hydraulic model and local knowledge to evaluate sub-area alternatives and develop sub-area solutions that would reduce maximum hydraulic grade (water surface elevatiorrs in manholes) to acceptable levels. Because potential problems were location-specific, alternatives and solutions to address them were re£erred to as "sub-area" alternatives and solutions. Sub-area alternatives were comprised of one or more of three technologies: system rehabffitation to reduce RDIL ~-lLqe and off-line storage facilities, and additional conveyance capacity. System rehabilitation was considered separately as either public only or public and private. Public only consisted of rehabilitation that would occur only in the public right-of-way. Public and private Lqcluded system rehabffitation on portions of the private system within sub-basirm identified for public rehabilitation. Once sub-area alternatives were re~ed such that they adequately accomplished Objective 1, they became sub-area solutions. To facilitate analysis of sub-area alternatives, the collection system was di,~dded into East and West portions. The East portion comprised the entire system upstream of the Willakenzie pump station. This included all of Springfield and Eugene's WJllakenzie sub- basins. The West portion included the rest of Re Eugene system. Sub-area alternatives were evaluated for both the East and West Each separately portions. sul~area alternative ~,ras MWMC_6 O_RE'V11.DOC J~WMC FACiLmES PLAN refined until it met the criterion of keeping maximum water surface elevations in martholes lower than critical elevations. These critical elevations included 3 feet above pipe crown in areas where there were basements. In areas without basements, the criterion was 2 feet below ground surface. Once this criterion was achieved, it became a sub-area solution. A total of 21 sub-area solutions in the East system and 26 in the West system were developed to meet Objective 1. Cost and effect on peak flows and volumes reaching the WPCF characterized sUb-area solutions. The prelLrrrinary hst of sub-area solutions was developed to ensure that all reasonable applications of the four technologies were considered. This preliminary, comprehensive hst resulted in a number of solutions that were clearly inferior to others from cost and implementation perspectives. In addition, a number of solutions were largely redundant, with primary components essentially the same. As a result, sub-area solutions were quickly reduced to a manageable number based on cost, implementation, consistency with ongoing programs, disruption, and redundancy. Four combinations of sUb-area solutions from the East and West systems were selected for further analysis to meet Objective 2. Sub-area solutions from each system with similar features were combined to form systemwide alternatives. The systemwide alternatives were evaluated with the hydraulic model adjusted to reflect implementation of each of the four sub-area solutions. Each systemwide alter~.ative produced a hydrograph at the WPCF that showed the excessive flow and volume that remained after implementation of sub-area solutions. A cost-effectiveness exercise (optimization) using model results combined with cost estimates of components of individual systemwide alternatives was performed to develop systemwide solutions. An economic optimLzation analysis was performed to determine the most cost-effective mix of technologies for managing the excess peak flow rates and volumes at the WPCF for each systemwide alternative. As with the sub-area alternatives and solutions, technologies included system rehabihtation for control of RDII (etther public or pubhc and private), storage, and expansion of primary treatment capacity. Additional conveyance beyond that required for sub-area solutions was found to be unnecessary. $.1.2 Selection The WWFMP CAC and steering committee decided, using the established evaluation criteria and associated discussions, that the solution summarized in Table 6.1.2-1 was most desirable from a cost, implementation, and public acceptance perspective. The selected alternative elements are shown graphically in Figure 6.1.2-1. TABLE 6.1 MWMC Wastewater Collection System Wet Weather Flow Management Plan (WWFMP) SeJected A~temative MWMC Facilities Plan, Eugene-Springfield Component of WWFMP Description ,, Public system rehabilitation in seven sub-basins Sub-Ama Solution E24 (Spdn§~ield) ~, Further investigation in the Gateway ama and remediation as necessary ~ Upgrades to the WBlakenzie pump station MWMC_60~REV~t 1 DOC 6. DEVELOPMENT AND EVALUATION OF ALTERNATIVES TABLE 6.1.2-1 MWMC Wastewater Collection System Wet Weather Flow Management Plan SeLected Alternative (WWFMP) MWMC Facilities Plan, Eugene-Springfield Component of WWFMP Description · No Storage Sub-Area Solution W25 (Eugene) · Public system rehabilitation in 21 sub-basins · Insta~lation of valve at 14th and Tyler · Upgrade to screw pumps at treatment plant · No storage Strategy to Manage Excess Flow at WPCF for Existing - Manage 100% of 82 mgd excess flow rate and Conditions 59.4 MG excess volume by adding pdmary clarification capacity to the WPCF. MG = million gallons mgd = million gallons per day The solution set in Table 6.1.2-1 includes those aspects of the WWFMP that were cost - effective in the optimization analysis relative to competing alternative technologies. Contributing to this recommendation were the following factors: It is the least-cost alternative. It relies heavily on RDII reduction of the public system, which is considered to be the most implementable approach to RDII reduction. RDII reduction has the dual benefit of achieving and maintaining good, long-term system pipeline conditions. Each city is already performing rehabilitation at various levels; therefore, this alternative builds on current programs. This alternative is consistent with the current theme within many cities of a sustainable approach to developing infrastructure programs. This approach promotes creating increased efficiency from existing systems versus accepting poor performance from some portions of the system and building more facilities to compensate for them. o It has a minimum of additional pipeline requirements and associated disruption. e It does not require storage facilities that could pose aesthetic and siting issues. The selected systemwide solution was evaluated under estimates of bmldout conditions and flows. To achieve sub-area solutions under bufldout conditions, additional pUblic-only system rehabilitation was evaluated and found to provide an acceptable solution. The 10-year Wet Weather Flow Management Plan Implementation Schedule is given in Figure 6.1.2-2. As mentioned previously, since the adoption of the WWFMP, both Eugene and Springfield have put into action positive management practices for the wastewater system as outlined in the WWFMP, and have aggressively pursued RDII source collection MW~IC_8 O_FIEV1LDOC 6-5 hlW~IC ~ACILFfIES PLAN detection and reduction projects, executing these projects according to the schedule recommended in Figure .6.1.2-2. 6.2 Wastewater Treatment Plant Liquid Stream Treatment Alternatives 6.2.1 Secondary Treatment Enhancement Secondary treatment facilities at the WPCF consist of biological treatment and clarification. Two 8.9-million gallon aeration bash'ts each with 4 cells (2.2-mill~on-gallons each), eight 130-foot-diameter secondary clarLfiers, an aeration system, and a PAS pump station provide biological treatment. Table 3.2.1-3 summarizes the existing secondary treatment unit processes and equipment. The capacity of the secondary treatment facilities is dependent on both the aeration basins and secondary darifiers working together. Either facility can limit capacity depending on the mode of operation and seasonal effluent limits. The original facilities could operate ~n four modes: plug-flow, step-feed, complete mix, and contact stabilLzation. The contact stabilization mode provided the highest capacity rating for the facility. The ex~sting original maximum month dry weather capacity was estimated at 49 mgd and the maximttm month wet weather capacity was estimated at 75 mgd. The existing secondary treatment capacity noted above was estimated prior to the dry weather nitrification reqmrement imposed by the 2002 NPDES permit. The new effluent ammonia limit requires a monthly average of 12 mg/L and a maximum day of 22 mg/L from May I through October 31. Current maximum month dry weatLher capacity assessments accounting for nitrification estimate the secondary treatment capacity with one aeration basin out of service and operating in a plug-flow mode at 35 to 40 mgd. High flows occurring in May, June, and late October combine with lower wastewater temperatures, making it difficult to achieve the monthly average ammonia limit. In addition, the higher solids loading to the secondary clarifiers as a result of nitrification make it difficult to achieve the low 10 mg/L monthly TSS concentration limit. Wet season (November 1 through April 30) operations do not require nitrification. The maximum month wet weather secondary treatment capacity is estimated at 75 mgd. The peak diurnal wet weather secondary treatment capacity has been assessed at 103- 111 mgd, limited by the secondary clarifiers' inability to provide sufficient effluent quality at high surface overflow rates. Historically, wet weather flows in excess of 103 mgd are diverted around secondary treatment and blended with primary effluent. Current and historical peak wet weather flows exceed 200 mgd. Exist~g secondary treatment capacity will need to be expanded to accommodate the future dry weather and wet weather peak day, peak week, and maximum month flows. In addition to providing a base capacity increase, this will also increase the facility's ability to handle peak wet weather flows. Alternatives have been developed to evaluate the most effective expansion approach to meet the future needs of the facility. These alternatives are presented below. 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES Alternative 1 - Modify Existing Secondary Treatment Facilities to a Step-Feed Plug-Flow System with Anoxic Selectors This alternative focuses on modifications to the existiztg aeration bash'~s to convert them to a step-feed plug-flow with anoxic selector process. The anoxic, stcp-fced, plug-flow air- activated sludge process is an improvement on the complete-mix or plug-flow activated sludge process used historically at the WPCF. It combines the well-known step-feed, plug- flow activated sludge process with the anoxic selector process. In the anoxic, step-feed, plug-flow air-activated sludge process, effluent from the primary clarifier is fed to various points along the aeration tank, which is compartmentalized into anoxic and aerobic zones. Figure 6.2.1-1 is a basic process flow diagram for the step-feed process. Selective organism growth in the anoxic selectors allows for sludge settleability control. Nitrification and denitrification occur in the aerobic and anoxic environment, allowing for removal of nitrogen forms from the wastewater effluent. In addition to these benefits, the anoxic, step-feed process allows the use of smaller aeration basins and secondary clarifiers, eliminates the need for mixed liquor recirculation pumping, and reduces process energy and alkalinity requirements. Thus it offers economic as well as process advantages. The basis for sizing the anoxic, step-feed, plug-flow air-activated sludge process is well-established and this process has been successfully used to meet similar criteria at a number of other treatment facilities. FIGURE 6,2.1-1 WPCF Anoxic, Step-Feed Plug-Flow Process MWMC Facil/ties Plan, Eugene-Springfield Cell 1 Cell 2 Cell 3 Cell 4 t DO Wea~r W~ Wea~ ~ WAS Because the pfima~y effiuenl is introduced in po~Qons ~o each zone, the to~a] dilution effec~ is delayed such that the mixed {iquo~ concenications in the eaHy zones a~e hi~he~ ~hau ~ subsequent zones. ~is is key to the stepdeed p~ocess as the mixed liquo~ ~mm the fi~st, to ~e second, to the third, and to the ~ou~th zones dec~eases. ~s confi~u~aQon increases the average mixed liquo~ concen[~a[io~ in the basins, while ~edudn~ ~he solids loadin~ ~ate o~ the secondary clarifie~s. For a ~ive~ mixed llquo~ concent~atio~ to the Hnal cla~ifiers, the s[epdeed anoxic se{ector p~ocess c~ support a hi~he~ sludge hwento~y a~d solids ~etentio~ time (SRT) than conventional desi~, increasing the treatment capacity of a given tank volume. Pumped recirculation of nitrified mixed liquor is not required for the step-feed m~oxic selector process. Nitrified mixed liquor flows out of each aerated cell directly into the MWMCJ O_REV11 DOC 6-7 MWMC FACIUI'IES PLAN subsequent anoxic selector of the following cell where derfitrificafion occurs. Therefore, the capital and operating costs associated with the nitrified mixed liquor pumping equipment are el/m/hated. RAS pumping/s required and RAS performs a dual function of biomas,s return as well as nitrate redrculation from the secondary clarifiers. The step-feed anoxic selector process provides for control of sludge settleabffity through selective organism growth, effectively reducing the sludge volume index (SVI). The reduction in SVIs enables the secondary clarifiers to be rated for a higher design solids loading rate. It is the effect of this increase in biological capacity in combination with improved sludge settleabflity that would allow the WPCF to increase its capacity using the existing aeration basin volume and secondary darifiers. It was assumed that as part of the secondary treatment modifications, the secondary clarffiers would be modified to include baffling to increase their capacity and provide a more reliable effluent qual/ty, as outlined in section 6.2.2. To fl,nplement this technology at the WPCF, the existing complete-nfix/plug-flow aeration basins would have to be sigrfificantly modified to provide complete ~vgxed anoxic selector zones physically separated from the aerobic zones. This may be accomplished by constructing a new dividing wall along the length of each cell in each bas/n to provide an a_noxic selector having approxLmately 20 percent of the total aeration volume. This would provide four identical cells in each basin containing an anoxic selector followed by an aerobic zone. Primary effluent could then be distributed to each of these cells in various quantifies to accommodate seasonal effluent requirements. Dry weather operations requiring nitrification could distribute primary effluent in the proportion of 25 percent to each cell, whereas wet weather operations where no nitrLficaiton is required could be distributed in the proportion of 33 percent to each of the last three cells in the aeration basin. Table 6.2.1-1 summarizes the dry and ,,vet season design criteria used for analysis of the step-feed anoxic selector process. TABLE 6.2.1-1 Design Cntena: Step-Feed Anoxic Selector Process MWMC Facifities Plan, Eugene-Springfield Parameter Dry Season Wet Season Temperature, degrees C 15.6 12.5 Nitnfication Safety Factor 2.0 N/A Aerobic Volume 80% 80% Aerobic SRT, days 7.8 4 Anoxic Volume 20% 20% Anoxic MCRT, days 1.7 1.0 PE Flow Split 25% to 4 cells, or 33% to 3 ceils 33% to 3 cells SV~, mJ/g 110 120 Table 6.2.1-2 sttmmarizes the facility requirements for the modified system to meet the 2025 projected flow and loads. DEVELOPMENT AND EVALUATION OF ALTERNATIVES TABLE Facility Requirements for Alternative 1 at 2025 MWMC Facilities Plan, Eugene-Springfield Total Required Secondary Capacity Capacity NPDES Permit Condition Aeration Basins Clariflers (mgd) (mgd) DWMM 2 (4 cells each) 9 60 59 DWMW 2 (4 cells each) 10 90 86 WW MM 2 (4 cells each) 10 119 VWV~ 2 (4 cells each) 10 165 165 Alternative 2 - Expand Existing Secondary Treatment Facilities to Match Current Operations This alternative requires expansion of the secondary treatment facilities to match the oarrent operational practices for biological treatment and secondary clarification. For this operation, all of the primary effluent and RAS is fed to the first aeration cell in each aeration basin. Sludge volume indexes from over 2600 days of operation show that 25 percent of the measurements fall between 150 and 175 rog/g; thus, 175 mg/g was used as the basis for estimating future capacity with expanded facilities. Table 6.2.1-3 summarizes the dry and wet season design criteria used for analysis for expanding the existing secondary system. TABLE 6.2.1-3 Design Criteria: Traditional Plug-Flow Aeration Basins MWMC Facilities Plan, Eugene-Springfield Parameter Dry Season Wet Season Temperature, degrees C 15.6 12.5 Nitrification Safety Factor 2.0 N/A Aerobic Volume 100% t00% Aerobic SRT, days 7.8 5 SVl, ml/g 175 175 Table 6.2.1-4 summarizes the facility requkements for expand~g the ex/sting secondary treatment facilities. MWMC_6.0_REV11 DOC 6-9 MWkiC FAC)LIlIES PLAN TABLE 62.1-4 Facility Requirements for Alternative 2 at 2025 MWMC Facilities Plan, Eugene-Springfield Total Required Secondary Capacity Capacity NPDES Permit Condition Aeration Basin Clarifiers (mgd) (mgd) DWMM 2 (4 ceils each) 12 60 59 DW MW 3 (4 celJs each) t 6 86 86 WWMM 3 (4 cells each) 12 119 ~ 11 WWMW 3 (4 cells each) 16 167 t 65 Results The capital cost comparison and non-monetary comparison are summarized in Table 6.2.1-5. TAI!~LE 6.2.1-5 Comparison of Facility Requirements, Cost, and Non-monetary Evaluation MWMC Facilities Plan, Eugene-Springfield Additional Aeration Additional Secondary Cost Basins Required ClarJfiers Required (mlllions of Nonmonetary NPDE$ Permit Condition for 2025 for 2025 do.ars) Evaluation A~ternative 1 0 2 $19.3 27 Alternative 2 I 8 $39 15 Alternative 1 is the recommended alternative for secondary treatment improvements. This alternative provides the following advantages: Increases bioreactor capacity by increasing the mixed liquor concentration Modifications can be constructed within the existing infrastructure footprint Process reduces loading to the secondary clarifiers Improves sludge settleability and provides for its control Will provide consistent and complete nitrification Provides process flexibility for seasonal operation - Operation is more efficient and provides financial benefits In addition, alternative 1 is far more cost-effective and maximizes the use of existing facilities. 6.2.2 Secondary Clarification Enhancements As stated in secfiort 6.2.1, the WPCF will need to increase zts secondary treatment peak capacity to address the projected increase in wastewater flows and the ever-cha_rtgLrtg and more restrictive NPDES effluent limitations. The current peak wet weather secondary 6-10 MWM6...80_REV'~ 1,DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNA~VES treatment capacity has kistorically been estimated at 103 mgd. Above 103 mgd the existing secondary effluent (SE) quality begins to degrade rapidly, limited by the capacity of the ex~stJng secondary clarffiers. The result is a SE with a higher effluent TSS than is acceptable. Alternatives for increasing the secondary clarification capacity include constructing new secondary clarifiers and enhancing the performance of the exist~g secondary clarffiers. Before considering construction of new secondary darifiers, alternatives that evaluate optimizing the exLst~g secondary clarifiers should be considered. Tiffs approach will maximize the facility's exist~g investment in secondary clarifiers. Alternative 1: Partia~ Retrofit: Baffling and I~lechanism Retrofit This alternative represents the minknum modifications required to achieve the operational performance results des[red. It includes a new energy dissipating inlet (EDI) installed on the existing influent colunm to address the inlet velocity issues. A new flocculation well sled to accommodate the larger influent flows would redirect surface velocity currents. This alternative would retain the exist~g inboard launder. The outboard weir of this launder would need to be either blocked or baffled to prevent density currents from pushing suspended solids over the outside of the weir. Ring and density cm~ent baffles may redirect suspended solids toward an inboard launder, which is more than 12 feet off the perimeter wall, and are not recommended. Retrofitting the exis~ng suction tubes to a single suction manifold with adjustable orifices would address the issues associated with the existing mechanism dragging on the floor, reduce the radial density currents associated with the horLzontal suction [-t~bes, improve the sludge withdrawal distribution, and increase the available head for sludge withdrawal. Alternative 2 - Partia~ Retrofit: Baffling and Mechanism Retrofit, New Effluent Launders This alternative would provide the same EDI, flocculation well, axtd mechanism retrofit as described in Alternative t. In addition, this alternative proposes to remove the corroded inboard launder and locate a new launder at the exterior of the clar~fier. The relocated launder would be fabricated steel, either painted or stainless. With the reloca~on of the launder a new scum baffle, as well as new scum skimmer arms, would be required. For outboard launders a density current baffle is recommended for density currents. This baffle could be either fiberglass reinforced plastic (FRP) or stainless steel. Alternative 3 - Compete Retrofit: Baffling Retrofit, ~techanism Replacement, l'{ew Effluent Launders This alternative would provide the same EDI, flocculation well, new outboard launder, skimmer arms, scum baffle, and density current baffle as described in Alternative 2. In addition, this alternative proposes to remove and replace the entire existing Lrffluent colunm and drive mecharfism. This alternative also proposes to replace the existing clarifier bridges. Results The capital cost comparison is summarized in Table 6.2.2-1. A non-monetary comparison was not performed because each of the alternatives was assumed to result in the same level of operational performance and effluent TSS reliability. MW~C_6 9_REV11 DOC 6-1 ~ k~WMC FACILITIES PLAN TABLE 6.2.2-1 Summary of Secondary Ctarff]er Baffling and Mechanism Improvements - Alternatives Comparison MWMC Facilities Plan, Eugene-Springfield CapitaJ Cost Alternative (millions of dollars) 1 - Partial Retrofit - Baffling and Mechanism Retrofit $2.9 2 - Partial Retrofit - Baffling and Mechanism Retrofit w~th $5.5 Hew Effluent Launder 3 - Complete Retrofit - Baffling with Complete $7.O Mechanism Replacement and New Effluent Launders The baffling and associated miscellaneous improvements for each alternative are anticipated to result in an increased secondary clarifier capacity of 20 to 30 percent. A capacity increase of 40 percent has been observed in some installations; however, in the absence of stress testing data for an WPCF secondary ctarifier, a conservative assumption of the increase in clarifier capacity is estimated at a minimum of 20 percent. This translates to a sustained peak surface overflow rate (SOR) of 1260 gpd/sf for each secondary clarifier and a total sustained peak flow capacity of 134 mgd with all eight secondary clarifiers on line. The three alternatives and their costs were presented at an October 2003 workshop with Eugene-Springfield staff and CH2M HILL staff. Eugene-Springfield staff unanimously chose to proceed with Alternative 2 as the preferred alternative. Stress testing of the retrofitted secondary clarifiers can be conducted to determine the actual estimated capacity increase resulting from the modifications. 6.2.3 Primary Clarification Enhancements The WPCF currently uses a total of four primary clarifiers to treat screened and degritted raw sewage. The existing primary clarifiers are circular, have outboard launders, and are 135 feet in diameter with 12-foot sidewater depths. The primary sludge is accumulated at the bottom of the clarifier and thickened through compaction. Primary sludge solids are drawn off with intermittent sludge pumpLng, and a sludge blanket is maintained within the clarifier. Equipment for the existing primary treatment facilities is outlined in Table 3.2.2-2 in Chapter 3.0. Plant operations personnel have observed that when the total plant flow exceeds approximately 72 mgd, the primary clarified effluent quality rapidly deteriorates. At flows around 86 mgd the primary sludge blanket begins to be washed out of the clarifier, resulting in negative TSS removals. An increase in prknary clarification capacity is necessary to address both current and fut~are PWWFs. Currently, all of the plant influent, including the P~VFs, must pass through the existing primary clarification facilities, which are limited in capadty. It is prudent to look at alternatives to optimize the performance of the existing primary clarifiers before considering the const~uc~on of new primary clarifiers. This approach will maximize the facility's existing investment in primary treatment facilities. MW~C_6.0_RE?I '~.DOC 6. DEVELOPMENT AND EVALUATION OF ALTERNATIVES Current WWPH flows into the plant exceed 200 mgd. The current secondary treatment capacity is lirmted to 103 mgd and any primary effluent (PE) flows over 103 mgd must be diverted and blended with SE. These blended flows must meet the current NPDES permit for secondary treatment. Future PWWFs are anticipated to increase and approach 277 mgd. In peak flow scenarios it is crucial that the diverted PE be of sufficient quality to ensure that the blended effluent can meet the current NPDES permit for both carbonaceous biological oxygen demand (CBOD) and TSS. Increasing both the capacity and the treatment performance of the existing primary clarifiers would ensure that the WPCF will continue to meet current NPDES permit requirements. As part of the evaluation, an initial capacity assessment was completed using historical performance data from the WPCF. The assessment resulted irt a capacity rating for the existing primary clarifiers of 86 mgd, removing 50 percent of the TSS. This capacity rating was then used as a baseline for evaluating three alternatives to enhance the existing primary treatment capacity and improve performance: A~ternative 1 - No ~mprovements This alternative would include no modifications or improvements to the existing pr~ary clarifiers. Alternative 2 - Add Bafflin§ to Primary Clarifiers This alternative would add EDIs, a new adequately sized feed well, and density current baffles at the perimeter of each primary clarifier. Alternative 3 - Add Baffling to Primary Clarifiers and Operate Without a Sludge B~anket This alternative would add EDIs, a new adequately sized feed well, and density current baffles as described Ln Alternative 2. This alternative would also include operating the primary clarifiers without a sludge blanket by pumping a thin primary sludge at a high flow rate from the primary clarifiers to an external thickener. This alternative would require replacing the exist~g primary sludge pumps and is based on adding two new 50-foob diameter gravity thickeners and a new thickened primary sludge pump station. Alternative sludge thickening approaches outside the primary darifier are available, but for purposes of cost estimating and alternative comparison, gravity thickeners were evaluated. Results The capital cost comparison and non-monetary comparison are summarized in Table 6.2.3-1. TABLE 6.2.3-1 Summary of Primary Clarification Enhancement Alternatives Comparison MWMC Facilities Plan, Eugene-Springfield Capital Cost Alternative (millions of dlo~lars) Non-Monetary Rating~ 1 - No ~mprovements $O 13 2 - Add Baffling to Primary Clarifiers $1.16 22 3 -Add Baffling to Primary Clarifiers and Operate $4.79 24 wilhout a Sludge Blanket Notes: a Non-monetary score is out of a possible maximum score of 30 points. MWMC_6.{)_REV1 ~.DOC 6-13 IVlWMC FACILITIES PLAN Alternative 1 would not increase capacity through the primary clanfiers. Alternative 2 is expected to increase the allowable SOR of the existing clarifiers, and thus the primary clarifier capadty, by approxLmately 20 percent. Although it will not be adequate to fully address the peak flow issue with respect to blending while meeting the NPDES permit, this alternative does provide an excellent increase in capacity using existing h~asb'ucture and can be done at a reasonable cost. It also provides increased reliability in performance; however, sludge blanket washout would still occur at peak flows, and eventual perm/t violations would be anticipated. Alternative 3 is anticipated to increase the allowable SOR of the existing cla~Lfiers, and thus the clarifier capacity, by up to 100 percent over Alternative 1. The resulting capacity of the primary clarffiers would be comparable to the proposed secondary treatment capacity. Alternative 3 is recommended because it would increase the existing primary clarffier capacity and improve the reliability of effluent quahty. Although it is the highest-cost alternative, most of the capacity gained is through existing infrastructure, wt'dch maximizes the plant's existing investment while occupying very little site space. The eqrdpment associated with the elimination of the sludge blanket in the primary clarif/er accounts for much of the cost. This alternative provides all the capacity and performance reliabiI/ty benefits of Alternative 2, plus 60 percent increased capacity, excellent operational flexibility,. high-quality PE at h/gh SORs, and meets all the primary clarification needs of the proposed secondary treatment system. Baffling improvements, new primary sludge pumps, two new pr/mary sludge thickeners, and a primary sludge pump station will be requLred for this alternative. 6.2.4 Preliminary Treatment The existing pretreatment facility at the WPCF has a peak capacity of 175 mgd. This is based on having one of the six screening channels and one of the four aerated grit chambers out of service during peak flow events. Equipment in the existing pretreatment fadlity is outlined in Table 3.2.2-1. The projected 2025 PWWF flow being used for facility planrdng analysis is 277 mgd. Pretreatment facilities, at a minimum, must be expanded to accommodate additional flows with the largest traits out of service. Two alternatives have been evaluated to expand the existing pretreatment capacity, both of which are based on an expanded capacity of 160 mgd. An expanded capacity of 160 mgd is necessary to accommodate the projected peak dry weather flow. It was used as the design basis so that the expanded facility capacity would match the capacity of modified secondary treatment facilities. Using this approach, the new facilities would be used to treat normal plant flows and the existing pretreatment facility would be brought online ordy as necessary during wet weather events to t~eat peak Alternative I - Expand Existing Pretreatment Facility Alternative 1 looks at expanding the existing pretreatment facility. New grit and screenings handling equipment would be located in a new building south of the existing pretreatment area. The influent channels of the expanded facilities would be hydraulically connected to the existing facilities so that flow could be transferred between them. The expanded facilities would use fine screening technology and the screenings would be handled separately from the existing facilities by new washer/compactors. This is necessary because the DEVELOPMENT AND EVALUATION OF ALTERNAT~¥ES characteristics of the fme screenings are so much different than those of the existing coarse screenings. Once the flow passes through the screenings channels, separate grit removal would be used for the expanded facilities. These grit removal facilities would be designed to nnplement new technologies than used in the existing aerated grit chambers. Pretreated effluent from the new facilities could then be routed back to the existing facility where the effluent would be combined prior to preaeration, or the two separate pretreated effluents could be combined downstream of grit removal and routed to primary clarification. Additional grit and screenLngs loadout facilities would be required as part of the expansion. The major new equipment and processes associated with this alternative include: Four (4) new fine screens (1/4-inch opening) , Two (2) new screenings washer/compactors Four (4) Parshall flmes for flow measurement Four (4) new cyclordc grit separators Four (4) new grit pumps and cyclones Two (2) new grit classifiers Two (2) new screenings/grit hoppers Alternative 2 - Construct New Pretreatment Facility Alternative 2 considers constructing a new pretreatment facility east of the existing influent screw pumps. This facility would be a new standalone facility that would require separate influent pumping up to the influent channels. All of the technologies used ha Alternative 1 would be applicable to Alternative 2 except all would be located in the new facility and would be independent. Flows in excess of the new facility capacity would be routed and processed at the existing pretreatment facility. The major new equipment and processes associated wiff~ this alternative include: Four (4) new fine screens (1/4-inch opening) Two (2) new screenings washer/compactors Four (4) Parshall flumes for flow measurement Four (4) new cyclonic grit separators Four (4) new grit pumps, concentrators, and classifiers Two (2) new screenings/grit hoppers Results For Alternatives 1 and 2, the screenings channels and grit separators would be covered and the odorous air collected and treated in bioscrubbers. The cost comparison developed for each alternative is relative because it does not include the costs associated with odorous air ducting and treatment. The relative capital cost comparison and non-monetary comparison are summarized in Table 6.2.4-1. 0_REVI 1 DOC 6-15 MWMC FACIUTIES PLAN TABLE 6.2.4-1 Summary of Pretreatment Expansion Alternatives Comparison MWMC Famlrties Plan, Eugene. Spnngfield Capital Cost Alternative (millions of dollars) Non-Monetary Ratinga I - Expand Existing Pretreatment Facility $12.8 21 2 - Construct New Pretreatment Facility $17 19 Notes: a Non-monetary score is out of a poss~bte maximum score of 30 points. Capital costs associated with const~action of a new pretreatment facility are approximately 30 percent higher than for the expansion of the existing facility. The non-monetary evaluation of the mo alternatives indicates that expansion of the exis~_qg pretreatment facility is shghtly more favorable than constructing a new facility. Both alternatives will have 160 mgd of capacity to minimize operation of the existing pre~reatment facility, which would only need to be brought online for peak flows. It was assumed that the new pretreatment facility would have full grit removal capacity. As more detailed planning and design efforts proceed for the expansion of the exisQng pretreatment facility, both of Lhese assumptions should be evaluated more closely. It may be more cost-effective to provide only the required 102 mgd of additional capacity and provide flexibility to bring the existing pretreatment facffity online and offline more frequently, although this would be extremely labor-intensive from an O&M standpoint. An alternative to providing grit removal during pretreatment would be to degdt thin from the clarifiers. This avoid construction o£ removal primary sludge primary may facgities in the pretreatment expansion. As part of the approach to expand primary clarffier capaci~, the abihty to pump ti,in sludge and thicken the primary sludge outside of the clarifiers will be assessed. Grit accumulation in the primary clarifier centerwells is an issue of concern that would have to be addressed if the degritting primary sludge approach is pursued. Based on the alternatives analysis, it is recommended that Alternative 1, expansion of the existing pretreatment facility, be carried forward for faciLity planning purposes. Further investigation of pretrea~ent capacity and grit removal will be carried out during predesign. Upon further refinement of the pretreatment expansion, selection and comparison of specific equipment associated with the selected alternative will be evaluated more comprehensively. 6.2.5 Odor Contro It is anticipated that the WPCF will need to increase its odorous air treatment system to address the projected increase in air flow rates resulting from the addition of new process units throughout the plant. The existing odor control system consists of a three-cell, organic media biofilter with a design capacity of 18,000 cubic feet per minute (ff~/mi~ute) and a connected capacity of 15,000 ff3/minute. The new odor control system would have sufficient capacity to treat the existing odorous air flow rates and an additional 23,000 anticipated for the new process units. Representative sLzes for new facilit-zes requiz-Lng odor control have been selected and the resulC_~g air flow rates calculated using the applicable M~c_60_REVI 1.DOC, DEVELOPMENT AND EVALUATION OF ALTERNATES criteria. 2~e resulffng exhaust air flow rates for all area and the assumed facility sizes are . s~arized in Table 6.2.5-1. TABLE 6.2.5-1 Exhaust Flow Rates by Area MWMC Facilities Plan, Eugene-Springfield Odor Source Unit Size Assumptions Air Total Air Flow Rate Changes Headworks Channels 4 Channels, 5' Wide, and 75' Long 20 (under 2000 CFM with 4' Average Headspace. vacuum) Truck Loadout Bay 50' Long, 20' W~de, and 20' High. 12 4000 CFM Primary Cladfier Floc 4 Units,35' Diameter with 2' Average 12 800 CFM Wells Headspace. Primary Clanfier Eil'luent 4 Units, 135' Outer D~ameter and 130' 12 7600 CFM Launders inner Diameter with 3' Average Headspace. Primary Sludge Thickener 2 Units, 50' Diameter w~th 12' 12 5100 CFM Average Headspace Equipment Enclosures Vadous 2500 CFM Ex~sting Odor Control Existing Connected Load 18000 CFM Total Flow Rate 41,000 CFM CFM = Cubic feet per minute The odor control system will be designed to achieve the specified removal efficiency based on hydrogen sulfide concentration, which is used as the surrogate for total odor. The design removal efficier~cies, based on inlet hydrogen sulfide concentration, are s~ammar~ed in Table 6.2.5-2. TABLE 6.2.5.2 Design Removal Efficiencies MWMC Facilities Plan, Eugene-Springfield If~iet H2S Concentration I~inimum H2S Removal Technology (ppm) Efficiency (°Io) Bioscrubber >10 99.0 <~0 95.0 ppm = parts per million by volume Alternative 1--Conventiona~ Open-Space Organic Media Biofilter This system consL~ts of an above- or partially belowgrade cordigurador~ with retelling wall or soil berm filled with an organic media, such as a mulch or composted yard debris, to grow sulfur-reducL~g bacteria. The media allows the cultivatior~ of a £i×ed-film growth that consumes the odors as a~r travels upward t_h.rough the filter bed and into the atmosphere. The odorous a~r is evenly distributed throughout the biofilter by distribution piping located MWMC_6 0_REV11 DOC 6-17 MWMC FACILITIES PLAN near the bottom within a layer of fiver rock. Below the rock is a sloped membrane for capturing the moisture. Above the river rock is a layer of media approximately 5 feet thick. Keeping the media moist is critical for proper operation of the biofilter. This is accomplished by supplying a spray nozzle in the ductwork upstream of the biofilter and by providing an irrigation spray system on top of the biofilter. Moisture sensors are provided for controlling the irrigation system. The footprint would be large because of a required loading rate of 4 to 6 cubic feet per minute per square foot (ft3/minute/ftc) and contact time of 60 seconds through the organic media. Alternative 2--Conventional Open-Space Soil I~edia Biofilter This system consists of an above- or partially belowgrade configuration with retaining wall or soil berm filled with an inorganic media, such as selected native soil, to grow sulfttr- reducing bacteria. The media allows the cultivation of a fixed-film growth that consumes the odors as air travels upward through the filter bed and into the atmosphere. The odorous air is evenly distributed throughout the biofilter by distribution pipkng located near the bottom within a layer of river rock. Below the rock a sloped membrane captures the moisture. Above the river rock is a layer of media, approximately 5 feet thick. A layer of washed rock is applied over the top of the soil media for aesthetics and weed control. Keeping the media moist is critical for proper operation of the biofilter. This is accomplished by providing a spray nozzle in the ductwork upstream of the biofilter and by supplying an irrigation spray system on top of the biofilter. Moisture sensors are provided for controlling the irrigation system. The footprint would be large because of a required loading rate of 2 to 3 fP/minute/ft2 to allow a contact time of 60 to 90 seconds through the soil media. Alternative 3--Bioscrubbers (Biotrickling Tower) In a biotrickling tower, odorous air is blown into the bottom of the tower and flows up through the media material. Treated air migrates out of the filter bed and into the atmosphere. The media may be a synthetic material or an inorganic material such as lava rock. The media allows the cultivation of a fixed-film growth that consumes the odors that pass through it. The bacteria also use other odor compounds as a food source, including ammonia and various organic reduced sulfur compounds. Recirculation pumps provide a continuous stream of water that keeps the media wet, provides nutrients, and carries away waste products. A source of water, preferably non-chlorinated secondary plant effluent, is needed for the unit. If potable water is used, a supplemental nutrient feed system is required. The redrculated water is continually blown down to a drain to control pH and remove waste products. Drain water will be low in pH and shottld be routed to a flow stream where it can be diluted. Design bed velocities for biotrickling towers are 50 feet per minute (fpm) maximum. The design head loss through the media is generally about 0.3 inches per foot of bed depth. A scrubbant recirculafion pump is required to keep the media moist, add necessary nutrients, and maintain pH. The footprint for the bioscrubber would be smaller than for the conventional filters because of the tower configuration. Results The order-of-magnitude capital cost comparison and non-monetary comparison are summarized in Table 6.2.5-3. ~-18 MW~C_6.0_REV11.DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES Summary of Odor Control ~ernat~ves Comparison MWM¢ Facilities Plar~, Eugene-Springfield Capital Cost Non~[~,~onetary Alternative (millions of dollars) Rating~ 1 -Conventional OpemSpace Organic Media Biofilter $3.75 17 2 -Conventional Open-Space Soil Media Biofitter $4.14 21 3 - Bioscrubbers (Biotdckling Tower) $4.55 24 Notes: ~ Non-monetary score is out of a possible maximum score of 30 points. MWMC views odor control as an extremely important issue. One of MWMC's highest priorities is to maintaLn their status as environmental stewards in the commurdty by providing facilities that are neighborhood friendly. Bioscrubber and biofilter technologies produced a nearly equivalent result in the evaluation. Considerations such as site space, more advanced technolog/es, and higher atmospheric dispersion make bioscrubber technology more favorable over biofilter technology. It is recommended that bioscrubbers be incorporated into the overall odor control design for future use and to replace the existing biofilter operations. The biofilters will be phased out over the next 20 years of facility operation so that they achieve their original intended design life. 6.2.6 Tertiary Filtration Unchanged dry weather mass lirrdts wilt drive effluent TSS and CBOD concentrations down below the current effluent concentration limits of 10 mg/L. As effluent concentrations are driven down over time it will become exceedingly more difficult to achieve the requRed effluent limits unless tertiary filtration is added. Figure 6.2.6-1 show how the effluent TSS concentration limits are reduced over time as the maximum month flows increase over the planning period. Operations must provide an effluent quality that is sufficiently below the effluent TSS requirements so that any process upsets may be absorbed by the system without resulting in perrrfit violaticrns. Figure 6.2.6-1 shows the desired operating performance to meet this requ/rement. Process upsets can occur in the secondary biological treatment process dudmg periods of operational transition and can result irt poor settling suspended solids for periods sufficiently long to adversely impact the monthly effluent CBOD and TSS concentrations. It is well established that process upsets may occur during periods of significant wastewater temperature changes, or during periods when the process ks transitioning from winter operations (where no nitrification is required), to summer operations (where nitrification/s required). Effluent filtration can provide an effective defense against these types of situations. Filtration also provides the added benefit of operational flexabil~ty, consistent performance reliability, and provides the opportunity to develop reuse ptogram_s. For those reasons previously outlined, it is recommended that 30 mgd of partial secondar~f effluent filtration be implemented over the planning period. The pre-filtered flow would be removed from the secondary effluent flow stream, pumped up to filtration for treatment, and then re-blended with secondary effluent prior to disinfection. Filtration will provide performance reliability O_REVI 1 DOC 6.19 MWMC FACILITIES PLAN m~matched by other trait processes when it comes to meeting the low effluent CBOD and TSS concentrations. 110 ...... 11 ~ 40 ........ ~ 4 30 - rating- 3 20 -- PeRormance to ~ 2 ~ 0 .... Meet Permit ~ 0 , , , , 0 2000 2010 2020 2030 2040 2050 {~ Dry CBOB5 and TSS Weather Flow Effluent FIGURE 6.2.6-1 CSOD and TSS Operating Pedormance MWMC Facilities Plan, Springfield-Eugene Wet weather operations will also benefit from eftluent filtration. Wet weather flows into the facility can provide very dilute wastewaters with low TSS and CBOD concentrations. For this reason the 85 percent removal requirement for both CBOD and TSS during the wet season are typically the most difficult standards to meet. When wet weather flows exceed the secondary treatment capacity of the facility those flows are diverted arotmd secondary treatment and do not receive the benefit of secondary treatment which sigmificm~tly reduces the CBOD and TSS of the effluent. For the blended flow stream, higher CBOD and TSS concentrations are anticipated. In a worst-case scenario, assuming that the PWWF occurs during the peak week flow and the peak week flow occurs during the peak month, the 85 percent monthly removal reqtdrement specified in the NPDES permit for BOD would require filtration of a port, on of the SE. This is necessary to lower the TSS and CBOD adequately in the SE to compensate for the higher TSS and CBOD as a result of the blended PE and SE. This is the case for all of the alternatives, and it was assumed that filtration would be available because it will be reqttired for TSS removal reliability during the dry season. Filtered flow required under this worst-case scenario would be 10 mgd at 2010, and 30 mgd at 2025. Figure 6.2.6-2 illustrates the tertiary filtration capacity required with respect to the maximum month projected flow in order to meet the 85 percent CBOD removal requirement during the worst case wet season flows. 8-20 MWMC_80_REVI 1 DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES 120 ...... 1 O0 - _9~2__ ~ 80 ---- i urn Month __ ~ Wet Weather Flow 0 Filtered Secondary -- Effluent Required to ~ 40 Meet 85 % Removal-- -- for MMWW 20 - !-0 20t0 2015 2020 2025 ~ Filtered F~ow FIGURE 6.2.6-2 F~ltration Required at Worst Case Maximum Month Wet Weather Flow MWMC Facilities Plan, Eugene-Springfield The following filtration technologies were identified as either appropriate or preferred for the WPCF. Deep bed granular media filtration Fabric disk or Fuzzy Filters - Membrane filtration A detailed cost evaluation m~d non-monetary analysis was not performed for these alternatives. Conventional deep bed granular media filtration is currently recommended to meet the large scale filtration needs identified above. This is due to the following reasons: The techrtology is well established in the industry ,, Siting of deep bed granular media filters will occupy the largest site space relative to other alternatives and thus the planning will be conservative The filters can be constructed using a modular approach to meet the projected facility needs in a "just in time" approach · The technology is well suited for large volumes of filtered flow The cost of constructing deep bed granular media filters will be adequate for plmming purposes. If MWMW would like to evaluated other technologies when the facilities are actually needed there would be adequate ftmds available. MWMC_6 O_REV/1 DOC 6-21 MWMC FACJUTiES PLAN Design criteria used for sizing and siting the facihty include the following: Average filter flow = 2.5 gpm/sf - Peak filter fl~w = 5 gpm/sf 75% TS$ removal Total filtered flow = 30 mgd Total filter area = 7200 sf ,, 8 modular filter ceils each at 26 ftx 35 ff. For granular media filtration a large supply of chlorinated water is needed to provide backwash flows to the filters. It was assumed that a new filter backwash pump station would be constructed in the existing chlorine contact basins utilizing vertical barbine pumps for this purpose. It was also assumed that in the initial stages one ceil of the existing aeration basins could be used for backwash equalization flow, as this volmme is currently unused. Other filtration technologies listed above are well suited for smaller filtration projects and should be considered to provide filtration for level IV reuse water. 6.3 Disinfection Alternatives The WPCF currently uses a liquid/gaseous chlorine disinfection system with sulbar dioxide for dechlorination. The primary use of chlorine at the WPCF is effluent disinfection. The current disinfect-ion design capacity is approximately 60 mgd at 60 minutes hydrauhc detention time and 175 mgd at peak wet weather flows hmited by chlorinator capacity. Flow in excess of 200 mgd during peak wet weather flows have been adequately disinfected in the facihty only because of the reduced chlorine dosage as a result of the diluted wastewater flows. Chlorine is also used to control filamentous bulking organisms through addition to the return activated sludge (R_AS) line. Table 3.2.2-4 outlines the existing WPCF disinfection unit process and equipment. Up to the secondary treatment capacity of 103 - 111 mgd, all of the PE is routed through the secondary system and disinfection facilities. During PWWFs, PE in excess of 111 mgd is diverted around the secondary treatment facilities and blended with the SE upstream of the disinfection facility. This is accomphshed through a dedicated diversion channel. Projected peak in~stantaneous flows to the facility are estimated at 277 mgd. The modified secondary treatment system will handle a peak flow of 165 mgd. Therefore, flows to the facility in excess of the secondary treatment system capacity will be diverted around secondary treatment and will need to be either disinfected separately or combined with the SE prior to disinfection. Because the effluent pipe from the current disinfection system is limited in its capacity to 165 mgd (once the secondary system is modified), it will be necessary to keep the diverted PE and SE flow separate for disirffection. Due to growing concerns about operator and public safety, M%TMC initiated an investigation to evaluate disinfection alternatives other than the use of chlorine and sulfur dioxide gas. Alternatives would be required to disinfect a projected peak flow of 277 mgd. The criteria for which chlorine alternatives were evaluated were taken from the guidelines published in the Washington Department of Ecology Orange Book, which are summarized MWM~6~REVI~DOC 8 DEVELOPME~f AND EVALLIATIO~I OF ALTERNA'~VE~ in Table 6.3-1. These detention time guidelines are commonly used by the Oregon DEQ for contact time criteria. TABLE 6.3-1 Guidelines for Chlorine Disinfection Design MWMC Fac~lrties Plan, Eugene-Springfield Projected 2025 Flow Required Detention Required Chlorine Condition (mgd) Time ( rain} Dosage ADWF 59 60 3,5 PDWWF 227 20 3,5 *PHWWF 277 15 3.5 (SE), 7,0 (PE) Provide a 1 mg/L residual in all cases Flows must be as measured at the disinfection facility 30 day chemical storage at average annual 14 day chemical storage at maximum month 6 day chemical storage at maximum week Additional criteria used as a basis for sizing and selecting UV d~s~fecdon alternatives are shown ~-t Table 6.3-2. TABLE 6.3-2 Design Critena for UV DisInfection MWMC Facilities Plan, Eugene-Springfield iVlinimum Maximum TSS Condition Transmittance (%) (rog/L) Secondary Effluent 65 20 Primary Effluent 25 45 Monthly geometric mean E, co/~ count = 126 MPN/IO0 mL Maximum single sample E. coil count = 406 MPN/100 mL Alternative 1: Hypochlorite Disinfection of Secondary and Primary Effluent This alternative involves conversion of both the SE and PE flow streams to sodium hypochlorite disLrffection. The sodium hypochlorite solution strength will be 12.5 percent; sodium bisulfite will be 38 percent. This alternative will require installation o£ rite following equipment: · Three (3) 20,000-gallon horizontalbulk storage tanks for hypochlorite MWMC_60_REV11 DOC 6-23 MWMC FACILITIEs PLAN One (1) 7,000-gallon vertical bulk storage tank for bisulfite Five (5) hypochlorite metering ptLmps for main plant flow chlorination Two (2) hypochlorite metering pumps for diversion flow chlorination Two (2) bisulfite metering pumps for main plant flow dechlorination Two (2) bisulfite metering pttmps for diversion flow dechlorination Piping, valves, mechardcal, electrical and control systems associated with chemical feed and storage for both the main plant flow and the diversion flow 1.3-million-gallon total chlorine contact basin volume providing 20 minutes of detention time for PE diversion flow and using diversion pipeline for partial detert~on time The existing final treatment building be used for liquid chemical feed and storage. The existing chlorine contact basins would not need major modifications and would be used for disinfection of the main plant flow. The existing chlorine feed and storage facklity would require remodeling to accommodate the new equipment. Additionally, walled secondary containment would be required for the bulk chemical storage tanks. Alternative 2: Ultraviolet Disinfection of Secondary Effluent and Hypochlotite Disinfection of Primary Effluent This alternative develops an ultraviolet (UV)/sodimm hypochlorite-based disinfection system. In this alternative, a medium-pressure, high-intensity UV system would be used to disinfect secondary effluent flows up to 165 mgd, which is the capacity of the secondary treatment process. UV is a viable alternative for SE because the flow has low TSS concentrations and a high percentage of trarrsmittance. Because of the low percentage of transmittance and high TSS concentrations, UV is not a viable option for PE diversion disinfection. Up to 140 mgd of PE flow will be diverted around secondary treatment and dis~kfected using sodium hypochlorite. The following equipment would be required for th_is alternative: ,, UV package system 800 kW back-up power generator or secondary power source One (1) 20,000-gallon horizontal bulk storage tanks for hypochlorite , One (1) 6,000-gallon vertical bulk storage tank for bisulfite Two (2) hypochlonte meterJ.ng pumps for diversion flow chlorination Two (2) bisulfite metering pmmps for diversion flow dechlorination Piping, valves, mechanical, electrical and control systems associated with chemical feed and storage for the diversion flow ~ 1.3-MG total chlorine contact basin volume for PE diversion flow. This alternative would require the construction of a new UV facility with UV channels, channel isolation gates, and level control gates. The UV system does not require chemical 0_REV! ! DOC 6 OEVELOP~ENFF AND EYt~LJJATIOhl OF ALTERtlAllYES handling, so the footprint required for this facility is relatively small. Experience at other facilities has proven there is very little cost savings gained through retrofitting existing chlorine contact channels with new UV channels over the construct/on of a new UV facility. Electrical room space requirements vary for different manufacturer's systems. Use of the existing chemical building should be considered for required electrical room space. Flow measurement would be incorporated into the UV facility to allow for UV dose pacing. A standby power source would be required for redundancy. The order-of-magnitude capital cost est4xnates and armual O&M costs are summarized in Table 6.3-3. The 20-year present worth costs are based on the order-of-magnitude capital cost estimates and annual O&M costs over 20 years at an interest rate of 3 percent. The UV costs were based on the Trojan UV4000Plus system. The present value comparison and non- monetary comparbon are summarized in Table 6.3-4. TABLE 6.3-3 Summary of Disinfection A~tematNes Order-of-Magnitude and Capital Cost Comparison MWMC Facihties Plan, Eugene-Springheld Capital Cost Annual O&M Cost A~ternative (millions of dollars) (millions of dollars) 1 - Hypochlonte Disinfection ol Secondary and $4. t $0.47 Primary Effluent 2 - Ultraviolet Disinfection of Seconda~J Effluent and Hypochlonte Disinfection of Pdmary Effluent $16.1 $0.46 TABLE 6.34 Summary of Disinfection AltematNes Present Value and Non-Monetary Cost Comparison MWMC Facilities Plan, Eugene-Springfield 20-yr Present Worth Cost' Hon~f~oneta~y Alternative (millions of dollars) Ratingb 1 - Hypochlorite Disinfection of Secondary and $11.1 25 Primary Effluent 2 - U~traviolet Disinfection of Secondary Effluent and $23.0 24 Hypochlorite Disinfection of Pdmary Effluent Notes: a 20-year present worth cost is based on capital and annual O&M costs over 20 years. b Non-monetap/score is out of a posmble maximum score of 30 points. By far the most cost-effective alternative on a capital cost basis is alternative 1, sodium hypochlorite for both SE and PE diversion flows. The O&M costs of alternative I are sensitive to increases in energy prices (electricity and natural gas) because of the large amounts of electricity and natural gas reqttired to produce sodium hypochlorite; however, it is tmlikely that the variability of the O&M costs wig overcome the capital cost difference. Alternative 2 would be easy to operate because sodium hypochlorite disivdection would be MWMC_6.O_REVI1.DOC 6-25 MWMC FACIUI'IES PLAN limited to prhna~y effluent diversion, which typically occurs only 1 or 2 weeks per year. The alternatives have nearly equal non-monetary ratings. Based on the analysis presented above, it is recom_mended that the WPCF prc~ceed with Alternative 1, conversion of the existing gaseous chlorine system to sodium hypoc~florite chlorination for both SE and PE diversion flows. Future Considerations and Recommendations At some h~ture time the WPCF will want to implement Level W reuse water on a relatively large scale and this will drive the expansion of the dis'refection system. Regulatory requirements for Level IV reuse water require either the construction of a new UV system or the addition of chlor~rte contact basins providing a 90 minute modal contact tLme. The requirement for a 90 minute modal contact th'ne using an industry accepted dispersion coefficient of 0.7 would require a total detention t~ne of 128 minutes, resul~g in extremely large chlorine contact basins. This will make the construction of a new UV facility much more cost-competitive with a new chlorine disinfection system. The recommended approach for disLrffecfion of bahare reuse effluent is to construct UV facihfies as reuse is implemented over the 20-year project life. The UV facilities would provide a reuse effluent with a 2.2 Mean Probable Number (MPN)/100 mL Total Coliform effluent on a 7-day median basis. A UV facility designed with this criteria would provide substantially more secondary effluent disinfection capacity at the lower dis~xffection requirement of 406 MPN/IO0 mL (this is for a single sample and is the criteria that would control secondary effluent disinfection design). Thus, a dLsinfection facility initially designed to provide reuse quality effluent could be used to provide disinfection of a much larger quantity of secondary effluent. In addition, the existing chlorine contact basins could easily provide the 90 minutes modal contact t/me required for Level IV reuse water using sodium hypochlorite diskffection. The recommended fiature approach to disinfection will be extremely flexible. 6.4 Effluent Disposal Alternatives Effluent reuse alternatives evaluated are based on application of Level II (secondary effluent) and Level IV (filtered) process water from the WPCF. Effluent quality influences the alternatives available for disposal. In general, effluent reuse alternatives were based on application of reuse to poplar trees, grass for hay, pasture, green spaces, and golf courses. Because of regional cl~rrate conditions, reuse alternatives are focused primarily on application during the dry season months of June through September. Regional crops uptake the greatest amok, mt of liquid during these months. Drivers for MWMC effluent reuse include: Develop public awareness and preference for reuse - Regulatory requirements related to temperature of effluent discharge to receiving waters Increasing biosol~ds (liquid and dewatered) loading rates to land application sites Filtration improvements identified in this Facilities Plan (see Section 6.2.6) will provide 30 mgd ot filtration capacity through the design period (2025). These improvements along with 626 MWMC_6.0_I~EV1 ~ DOC 6 DEVELOPMENTAND EVALUATION OF ALTERNATIVES provisions for a disinfection system that can meet the Level IV reuse requirements will provide Level IV effluent. Current planning efforts a~e to provide 10 mgd of reuse through the design period, through phased implementation. For perspective purposes, during the maximum crop uptake (liquid) months of July and August, an est/mated 620 acres of land is required for 2.5 mgd of reuse, based on applying the reuse to grass. If reuse were applied June through September, more acreage would be required because crop water uptake during the months of June and September is almost half of the peak uptake during the months of July and August. 6.4.1 Reuse g ternatives Five effluent reuse alternatives have been developed for the application of Level II and Level IV quality effluent. These alternatives are based on developing 10 mgd of reuse within the design period. Alternative 1 - Local Reuse Demonstration Site (keve~ IV) Alternative 1 represents an initial reuse demonstration project. This alternative would provide 0.5 to 1.0 mgd of Level IV effluent reuse to pubhc areas located within a two-mile radius of the WPCF. The demonstration project would most likely supply water to park vegetation and areas with high public visibility. Assuming the reuse water were applied on grass, approximately 125-250 acres would be required during an appl/cation period of July and August. This is based on providing a daffy reuse application rate of 0.5 to I mgd. Advantages: - Provides the ability to gage pUblic reaction and receive public response from the use of reclaimed water on public areas without fully developing a Level IV reuse program * Less restrictions associated with application of Level IV reuse as compared to Level II effluent - Level IV effluent can be applied on a greater variety of sites (e.g., golf courses) than Level II effluent Disadvantages: Level IV reuse is more costly to achieve than Level II Need to develop conveyance and distribution system Study required to evaluate all potential urban reuse sites Requires significant amount of land in proximity to WWTP Requires public awareness and education program This alternative would require the installation of a UV disinfection system capable of treating the desired quantity of Level W effluent; a conveyance pipeline; and a distribution system (i.e., laterals, sprinklers, etc.). The cost assumptions for this alternative are based on identifying land within 2 miles of the WPCF, a 1-mgd UV disinfection system, and leasing a transportable, pilot filtration unit. Estimated Cost: $2,100,000 Alternative 2 - Level !1 Reuse at the Seasonal Industrial Waste Facility (SIWF) Altemative 2 is to apply Level 11 reuse on the agricultural land available at the SIWF site, which is approximately 190 acres. A reclaimed water main (RWM) is currently connected MWMC_60_RE¥11.00C 627 ~W~C FACILI-rlES from the WPCF to the SIWF. This pipeline conveys Level II plant water. Improvements to the RWM have been made such that 2,400 gpm (1.24 mgd assuming 8 hours per day irrigation) of effluent could be conveyed to the site. Assuming that grass continues to be grown at the SIWF, the net irrigation requirement is 14 inches. This corresponds to reuse of approximately 0.5 mgd in June, 0.9 mgd in July, 0.75 mgd in August, and 0.4 mgd in September, based on applying reuse 8 hours/day. Advantages: Because the RWM already extends to the SIWF, effluent can be applied at the site almost immediately Minimal financial investment , Rural SIWF site meets all Level II reuse requirements Minor/nspect/on and retrofitting of the sprinklers on the center pivots at the SIWF would be required Disadvantages: * Only provides for 0.9 mgd (maximum) of reuse This alternative would require the following modifications: rerouting of the RWM piping at the SIWF such that effluent could be applied through the center pivots, and replacement of the sprinklers on the center pivots. Estimated Cost: $400,000 Alternative 3 - Level !1 Reuse at the Bioc¥¢le Farm Alternative 3 is to apply- Level II effluent at the BF. The RWM mentioned in Alternative 2 is also routed to the BF pump station located at the BMF. At the BF pump station, effluent is blended with liquid biosolids from the FSLs and then pumped to the BF, where it is applied through hose reels to poplar tree and grass crops. In this alternative a dedicated effluent reuse pipeline would be installed at the BF, parallel to the existing biosolids irrigation pipeline. Assuming an available flow rate of 2,400 gpm, a peak application rate of 0.5 inches a day of effluent could be applied. Assuming 8 hours/day operat/on, approximately 1.5 mgd of reuse could be applied to the BP. A further evaluation between reuse and biosolids applicahon already occurring at the site is needed to ensure that the site is maximized for the biosolids application strategies outlined as part of this Facilities Plan. Advantages: Because the RWM already extends to the BMF, only the effluent irrigation pipeline would have to be constructed * Dilution of biosolids with reuse water increases the biosolids receiving capacity of the BF, thus providing additional program flexibility in the future - Uses the ball potential of the BF as a deal/cared biosolids and reuse site 6 DEVELOPMENT AND EVALUAT)ON OFALTERNATNES Disadvantages: e Only provides for 1.5 mgd of reuse The reuse irrigation system would consist of two new effluent reuse pumps (one for redundancy) located at the BF pump station, a 14-inch buried pipel/ne, and irrigation tubes on 20- to 30-foot gr/ds with microsprays on a minimum spacing of 20- to 30deer. Tb~e irrigation tubes would be connected to a sub-main manifolded off the 14-inch reuse main. Estimated Cost: $3,600,000 Alternative 4 - Level ~V Reuse Phase AIternat/ve 4 would provide approximately 1.5 mgd of additional Level Iv' effluent, for a total of 2.0 to 2.5 mgd of Level IV reuse. The implementation of this alternative would be based on the publ/c acceptance of Alternative 1, as well as general operational results. Similar to Alternative 1, the Level IV effluent would be applied to areas in proximity to the WPCF. The application area would have to be expanded. AsstLming the reuse were applied on grass, approximately 370 additional acres of lm~td would be required during an application period of July and August. This is based on providLng an additional daily reuse application rate of 1.5 mgd (2.0-2.5 mgd total). Advantages: Less restrichons associated with application of Level IV reuse compared to Level II effluent Level IV effluent can be applied on a greater variety of sites (e.g., golf courses) than Level II effluent · Provides a buffer for future effluent thermal load regulations ~ Potential to fixrther strengthen public perception of reuse Disadvantages: Level IV reuse is more costly to achieve th_an Level II Must expand the conveyance and distribution system constructed irt Alternative 1 o More public land required - Requires public awareness and education program This alternative would require the expansion of the UV disinfection system installed as part of Alternative 1, and expansion of the conveyance pipeline and distribution system. A permanent structure housing the reuse equipment at the WPCF would also be needed. The cost assumptions for this alternative are based on identifying land within 3 miles of the WPCi~, and an additional 1.5 rngd of UV dis/nfection capacity. Estimated Cost: $4,100,000 Alternative 5 - Full Scale Level iV Reuse Alternative 5 represents full development of reuse during the desigm per~od. This alternative assumes that all, or part of Alternatives 1 through 4 have been implemented. The intent of this alternative is to implement full-scale reuse of Level IV effluent. T1Ms would be accomplished through the additional application of effluent on green spaces, golf courses, and agricultural lands. 2.5- (poplars) to 5.0- (grass) mgd of reuse would be developed under MWMC FACILITIES PLAN this alternative, based on application during July and August. Approximately 450 and 1250 acres would be required for application on poplars and grass, Tespec [~vely. Implementation of Alternative 5 would provide an overall reuse (Level II and IV) production rate of 7.75- to 10.25-mgd. Advantages: · Provides for up to 10 mgd of total (Level II and IV) reuse Disadvantages: Costly Extensive amount of land required Requires public awareness and education program This alternative would require the expansion of the UV disinfection system installed as part of Alternatives I and 4, expansion of the conveyance pipeline and distribution system, and upgrade of the reuse pumps. The cost assumptions for this alternative are based on identifying land within 6 miles of the WPCF, and an additional 2.5 to 5.0 mgd of UV disinfection capacity. Estimated Cost: $9,800,000 6.4.2 Reuse Conclusions and Recommendations The following general conclusions can be made regarding reuse of effluent produced from the WPCF: Because of the regional climate, wet season reuse is not available. Dry season reuse is recommended from June through September, with the most optimal months being Jtdy and August. Local, urban reuse will provide the potential to develop public acceptance and preference of retr~e. Urban reuse will require application of Level IV effluent, w?dch is more expensive to produce than Level II. ,* The SIWF and BF are owned by MWMC and provide a combined 748 acres of land on which reuse could be applied. Application of reuse on the BF must be determined in relation to maxim2zing the biosolids application of the BF. Biosolids application at the BF is discussed in section 6.5. Based on the above conclusions, the following recommendations have been made: Develop a Level IV effluent reuse demonstration project close to the WPCF, ~tially capable of producing 0.5 to 1.0 mgd of Level IV effluent. · Assuming public acceptance of the Alternative 1 reuse demonstration project, fiarther develop Level IV reuse as identified in Alternative 4. · Proceed with Alternative 2 - use the SIWF for effluent reuse and apply on the existing grass crop. MWMC_6~REV1LDOC AND EYALUAT}ON OF: ALTERNA'~tYE$ Proceed with Alternative 3 - develop the BF for effluent reuse through the construction of a dedicated effluent irrigation pipeline and installation of irrigation pumps. If all reuse projects identified irt Alternatives 1 through 4 are successful (publicly and operationally), go forward with measures to implement Alternative 5 - full scale Level IV reuse of 2.5- to 5.0-mgd of additional Level IV reuse. 6.5 Biosolids Management Solids management Ls accomphshed through processes located at the WPCF, BMF, and Biocycle Farm. Processes located at the WPCF include two gravity belt thickeners (GBTs) and three mesophilic anaerobic digesters. Processes located at the BMF include four FSLs, three belt filter presses, and thirteen air-drying beds. The Biocycle Farm is a 595-acre dedicated biosolids land apphcation site planted in poplars and grass. Approxh~ately 7,500 acres of local cooperative farms are also available for lemd-applying dewatered biosolids. Primary clarifiers thicken settleable solids and skim fats, oils and greases. These solids are pumped to anaerobic digesters. Waste activated sludge produced in the secondary treatment process at the WPCF is thickened through the GBTs and ~s then pumped to the anaerobic digesters. Anaerobically digested sludge overflows to sludge holding tanks. Sludge holding tank solids are then pumped from the sludge holding tanks at the WPCF through a 5.5-rrdle pipehne (biosolids force main) to the FSLs at the BMF. Biosolids are discharged into the FSLs where it remains for approximately 3 years. Each year from March through September the biosohds in the FSLs are removed. A dredge ~s used to pump biosolids (stabilized sludge), out of the FSLs, where it is then dewate~ed through three belt filter presses. Dewatered biosolids are then stored in static piles in the air-drying beds where they are periodically turned and windrowed. A small portion of the annual biosolids production (less than 5 percent) is composted through aerated static piles. Beginning in July the dewatered biosolids are trucked to local cooperative farms where they are land-applied as a Class B biosolids product. Beginning in the summer of 2004 the first of three phases of development at the Biocycle Farm will become operational and will be able to receive liquid biosolids from the FSLs, as well as dewatered biosolids from the belt filter presses. MWMC also owns the 290-acre Seasonal Industrial Waste Facility (SIWF), which is located approximately I mile northeast of the BMF. The site includes a 14-acre lagoon and approximately 215 acres of farmable land. The site was originally constructed to treat industrial liquid waste. The farmable land is currently being leased to a farmer. Currently, the SIWF provides MWMC with a buffer against future regulatory, environmental, and process changes. 6.5.1 Biosolids Stabilization Processes MWMC achieves biosolids stabilization through anaerobic digestion FSLs, and dewatering (primarily mechanical). Anaerobic digestion and the FSLs are interrelated in functioning to stabilize solids through the reduction of pathogens and volatile su~pended solids (VSS). Further pathogen destruction occurs following the dewatering process when the dewatered cake is windrowed to a dry solids content of 40 to 50 percent, l~e capacities of these processes are sufficient to treat the current flows and loads seen at the WPCF. However, MWMC_60_REVI 1 DOC 6-31 MWMC FACILITIES PLAN projected flows and loads indicate that additional digestion and FSL capacity may be needed during this study per/od. The BMF historically was not able to with solids keep Lip production from the WPCF. Construction of the dewatering facility has increased biosolids processing capacity but the FSLs still have a solids inventory above optimal levels. A study has been conducted to analyze the capacity of the biosolids stabilization processes and to develop alternatives that provide the necessary capacity and optimal operating conditions. ~-l-te pr/mary purpose of sludge stab/lizafion is to reduce pathogens and vector attractions (VSS destruction) in the use and disposal of treated sewage sludge (biosol/ds). Both pathogen and vector atx~raction reduction are regulated primarily by federal requ/rements set forth in EPA's 40 CFR Part 503. Subpart D of Part 503 includes criteria to classify biosolids as Class A or Class B with respect to pathogens. These classifications are based on the level of pathogens present in biosolids that are used or disposed. Biosolids produced by MWMC's solids treamtent processes are classified as Class B. The following text will focLis on Class B products and requirements. Pathogen Reduction Pathogen reduction alternatives are identified in 40 CFR Part 503 and are intended to ensure that pathogen levels in biosolids are reduced to levels considered safe for biosolids to be land-applied or surface-disposed. To meet Class B biosollds pathogen requirements, one of the following three alternatives can be used: Alternative 1: Monitor indicator organisms. A test of fecal coliform density is required as an indicator for all pathogens. The geometric mean of seven samples shall be less than 2 million MPN (Mean Probable Nttmber) per gram of total solids. · Alternative 2: Treat biosolids in a process to significantly reduce pathogens (PSRP). PSRPs include aerobic digestion, air drying, anaerobic digestion, composting, and lime stabil~ation. · Alternative 3: Treat biosolids in a process equivalent to a PSRP. Anaerobic digestion is a PSRP as defined in 40 CFR Part 503.32(b)(3) if the solids are retained in the digesters for at least 15 days at a minimum temperature of 35 °C. Currently, MWMC's anaerobic digesters meet these cr/teria and produce Class B biosolids. The liquid biosolids are further processed in the FSLs, where additional solids stabil2ation occurs. Vector Attraction Reduction It is critical to reduce the potential for exposing hun-tans or other susceptible hosts (plants or animals) to pathogens contained in biosolids. Exposure may be initiated through vectors (flies, mosquitoes, fleas, rodents, and birds) that can potentially transm/t pathogens to humans and other hosts through physical contact or by playing a specific role in the life cycle of pathogens. Reducing the attractiveness of biosolids to vectors is regulated through twelve options identified in the Part 503 rule. The first of the twelve options ks to achieve 38 percent reduction/n volatile solids content. MWMC biosolids have consistently met vector attraction reduction requirements by achieving greater than 38 percent volatile solids reduction through both anaerobic digestion Anaerobic digestion alone achieves greater than and additional treatment the FSLs. 6-32 MWMC_60_REV11.DCC 6 DEVELOPMENT A~D EVAIUAllON OF ALTERNAtiVES 38 percent volatile solids reduction. With the comb/nation of anaerobic digestion and treatment in the FSLs, it is anticipated that VSS reduction in projected solids production through the design period will continue to exceed the 38 percent reduction requirement. 6.5.2 Anaerobic Digestion Capacity, both near- and long-term, is the primary issue to be addressed with regards to the anaerobic digesters. A lithium chloride analysis to evaluate digester capacity was conducted approximately 10 years ago. Results from the test indicated that the active volume of the digesters was 63 percent. Since that analysis, no major modifications have been made to the digesters to increase the active volume. As flows and loads continue to increase, the solids retention time in the digesters decreases. This may affect MWMC's potential to meet effluent biosolids pathogen and VSS reduction requirements. Modification of the existing digester gas rnJxing system with a pump mixing system would increase the active volume of the digesters to above 90 percent. Long-term capacity of the digesters was also evaluated. Projected upper limit flows and loads presented kt Chapter 4.0 were used to determine future capacity requirements. It was assumed that digester mixing improvements had been implemented and had improved the active volume of the digesters to 95 percent. Solids and hydraulic loading rates to the digesters were evaluated and the annual average hydraulic loading, with a 20-day solids retention time (SRT), was determined to be the limiting criteria. Figure 6.5.2-1 i~ustrates the capacity of the digesters based on processing the projected annual average flows. As seen in Figure 6.5.2-1, additional capadty is needed in approximately year 2010. The fourth digester shown in Figure 6.5.2-1 assumes a traditional mesophilic digester of the same size as the existing units. However, to provide MWMC with future biosolids flexibility, advanced digestion treatment processes were also evaluated. Alternatives were evaluated on monetary and non-monetary issues. Non-monetary issues include siting, cons~actability, performmnce, affect on downstream equipment, operat4onal flexibility, and maintenance. Processes selected for preliminary consideration were: Conventional, mesophilic digester ,, Pre-pasteurization Temperature-phased anaerobic digestion (TPAD) Table 6.5.2-1 provides a process comparison sttmmary of the three alternatives. MWMC FACILITIES PLAN FIGURE 6,5.2-1 D~gester Phasing MWMC Facl/l~es P~an, (Annual Average Cond#~ons, 20 day SR T, O, ~ 5 lb VSS/day) I ~One U~i~ Offline j 40~ .......... t .... ~ 3 D~esters ] 120,~ 140~ 1 ~, ~ 180,~ 2~,~ 220,~ Upper L~mit D~gester Influent Flow TABLE 6,5.2-1 Comparison of Digestion Treatment Processes MWMC Factltt;es Plan, Eugene-Springfield Max VSS Loading at Max Pathogen Modifications SRT at Max Operating Month (lbslft3- Level Required / New Process Month (days) Temperature day) Produced Equipment Conventional 15 Me$ophdic 0.15 C~ass B N/A (Mesophilic) (35 °C) Pre- 30 min / 15 ~70oc / 0.20 CJass A Medium Pasteurization Mesophfl~c TPAD 5 / 10 Thermophihc / 0 30 Class A (when Moderate Mesophilic Thermophilic operated m Batch or Draw/Fffl/Hold mode) 6-34 MWMC_60_REV1 ~,DOC DEVELOPMENT AND EVALUATION OF ALTERNATIVES Alternative 1 - Conventional, ~lesophilic Digester Alternative 1 consists of constructing a traditional mesophilic digester. It is likely that the anaerobic digestion process would be the typical h~gh-rate, single-stage process. Advantages and disadvantages o£ this alternaQve are listed below. Advantages: A conventional process recognLzed and £amffiar to WPCF staff Non-proprietary process Proven performance record in municipal wastewater treatment plants Operating schemes more in line with current digestion process o Most widely implemented digestion process at publicly owned treatment works (POTWs) across the U.S Disadvantages: Potential foaming problems Low volatile solids reduction compared with other alternatives May require larger retention times to achieve required volatile solids reduction · Good mixing system required to maintain active digester volume The major equipment that would be necessary under this alternative includes sludge recirculation pump(s), heat exchanger(s), a digester mixing pump(s), a digested sludge transfer pump, and hot water recircttlahon pump(s). Alternative 2 - Pasteurization Pre-pasteurization of predigested sludge involves heating raw sludge to 70°C (160°F) before transferring it to a separate holding tank, in this case one of the existing digesters. The temperature of the solids in the holding tank is maintained at a minimum of 70°C for 30 minutes. Upon completion of the pasteurization process, the temperature of the solids is decreased to 40°C (100°F) in a spiral heat exchanger and transferred to the digester. By using a sludge/sludge spiral heat exchanger, it is possible to recover greater than 50 percent of the required thermal energy prior to entering the digester. Advantages: Requires minimal solids retention time and also provides Class A biosolids that satisfy regulatory requirements Although more heat is required and higher heating costs are incurred, this process has been reported to recover over 50 percent of the thermal energy May improve dewatering characteristics · Greater flexibLlity in reverting to mesophilic operations because thermophilic organisms do not need to be developed Abil/ty to meet vector attraction reduction (VAR) requirements, when combined with anaerobic digestion · Small reactor is required ahead of the existing digestion process · Public recognizes the "pasteurization" term and, therefore, public education and acceptance may be easier IVIWMC_60_REVI 1 DOC 6-35 ~MC FACILFrlE$ PLAN Disadvantages: There are few pasteurization treatment systems operating in the U.S. Pre-pasteurization systems have been installed in Perris, CA; Franklin Township, PA; and Cannel, IA; and* one is under construction in Alexandria, VA. Fouling tendencies in sludge-sludge heat exchangers Production of odorous air Does not provide additional VSS destnaction or volume reduction If heat is not recovered, then energy requirements are bigh The major components associated with pre-pasteurization include sludge/sludge heat exchangers for pre-heating undigested sludge and for recovering heated digested sludge, hot water heat exchangers for primary sludge heating, pasteurization tank(s) (three small tanks are commonly used to maintain a batch process: fill, hold, and draw pasteurization cycles), mesophilic digester, and recycle and transfer pump. Site-specific issues associated with the implementation of pre-pasteurization at the WPCF are as follows: New pasteurization tank(s) wotdd be needed prior to sludge entering the digester(s). The tank(s) would need volume for 30 minutes of theoretical SRT. This detention time is equivalent to 6000 gallons of storage (based on 2025 WWMM flows), or 1500 gallons per mesophilic digester. Typical pasteurization processes use three pastem4zation tanks (fill, hold, and draw cycles). New hot water heat exchangers will most likely be needed. Undigested sludge must be heated to 70°C (160°F) prior to entering the pasteurization tank(s). Further evaluation of the heat exchangers is needed. New boilers may be needed to supply the necessary hot water to the exist'Lng heat exchangers. Further evaluation of the boilers is needed to determine ff they can supply enough hot water to increase undigested sludge to pasteurization temperatures. New sludge/sludge heat exchangers are needed. These will serve as pre-heat treatment to the hot water heat exchangers and in recovering heat from the heated sludge after the pasteurization process. A fourth mesophilic digester, similar in size to the existing three units, would be installed. o The existing digestion system, would remain unchanged. Mesophilic digestion would still occur. New instrumentation and controls (I&C) would be needed for the pasteurization tanks and heat exchangers. Longer-term, new I&C would be needed with the construction of the third digester. If the pasteurization process were immediately implemented, it could be fully automated. Plant staff would be able to monitor and operate the process in one shift per day. With future facility modifications, the process would remain automated. 5-36 ~WMC_60_REVll DOC DEVELOPMENT AND EVALUATION OF ALTERNAlqVE$ Alternative 3 - Temperature-Phased Anaerobic Digestion (TPAD) TPAD is a two-step process in which a small thermophihc digester ~s followed by a large mesophilic digester. Typical retention time requirements are 5~day thermophilic and 10-day mesophilic. The majority of pathogen destruction and solids treatment occurs in the first digester, including volatile solids deskruction reported to be 80 to 90 percent, and greater methane gas production. Additional pohshing, deodorizing, and sludge conditioning for subsequent dewatering occurs in the second digester. Advantages: Digester volume reduction can be achieved through higher loading (higher concentration and lower retention t/me). Less capital expense (lower digestion capacity required) than other advanced digest/on processes. Currently being used/n the U.S. Four operating plants that have converted to TPAD from convent/onal digesters include Newton, IA; Sturgeon Bay, WI; Omaha, NE; and Mobile, AL. Additional plants in Waterloo, IA; Mason Farm, NC; Neenah-Menasha, WI; and Independence; IA have recently been constructed. e Relatively sLmple to modify an existing mesophihc digestion process. · Increased volat/le sohds reduction and greater methane gas production. Disadvantages: - The main disadvantage of the TPAD process is that it is not a Process to Further Reduce Pathogens (PFRP) (Class A process) and will require Class A verification by EPA Process is patented (patent held by Iowa State University) Sludge-sludge heat exchangers are required Increased production of ammonia in sidestream (from higher VSS destructaon) Holding tank for undigested sludge requires odor control The major components associated with the TPAD process include thermophilic (5-day minimum SRT, typical) and mesopt'dlic (10-day minim~ SRT, typical.) digesters, sludge- sludge heat exchangers for pre-heating undigested sludge and for recovering thermophilically heated digested sludge, hot water heat exchangers for pr/maW sludge heating, and recycle and transfer pumps. To convert TPAD to a Class A process, the draw/fill cycles need to be discontinuous for the thermophilic reactor (between ~ - and 1-day gap in feed and withdrawal cycles). A holding tank (1-day retention time) prior to digestion is required to achieve batch feeding. To improve destruction of pathogens, Infilco Degremont, Inc. (IDI) has developed and pilob tested a variation of the TPAD process at the Belmont wastewater treatment plant (WWTP) m Indianapolis, IN. This variation is in the operation of a thermoph/lic first-phase reactor in a draw/fill mode with four feedings per day. Site-specific issues associated with the/mplementafion of TPAD as a Class A treatment option at the WPCF are as follows: MWMC_60_REVI 1 DOC 6-37 MWMC FACILITIES PLAN New hot water heat exchangers will be needed. A typical TPAD process requires undigested sludge to be heated to 54°C (130°F) prior to entering the thermophilic digester. Further evaluation of the heat exchangers is needed. New boilers may be needed to supply the necessary hot water to the existing heat exchangers. Further evaluation of the boilers is needed to determine if they can supply enough hot water to increase undigested sludge to thermophilic temperatures. New sludge/sludge heat exchangers are needed. These will serve as pre-heat treatment to the hot water heat exchangers and in recovering heat from the heated sludge after the therrnophilic retention time. · Four new 5-day SRT thermophilic tanks and one mesophilic tank would be constructed, The existing digesters could be used in the TI>AD process (they would serve as the mesophilic tank). Volume required for thermophilic digestion would need to be 1.4 MG (based on 2025 W~VMM flows), or 354,000 gallons per tank (based on four tanks). The new mesophflic digester would be the same size as the existing digesters. · I&C modifications would be required. Recommendations Table 6.5.2-2 presents a preliminary project cost and non-monetary comparisor~ between the alternatives. Costs are based on industry averages for treatment plartts of a size similar to the WPCF. TABLE 6.5.2-2 Digestion Alternabves Cost Comparison MWtt4C Facilltles Plan, EugeneoSprinCeld Project Cost Process (millions of dollars) Non-Monetary Rating(~) Mesophllic Digeshon $5-$6M 21 TPAD $11 -$13.5M 21 Pre-Pasteunzation $13,5-$16M 16 Maximum possible score ot 30 points As can be seen ~rom Table 6.5.2-2, construction of a conventional mesophilic digester has the lowest project cost and is the same as TPAD for the highest non-monetary rating. The primary reason for the high non-monetary rating is that the process performance is well- known and Eugene operational staff are accustomed to operating and maintaining digesters of this type. Pre-pasteurization has the highest project cost and ~te lowest non-monetary rat/rig. However, the thermophilic pasteurization tanks are much smaller (6,000 gallons versus 354,000 gallons) than those required for TPAD operation and siting may be easier. TPAD has the second highest project cost and is the same as mesophilic digest/on for the highest non-monetary rating. The benefits that TPAD provides, when considering the issues associated with downstream processes (VSS loading on the FSLs), makes this alternative attractive for achieving long-term goals of meeting solids stabilization requirements with MWMC_60~REV11.DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES the potential of not having to construct a fifth FSL. Consequently, to provide for future flexibility of solids at the WPCF, both pasteurization and TPAD should be considered and evaluated further. 6.5,3 Facultative Sludge Lagoons Futttre capacity a2~d reduction of the current overloaded solids inventory are the primary issues that alternatives should address with regards to the FSLs. Capacity - VSS Loading Projected upper limit flows and loads presented in Chapter 4.0 were used to determine future capacity requirements for the FSLs. It is conservatively assumed that a fourth mesophilic digester will be online between 2010 and 2012 and that ~e digested sludge contains 63 percent VSS. ~s value is based on the an2ual average VSS content of digested sludge over the past 3 years. Figure 6.5.3-1 illustrates the phasing chart for the FSLs based on the design criteria of 25 lbs VSS/1000 sf-day. As seen in Figure 6.5.3-1, additional FSL surface area is needed in year 2015. ~is aisc accotmts for the current operational procedures of taking one FSL offline for approximately 6 months during the FSL harvesting season. ~e additional FSL voh~e added in 2015 assumed either construction of a new 5- acre FSL, or using the existing 14-acre lagoon at ~e SIWF. FIGURE 6.5.3-1 Facultat~ve Sludge Lagoon Phasing MWMC Fac~l#/es Plan, Eugene-Spnnheld (~nual Average Cond~ns, 25 lbs VS~IO00 sfi~y loading) ~ ~ 4 Ex*s~mg Lag~ns + ~ ~ SIW (14 acres) ~ 17~ .... 5~ o 2~5 2010 2015 2020 ~5 Year Increased VSS loading to the FSLs may result in increased odors and may also affect the FSLs' ability to achieve the regulatory requirement of an overall plant VSS reduction of 38 percent. However, MWMC has consistently exceeded the 38 percent VSS reduction MW~C_60_REV11,DOC 6-39 FACILITIES PLAN requirement in the anaerObic digesters alone. Providing additional volume through either construction of a new FSL or using the SIWF lagoon is based on meeting the VSS loading design criteria at the current projected flows and VSS loads to the existing FSLs. If the fourth digester uses an advanced digestion process, the VSS loading to the FSLs w/Il be less than the current projections. At rids time it appears most likely that a fifth FSL will not be needed within the design period. There are several reasons for this assumption. The first is that overall plant VSS reduction requirements are likely to be achieved even ff VSS loading to the existing FSLs exceeds design criteria. The second is that digester mixing improvements will increase active digester volume and further improve VSS destruction. The third ks that the fourth digester (constructed between 2010 and 2012) may use an advanced digest/on process that will improve reduction in VSS loads to the FSLs. Based on the phasing Shown irt Figure 6.5.3-1, there will be 3 to 5 years between construction of the fourth digester and when a fifth FSL ks required. Solids Inventory Currently, the solids in the FSLs are processed through mechanical and passive dewatering processes. Mechanical dewatering is accomplished through three 2-meter BFPs. Passive dewatering is accomplished using thirteen air-drying beds. Mechanical dewatering is the primary processing method. The FSLs are harvested seasonally, typically from March through September. Beginning in February, one FSL is taken offline to provide a minimum of thirty days residence time before harvest. Beginning in March a dredge is used to pump solids from the FSLs into two 370,000-gallon mix tanks that then feed the BFPs. Dewatered cake is then placed in windrow piles in the air drying beds where it is further dewatered to approximately 40 to 50 percent solids. In rrdd-summer the windrowed piles are trucked to local cooperative farms for land application. Solids (digested sludge) sent to the FSLs year- round exceed the seasonal capacity of the dewatering processes, based on current operation, thus leading to increased inventory. As the solids inventory in the FSLs has increased to levels above typical operating conditions, the increase in the FSL solids blanket has decreased the water cap on the FSLs. The water cap helps to control odors in the FSLs by decreasing the potential for tttm over of the solids blanket. Turn over occurs when the upper layers of the solids blanket become warmer than the bottom layer and the organic material in the bottom layer flips with the warmer upper layer. This flip (tltrn over) brings anaerobic organic material from the bottom to the top and resrflts in the release of odorous fumes. Maintaining a water cap depth greater than the solids depth helps to control the temperature of the solids layer beneath and, therefore, odors. On-site staff have recognized the increased solids inventory and they have anticipated that the solids inventory would be reduced once the BF Phase I came online in the smm~er of 2004. Recommendations for future operating strategies to reduce the solids inventory in the FSLs are discussed below. Recommendations At this time the need to construct a fifth FSL by a specific year is not recommended, nor is it expected that a fifth FSL will be needed within the design period. It is recommended that 6 DEVELOPMENTAND EVALUATION OFALTERNATIVES FSL VSS loading rates be closely monitored as upstream process improvements and additions are implemented. With Phase 1 of the BF becoming operational in the summer of 2004, the future recommended operating strategy for processing solids/n the FSLs shotdd be as follows: , Apply 1/quid biosolids from the FSLs to the BF at the maximum non-irrigated capacity of the BF Dewater biosolids in the BFPs on a reg~ztlar operating schedule, from March through September Key elements of this operating strategy are listed below: Biocycle Farm 165 acres will be available in Phase 1, to be online Lq the summer of 2004 - 130 acres will be available in Phases 2 and 3, to be online in 2006 and 2008, respectively The BF is assumed to be non-irrigated Belt Filter Presses - Operation: March through Septeraber, 12 hrs/day, 5 days/week, ail units online approximately 85 percent of the time BFP pressate recycle is 42.5 million gallons (MG)/year to the FSLs, with 300 gallons per minute (gpm) of washwater Facultative Sludge Lagoons Solids are harvested at approximately 3 percent dry solids The current solids depth is approximately 10 feet (72 MG) ,, The optimal depth of the solids blanket is 6 feet Normal total operating depth is 13.5 feet (102 MG) Annual precipitation is 44 inches (29.9 MG/year) Annual liquids evaporation is 35 inches (23.8 MG/year) A maximum of 206 MG of supematant can be pumped from the FSLs; however, typical operation is most likely to be 100 MG/year Graphical results of this operating strategy are shown in Figure 6.5.3-2. As can be seen from Figure 6.5.3-2, the solids inventory could be reduced to art optimal solids depth of 6 feet (41 MG) between ),ear 2006 and 2007. This assumes that the operating conditions listed above are followed. Reducing the solids inventory in this time frame would require the dredge pump to operate at a maximum pumping rate of less than 600 gpm. The dredge has a capacity of 2000 gpm. Capacities for the dewatering equipment and the BF are listed in section 3.2.2 in Chapter 3.0. MWMC_60_REV11 DOC 6--4I MWMC FACILITIES PLAN FIGURE 6,5.3-2 Facultative Sludge Lagoon Sol~ds inventory MWMC Facda~ee Plan, Eugene-$pnngheld (Annual Average Condlt¢ons, BFP and BF Operation) t00 - ~ - 220000 80 ......... ~_~ ~ ~ _ ~ ~_~OptlmalFSLSol~dslnvenlo~O'Dep~(41MG)~ ~ ~ ~ 2~3 2~8 20 i 3 2018 2023 6,5.4 Biocycle Farm Land Application Alternatives MWMC biosolids disposal methods have traditionally involved the land application of dewatered biosolids on local cooperative farms. Approximately 7,500 acres of land is available as part of the cooperative farm program. To expand their biosolids application program, MWMC purchased a $96-acre parcel of land adjacent to the BMF with the intent that the site would be developed to land- apply dewatered and liquid biosolids and effluent on poplar trees and grass hay. The site is referred to as the Biocycle Farm (BF). The BF will initially be planted with grass and poplars and will be phased in over the next 6 years, as h'~dicated in Table 6.5.4-1. The poplars will be developed in six management traits (MU) and harvested on 10-year cycles. The first phase, scheduled to become operational in the summer of 2004, consists of the distribution system installation (pipelh~e, hose reels, and pump stations), and site preparation and tree planting in MU1 and MU2. Additional hose reels (two for each additional phase) will need to be purchased as phases 2 and 3 come online; however, the pipeline and pump stations installed as part of Phase 1 will satisfy buildout conditions for the entire BF. 6-42 MWMC_6,0_REVt ! OOC 6 DEVELOPI~ENT A~D EVALUATION OF ALTERNATIVES TABLE 6,5.4-1 Biocycle Farm Management Unit Acreage and Planting Schedule MWMC Facilities Plan, Eugene-Springfield Management Units Type Acres Planting Date Replanting Date MU 1 & MU 2 Non Buffer 165 2004 2014 MU 3 & MU 4 Non Buffer 130 2006 2016 MU 5 & MU 6 Non Buffer 130 2008 2018 All MU Buffers 84 NE Corner field Buffer "Type" 48 Application(a) TOTAL BUFFER AREAS 132 TOTAL NON-BUFFER AREAS 425 Notes a Although the comer lot is not a buffer area, ~f used in the future it would only receive dewatered biosolids, because of access difficullies, As seen in Table 6.5.4-1, 425 acres are available for land application of liquJd biosolids. The remainder of the BF is comprised of: Roadways - approximately 23 acres Non-developed NE corner - approximately 48 acres Feed store - approximately 16 acres Buffers - approximately 93 acres The BF biosolids capacity is related to three components: the amount of land developed for land application, the type of product applied (effluent, liquid or dewatered biosolids) and the crop mix. The capacity of the BF will vary over the years as the mix of grass and poplars (young and mature) evolves. There are two mare alternatives that exist at the BF, both relating to the total capacity the BF can receive. Alternative 1 - Operate BF as a Non-Irrigated Land Application Site Operating the BF under Alternative 1 represents the "no action" alternative. Under this alternative biosolids could be applied to the BF at the capacities shown in Table 6.5.4-2. TABLE 6.5.4-2 Biocycle Farm Alternative 1 Capacity (dry tons) MWMC Facilities Plan, Eugene-Springfield Liquid Biosolids on Dewatered Biosolids on Non-Buffet Areas Buffer Areas Year (425 Acres) (132 Acres) Total 2005 1609 612 2221 2010 2228 675 2903 2015 1868 612 2480 ~V~MC_60_REVll DOC 643 MWMC FACILmES PLAN Bi0cycle Farm Alternative 1 Capacity (dry tons) MWMC Facilities Plan, Eugene. Spnngfield Liquid Biosotids on Dewatered Biosolids on Non-Buffer Areas Buffer Areas Year (425 Acres) (132 Acres) Total 2020 2228 675 2903 2025 2128 612 2740 The majority of the costs associated with Alternative 1 have already been absorbed in the purchase of the land, installation of the distribution pipeline, construction of the BF pump station (under construction), and the purchase of four hose reel application systems. Future costs under this alternative include development of Phase 2 and Phase 3 expansions, and are l~sted in Table 6.5.4-3. TABLE 6.5.4-3 B0cycle Farm A~temative 1 Cost Estimate MWMC Facilities Plan, Eugene. Springfield Capital Cost Expansion Phase item (2004 $) Phase 2 Site preparation of 130 acres $300,000 Purchase 2 hole reels $110,000 Phase 3 Site prepara[ion of t 30 acres $300,000 Purchase 2 hole reels $110,000 ~roTAL COST $820,000 Alternative 2 - Operate BF as an Irrigated Land Application Site Alternative 2 rel>resertts operating the BF as an Lrrigated land alppl/catior~ site. The t>rimary benefit of this alternative is that a greater amount of biosolids (liquid and dewatered) could be applied to the site. Under this alternative biosolids could be applied to the BF at the capacities shown in Table 6.5.4-4. TABLE 65.44 Biocycie Farm Alternative 2 Capacity (dry tons) MWMC FaclTities Plan, Eugene-Springfield Liquid Blosolids on Dewatered Biosolids Non-Buffer Areas on Buffer Areas Year (425 Acres) (132 Acres) Total 2005 1880 824 2704 2010 2561 905 3466 644 MWIVtC_60_REV1 ~ DOC § DE~/ELOPMENT~ND EVALUATION OFALTERNATh~ES TABLE 6.5.4-4 Biocycle Farm Alternative 2 Capacrb/(dry tons) MWMC Facilities Plan, Eugene-Springfield Liquid Biosolids on Dewatered Biosolids Non-Buffer Areas on Buffer Areas Year (425 Acres) (132 Acres) 1total 2015 2165 824 2989 2020 2561 905 3466 2025 2451 824 3275 As seer, in Table 6.5.4-4, Alternative 2 provides an average of 17 percent more capacity than Alternative 1. Similar to Alternat4ve 1, the majority of the costs associated with Alternative 2 have already been absorbed in the purchase of the land, installation of the distribution pipeline, construction of the BF pump station (under construction), and the purchase of four hose reel application systems. However, Alternative 2 contains the future additional cost of installation of a dedicated irrigation pipeline. Table 6.5.4-5 lists the major costs associated with Altemative 2. TABLE 6.5.45 Biocycle Farm Alternative 2 Cost Estimate MWMC Facilities Plan, Eugene-Springfield Capital Cost Expansion Phase Item (2004 $) Phase 2 Site preparation of 130 acres $300,000 Purchase 2 hole reels $110,000 Phase 3 Site preparation of 130 acres $300,000 Purchase 2 hole reels $110,000 TBD Dedicated irrigation pipeline $1,500,000 TOTAL COST $2,320,000 The dedicated irrigation system would consist of irrigation tubes on 20- to 30-foot grids with microsprays on a minimum 20- to 30-foot spacing. The irrigation tubes would be connected to a submain manifolded off of a 14-inch buried pipeline. There are several advantages to building a dedicated irrigation pipeline. The system wotad provide a more efficient irrigation application and increase the biosolids receiving capacity at the site. The pipeline would also reduce the labor requirements associated with current h'rigation methods. Thus, better application, less labor, and less money toward labor associated with moving hose reels would result. MWMC_60_REVll DOC 6~45 MWMC FACILITIES PLAN Biocycle Farm Alternative Recommendation The BF is a valuable asset to MWMC's biosolids application program. As shown above, modifications could be made to the BF to provide even greater biosolids receiving capacity. As shown in section 6.5.3, however, the BF as a non-irrigated land application site provides enough capacity to reduce and maintain solids inventory in the FSLs throughout the design period. Similarly, Lhe reduction in labor costs associated with Alternative 2 do not appear to outweigh the increased cost in installing a dedicated irrigation system. Consequently, it is recommended that Alternative 1 be carried for-ward. 6.5.5 Seasonal industria Waste Facility Alternatives The SIWF is a 290-acre site with 190 acres of irrigated cropland and 25 acres of non-in'igated cropland. The total farmable area is approximately 215 acres. The site is located approximately I mile from the BMF and 5 miles north of Eugene. It is currently developed with three 60-acre circles and one 16-acre circle of grass. The irrigation system consists of 1996 Pierce center pivots. A 14-acre, 57-MG storage lagoon is also located at the SIWF site. The lagoon no longer receives influent cannery waste but still contains residual waste from prior years influent. Potential future uses for the lagoon include effluent equalization/storage, BFP filtrate storage, and FSL supernatant equalization/storage/treatment. The SIWF was bt~t in 1983 to avoid introducing high-strength organic waste loads into the WPCF on a seasonal basis. Since the purchase of the land by Eugene-Springfield, the SIWF has not been used for any land application or liquid storage of non-carmery wastewaters, as the site has been dedicated solely to irrigation of cannery wastewater. The land has been leased to a farmer and forage producer to ensure that the site is continuously farmed using sound farm management practices. The land is leased for $6,450 per year. Alternatives for future use of the SIWF have been evaluated. These alternatives include: Alternative I - Continue to lease the SIWF and not develop the site further (No Action) - Alternative 2 -Selt the land Alternative 3 - Convert the 14-acre lagoon at the SIWF into a fifth FSL Alternative 4 - Land-apply effluent and biosolids at the SIWF without upgrading the lagoon {assumes that no upgrade of the lagoon will be required) Alternative 1 - No Action, Continue to Lease the SIWF Alternative 1 consists of not developing the SIWF and continuing to lease the land. Advantages and disadvantages of this alternative are listed below. Advantages: e This alternative provides a small annual revenue from leasing the land ($6,450) e Maintains ownership of the SIWF for future use Disadvantages: Not a profitable alternative for MWMC if the ex~sting permitting structure is maintained. The existing cost for a 5-year NPDES permit for the SIWF is $11,500. 6-46 MWMC_6,0_REV11 .DOC 6 DEVELOP)&ENTAND EVALUATION OF ALTERNA'flVES It would be financially beneficial to investigate adding the SIWF to the WPCF's NPDES permit to decrease annual permit costs. The cost-benefit analysis for this alternative is presented in Table 6.5.5d. Alternative 2 - Sell the $1WF Alternative 2 is to decommission and sell the la_nd. Advantages and disadvantages of this alternative are lksted below. Advantages: Selling the SIWF would avoid the capital costs associated with the/rdrastructure on site Eliminates annual O&M costs Would eliminate future site liability Revenue could hand other costs Disadvantages: Lose a potentially valuable asset (land and existing facilities) ~elated to the overall long- term strategies of IVFNMC's biosolids and effluent reuse program, as well as to potential regulatory changes. To receive the highest possible value for the site, decommissioning efforts will be required. This is based on selling the land as it is currently zoned (E-30, exclusive farm use). , Availability and proximity of land, if required in the future, may be scarce commodities. · Future cost for development of a site similar to the SIWF will be great. Alternative 3 - Convert the 14-acre Lagoon at the $1WF into a new Facultative Sludge Lagoon Alternative 3 consists of upgrading the S1WF lagoon to a new FSL. Under this alternative, liquid biosolids could be applied on site. It is also assumed that bmsolids, if applied at the SIWF, would be applied on grass crops at the SIWF and that the existing land 1ease agreement would remain in place. The SIWF lagoon would become the fifth FSL. Advantages and disadvantages of thks alternative are listed below. Advantages: Provides additional sludge stabilization and solids storage, which rnay be needed in the future · Continued leasing of the land for local farming activity ensure that the site is continuously farmed using sound farm management practices · Maintains flexibility in MWMC's biosolids management program Disadvantages: The FSL would be remote from the other four FSLs located at the BMF Piping intercormections and primping facilibies would need to be h~stalled between the SI-WF and BMF · Potential for increased complexity of control strategies ,~ O&M ks remote from the BMF facilities MWt~3_6 O_RE'Vi 1,DOC 6-47 ~WMC FACILITIES PLAN · Increased risk associated with potential groundwater contamLnation if lagoon liner failed - Conversion to FSL could require complete relining of lagoon As mentioned above, the conversion of the S1WF lagoon into a fifth FSL would provide the FSL capacity needed by 2015. This assumes that future modifications and additions to the digestion process at the WPCF do not decrease the VSS loads to the existing FSLs. The FSL conversion would require cleaning out the SIWF lagoon and repairing the liner ~f an inspection showed signs of leakage. An equipment inventory and condition assessment would also be required. For comparison purposes, the estimated cost to construct a new FSL is approximately $2 million. This assumes that 10 acres of new land (agriculturally zoned) can be purchased for approximately $50,000/acre. This does not include additional mechanical costs (piping and pumping) to connect the FSL to the existing FSLs. Under this alternative the following modifications would be required: A tee and an 8-inch pipeline off of the existing 8-inch biosolids force main that conveys digested sludge from the WPCF to the BMF. This extension would serve the dual purpose of conveying liqtud biosolids to the SIWF and back from the StWF to the nuxmg tanks, if required. It is assumed that the existing digested sludge pumping capacity at the WPCF would be sufficient to convey digested sludge to the SIWF lagoon. A pump station would be required to pump liquid biosolids from the SIWF lagoon to the mixing tanks at the BMF. A 10-inch pipeline and pump station to convey supernatant overflow from the SIWF lagoon to the existing collection system. · An optional pipeline and pump station to convey filtrate from the BFPs at the BMF to the SIWF lagoon. Further analysis of this option would be recommended if this alternative were selected. For cost purposes, a filtrate flow of 500 gpm and pipeIine diameter of 6 inches were assumed. In this alternative, MWMC could either continue to lease the SIWF for farming activity, or develop the site to apply liquid biosolids and/or supernatant and effluent. If s-upernatant and/or effluent were applied on the SIWF land, the exist~mg center pivots would require retrofitting the sprinklers on the center pivot to allow for irrigation of this material. The site may require a pump station and hose reel system or other irrigation system if liquid biosolids were to be applied. Biosolids could alternatively be land applied by truck. This alternative would provide a source of supernatant and liquid biosolids at the SIWF for effluent and biosolids reuse on the 215 acres, as well as a convenient "lower-cost" location for future biosolids overflow/storage. This alternative appears to be attractive with regards to MWMC's long-term biosolids and effluent reuse program. Alternative 4 - Use the SIWF for Biosolids and Effluent Reuse Alternative 4 represents using the SIWF for biosolids and effluent reuse only. It is assumed that biosolJds and/or effluent reuse would be applied on grass crops at the SI~/F and that 6.-48 UWMC_6,O_REV11,00C 6 DEVELOPMENTAND EVALUATION OFALTERNAT~VES the land lease agreement would remain in place. Advantages and disadvantages of this alternative are listed below. Advantages: o Reclaimed water main already constructed to the SIWF Lowest cost alternative for beneficially using the SIWF Provides MWlvIC with a readily available effluent reuse location Maintain small revenue source through lease agreement Disadvantages: Costs associated with modifications and equipment required to apply liquid biosolids to the site The fact that the reclaimed water main from the WPCF is connected to the SIWF makes this an attractive alternative. Effluent could be applied at the SIWF with minor ~_spection and retrofitting of the sprinklers on the center pivots. This cost is estimated at approximately $2,000 per pivot. Liquid biosolids from the BMF could also be applied to the SIWF with relatively minor piping/equipment additions. Applying liquid biosolids from the BMF to the SIWF would require the following improvements/modifications: , A new pipeline from the BF pump station to the SIWF that would convey liquid biosolids. It is assumed that the existing liquid biosolids pumps would have enough capacity to pump to the SIWF. · A hose reel system with distribution pipeline. The onsite distribution system would consist of three hose reels to spread the liquid biosolids on poplars or grass. · A booster pump station to distribute biosolids to the hose reels. Alternatives Cost Comparison Table 6.5.5-1 provides a cost esFnnate comparison between alternatives. The net cost presented in the table is the difference between revenue and cost. TABLE $.5.5-1 Alternatives Cost Benefit Comparison MWMC Facil[ties Plan, Eugene-Spnngfield Alternative Revenue Cost Net Cost Comments Alternative 1 $6,450 $11,500 ($5,050) only 1 year of annua~ costs No action - continue to lease the SIWF Alternative 2 $2,030,000 $300,000 $I,700,000 excludes site replacement cost; Sell the S]WF assumes $7K/ac; 6% c~osing costs and decommissioning DOC ~4~ MWMC FACILITIES PLAN TABLE 6.5.5.1 Alternatives Cost Benefit Comparison MWMC Facilities Plan, Eugene-Springfield Alternative Revenue Cost Net Cost Comments AJternafive 3 $6,450 $2,200,000 ($2,193,550) capita~ costs onJy- does not Convert the 14-acre include annual O&M costs lagoon at the S1WF into a new FSL Alternative 4 $6,450 $1,400,000 ($1,393,550) capita~ costs only - does not Biosolids and Effluent include annual O&M costs Reuse only. Conclusions and Alternative Recommendation The SIWF provides long-term program flexibility for IVIWMC's biosolids and effluent reuse program. General conclusions regarding the SIWF can be grouped into three categories: ,, Financially - the prox~nJty to the BF and BMF and the value of the land will help reduce costs in the future for any expansion of the current [-reatment and reuse program. e Politically - the current program and facLlities are accepted by the surrounding community. Siting and construction at another locatiov, will likely incur additional regulatory costs and obstacles. Strategically - the SIWF lagoon can provide additional storage for sludge, effluent, or supematant as these needs occur in the future. The land itself offers a signLficant buffer capaczty and a strategic location for reuse of effluent, biosol~ds, BFP pressate a_qd/or supernatant. Based on the above cor~ch, zsions and the previous dLscrtssion of the alternatives, the following recommendations have been made: ,, Selling the land Ls not recommended. Alternative 4 is the preferred alternative. A reclaimed water pipeline is already in place, and with fairly mia~,imal additional investment it could receive effluent. The secondary option within fids alternative is to implement the modifications that w~ also allow the site to receive liqrdd biosolids. Dewatered biosolJds could also be applied to the site at any fuVare t~ne. ,, At a minimum, I¥~VMC should continue to lease the land and attempt to reduce its permitting fees at the site to make the lease more profitable. Because the need J[or effluent or liquid biosohds storage is not currently required based on other analyses, upgrading the FSL for storage purposes is not recommended at this 6-50 ~W~C_6 0_REV~ 1.DOC 6 DEVELOPMENT AND EVALUATION OF ALTERNATIVES - Does not preclude conversion of the existing lagoon for additional FSL space in the future. 6.6 Development and Eva uation of System Alternatives The Oregon DEQ has mandated el/ruination of SSOs resulting from less than a 5-year, 24- hour rainfall event ha the wet season and a 10-year, 24-hour rainfall event in the dry season [OAR 340-41-0009 (6) and (7)].This nde will take effect by the year 2010. Influent wastewater flows up to these quantifies will be required to be treated to a level so that the effluent meets secondary treatment standards. The projected 2025 PWWF at the WPCF that is being used for planning purposes is 277 mgd. Collection system modeling efforts and studies have concluded that peak flows could be conveyed by the collection system to the WPCF. Once flows have been conveyed to the WPCF, significant modifications to the facility would be required to treat the PWWF flow. 6.6.1 Common Parameters Several improvements will be constructed/ndependent of the system alternative ultimately implemented, because they serve multiple benefits (e.g., ammonia removal, dry season mass limits, etc.) and/or they will still be required for all peak flow management alternatives. These improvements include enhancements to the existing primary and secondary darifiers, additional secondary clar~iers, new tertiary filters, expansion of the pretreatment facil/ty, primary sludge thickening, a new high-rate disinfection facility, a new effluent blending structure, new thermophilic digesters (or other digestion process to produce Class A biosolids), WAS thickemng facility expansion, odor control facilities, and reuse disinfection with UV. Only System Alternative I will not include implementation of these common improvements. All system alternal4ves assume the capacity of the existing four primary ctarifiers would be increased to exceed 160 mgd by adding energy dissipating inlets, flocculation feed wells, density current baffles, and by operation without a sludge blanket. All system alternatives also include an increase in secondary treatment capacity to 165 mgd by enhancing secondary clarifiers, modifying the aeration basins to a step feed configuration with anoxic selectors, and by constructing two additional secondary clarifiers. The evaluation was performed assuming that future permits would not include an increase ha allowable TSS and CBODs effluent mass limits. 6.6.2 System Alternatives Development Many alternatives were considered in develop/rig system alternatives. Previou~s sections of Chapter 6 and technical memorandums developed for the Fac/liPy Plan update deta/l alternatives analysis for trait processes in order to treat the projected peak week wet weather flow (PWWWF). The system alternatives proposed in this section focus on the treatment alternatives required to treat the entire PWWF flow to secondary treatment standards. The proposed system alternatives use a combination of pretreatment, prknary treatment, secondary treatment, and tertiary filtration in conjtmction with high-rate disinfection and MWMC_§ O_REVI ~.DOC 6-5'J MWMC FACILiTiES PLAN effluent blending to treat the peak flows. Current effluent blending policy is st~ evolving; however, system alternatives 3, 4, and 5 assume that some level of effluent blending will continue to be an acceptable approach for treating PWWFs. For alt alternatives it has been assumed that the existing primary clarifiers and secondary treatment have been modified to treat a peak flow of 165 mgd. An addiQonal 112-140 mgd [277 mgd (or 300 mgd to account for uncertainty) less 165 mgd] of treated flow must be combined with the secondary effluent flow of 165 mgd from the existing facilities, and the combined flow must be blended to meet the exist-lng NPDES permit requirements and secondary treatment standards. Prescreening of system alternatives led to the development of five system alternatives: 1) no action, 2) addition of primary and secondary treatment, 3) addition of primary clarifiers, 4) use of high-rate clarification, and 5) parallel primary and secondary treatment. System Alternative 1 - No Action Alternative No hnprovements would be made for system alternative 1. The ex~sting W?CF £acflities would continue to operate with no increase ~ system capacity. Upgrades and replacement of fadlities and equipment would occur under normal maintenance with no major expansion or improvements. Although modifications could result in greater efficiencies and higher treatment capacities, the projected PWWF flow of 277 mgd would exceed the existing capacity. System Alternative 2- Additional Primary and Secondary Treatment and Disinfection Four new primary cladfiers, one new aeration basin, and six pew' secondary cb. riflers would be constructed to provide another primary and secondary treatment train used in conjunction with existfl~g treatment facilities to treat the entire 277-mgd PWWF. Pretreated effluent in excess of 134 - 165 mgd would be split to the new treatment train. Primary influent flow would be split with a new primary influent splitter box and would flow by gravity to both the new and existing primary clarifiers. After d/sirffection, SE from new and exist/ng treatment tra]_ns would be combined at the blending box prior to discharge into the Willamette River. This alternative would be required if a "no blending" policy was adopted by DEQ or imposed by EPA. System A~ternative 3- Additional Primary C~adfiers Four new primary clarifiers would be constructed and used in conjunction with the existing primary clarifiers to treat the entire 277-mgd PWWF. Pretreated effluent in excess of 134 - 165 mgd would be split to the new primary darifiers and PE would be combined. PE in excess of 134- 165 mgd would be diverted around the secondary treatment system. Tb_e primary and secondary effluents would be disinfected separately and blended prior to discharge to the river. This system alternative essentially continues MWMC's current approach to accommodating peak flows. Figure 6.6.2-1 shows the process flow schematic for system alternative 3. 6-52 MWMC_6 0_REV11 DOC 6 DEVELOPk~ENT AND EVALUATION OFALTERNATIVE$ ~ 30 mgd through Tertiary Filtration mgd through ~ 160 mgd through Primary Clarification Secondary Treatment ~ 140 mgd through "Blending" Diversion FIGURE 6.6.2d Process Flow Schematic for System Alternative 3--Additional Primary Clarifiers MWMC Facilities Plan, Eugene.Springfield System A~ternative 4 - High-Rate Clarification A new high-rate clarification (HRC) trait process would be constructed and used irt conjunction with the existing primary clarifiers to treat the entire 277 mgd PWWF A ptunp station would divert pretreated effluent in excess of 160 mgd from preliminary treatment to the new HRC facility. Primary effluent from the HRC facility would be diverted around the secondary treatment system via gravity. The HRC primary and secondary effluents would be disinfected separately and blended prior to discharge into the river, Figure 6.6,2-2 shows the process flow schematic for system alternative 4. ~ 30 mgd through Tertiary Filtration - 160 mgd through Primary / Secondary ~!I ~ ,.,~ ~,~,~,~ ~ 140 mgd through High ' Rate C~arification FIGURE 6,6.2-2 Process Flow Schematic for System Alternative 4--HRC MWMC Facilities Plan, Eugene-Spnngfietd System Alternative 5 - Parallel Primary and Secondary Treatment During peak flow events a dynamic flow management strategy would be used to optimize the existing primary and secondary treatment capacities. Two new pump stations would be used to divert preliminary treated wastewater directly to secondary treatment and divert PE arotmd secondary treatment. Pretreated effluent would flow to the existing primary MWMC...60_REVI LDO0 6.53 MWMC FACILITIES PLAN clarifiers up to their modified capacity of 134-165 mgd. Pretreated flows in excess of this would be pumped directly the aeration basins, taking advantage of the large volume and long detention time. PE from the existing primary clarifiers in excess of the secondary treatment capacity would be diverted arotmd secondary treatment with a new pump station, resulting in primary and secondary treatment processes operating in parallel. The primary and secondary effluents would be disinfected separately and blended prior to discharge to the river. Figure 6.6.2-3 shows the process flow schematic for system alternative 5. ~ 30 mgd through Tertiary Filtration Secondary Flow Management ~ 160 mgd 4~~ ~ 160 mgd through Primary / Secondary Primary Flow Ma~gement ~ ~ FIGURE 6.6.2-3 Pro.ss Row Diagram for System Alternative 5--Parallel Pfima~ ~nd Seconda~ Treatment MWMC Facilities Plan, Eugene-Springfield 6,6,3 Matrix Evaluation Evaluation of the system alternatives includes both a relative cost comparison and a non- monetary evaluation. Improvements that are common to all system alternatives were not considered in the cost comparison; only improvements that were tmique to each system alternative were included. The results from the relative cost and non-monetary comparisons are summarized in Table 6.6.3-1. TABLE 6.6.3-1 Summary of Peak Flow Management Alternatives Companson MWMC Facilities Plan, Eugene~Spnngfietd Capital Cost System Alternative (millions of dollars) Non-Nlonetary Rating" 1 - No Action $0 16 2 - Additional Pnmary and Secondary Cladfiers, Aeration $57 17 Basin 3 - Additional Pnmary Clarifiers $31 20 4 - High-Rate Clarificabon $25 20 5 - Parallel Primary and Secondary Treatment $11 23 Notes: '~ Non-monetary score is out of a possible maximum score of 30 points. 6.54 MWMC_60_REV'f I DOC DEVELOPMENT AND EVALUATION OF ALTERNAllVES System alternative 1 does not increase treatment capacity or alter existing operations to system efficiency. Although cost is zero, the ability to meet future NPDES increase the permits and EPA requirements for projected plant capacities is unlikely, if not impossible, without substantial upgrades or improvements to existing facilities. Therefore, this alternative was eliminated for further consideration. Figure 6.6.3-1 shows a potential site layout for system alternative 2. In addition to those facilities required for all alternatives, this alternative includes the construction of four new primary clarifiers, a new aeration basin, and six additional new secondary clarifiers. This system alternative would result in the highest capital investment and requires the most site space. This is significant because the only available site space that could be used is reserved for future build-out of secondary treatment capacity. Additionally, the primary clarifiers would be located a long distance from the existing primary clarifiers, requiring separate primary sludge handling and odor control facilities. Thickening of primary sludge outside the primary darifier would not be required with this alternative; however, it is recommended. This system alternative would be capable of treating 100 percent of the projected PWWF thi'ough primary and secondary treatment and no blending would be required. However, all these additional new facilities would be constructed to mitigate PWWF that only occurs on a relatively infrequent basis. It is therefore recommended that this alternative be removed from further consideration because of its extremely high capital cost. Figure 6.6.3-2 shows a potential site layout for system alternative 3. In addition to those facilities required for all alternatives, this alternative includes the construction of four new primary clarifiers. Less costly than system alternative 2, this system alternative has the benefit of providing primary treatment for 100 percent of the PWWF. As in system alternative 2, this alternative provides redundant primary treatment capacity, because a total of eight prLmary clarifiers would be available. The new primary clarifiers will occupy excessive site space allocated to future expansion of secondary treatment facilities. Additionally, if these clanfiers were constructed they would be located a long distance from the existing primary clarifiers, further complicating primary sludge handling and odor control facilities. Thickening of primary sludge outside theprimary clarifier would not be required with this alternative; however, it is recommended. Blending would be required for this alternative to meet the anticipated NPDES permit requirements. This alternative is feasible cost-wise, and should be considered further for permit compliance. Figure 6.6.3-3 shows a potential site layout for system alternative 4. In addition to those facilities required for all alternatives, this alternative includes the construction of a new high-rate clarification pump station and new high-rate clarification facilities. System alternative 4 offers the greatest operational flexibility as it would allow the HRC to function as primary clarifiers and would allow the existing primaries to be taken off line if necessary. Thickening of primary sludge outside the existing primary clarifiers would be required with this alternative to reduce the overall HRC needs. HRC can function in multiple modes, either to treat base dry season flows or to treat WWPH flows. The HRC system would reqttire more extensive O&M than either system alternatives 1, 2, 3, and 5 because the monthly exercising of the system would be significantly more involved. This system would also experience higher operational costs because of chemical requirements and electrical costs associated with the would be for this alternative system. Blending required to meet the MWMC_60_REV11.DOC 6-55 MWMC FACILmE$ PLAN anticipated NPDES permit requirements. However, HRC is being cor~idered for application as equivalent secondary treatment. If equivalent secondary treatment status is gained for this technology, the effluents would no longer be considered blended and the regulatory uncertainty would no longer be an issue. This alternative is feasible cost-wise and should be considered further for permit compliance. Figure 6.6.3-4 shows a potential site layout for system alternative 5. In addition to those facilities required for all alternatives, fids alternative includes the construction of a new primary diversion pump station and a new secondary diversion pump station. Thickening of primary sludge outside the existing primary clarifiers would be required with this alternative. The hydraulic control strategy associated with system alternative 5 would be more complicated to operate than the other system alternatives because of the complexity of achieving proper flow splitting and balancing using two pump stations. Blending would be required for this alternative to meet the anticipated NPDES permit requirements. System alternative 5 might present a greater challenge from a regulatory standpoint as state and federal blending policies are still evolving. This alternative is feasible cost-wise and should be considered further for permit compliance. 6,6.4 Permit Compliance Assessment System alternatives 3, 4, and 5 were selected for further analysis regarding permit compliance relative to cost. These system alternatives were analyzed usLng a spreadsheet model developed to simulate the projected peak flows and estimate the resulting effluent BOD and TSS concentrations. The model used historical urtit process performance data from peak flow events in conjunction with anticipated unit process performance to simulate worst-case average weekly and monthly values for BOD and TSS. Compliance with the monthly average 85 percent removal requirement was also assessed. The results of each model run were compared with current NPDES BOD and TSS permit requirements to evaluate a system alternative's ability to meet both current and potential future effluent limits. Figures 6.6.4-1 and 6.6.4-2 show the results of the permit compliance analysis relative to cost for each alternative. These figures illustrate that the predicted effluent loadings are comparable for each alternative even though the construction costs vary considerably. All three alternatives would be able to meet the current and future peak week and peak month effluent requirements, provided the mass limits remain constant. In a worst-case scenario, assuming that the ?WWF occurs during the peak week flow and the peak week flow occurs during the peak month (likely in May), the 85 percent monthly removal requirement specified in the NPDES permit for BOD would require filtration of a portion of the SE. This is the case for all of t_he alternatives, and it was assumed that filtration would be available because it will be required for TSS removal reliability during the dry season. Filtered flow required trader this worst-case scenario would be 10 mgd at 2010, and 30 mgd at 2025. System alternative 5 - Parallel Primary and Secondary treatment is recommended for treating PWWFs at the WPCF. Although the three alternatives had similar non-cost evaluation results and all system altematives were anticipated to meet future NPDES permits, system alternative 5 provides MWMC with the most cost-effective solution to treating infrequent PWWFs with no environmental impacts to the receiving stream. However, there is some regulatory uncertainty regarding blending policy that puts system NIWIVlC_6 O_RE-Vi 1 DOC 6 DEVELOPMENT ,kND EVALUATION OF ALTERNATIVES alternative 5 at risk for DEQ approval. For this reason it is recommended that MWMC consider system alternative 4 - High-Rate Clarification as a contingency plan if regulatory approval is not granted for system alternative 5. HRC is the next-best alternative because of its cost, operational flexibility, and ability to treat all PWWF through primary treatment. Cost and Weekly TSS Loading Sac) "''~'''' :~';'":' ....... ' "'" """" ~ $15 .... , · , ~ ,,. . ,, . ,, , ,, . , ,, ' .. ,. ~-~'.~,t. ~ ~[ ~..~: '~ ~k ~ , , - ~ ' l~ t~ ~ ~ ' ~ .~ ~ :~ ' " - Convenhonat App¢oach - AddJhonal Pnmanes High Rate ClanhcatJon Parallel Primary and Secondary B C~st ID Weekly TSS Loading (lb/day) FIGURE 6.6.4-1 Cost and Weekly TSS Loading MWMC Facilities Plan, Eugene-Springfield MWMC_6,0_REV11 DOC 6.57 MWMC FACILITIES PLAN Cos[ and Weekly CBOD Loading ~, ,n,~ j, ,,,/ , ~' - , ,' "' $25 "-'""r ",, . ..... '.' .' --~ ' ...... '.~ ~' ', ' / ,....~'CB~Week,yAverage . '.".". '.. ~ ~ . .;." '..;' ' ~ ~ ' """ '~24~day , ,,, , , .... ' , , , . , , ,, , , ,, ,~_ ~, ,, ~,,,,,, , ,,, ,,,, , ..... ,,,,,, ,,o: ......,~.:..:~... ' "%. " ~ ': ~"' ~'~'~.': '.t~ .... Co~en~on~ A~ro~h - ~dltiond Pnmanes High Rate CMnha~n Partial Pnmary ~d ~nda~ Trident ~tions ffi ~$~ D We~ C~ Loading (l~day) FIGURE 6.6.4-2 Cost and Weekly CBODs Loading MWMC Facilities Plan, Eugene-Springfield 6-58 MWMC_6,O_REV'~ l DOC 7.0 Recommended Plan This chapter documents further development of System Alternative 5, file system expansion and improvement alternative selected in Chapter 6.0, and provides more detailed design and cost information for this alternative. Both collection system and treatment plant improvements recommended as part of this alternative are described. The treatment plant components includes sizing and costing of liquids and solids processes developed in Chapter 6.0. 7.1 Recommended Collection and Conveyance System improvements 7.1.1 Collection System A rigorous analysis was made of potential wastewater collection system flow management alternatives as part of the September 2000 MWMC WWFMP (CH2M HILL, 2001). Recommendations included targeted RDII reduction projects and ongoing flow monitoring throughout the collection system. Additional conveyance system improvements beyond targeted RDII reduction via public system rehabilitation as discussed in Chapters 4.0 and 6.0 of this document are not necessary. 7.1.2 Conveyance System Because of the consistency between the hydraulic modeling results for the '¢,rWFMP study and the current facilities plan, the conclusions and recommendations made in the WWFMP analysis also remain valid for the current wastewater conveyance system. Those recommendations included pump station upgrades to meet DEQ capacity and redundancy requirements. Recommended pump station improvements based on the current hydraulic model results and the pump station and force main analysis are shown in Table 7.1.2-1, which summarizes the existing and proposed 2025 unit process, equipment, and design criteria. Table 7.1.2-2 (at the end of this chapter) lists the system conveyance design criteria for existing and 2025 capacity needs. TABLE 7.1.2-1 Recommended Conveyence System improvements MWMC Facilities Plan, Eugene-Springffeld Existing Capacity Recommended Responsible Pump Station (mgd) Capacity (mgd) Proposed improvement Entity Willakenzie 80.0 127,5 Install additional pump station with MWMC four new 10 mgd pumps; install new ~orce main connections. MWk~C_7 O_REV4.DOC 74 MWMC FACILFftES PLAN TABLE 7,1,24 Recommended Conveyance System Improvements MWMC Facilities Plan, Eugene-Springfield Existing Capacity Recommended Responsible Pump Station (mgd) Capacity (mgd) Proposed improvement Entity Division Street 1 ~4 2.0 Upgrade pumps for higher head Eugene conditions at force main connecbon point. Skipper 8,0 10.5 Upgrade pumps for higher head Eugene conditions at force main connection point; install additional pump to meet redundancy requirements, Greenwich 1.5 3.0 Upgrade pumps for higher head Eugene conditions at force main connection point. Irvington 13.5 15.0 Upgrade pumps for higher head Eugene conditions at force main connection point; install one additional pump. West irwin 21.0 28.5 Upgrade pumps for higher head Eugene conditions at force main connection point. Terry Street 14.0 28.0 Upgrade pumps for higher head Eugene conditions at force main connection point; install additional pump to meet redundancy requirements. Barger-Greenhill 7.5 32.0 Install phase 2 and phase 3 pumps in Eugene existing pump station; install new 24- inch force main. WPCF Screw 84.0 99.0 Install one additional screw pump, JVW~/MC Pumps 7,2 Recommended Liquids Process Improvements 7.2.1 Secondary Treatment Recommended enhancements to secondary treatment facilities include conversion of each aeration basin (4 cells) to a step feed, plug flow activated sludge process with anoxic selectors. The following modification are required and are shown in Figure 7.2.1-1: Addition of PE flow control gates for step feed of PE to each cell Addition of PI spkitter control boxes to mix PE and RAS at each cell o New primary effluent and RAS distribution header to each cell Addition of anoxic zone and ano×ic mixers in each cell of each aeration basin Conversion of all coarse bubble aeration grids to fine bubble aeration · New mixed liquor effluent gates in last cell of each aeration basin o Enhance existing secondary clarifiers (see section 7,1.2) · Two new secondary clarLfiers 7-2 MWMC_7.0_REV4 [X3C 7 RECOMMENDED PLAN Modifications provide flexibility for dry and wet weather operations to achieve seasonal effluent requirements. Bioreactor capacity is increased through increased average mixed liquor concentrations, however, solids loading to the secondary clarifiers is reduced. Table 7.2.1-1 (located at the end of this chapter) summarizes the existing and proposed 2025 unit process, equipment, and design criteria. FIGURE 7.2.1-1 Recommended Aeration Basin Modifications to Step-Feed, Plug-Flow Activated Sludge with Selectors MWMC Facilities Plan, Eugene.Springfield 7.2.2 Secondary Clarification Enhancements Recomrnended enhancements to each of the secondary clarifiers include the following items and are shown on Figure 7.2.2-1: New energy-dissipating inlet New flocculation well New outboard launder New weir and scumbaffle New scum skimmer arms New density current baffle ,, Convert existing mechanism to suction manifold Modifications to the operation of the existing secondary clarifiers will include adjustments to the tmderflow concentrations and flow rates required to maintain a high solids compaction zone and a low solids inventory in the clarifier. Additional RAS pumping is not MWMC_7,0_REV4,DOC 7-3 MWMC FACILITIES PLAN anticipated. Table 7.2.1-1 summarizes the existing and proposed 2025 trait process, equipment, and design criteria. FIGURE 7.2.2-1 Secondary Cladfier Enhancements MWMC Facilities P/an, Eugene-Springfield Relocate Launder Trough New Scum to Exterior Wall of Cladfler, Skimmer Arms -,., /New Ene[gy ',~ "~ _. ,/-Dissipating - ~ /inlet ~ New Floc Manifold with ' - Adjustable Orifices 7.2.3 Primary CLarification Enhancements Recommended Enhancements to each of the existing primary clarifiers include the following items and are shown on Figure 7.2.3-1: New energy-dissipating inlet New weir and scum baffle New feedwell ,, New scum skimmer arms New density current baffle Modifications to the operation of the existing primary clarifiers include thickening of primary sludge outside the clarifiers. This requires a higher primary sludge flow rate to keep sludge from accumulating at the base of the clarifiers. New facilities required to accommodate these operational changes include the following. Table 7.2.1-1 summarizes the existing and proposed 2025 trait process, equipment, and design criteria. New primary sludge pumps New gravity thickeners, or gravity belt thickeners, or other unidentified technology ,, New thickened primary sludge pump station 7-4 MWMC_70_REV4,DOC 7 RECOMMENDED PLAN FIGURE 7.2.3-1 Recommended Primary' Clarifier Enhancements MWMC Facilities Plan, Eugene-Springfield / Skimmer Arms Dissipating ~m aaffie .. E~isfin~ ~ ..... Intuit Exi~ng Sludge ~'~ ........... ~ [~" Column Removal / ~ma~ Sludge .... Hoper 7,2.4 Preliminary Treatment Expansion of the existing pretreatment facility is recommended to provide future capacity needed to accommodate wet weather flows and provide for consistent operations during dry weather flows. Expansion facilities include the following items: New vertical fine screens (1/4-inch opening) New screenings washer/compactors New flow measurement structures ,, New cyclonic grit separators New grit pumps and cyclones New grit classifiers New screenings/grit hoppers and loadout The new facilities would be constructed to accommodate 160 mgd of dry weather capacity even though less capacity is required for total wet weather flows. This is because the fine screening technology produces a substantially different screenings product that must be handled separately from the coarse screenings in the existing facility. The facility should be operated so that the frequency with which the existing pretreatment facility would have to be brought on and of tine during dry weather is minimized. Table 7.2.1-1 summarizes the existing and proposed 2025 unit process, equipment, and design criteria. 7.2.5 Odor Control Expanded odor control facilities are recommended to accommodate future odor control needs at the primary clarifiers, new pretreatment addition, existing pretreatment facility, existing WAS thickening facility, expanded WAS thickening facility, and the primary sludge thickening facility. Expanded facilities include the following items: · New 14-foot-diameter bioscrubber vessels (5 total) o Bioscrubber secondary effluent pump station (2 total) MWMO_7,0_REV4 DOC 7-5 MWMC FACILITIES PLAN Odor control covers at the primary clarifier effluent launders Odor control covers at the primary clarifier feedwells Odor control covers at the primary sludge thickening facility Odor control covers at the new screening channels Odor control hoods at the expanded screenings and grit loadout facilities With the implementation of bioscrubber vessels, the existing biofilters can be phased out of service and the new bioscrubbers will handle the existing odor control needs in addition to the new needs. Bioscrubbers occupy significantly less site space and disperse odorous air more effectively than biofilters. They are easily phased in as needed for additional odor control capacity. Table 7.2.1-1 summarizes the existing and proposed 2025 unit process, equipment, and design criteria. 7.2.6 Disinfection Sodium hypochlorite disinfection facilities are recommended for disinfection of both primary and secondary effluent flow streams as shown in Figure 7.2.6-1. Recommended new facilities include the following items: Horizontal bulk storage tanks for hypochlorite (3 at 20,000 gallons) Vertical bulk storage tank for bisulfite (1 at 7,000 gallons) Hypochlorite meterh'~g pumps for chlorination of secondary effluent ,, Hypochlorite metering pumps for chlorination of primary effluent diversion flow Bisulfite metering pumps for dechlorination of secondary effluent Bisulfite metering pumps for dechlorination of primary effluent diversion flow 1.3-million-gallon chlorine contact basin for primary effluent diversion flow Disinfection of primary effluent and secondary effluent flow streams will be treated separately. Each flow stream will require separate dosage control for chlorine and bisulfite. The existing chlorine building will house the new storage tanks and facilities. Table 7.2.1-1 summarizes the existing and proposed 2025 unit process, equipment, and design criteria. F~GURE 7.2,6-1 Proposed Effluent Stream D~s~nfection Operation MWMC Facilities Plan, Eugene-Springfield Prchmmary Raw Treatment Primary S~ondavy $ochum To ~tfalI~ Sewage re ~ehmm~y Elfluent Effluent ~ Aeranon Effluent Hyp~nlorile Treatment ~lm~ Effluent High-RaI~ ~cr~on t Sodmm Hyp<hlonte 7-6 MWMC_7,0_REV4 DOC 7. RECOMMENDED PLAN 7.2.7 Tertiary Filtration Tertiary filtration is reqm.'red for dry weather operations to provide performance reliab~ity and operational flex~l>il/ty to consistently meet the effluent TSS requirements. Filtration is also required for wet season flows to meet the monthly average 85 percent removal requirement for CBOD during peak wet weather flows. Filtration also provides the opporttmity to develop effluent reuse programs. It is recommended that 30 mgd of partial secondary effluent filtration be implemented over the planning period. The current recommended technology is deep bed granular media filters. Table 7.2.1-1 summarizes the proposed 2025 unit process, equipment, and design criteria for tertiary filtration. Expanded facilities include the following items: 8 modular 26 ftx 35 ft deep bed granular media filters Piping gallery Coagulation facilities and chemical room Filter backwash pump station Backwash equalization pumps (located in existing aeration basin) Other filtration technologies that are well suited for smaller filtration appl/cation will be considered to provide filtration for level IV reuse water. 7.3 Recommended Effluent Disposal and Biosolids Improvements 7.3.1 Effluent Disposal Recommendations for reuse ultimately include the development of a lCkmgd Level IV reuse program. The initial reuse demonstration project would include up to I mgd of effluent reuse to a site located near the WPCF. Subsequent reuse projects would be phased in to provide an additional 9.0 mgd of total Level IV reuse. New facilities for the demonstration project include the following: Movable effluent filtration system adequate for 1 mgd of secondary effluent in demonstration project In-line coagulation injection facilities for 1 mgd o Expandable UV system initially adequate for I mgd of Level IV reuse , Pipeline and distribution system adequate for I mgd Upon public acceptance of the reuse facilities, the reuse program can be expanded to 10 mgd of Level IV effluent reuse. Permanent filtration facilities required for dry season permit compliance are necessary prior to expansion of the reuse program. Recommended permanent reuse facilities indude the following: · Tertiary filtration facilit-ies for secondary effluent (required for dry weather permit compliance) · In-line coagulation injection facilities expanded for 10 mgd MWMC_7.0_REV4.DOC 7-7 UV system expanded for 10 mgd of Level IV reuse - Pipelines to additional reuse sites up to 10 mgd Reuse pump station and distribution system expanded to 10 mgd Additional reuse projects include the application of 1.25 mgd of Level II reuse effluent to the SIWF and 1.5 mgd of Level II reuse effluent at the Biocycle Farm. The Biocycle Farm would require an irrigation pipeline and microspray distribution system. Table 7.3.1-1 (located at the end of this chapter) summarizes the existing and proposed 2025 unit process, equipment, and design criteria. 7.3.2 Biosolids Stabilization Temperature-phased anaerobic digestion is currently recommended to provide for future solids stabilization needs at the WPCF. Conversion to a two-phased digestion process will delay or eliminate the need to construct a fifth lagoon and would provide for Class A biosolids stabilization. Recommended new facilities include the following: Digester mixing improvements for existing three digesters Construct fourth conventional mesophilic digester - Construct thermophilic digesters to provide Class A biosolids Pre-pasteurization processes may also be considered for future solids stabilization to provide Class A biosolids. However, the current recommended plan is based on two-phase anaerobic digestion. Table 7.3.2-1 (located at the end of this chapter) sttmmarizes the existing and proposed 2025 unit processes, equipment, and design criteria. 7.3.3 Facuitative Sludge Lagoons At this time the need to construct a fi£th lagoon by a specific year is not recommended, nor is it expected that a fifth lagoon will be needed within the design period. Overall plant VSS reduction requirements are likely to be achieved even if VSS loading to the existing lagoons exceeds design criteria due to proposed digestion system modifications. It is recommended that lagoon VSS loading rates be closely monitored as upstream process improvements and additions are implemented. Digester mixing improvements will increase the active volume of the existing digesters, the addition of a fourth digester will provide additional digester volume, and the potential use of an advanced digestion process will all contribute to improved reduction in VSS loads to the lagoons. It is recommended that the existing lagoons be relined in accordance with previous planning activities that are not part of this facilities plan. Table 7.3.2-1 summarizes the existing and proposed 2025 unit processes, equipment, and design criteria. 7.3.4 Biocycle Farm Land Application The Biocycle Farm is a valuable asset to MWMC's biosolids application program. The current operation as a non-irrigated land application site provides enough capacity to reduce and maintain solids inventory in the FSLs throughout the design period. Therefore, it is recommended that the site continue to operate in its current mode. The majority of the costs associated with continued operation of the site have already been absorbed in the purchase of the land, installation of the distribution pipeline, construction of the Biocycle 7-8 MWMC_70_REV4 DOC 7 RECOMMENDED PLAN Farm pump station (under construction), and the purchase of four hose reel application systems, developing to receive liquid biosolids include the Future needs con[5/2ue site following facilities: · Site preparation of an additional 260 acres for further liquids biosolids application · Addition of four hose reels Table 7.3.1-1 surrm~rizes the existing and proposed 2025 m~t processes, equipment, and design criteria. 7,3.5 Seasonal ndustria Waste Facility The SIWF provides long-term program flexibility for MWMC's biosolids and effluent reuse program and selling the land is not recommended. The recommended beneficial use of the facility includes land application of approximately 1.25 rngd of Level II reuse effluent. A reclaimed water pipeline is already in place from the existing WPCF to the SIWF, and with fairly minimal additional investment it could receive effluent. Retrofitting the sprinklers on the center pivots would be required. It would also be financially beneficial to investigate adding the SIWF to the WPCFs NPDES permit to decrease annual permit costs At some time in the future, MWMC may want to consider implementing modifications at the facility that would allow the site to receive liquid biosolids for land application. Table 7.3.2-1 summarizes the existing and proposed 2025 unit processes, equipment, and design criteria. 7.4 Recommended System improvements 7.4.1 Peak Flow t anagement improvements Recommended liquids and solids treatment process improvements combine to form art overall facility base solution used to treat normal dry and wet season flows and loads. PWWFs require additional facilities to handle tow frequency, short duration, but high peak flow events. The recommended strategy for treating PWWF events in excess of the facilities' base treatment capacity is to implement a dynamic flow management strategy that optimizes the primary and secondary treatment capacities. This flow management strategy is shown in Figure 7.4.1-1. Additional new facilities required to implement the recommended peak flow management strategy include the following: Pretreatment diversion pump station and pipeline front pretreatment to aeration basins Primary treatment diversion pump station and pipeline from primary effluent box to new high-rate disinfection structure - Effluent blending and ouffall structure ~ Additional bank outfall Operational practices during peak flow events require that PWINFs in excess of the primary darifier capacity (estimated between 134 -160 mgd) be diverted from preliminary treatment directly to the aeration basins for secondary treatment. PE flows in excess of the secondary treatment capacity (estimated at 165 mgd) are to be diverted around secondary treatment for separate disinfection and subsequent blending with disinJected SE. Table 7.2.1-1 MWMC_70._REV4 DOC 7-9 MWMC FACILiTiES PLAN summarizes the existing and proposed 2025 trait processes, equipment, and design criteria for the peak flow management facilities. Figure 7.4.1-2 shows all the recommended facilities for the systemwide solution. ~ 30 mgd through Tertiary Filtration Secondary Flow Management - 160 mgd ~ - 160 mgd through Primary/Secondary ~ Primary Flow Managemept ~ ~ - 140 mgd FIGURE 7.4.14 Recommended Process Flow Diagram for Peak Flow Management-- Parallel Pdma~ and Secondaw Tmatmem MWMC Facilities Plan, Eugene-SpringfieD 7,4.2 Process Flow Diagrams Figures 7.4.2-1 and 7.4.2-2 (located at the end of this chapter) show the 2025 l~qtdds and solids balances for the recommended system approach respectively. 7.5 Summary of Recommended Improvements This Facility Plan outlines improvements to the regional wastewater facilities through the design year of 2025. The recommended improvements result from those projects identified in the current plmming process, and previously identified projects from other studies. Table 7.5-1 summarize the projects required to meet the 2025 facility needs. TABLE 7.5-i Summary of Recommended Improvements through Year 2025 MWMC Facilities Plan, Eugene-Springfield Unit Process Improvements Springfield Coltecbon System * Rehabilitate pubhc system in seven sub-basins. ,, Invest~gate further into the Gateway area and remediate as necessary. Eugene Collection System · Rehabilitate public system in 21 sub-basins. ,, Install valve at 14th and Tyler. W~llakenzie Pump Station ,~ Install additional pump station with four new 10 mgd pumps. · Install new force main connections. 7-10 MWMC_70_REV4 DOC 7 RECO~,~ENDED PLAN TABLE 7.5-1 Summary of Recommended Improvements through Year 2025 MWMC Facilities Plan, Eugene-Springfield Unit Process Improvements Influent Pump Station ,, Install one additional screw pump. Screening ,* Install four new fine screens. · Install two new screenings washer/compactors. ,, Install four new Parshall flumes for flow measurement. Grit Removal · Install four new vortex grit separators. ,, Install four new grit pumps and cyclones. e Install two new gnt classifiers. ,, Install two new screenings/gdt hoppers. Parallel Primary and · Construct new Preliminary Treatment Diversion Pump Station with four Secondary Treatment new preliminary treatment diversion pumps. o Construct new Primary Treatment Divermon Pump Station with four new primary treatment diversion pumps. ,, Install piping to enable primary and secondary treatment to be operated in parallel. Primary Clarifiers · Install a new feed well. ,, Install new EDIs for increased energy dissipation from feed well. ,, Install new density current baffles at outboard launders. ,, Operate primary clanfiers without a sludge blanket by pumping a thin pdmary sludge at a high flow rate from the primary clariflers to an external thickener. o Install two new 50-foot gravity thickeners. · Construct new thickened primary sludge pump station, Gravity Belt Thickenem · Install one new gravity belt thickener. Aeration Basins · Install new step feed equipment and piping. , Install new anoxic selectors. ,, Install new fine bubble d~ffusers. · Remove effluent gates. · Install new primary effluent flew control gates. MWMC_7 0_REV4.DOC 7-~ 1 MWMC FAC}LfflES PLAN TABLE 7.5.1 Summary o4 Recommended ~mpm~ements through Year 2025 MWMC Facilities Plan, Eugene-Springfield Unit Process improvements Secondary Clarifiers · install a new flocculation well. e Install new EDIs for increased energy dissipation from feed wail Retrofit existing suction tubes to a single suction manifold with adjustable orifices. Remove in inboard launder and locate a new ~aunder at the exterior of the clafifier. ,, Install new scum baffle, as well as new scum skimmer arms. Install new density current baffles at outboard launders. ,, Construct two new secondary clarifiers. Tertiary F~lters · Construct new tertiary filter pump station with three new filter influent pumps. Construct eight new tertiary filters Construct new backwash pump station at existing contact basins and add three new pumps. Disinfection · Convert existing chlodne and sulfur d~oxide feed and storage rooms for hypochlonte and sodium bisulfite system. Construct new contact basin for disinfection of pnmary effluent diversion flow. o Construct new UV facility for reuse. Effluent Ouffall o Construct new blending box for parallel primary and secondary treatment. ~ install new bank outfalL Reuse ,, Install piping for new distributiort/irdgation system. · Construct Reuse Pump Station. Odor Control ,, Replace existing 3-celled organic media biofilter with five new b~oscrubbers. Biosolids Management , Reline lagoons. Facility · Expand composting facdlty. Sludge Digesters ,, Improve digester mixing by modifying existing gas mixing system with pump mixing system. ,~ Construct one new mesophillic digester. · Convert dIgesters to thermophlhc digestion to achieve Class A sludge. 7-12 MWMC_7.0_REV4.DOC 7 RECOMMENDED PLAN 7.6 Identification of Project Phasing The recommended improvements identified in Table 7.5-1 form the basis for the development of a 20-year project list. To develop the project list, the t/ming of individual facility improvements had to be ident/fled so that the overall regional wastewater needs could be rnet without a deficit in capacity. For some of the recommended improvements, a phased approach would provide flexibility in the level of improvements made. For example, modifications to both the north and south aeration basins to convert them to a step-feed, plug-flow air-activated sludge system with anoxic selectors do not have to be complete in both basins to meet the/rdtial capacity needs. These modifications could be phased so that the south basra is mod/fled initially, and the north basin is modified when futtrre flow and loads demand additional capacity, although frorn an operational standpoint, having both basins configured the same would be simpler. A phased approach to constructing facilities provides a more stable ftmding process, delays tmnecessary capital investments until they are needed, and allows for potential re-evaluation to implement appropriate future technologies. Using this approach, the recommended improvements were broken down into individual projects according to the facility needs over the planning period. For each project component, a fact sheet was prepared that outlines the project name, project description, project justification, project driver, and project trigger. The fact sheets are provided at the end of this chapter. 7.7 Implementation Schedule Using the project fact sheets, individual improvement projects were consolidated into phases based on the project trigger, which defines when the project must come on line to address capacity, regulatory, or other facility needs. Adjustments to the timing of some projects were made so that large variations in annual capital improvement costs were avoided. This was done without compromising facility needs and the approach resulted in a relatively level cash flow requirement. The estimated cost of each phase is presented in Table 7.7-1. The est/mated total cost for the recommended improvements in all phases is approximately $144,000,000. The anticipated projects and estimated project costs that are packaged in each phase are summarized in Table 7.7-2. The project costs estimated for each of the phases are order-of-magnitude estimates for construction and non-construction in 2004 dollars. The accuracy of this type of cost estimate typically ranges from -30 percent to +50 percent. Costs are based on 10 percent for mobilization/demObilization, bonds, and insurance; construction contingency of 25 percent; and engineering, legal, and administrative (ELA) of 25 percent. Construction costs are based on previous cost estimates or bid tabulations from similar projects. Costs for individual processes include site work, piping, electrical, I&C, and contractor markups. The 25 percent construction contingency is intended to cover unidentified and/or unknown items such as construction dewatering and subsurface structural support of buildings or structures. The project phasing is shown in Figure 7.7-1, and represents the twelve initial project phases. Figure 7.7-1 does not show offsite projects, such as the improvements to conveyance pump stations, the SIWF, the Biocycle Farm, and the BMF facilities. Figure 7.7-2 shows the project phasing required if the High-Rate Clarification alternative is required by DEQ. This MW~C_7.0_REV&DOC 7-13 MWMC FACILFrlEs PLAN approach ks possible because of hhe regulatory uncertainty surrounding future blending policy. If this alternative is required by DEQ, an additional 13 mill/on dollars in project cost would be required at phase 5. TABLE 7.7-1 Project Phasing Estimated Cost Summary MWMC Facdit~es Plan, Eugene-Springfield Phase Fiscal Year Estimated Cost ($) Phase 1 2004/2005 $15,660,000 Phase 2 2005/2006 $13,890,000 Phase 3 2006/2007 $10,000,000 Phase 4 2007/2008 $20,800,000 Phase 5 2008/2009 $23,400,000 Phase 6 2009/2010 $6,200,000 Phase 7 2010/2011 $17,850,000 Phase 8 2011/2012 $2,100,000 Phase 9 2012/2013 $4,100,000 Phase 10 2013/2014 $5,050,000 Phase 11 2014/2015 $800,000 2015/2016 $16,650,000 Phase 12 2017/2018 $1,500,000 Phase 73 $5,050,000 Miscellaneous Projects 2019/2020 $150,000 2023/2024 $800,000 Total Cost $144,000,000 TABLE 7.7-2 Recommended Project Phasing Plan with Capital Cost Estimates MWMC Facdtties Plan, Eugene-Springfield Cost Estimates Phase Description ($) Phase 1 (2004/2005) Secondary Ctarifier Baffle, add inlet energy dIssipation, change out fiocculation well, $5,300,000 Enhancements - Part construct outboard launder, and retrofit suction header for e×mting I eight ctarihers; enhancement conducted in two pads, each part consisting of four clarifiers Primary Cladfier Baffling of primary cladfiers and remove hydraulic restnctions. $t ,200,000 Enhancements 7-14 MWMC_70_REV4.DOC RECOMMENDED PLAN TABLE 7.7-2 Recommended Project Phasing Plan with Capital Cost Estimates MWMC Facilities Plan, Eugene~Springfield Cost Estimates Phase Description ($) South aeration basin Add step feed, anoxic selectors, and fine bubble diffusers. Remove $6,900,000 hydraulic restrictions in both south and north basins (effluent gates). Includes future pdmary effluent flow control gates for both north and south basins. Outfall mixing zone Update 1994 Mixing Zone Study to account for additional 100 mgd $150,000 study (approximate) bankside outfall capacity and for changes to the Willamette River morphology that may have occurred since the last study was conducted Temporary Modular space at WPCF for staff to manage construction of capital $100,000 construction projects management facilities Fiber Optic Widng Install wiring between BMF and WPCF $10,000 Digester Digester mixing improvements for existing three d~gesters $2,000,000 Improvements Phase 1 Subtotal $15,660,000 Phase 2 (2005/2006) Secondary Clarifier Baffle, add inlet energy dissipation, change out flocculation well, Funded in Enhancements - Part construct outboard launder, and retrof;t suction header for existing FY2004/2005 2 eight clarifiers; enhancement conducted in two parts, each part consIsting of four clanfiers R~ver Avenue From existing MWMC FY 03/04 Budget - Regional Wastewater $330,000 ~mprevements Program; assessment to I~,%~'¢MC from Eugene revised from $228K to $330K in February 2004 Biocycle Farm - Part 130 acres - site preparation begins in 8/05; planting in 3/06 $300,000 2 GBT Building Add a third gravity belt thickener (GBT) with associated at grade $2,500,000 Expansion (Waste building. Assumes additional basement floor space is not required. Activated Sludge Thickening) Odorous Air Two 14-foot diameter, 30 foot tall bioscrubber tower for air $2,300,000 Treatment collected from two pdmary clarifier center wells and launders and Expansion - Part 1 new sludge building addition Biocycle Farm Four hose reels for Biocycle Farm $260,000 Distribution Equipment WWFMP Update Evaluate recently collected collection system flow monitoring data, $250,000 update and run collection system model, and confirm (or revise) convey and treat approach MWMC_70_REV4 DOC 7-05 MWMC FACILITIES PLaN TABLE 7.7-2 Recommended Project Phasing Ptan with Capital Cost Estimates MWMC Facilities Plan, Eugene-Springfield Cost Estimates Phase Description ($) Support MWMC Incentive Money $250,000 development of private lateral program Screw Pump Station instal~ 5th pump to increase capacity from 84 to 99 mgd $1,700,000 Expansion Willakenzie Pump install four additional 14-mgd pumps to increase capacity from 80 $6,000,000 Station Expansion to 135 mgd Phase 2 Subtota~ $13,890,000 Phase 3 (2006/20{)7) Secondary Cladfier Construct 9th and 10~h secondary clarifiers $6,300,000 Addition Level l~ Reuse at Provide 1.25 mgd of Level II reuse water at the SIWF $400,000 SIWF Leve~ iV Reuse local 0,5 - 1.0 mgd of Level IV reuse, install movable filter, coagulation $2,100,000 demonstration system, UV, p~ping, and distribution system. S~te TBD. preject Re~ine lagoons at Re~ine lagoons, Phase 1 - from existing MWMC C~P $1,200,000 BMF - Part 1 Phase 3 Subtotal $10,000,000 Phase 4 (2007/2008) Dry Weather Expand headworks so that all of the 2025 wet weather peak flow $12,800,000 Headworks receives prehminary treatment. Expansion includes four fine Expansion mechanical screens, four Parshall flumes, and four vortex grit separators. Primary Sludge Construct thin primary sludge pumping and piping systems to $3,600,000 Gravity Thickeners gravity thickeners, two 50-foot-diameter GBTs (covered for odor control), supematant overflow pumping and piping, thickened sludge p~ping/pumping to digesters. See Odorous Air Treatment for treatment of odors in Phases 2, 5, and 7 Biocycle Farm - Part 120 acres - sIte preparation begins m 8/07; planting in 3/08 $300,000 3 Conversion to Convert ex~sting chlodne gas system to sodium hypochlodte for the $4,100,000 Sodium Hypochiorite base flow. Retain the existing chlorine contact basins. Install System system with capability for high-rate disinfection of pdmary effluent dIversion assuming high dosages of chlorine into a 72-inch pipe. Phase 4 Subtotal $20,800,000 7-16 MWMC_7 O_REV4.DOC 7. RECOMMENDED PLAN TABLE 7.7-2 Recommended Project Phasing Plan with Capital Cost Estimates MWMC Facilities Plan, Eugene-Springfield Cost Estimates Phase Description ($) Phase 5 (2008/2009) Odorous Air Construct two 14-foot-diameter, 30-foot-tall b~otowers for air $2,300,000 Treatment collected from two primary cladfier centerwelLs and launders and Expansion - Part 2 new GBT Parallel Primary/ Construct piping, pumping, and flow split boxes to enable primary $11,000,000 Secondary Flow and secondary treatment te be operated in parallel Route Filtration - Pad 1 Filtration: includes infrastructure/support facilities for 30 mgd of $10,100,000 filters; install filter cells sufficient for only 10 mgd Phase 5 Subtotal $23,400,000 Phase 6 (2009/20~ 0) New Bankside Construct a new bankside outfall to accommodate up to 140 mgd $1,500,000 Outfall (300 mgd less 160 mgd, which is the capacity of the existing outfall system) Level II Reuse at BF Provide 1.5 mgd of Level ii reuse. Installation of dedicated reuse $3,600,000 irrigation pipeline and microspray system. Total reuse of 3.75 mgd July - August. Reline Lagoons at Reline lagoons, Phase 2 - from existing MWMC CIP $1,100,000 BMF - Part 2 Phase 6 Subtotal $6,200,000 Phase 7 (2010/2011 ) Glenwood Pump From existing MWMC FY 03/04 Budget - Regional Wastewater $500,000 Station Upgrade Program ~ncrease Digestion Fourth digester and/or conversion to thermophllic digestion to $13,800,000 Capacity and achieve Class A; fourth digester is $4.8 million, thermophiJic is -$9 Provide Class A million; use $13.8M in CIP and re-evaluate options in future when Capability decide to go to Class A. Odorous Air Construct one 14-foot-diameter, 30-foot-tall biotower for air $2,300,000 Treatment collected from new dry weather headworks and conversion of the Expansion - Part 3 existing air sources from biofilter to biotowers. Reline Lagoons at Reline lagoons, Phase 3 - from existing MWMC CIP $1,t00,000 BMF - Part 3 Facility Plan Update Update to portions of the MWMC Facility Plan (FY2010/11) $150,000 (FY2010/11) Phase 7 Subtotal $17,850,000 MWMC_7 0_REV4.DOC 7-~7 MWMC FACILITIES PLAN TABLE 7.7-2 Recommended Project Phasing Plan with CapItal Cost Estimates MWMC Facilities Plan, Eugene-Springfield Cost Estiraates Phase Description ($) Phase 8 Reline ~agoons at Re~ine lagoons, Phase 4 - from existing MWMC CIP $1,100,000 BMF - Part 4 RepaidPartial Repaidreplace sections of the biosol~ds force main where strubite $1,000,000 replacement of deposits limit pipe diameter and cannot be removed by acid wash. biosolids force main Phase 8 Subtotal $2,100,000 Phase 9 (2012/2013) Permanent Level IV Provide 2.5 mgd for permanent Level IV reuse to local $4,100,000 Reuse - Part 1 greenspaces and community areas. Modify/install UV system capable of 3 mgd and modify/install piping system installed in demonstration projecL Total reuse of 5.25 mgd Phase 9 Subtotal $4,190,000 Phase 10 (2013/2014) Filtration Expansion - Filtration: 10 mgd of filter cells for a total capacity of 20 mgd $5,050,000 Part 2 Phase 10 Subtota~ $5,050,000 Phase 11 (2014/2016) Comprehensive Comprehensive update to portions of the MW MC Facihty Plan $800,000 Facility Plan (FY2014/2015) (FY2014/2015) North Aeration Basin Add step feed, anoxic selectors, and assume existing diffusers w{]] $6,200,000 Enhancements be replaced in 15 years but main air header is not replaced. Permanent Level iV Provide 2.5 - 5 mgd for permanent Leve] IV reuse, increase $9,800,000 Reuse- Part 2 pumping capacity, reuse pipeline, and UV system. Total reuse of 7.75 - 10.25 mgd Composting Facility Expand compostmg facility at Biosolids Management Facility - from $650,000 Expansion existing MWMC CIP (FY2015/2016) Phase 11 Subtotal $17,450,000 Phase 12 (2017/2018) Operation and Update/upgrade the operations and maintenance facilities at $1,500,000 Maintenance Facility WPCF ~mprovements (FY2017/2018) 7-18 MWMC_7.O_REV4 DOC RECOMMENDED PLAN TABLE 7.7-2 Recommended Project Phasing Plan with Capital Cost Estimates MWMC Facilities Plan, Eugene-Springfield cost Estimates Phase Description ($) Phase 12 Subtotal $1,500,000 Phase 13 (201S~2019) Filtration Expansion - Filtration: Add 10 mgd of filter ceils for a total capacity of 30 mgd $5,050,000 Part 3 Phase 13 Subtotal $5,050,000 Other Projects Facility Plan Update Update to portions of the MWMC Facility Plan (FY2019/20) $150,000 (FY2019/20) Comprehensive Comprehensive update to portions of the MWMO Facility Plan $800,000 Facility Plan (FY2024/25) (FY2024/25) Other Projects Subtotal $950,000 MWt~__70_REV4 DOC 7-19 TABLE 7.1.2-2 Wastewater Conveyance System Design Critena- Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing CriteriafConditlons Year 2025 FLOW CONDITIONS Design Flows DWA 49 mgd 38.4 mgd WWA 70 mgd 68.2 mgd WWMM 107~2 mgd 110.8 mgd WWPH 175 mgd 300 mgd INFLUENT PUNIPING SYSTEM Total ~nfluent Pumping System Capacity Total 143.88 mgd 346 mgd Firm (~argest unit out) 113.64 mgd 272 mgd E/$ WPCF Influent Pump Station Pumps Number of Pumps 4 5 Size 21 mgd each 4 @ 21 mgd each 1 @ 15 mgd Type Helical Screw Helical Screw Horsepower 200 hp 4 @ 200 hp 1@ Drive Capacity Total 84 mgd 99 mgd Firm (~argest unit out) 63 mgct 78 mgd Willakenzie Pump Station Pumps Number of Pumps 5 9 Size 17.5 mgd each 5 @ t7.5 mgd 4 @ 10 mgd Type Dry pit centnfugal Dry pit centrilugai Horsepower 5 @ 300 hp 5 @ 300 hp 3 @ 250 hp 1 @ 225 hp Drive VFD VFD Capacity Total 80 mgd 127.5 mgd Firm (,largest unit out) 70 mgd 110.0 mgd Division Street Pump Station Pumps Number of Pumps 2 2 Size 2 @ 0.7 mgd 2 @ 1,0 mgd Type Dry pit centrifugal Dry pit centrifugal MWFAC_TABLE 7.1 2-2_REV4.DOC I TABLE 7.1.2-2 Wastewater Conveyance System Design Cntena - Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Horsepower 2 @ 20 hp 2 @ 30 hp Drive on/off on/off Capacity Total t .4 mgd 2.0 mgd Firm (largest unit out) 0.7 mgd 1.0 mgd Skipper Pump Station Pumps Number of Pumps 2 3 Size 2 @ 3 mgd 3 @ 3.5 mgd Type Dry pit centrifugal Dry pit centrifugal Horsepower 2 @ 60 hp 3 @ 100 hp Drive on/off on/off Capacity Total 6.0 mgd 10.5 mgd Firm (largest umt out) 3.0 mgd 7.0 mgd Greenwich Pump Station Pumps Number of Pumps 2 2 Size 2 @ 0.7 mgd 2 @ 1.5 mgd Type Dry pit centrifugal Dry pit centrifugal Horsepower 2 @ 30 hp 2 @ 30 hp Drive on/off on/off Capacity Total 2.1 mgd 3.0 mgd Firm (largest unit out) 1.0 mgd 1.5 mgd Irvington Pump Statio~ Pumps Number of Pumps 2 3 Size 2 @ 7.2 mgd 3 @ 5 mgd Type Dry pit centrifugal Dry pit centrifugal Horsepower 2 @ 150 hp 3 @ 250 mgd Drive VFD VFD Capacity Total 13.5 mgd 15.0 mgd Firm (largest unit out) 7°2 mgd 10~0 mgd West in, in Pump Station Pumps Number of Pumps 3 3 Size 3 @ 9 mgd 3 @ 9,5 mgd Type Dry pit centrifugal Dry pit centrifugal Horsepower 2 @ 200 hp 3 @ 250 hp 1 @ 250 hp MWMC_TABL£ 712.2_REV4.DOC 2 TABLE 7.1.2~2 Wastewater Conveyance System Design Criteria - Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing C~iteriaJConditions Year 2025 Drive VFD VFD Capacity Total 21.0 mgd 28.5 mgd Firm (largest umt out) 18.0 mgd 19~0 mgd Terry Street Pump Station Pumps Number of Pumps 3 4 Size 3 @ 6.6 mgd 4 @ 7.0 mgd Type Dry pit centrifugal Dry pit centrifu§al Horsepower 3 @ 200 hp 4 @ 225 hp Drive VFD VFD Capacity Total 14.0 mgd 28.0 mgd Firm (largest unit out) 10.0 mgd 21.0 mgd Ba;ger-Greenhill Pump Station Pumps Number of Pumps 2 4 Size 2 @ 3.74 mgd 4 @ 8 mgd Type Dry pit centritugal Dry pit centnfuga~ Horsepower 2 @ 188 hp 4 @ 400 mgd Ddve VFD VFD Capacity Total 7.48 mgd 32 mgd Firm (largest unit out) 3.74 mgd 24 mgd Barger-Greenhiti to Terry Street Force Main Force Main Number of force main pipelines 2 3 Material DIP DiP S~ze 14-in, 24-in 14-in, 24-in, 24-in Length 7,350 ft (each) 7,350 ft (each) MWI~TABLE 7.t.Z-E_flEV4.DOC 3 TABLE 7.2.1-1 Liquid Processes Design Cdtena, Existing and 2025 Capacity Needs · MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 FLOW CONDITIONS Design Flows DWA 49 mgd 38.4 mgd WWA 70 mgd 68.2 mgd WWMM NA 110.8 mgd WWPH 175 mgd 300 mgd PRELIMINARY TREATMENT Mechanical Bar Screens Clear opening Y~" Number of 4.5 foot-wide units 6 6 Capacity, each 35 mgd 35 mgd Clear opening ¼" Number of un,ts NA 4 Maximum Capacity, each NA 40 mgd Washer/Compactor Number of Units 2 Capacity 2 @ 2,000 gpm 2 @ 2,000 gpm 2@ Screenings Conveyor Number of Units and Size 3 @ 300 gpm 3 @ 300 gpm Type Sluice Water Pumps Sluice Water Pumps Horsepower Drive Total 900 gpm 900 gpm Firm (largest umt out) 600 gpm 600 gpm PLANT INFLUENT FLOW MEASUREMENT Type Parshail Flumes Downstream Parshall Flumes Downstream of Influent Screens of in[iuent Screens Size 4 @ 6 fl-wide throat 8 @ 6 ft-wide throat GRIT REMOVAL Grit Chambers Design criteria 2.5 min HRT @ QWSPH 2.5 rain HRT @ OwsP, Number to meet design criteria 2 2 Total number installed 4 4 Length × Width 85-fl x 13-ft 85~ft x 13-fl Volume, each 101,000 gal 101,000 gal Total Volume 404,000 gal 404.000 gal Capacity, each 58.3 mgd 58.3 mgd Actual HFfT @ QwsPH, all grlt bays in so.ice 2.16 rain @ QWWP~2005 2.16 rain @ Actual HRT @ QWsPH, with redundancy 1.62 min @ QwwPH-~O05 1.62 min @ (~NWPH-2005 MWivIC_TAgLE 7 21-1_REV7 DOC TABLE 7.2.1-1 Liqu~ Processes Design Criteria, Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Number of Units NA 4 Diameter NA 20-ft Capacity, each NA 40 mgd Grit Handling Number of Grit Pumps 4 8 Pump Capacity Per Pump/Total Capacity 300 gpml1,200 gpm 4 @ 300 gpm/I,200 gpm 4@ Pump Type Recessed Impeller, Centrifugal Recessed Impeller, Centrifugal Cyclone Degritters Number of Units 4 8 Cyclone Capacity/Tota~ Capacity 300 gpm/I,200 gpm 4 @ 300 gpm/1,200 gpm 4@ Classifiers Number of Units 2 4 Type Inclined Screw Inclined Screw Size 12-inch 12-inch Capacity, each/Total Capacity 600 gpm/1,200 gpm 2 @ 600 gpm/1,200 gpm 2@ Screenings/Grit Conveyance and Storage Compacted Screenings/Grit Conveyor Number of Units 2 2 Type Shaftless, Dual-Drive Shaftless, Dual~Dnve Capacity/Total Capacity Gnt - 900 lb/hr / 1,800 lb/hr Gdt - 900 lb/hr / 1,800 lb/hr Screening - 1,400 lb/hr / 2,800 Screening - 1,400 lb/hr / 2,800 lb/hr lb/hr Solids Loadout Conveyor Number of Units 2 2 Type Shafftess Screw Shaftiess Screw Capac~ty/Tota~ Capacity Gr~t - 900 Ih/hr / 1,800 lb/hr Grit - 900 lb/hr / 1,800 lb/hr Screening - 1,400 lb/hr / 2,800 Screening - 1,400 lb/hr / 2,800 lb/hr lb/hr Screenings/Grit Hopper Number o[ Units 2 2 Type Shaftless Screw Sha[tless Screw Capacity/Tota~ Capacity Grit - 900 lb/hr / 1,800 Ih/hr Grit - 900 lb/hr / 1,800 lb?hr Screening - 1,400 lb/hr / 2,800 Screening - 1,400 lb/hr / 2,800 lb/hr lb/hr PREAERATION Preaeration Basins Number of Units 4 4 HRT @ QDWA 15 rain 22.8 rain (if used for DWA) MWMC_TABLE 7 21.1_REV7 DOC 2 TABLE 7.2.t-1 Liquid Processes Design Criteria, Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 HRT @ QwwP~ 5 min 8.25 rain Volume, each/Tota~ 152,000 gal / 608,000 gal 152,000 gal / 608,000 ga~ Length x Width 130-fi 2-in x 13-ff 130-ft 2-in x 13-ft Capacity, each//Tota~ @ QDWA 14.6 mgd/5&4 mgd 9.6 mgd/38.4 mgd PRIMARY CLARIFICATION Primary Ciarifiers Design Criteria SOR = 1,250 gpd/ft2 @ 71.5 mgd Diameter 135 ft 135 ft Side Water Depth 12 ft 12 ft Number of Units 4 4 Actual SOR @ QwwP~ all units in servme 3,058 gpd/ft~ 2,794 gpd/f¢ Actual SOR @ QwwMM W/1 untt out of service NA 1,935 gpd/ft2 Actual SOR @ Qww^ all unrts in service 1223 gpd/~ 1,191 gpd/ft2 Actual SOR @ QOWMM all units in service NA 1,036 gpd/ff2 Actual SOR @ QDw^ all umts in service 856 gpd/ft2 671 gpd/ft2 TSS Removal % @ QwwP~ 0 % 40% TSS Removal % @ QwwA 50% 50'/0 TSS Removal % @ QDWA 50% -50% Primary Treatment Diversion Pumps Number of units NA 4 Capacity, each/total NA 50 mgd/200 mgd Type NA Vertical Turbine SECONDARY TREATMENT Step Feed With Anoxic Selector Process Parameters SRT in July through Sept., days 5 days until 2010; 6 days from 2010 to buildout DO, mg/L 2 Dry Season Temperature in Biological Process, 20 °C Wet Season Temperature in B~ological 12 Process, °C Dry Season Max Month MLSS, mg/L 3,200 Wet Season Max Month MLSS, mg/L 2,200 Period for Complete Nitnfication July - September July - September Aeration Basins Number of Basins 2 (8 cells) 2 Step Feed Basins (4 cells per train) Volume, Each,"Totat 2 Mgal/16 Mgal ~).5 Mgab/19 Mgal Sidewater Depth 15 ft 17 ft Number of Aerobic Zones 8 4 cells per basin Number of Anoxic Zones NA 4 cells basin per MWMC~TABLE 721-1_REV7 DOC 3 TABLE 7.2,1-1 Liquid Processes Design Cdlefia, Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 HRT, hours @ Q[~w^ 7.84 hr 11.58 hr HRT, hours @ QDWMM NA 7.54 hr HRT, hours @ Qww~M NA 4.02 hr HRT, hours @ QWWPH 2.45 hr 2.78 hr Temp (C) @ QDsu~,~ 60 deg. F (May 1996) 60 deg. F (May 1996) Temp (C) @ QwsMM 54 deg. F (May 1996) 54 deg. F (May 1996) Pd TSS Rem (%) @ Q[~w^ 50% 50% Pri TSS Rem (%) @ Qww^ 50% 50% Pn CBOD Rem (%) @ QDWA 32% Pti CBOD Rem (%) @ QwwA 30% SRT (days) @ Q[~wuM 9.5 SRT(days) @ Qwwu~ 9.5 MLSS-average (rog/L) @ QDSMM ~: MLSS-average (mg/L) @ Q~s~M 3,427 mg/L Net Y~eld (WAS-TSSICBOD) applied @ QosM~ 1 lb/lb Net Yield (WAS-TSS/CBOD) applied @ OwsM~ 1 lb/lb Blowers Number of Units 8 6 Capacity, Each 10,500 to 17,000 clm 10,500 to 17,000 cfm Hp, Each 1000 hp 1000 hp Type 5 stage centrifugal 5 stage centrifugal Control Constant Speed Constant Speed Secondary Clarifiers Mechanism Type Rapid Sludge Removal (RSFI) Suction Header Capacity, Total Peak 134 mgd 167 mgd Design Criteda - Peak Overflow Rate SOR= 1,050 gpd/f¢ $OR= 1,260 gpd/ft2 Design Criteria- Solids Loading @ DWMM & 15 lb/day-fO WWMM Design Cdteda - Solids Loading @ WWPH 37 Ib/day-ft2 Number of Units 8 10 Diameter, ft 130 ft 130 it Sidewater Depth 14 fl 14 ft Actual SOR @ Qww~, all un,ts in service NA 835 gpd/¢ Actual SOR @ QwwA, all units in service 659 gpd/f¢ 514 gpd/ft2 Actual SOR @ QwwP~, all units in service 1,648 gpd/ft2 1,205 gpd,'lt2 RAS Flow (percent o~ influer~t flow) @ Q~w~ 30-35°/° 38.7% RAS Flow (percent of influent flow) @ QwwM~ 30% 38.7% TERTIARY TREATMENT (of Secortdar¥ Treatment Effluent) Secondary Effluent Filters Number of units NA 8 Filter Type NA Multi-media Surface Area, each NA 7,200 f~ MWMC_TABLE 7,2.1-1_REV7 DOC 4 Liquid Processes Design Criteria, Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Capacity, each/Total NA 3.75 mgd / 30 mgd Hydraulic Loading Rate @ QwwA NA 2.79 gpm/fl2 Hydraulic Loading Rate @ Qwwp, NA 7.77 gpm/f~ TSS Removal Efficiency @ Qv~v,~ and QwwPH NA 75% Solids Loading Rate @ Qww^ NA 0.07 lb/day-it2 Solids Loading Rate @ QWWPH NA 0.29 lb/day-ft2 Filter Backwash Pumps Number of units NA 3 Capacity NA Type NA PLANT APR Compressed Air System Number of units 4 4 Capacity, each 2 @ 33 cfm @ 90 pslg 2 @ 33 cfm @ 90 psig 2 @ 150 cfm @ 100 pslg 2 @ 150 cfm @ 100 psig PLANT WATER PUI~PS Reclaim Water Pumps (W2) Number of units 3 3 Type CentnfugaI Centrifugal Capacity, each/total 3.4 mgd/10.2 mgd @ 80 psi 3.4 mgd/10.2 mgd @ 80 psi Drive VFD VFD Motor Horsepower, each 150 hp 150 hp DISINFECTION Chlorine Gas Disinfection (total flow stream) Number of Contact Tanks 4 NA Volume, ea (fl3) 132,700 f~ NA Number of Chlorine Evaporators 2 NA Evaporator Cspacity, each/Total 8,000 lb/day / 16, 000 lb/day NA Number of Chlorinators 5 NA Chlorinator Capacity, each/Tota~ 1,000 lb/day / 5,000 lb/day NA Number of Sulfur Dioxide Evaporators 1 NA Evaporator Capacity, each/Total 450 lb/day NA Number of Sulfonators 1 NA Sulfonator Capacib/, each/Total 1000 lb/day NA Actual Detention Time Dry Season Average Month (QDs~M) 117 minutes NA Wet Season Average Max Month (QwwA) 82 minutes NA Peak Hour (Qww~H) 35.7 minutes NA Chlorine Dose Average 3.25 mg/L NA Maximum 4.94 mg/L NA MWMC_TABLE 7.2~1 .t _RF. VT.DOC 5 TABLE 7.2,1-1 Liquid Processes Design Cr~eria, Existing and 2025 Capacity Needs MWMC Fac/I/ties Plan, Eugene-Springfield Unit Process Existing Criteria/Conditior~s Year 2025 Minimum 1.76 mg/L NA Chlorine Usage Average 26.9 lb/day NA Maximum 33.6 lb/day NA Minimum 14.6 lb/day NA Chlorine Storage Ton Cylinders On-Site (Assumed) ~ NA Number of Cylinders Used Dudng Max NA Week Storage Capacity at Max. Week NA Hypochlorite and Bisulfite Storage and Conveyance Number of Hypochlorite Tanks NA 3 Hypochlorite Tank Capacity, each/Total NA 20,000 gal ! 60,000 gal Number of Bisulfite Tanks NA 1 Bisulfite Tank Capacity, each/Total NA 7,000 ga~ Storage Criteria Average Annual NA 30 day Maximum Month NA 14 day Maximum Week NA 6 day Hypochiorite Disinfection (secondary treatment flow stream) Number of Contact Tanks NA 4 Volume, ea (ft3} NA 132,700 ft3 Design Cnteda NA 35 minutes @ QWWPH Hypochlorite Solution Strength NA 12.50% Number of Hypochlofite Pumps for Secondar~ NA 5 Treatment Flow Hypochlorite Usage Average Dose NA .3.5 mg/L Average @ WWMM NA 3,255 gal/day Bisulfite Dechlorination (secondary treatment flow stream) Solution Strength (assumed) NA 38% Chlorine Residual (assumed) NA 2-~,~ Number of Bisulfite Pumps for Secondary NA 2 Treatment Flow Bisulfite Usage Average Dose NA 1.1 mg/L Average @ WWMM NA 14i~.~.~_ Hypochlerite Disinfection (primary diversion flow stream) Number of Contact Basins NA Volume, ea (ft3) NA 1.3 Mgal (basins) 0.6 Mgal (pipeline) Design Cntena NA 20 minutes @ QwwPH Hypochlofite Solution Strength NA 12.50% MWMC_I~ASLE 721-1_REV7 DOC 6 TABLE 7.2.1.1 Liquid Processes Design Criteria, Existing and 2025 Capacity Needs MWMG Facilities Plan, Eugene-Spnngfield Unit Process Existing Criteria/Conditions Year 2025 Number of Hypochlorite Pumps for Primary NA 2 Diversion Flow Hypochlorite Usage Average Dose NA 7,0 mg/L Average @ WWPH NA 8,960 gal/day Bisulfite Dechiorination (primary diversion flow stream) Solution Strength (assumed) NA 38% Chlorine Residual (assumed) NA 2 trig/I_~ Number of Bisulfite Pumps for Primary NA 2 Diversion Flow Bisulfite Usage Average Dose NA 1.1 mg/L Average @ WWPH NA :~41,'galJday ODOR CONTROL Type Organic Media NA Ceils 3 NA Capacity, Each/Total 15,000 cfm/18,000 cfm NA Bioscrubbers Number oi Bioscrubbers NA 5 Number of Exhaust Fan NA 5 Vessel Maximum Diameter NA 14 feet Capacity, Each/Total NA 8,200 cfm/41,000 cfm Minimum Gas Residence Time NA 12 seconds Maximum Gas Loading Rate NA 60 cfm/~ Minimum Media Depth NA 12 feet Media Type NA Porous Volcanic Rock Media Size NA 0.75 to 1,5 inches Media Pressure Drop NA 0.3 ~nches WC/ft Minimum Inlet temperature NA 50 °F Maximum inlet temperature NA 100 DF Scrubbant Rec~rculation Rate NA 0,0236 gpm/cfm Basin pH setpoint NA 2 0 Makeup Water Source NA Secondary Effluent Inlet Hydrogen Sulfide Concentration NA 5 ppm OUTFALL Outfall Control Structure Type 1 Bank Outfall 1 Bank Outfall 1 Submerged Outfall 1 Submerged Outfall Bank Outfall Diameter 84 inch 84 inch Submerged Outfall Diameter 96 inch 96 inch Diffuser 96-inch Out'fall on Submerged MWMC_TABLE 72 I-I_REV7.DOC 7 TABLE 7.2.1-1 bquid Processes Design Criteria, Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Number of Ports 8 8 Port Diameter (inches) 42 42 New Outfail Type NA 1 Bank Outfall Bank Outfall Diameter NA 96 inch Notes: ~ Detention t~me computed does not include outfall pipe volume N~,WtJC_TA~LE 721-1_REV7 DOC TABLE 7,3.1-1 Seasonal Land Application Design Criteria - Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Spnngfield U~it Process Existing Criteria/Conditions Year 2025 SITE CHARACTERISTICS Site Delineation Poplar Trees (non-buffers) 165 acres 425 acres Grass (buffers) 20 acres 132 acres Roads 23 acres 23 acres Feed Store Lot 16 acres 16 acres S~te Capacl~ (based on non-irrigated loading) Poplar Trees (flquid b~osolids) 1,4~ d~ tons 2,128 d~ tons Grass (dewatered biosolids) 549 dw tons 612 d~ tons Poplar Ha~est Rotation 10 yearn 10 yearn Pement DW Solids in Applied Liquid Biosolids 1-4% 1-4% S~te Loading Cdtena N~trogen Loading Poplar Trees (liquid biosolids) 220 lbs N/acre 220 lbs N/acre Grass (dewatemd biosolids) 120 lbs N/acre 120 lbs ~acm Biosol~ds Loading Poplar Trees (liquid biosolids) 3.4 dw ton~acre 5~4 dw tons/acre Grass (dewatered biosolids) 4,2 dw tonCacre 4.2 dw ton~acre LIQUID BIOSOLIDS EQUIPMENT Mixed Sludge Trans[er Pumps Number of Units 2 3 Drive VFD VFD Mixed Sludge Strain Presses Number of Units 2 3 Liquid Biosol~ds Storage Tank Number of Units 1 1 Volume, each 50,000 gal 50,0~ gal Liquid Biosolids Storage Tank Mix Pump Number of Units 1 L~quid Biosolids Disposal Loading Pump Number o~ Units 1 1 Liquid Biosolids irrigation Pumps Number of Units 3 3 Drive VFD VFD Liquid Biosolids ~rfigation Pipeline Diameter 16 inch 16 inch Material PVC Class 150 PVC Class 150 Capacity 2,400 gpm 2,400 gpm Liquid Bioso~ids Application Method Number ct Units 4 8 MWMC_TABLE 7 $.1 ~t_REV4.DOC Seasonal Land Application Design Criteria- Existing and 2025 Capacity Needs MWMC Facilities Plan~ Eugene-Spring,eld Unit Process Existing Criteria/Condifior~s Year 2025 Type ~{ ~[~ S~?E CHARACTER~STICS Available Land, total 7500 Unknown Dewatemd Biosolids Capaci~, ~etal 31,200 d~ tons/year Unknow~ MW~C_TABLE 7 31-1_REV4.DOC 2 TABLE 7.3.2-1 Solids Processes Des~§n Cntena- Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 PRIMARY SLUDGE Primary Clarifiers Pement Volatile Solids Dry Season Average 87% 80% Dry Season Maximum Month 88% 80% Dry Season Maximum Week 88% 80% Wet Season Average 85% 80% Wet Season Maximum Month 88% 80% Wet Season Maximum Week 88% 80% Solids Concentration 4,4% 1% - 4.5% TSS Removal E~hciency Dry Season Average 63% 60% Dry Season Maximum Month 67% 60% Dry Season Maximum Week 71% 60% Wet Season Average 57% 50% Wet Season Maximum Month 67%, 50% Wet Season Maximum Week 73% 50% BCD Removal Efficiency Average 31% 25% Dry Season Dry Season Maximum Month 36% 27% Dry Season Maximum Week 47% 31% Wet Season Average 35% 27% Wet Season Maximum Month 43% 28% Wet Season Maximum Week 61% 34% WASTE ACTIVATE SLUDGE (WAS) Pement Volatile Solids Dry Season Average 74% 83% Dry Season Maximum Month 76% 82% Dry Season Maximum Week 78% 82% Wet Season Average 76% 78% Wet Season Maximum Month 78% 75% Wet Season Maximum Week 80% 75% WAS Net Yield (lbs WAS/lbs BCD) Dry Season Average 0.87 Dry Season Maximum Month 0.92 Dry Season Maximum Week 0.99 Wet Season Average 1.32 Wet Season Maximum Month 1.36 Wet Season Maximum Week 1,55 SOLID PROCESSING OPERATIONAL CRITERIA hfs/day, days/wk 24 hrs/day, 7 days/wk Thickening 1 6-24 7 One standby unit One standby unit MWMC_TA~,LE 7.32-1_REV4 DOC 1 TABLE 7.3.2-'i Solids Processes Design Criteria - Existing and 2025 Capacity Neecls MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Dewatedng 13 hfs/day (Mon-Thur) 12 hm. Jday, 5 days/wk, Mar- 9 hfs/day (Fd) Sept Mar~Sept Alt units online 85% of time Trucking 3-4 trucks for 14 days 3~4 trucks for 14 days 10-12 hfs/day; 6 days/wk; 10-12 hrs/day; 6 days/wk; 6-7 trips/day/truck 6-7 trips/day/truck WAS THICKENING Gravity Belt Thickeners (GBTs) Number of Umts 2 3 Size 3 meters 3 meters Sohds Loading Rate, eacWtotal 2010 lbs/hour/4020 lbs/hour 2010 lbs/hour/6030 lbs/hour Hydraulic Loading Rate, each/total 720 gpm / 1440 gpm 720 gpm / 2160 gpm Thickened WAS Concentration 4% dry solids 4% dry solids Capture Efficiency 95% 95% WAS Pumps Number of units 2 3 Capacity, each/tota~ 800 gpm / t600 gpm 800 gpm / 2400 gpm Type Screw Centrifugal Screw Centrifugal Drive AFD AFD Horsepower, each 15 15 TWAS Pumps Number of umts 2 3 Capacity, each/total 120 gpm / 240 gpm 120 gpm / 360 gpm Type Progressing Cavity Progressing Cavity Drive AFD AFD Horsepower, each 20 20 SLUDGE STABILIZATION Anaerobic Digesters Number of Units 3 4 Diameter, each 85 ft 85 ft Sidewall Depth 27.6 ft 27.6 Type Fixed Cover Fixed Cover Volume, each Active Digestion 969,000 gal / 2,907,000 gal 1,083,000 gat / 4,332,000 gal Total 1,140,000 gal / 3,420,000 gat 1,140,000 gal / 4,560,000 Detention Time (based on active volume with ali units in service) Annual Average 20 to 22 days 20.2 days Maximum Monthly Average 22 days 15.3 days Detention Time (based on active volume with one units out of service) Annual Average 16.5 days 15.2 days Maximum Monthly Average 15 days 11.5 days Volatile Solids Loading (based on active volume with all units in service) Primary Sludge 83 percent volatile 83 percent volatile MWMC_TABLE 7.32-1_REV4 DOC 2 TABLE 7.3.2-1 Solids Processes Design Criteria - Existing and 2025 Capacity Needs MWMC Facilrties Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Waste Activated Sludge 75 pement volatile 75 pement volatile Annual Average 0.10 lbs/cf/day Maximum Monthly Average 0.13 lbs/cf/day Maximum VS loading criteda at Max Month 0.15 lbs/cf/day 0.15 lbs/cf/day Average VS Destruction 45% 55% Average Pement DS from Digestion 2.3% 2.5% Anaerobic Digester Auxiliary Equipment Waste Gas Incinerator Number of Umts 1 Engine Generator Number of Units 2 Peak Output Capacity 420/KVV & 800 kW RPM Fuel System, primary Digester gas Fuel System, secondary Digester gas Hot Water Boiler Number of Umts 1 Output Capacity ~ Fuel System, primary Digester gas Fuel System, secondary Natural gas Sludge Heat Exchanger Number of Un,ts 3 Type External spiral Digested Sludge Transfer Pumps Number of Umts 1 Digested Sludge Pumps Number of Umts 2 2 Capacity, each/tota~ 430 gpm / 860 gpm 430 gpm / 860 gpm Type Progressing Cavity Progres.sing Cavity Drive AFD AFD Horsepower, each 75 75 Facultatlve Sludge Lagoons Number of Units 4 4 Area, each/total 6.25 acres / 25 acres 6.25 acres / 25 acres Depth, normal 13.5 ft 13.5 ft Depth, maximum 14.5 ft 14.5 fi Freeboard, norma~ 2.0 ft 2.0 ft Freeboard, maximum 3.0 ft 3.0 ft VS Loading Criteria 25 lbs/1000 cf-day 25 Ibs/t 000 cf*day Annual Average VS Loading 16 lbs/1000 cf-day TBD Facultafive Sludge Lagoon Auxiliary Equipment Sludge Dredge Pump MWNIC..TABLE 7.3,2-I_REV4 DOC 3 TABLE 7,3.2-1 Solids Processes Design Criteria - Ex~ting and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Crlterla/Conditior~s Year 2025 Number of Units I 1 Capacity 2000 gpm 2000 gpm Supematant Pump Number of Units 1 Capacity 600 gpm 600 gpm LIQU~D SLUDGE STORAGE Digested ~ludge Storage Tanks Number of Units 2 2 Type Floating Cover Floating Cover Volume, each/total 360,000 gal / 720,000 gal 360,000 gal t 720,000 gal Diameter 60 ft 60 It Sidewater Depth 14 to 17 ft 14 to 17 ft Belt Filter Press Feed Tanks Number of Units 2 2 Volume, each 370,000 gal / 740,000 gal 370,000 gal / 740,000 Diameter 48 ff 48 ft Sidewater Depth 26 to 27 ft 26 to 27 ft Belt Filter Press Feed Mixing Pumps Number of Units 2 2 Type Screw Centrifugal Screw Centnfugal Capacity, each 1600 gpm 1800 gpm Horsepower, each 25 25 SLUDGE DEWATERING Belt Filter Presses (BFPs) Number of Units 3 3 Size 2 meter 2 meter Solids Loading Rate, each/total 2440 lbs/hr/7320 lbs/hr 2440 Tbs/hr/7320 lbs/hr Hydraulic Loading Rate, each/total 140 gpm / 420 gpm 140 gpm / 420 gpm Average Solids Feed Concentration 3% 3% Capture Rate 98% 95% Dewatered Cake Solids 16,5% dry solids 17% dry solids Belt Filler Press Auxiliary Equipment Polyme[ Feed System Polymer Dose 15 Ihs/dry ton 1,5 lbs/d~ ton Polymer Consumption, average 310 lbs/day Capacity, average 55 dry tbs/hr Capacity, maximum 104 dry Ihs/hr Raw matedal form Dry Supersack Solution Strength - Target 0.50% 0.50% Polymer Mixing Tanks Number of units 2 2 Volume, each/total 3700 gal / 7400 gal 3700 gal / 7400 gal MWb~C_TABLE 7 3 2-1_REV4 DOC 4 ~ABLE ?.3.2-~ Solids Processes Design Criteria - Existing and 2025 Capacity Needs MWMC Facilities Plan, Eugene-Springfield Unit Process Existing Criteria/Conditions Year 2025 Diameter, each 7 ft 7 ft Polymer Feed Pumps Number of units 3 3 Capacity, each/tota~ 20 gpm / 60 gpm 20 gpm / 60 gpm Type Progressing Cawty Progressing Cavity Drive Single speed Single speed Belt Filter Press Feed Pumps Number ot Units 3 3 Type Progressing Cawty Progressing Cavity Capacity, each/total 200 gpm / 600 gpm 200 gpm / 600 gpm Ddve AFD AFD Horsepower, each 15 15 Belt Filter Press Feed Sludge Strain Press Number of Units 3 3 Type Parkson Strainpress Parkson Strainpress Capacity, each/tota~ 150 gpm /450 gpm 150 gpm /450 gpm Belt Filter Press Filtrate Pumps Number of UnIts 3 3 Type Submersible Submersible Capacity, each/tota~ 575 gpm / 1725 gpm 575 gpm / 1725 gpm Drive AFD AFD Horsepower, each 15 15 Belt F;tter Press Cake Conveyance Number of Umts Type Screw Auger Screw Auger Capacity 30 wet tons/hr 30 wet tons/hr Drive Single speed Single speed SOLIDS STORAGE Air Drying Beds Number of Units 13 S~ze, each/total 1.85 acres/25 acres Equivalent Average Depth 0.50 ~t Storage Volume, each/total t 485 CY / 19,300 CY Storage Volume, dry weight basis, total 3130 dry tens Storage Volume, wet weight bas~s, total 17,400 wet tons Facultafive Sludge Lagoons Number of Units 4 4 Operating Depth 10 ft 6 ft Storage volume at operating depth, each/total 18 MG / 71 MG 10.25 MG / 41 MG (based on 2.5% solids in and 3% solids out) BFP Cake Hopper Number of Units 2 I,/RNMC_TAE~LE 7~3 2~1_REV4 DOC 5 TABLE 7.3.2-1 Solids Processes Design Criteria - Existing and 2025 Capacity Needs MWMC Facilities P/an, £ugene-Spdngf~eld Unit Process Existing Criteria/Conditions Year 2025 Type Elevated steel hopper Capacity, total (weight) 163 tons Capacity, total (volume) 180 CY MWMC_TABLE 7,3 2-1_REV4LDOC 6 MWMC Facilities Plan: MWMC 20-Year Project List And Project Fact Sheets Project Name: Secondary Clarifier Enhancements Description: Baffle, add inlet energy dissipation, change out floccu~ation well, construct outboard launder, and retrofit suction header for existing 8 clarifierso Justification: Enhancing the existing clarifiers will increase the secondary treatment capacity, alleviate current operational problems, and will maximize the facilities investment in existing infrastructure. Project Driver: ~ncrease capacity of secondary treatment for base flows and for peak flows. ~mprove effluent quality and performance reliability to meet the current NPDES total suspended solids limits. Project Trigger: Average secondary ctarifier surface overflow rates exceeding 750 gpd/sf or wet season maximum month flows exceeding 80 mgd. Type of Project 50% Capacity; 50% Performance Estimated Project Cost $5,300,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: Primary Ciarifier Enhancements Description: Baffling of primary clar~flers and remove hydraulic restrictions. Justification: Enhancing the existing clarifiers witt increase primary treatment capacity and will maximize the facilities investment in existing infrastructure. Project Driver: ~ncrease capacity to treat base and peak flows and improve effluent quality and reliability so that a blended primary and secondary effluent can meet the current NPDES total suspended solids limits. Project Trigger: Primary clarifier surface overflow rates exceeding 1500 gpd/sf, or total plant influent flows exceeding 86 mgd. Hydraulic restrictions removed when peak wet weather flows exceed 200 mgd. Type of Project 100% Capacity Estimated Project Cost $1,200,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: South Aeration Basin Improvements. Description: Add step feed, anoxic selectors, and fine bubble diffusers to south aeration basin. Remove hydraulic restrictions in both south and north aeration basins (effluent gates). Includes future primary effluent flow control gates for both north and south aeration basins. Justification: Increase the dry weather aeration basin treatment capacity to 65 mgd with respect to ammonia (i.e., with nitrification) and increase the sustained on a weekly basis) wet weather treatment capacity to 130 mgd. Project Driver: NPDES permit includes ammonia ~imit requiring nitrification in dry weather and expansion of wet weather capacity to treat wet weather flows to meet NPDES monthly and weekly suspended solids limits. Project Trigger: Maximum month dry weather flow of 25 mgd requiring nitrification. May flows and temperatures could require the use of the south aeration basins in conjunction with the north aeration basins. Peak wet weather flows above 103 mgd require hydraulic modifications. Type of Project 50% Capacity; 50% Performance Estimated Project Cost $6,900,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: Outfall Mixing Zone Study Description: Update 1994 Mixing Zone Study to account for additional 100 mgd (approximate) bankside outfall capacity and for changes to the W~llamette River morphology that may have occurred since the tast study was conducted Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $150,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: Temporary Construction Management Facilities Descripfiori: Modular space at E/S WPCF for staff to manage CIP program. Justification: Space needed for staff to manage the construction of the 5-Year CIP. Project Driver: Increased construction effort relative to previous 5 years. Project Trigger: Commence to implementing 5-year CIP. Type of Project 100% Performance Estimated Project Cost $100,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: Fiber Optic Wiring Description: Install wiring between BMF and E/S WPCF. Justification: Project will provide more efficient communication bet~,Jeen facilities. Project Driver: Current communication system is inadequa~te Project Trigger: N/A Type of Project 100% Performance Estimated Project Cost $10,000 (2004 Dollars): Phasing: Budgeted ~or FY2004/05 Project Name: Digester improvements Descriptior~: Replace gas mixing system for existing three digesters with ~ pump mixing system. Justification: This project will increase the active volume of the digesters, thus allowing for additional solids stabilization volume and potentially deferring the need to construct an additional digester. Project Driver: Need for improved digester mixing to increase active digester volume. Project Trigger: S~udge residence time (SRT) and vo;atile solids reduction design criteria. Type of Project 50% Capacity; 50% Performance Estimated Project Cost $2,000,000 (2004 Dollars): Phasing: Budgeted for FY2004/05 Project Name: River Avenue Improvements Description: Construct road improvements (from existing FY03/04 Budget) [MWMC staff to insert more detail as necessary] Justification: [MWMC staff insert] Project Driver: [MWMC staff insert] Project Trigger: N/A Type of Project 100% Rehabihtation Estimated Project Cost $330,000 (2004 Dottars): Phasing: Budgeted for FY2005/06 Project Name: Biocycle Farm Phase 2 Description: An additional 13(~ acres - site preparation begins in 8/05; planting in 3/06. Justification: Land already purchased and provides additiona~ area adjacent to BMF for application of liquid and dewatered biosolids, Expansion of the BF provides MWMC with more flexibility and control of overall biosolids management program. Project Driver: ~ncreased solids production at the E/S WPCF and currently storing an excess inventory of biosolids in the lagoons. Project Trigger: BF Phase I loading limits for liquid and dewatered biosolids are reached, Also, might accelerate if loss of cooperative farming land application sites. Type of Project 100% Performance Estimated Project Cost $300,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: GBT Building Expansion (Waste Activated Sludge Thickening) Description: Third gravity be~t thickener (GDT) w~th associated at grade building. Assumes additional basement floor space is not required. Justification: Provides additional capacity for WAS thickening and potentially delays the construction of additional digesters. Project Driver: Additional capacity to provide WAS thickening with one unit offline at WWMW upper limit flow project~ons, Nitrification required by the NPDES permit and increasing wastewater flows and loads generates more WAS solids. Provide ability to conduct recuperative thickening so that need for additional digestion volume can potentially be deferred. Project Trigger: Exceeding solids and hydraulic load~ng rate design criteria, Type of Project 100% Capacity Estimated Project Cost $2,500,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Additional Odorous Air Treatment - Part 1 Description: Two 14-foot diameter, 30 foot tall biotower for air collected from two primary clarifier centerwells and launders and new sludge building addition. Justiflcattor~: Primary clarifier weirs and launders are odor sources. The new sludge building addition is also an odor soume. Project Driver: Maintain MWMC's status as environmental stewards. Address neighborhood odor complaints and community concerns regarding odors. Project Trigger: Construction of GBT expansion provides opportunity to capture odors at the GBT and primary clarifiers. Type of Project 100% Performance Estimated Project Cost $2,300,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Biocycle Farm Distribution Equipment Description: Purchase 4 hose reels for Biocycle Farm. Justification: Improve liquid biosolids application. Project Driver: Operabonal and efficiency improvements related to liquid biosotids application. Project Trigger: Biocycle Farm's ability to begin receiving liquid biosolids. Type of Project 100% Pedormance Estimated Project Cost $260,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Update of 2000 Wet Weather Flow Management Plan (WWFMP) Description: Evaluate collection system flow momtoring data collected since the original WWFMP was finalized in 2000, update and run collection system model, and confirm (or revise) convey and treat approach. Justification: Ongoing monitoring data might impact I11 reduction priorities, Project Driver: Ongoing goal to find the most cost effective means of reducing I/I, Project Trigger: Once sufficient monitoring data is available. Type of Project 100% Performance Estimated Project Cost $250,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Support Development of Private Lateral Program Description: MWMC Incentive money. Justification: Private lateral program would make the overall facilitate a more comprehensive I11 reduction program. Project Ongoing goal to find the most cost effective means of reducing Itl, Driver: Project Trigger: Consensus with cities to proceed with program. Type of Project 100% Rehabilitation Estimated Project Cost $250,000 (:2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Screw Pump Station Expansion Description: Add 5th pump to increase capacity from 84 to 99 mgd. Justification: New pump is required to increase total influent pumping capacity to 277 mgd. Project Driver: Systematic elimination of sanitary sewer ovedlows by the year 2010, Project Trigger: Collection system computer model estimates the current wet weather peak flow to plant to be 264 mgd. Overall existing peak flow capacity is 175 mgd so there is already a capacity deficit. Type of Project 100% Capacity Estimated Project Cost $1,700,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: Witakenzie Pump Station Expansion Description: Add four, 14-mgd pumps to increase capacity from 80 to 135 mgd. Justification: Addibonal pumping capacity is required to increase tota~ influent pumping capacity to 277 mgd. Project Driver: Systematic elimination of sanitary sewer overflows by the year 2010. Project Trigger: Collection system computer model estimates the current wet weather peak flow to plant to be 264 mgd. Overall ex~stin9 peak flow capacity is 175 mgd so there is already a capacity deficit. Type of Project 100% Capacity Estimated Project Cost $6,000,000 (2004 Dollars): Phasing: Budgeted for FY2005/06 Project Name: 9th and 10th Secondary Clarifier Desc~'ipfion: This project adds two new 130-ft concrete secondary clarifiers. Justification: The project provides additional secondary treatment and peak flow management capacity. Project Driver: This project expands the wet weather base capacity (maximum month and maximum week conditions). DEQ requirement that the peak wet weather flow (5-year, 24-hour rain event) be treated by the E/S WPCF by the year 2010; need to increase the sustained secondary capacity from approximately 100 mgd to 160 mgd. Project Trigger: Wet season flows through secondary treatment exceeding 134 mgd. Type of Project 100% Capacity Estimated Project Cost $6,300,000 (2004 Dollars): Phasing: Budgeted for FY2006/07 Project Name: Level II Reuse at Seasonal Industrial Waste Description: Provide 1.25 mgd of leve~ Il reuse water at the S~W Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $400,000 (2004 Dollars): Phasing: Budgeted for FY2006/07 Project Name: Local level IV effluent reuse demonstration project Description: 0.5 to 1.0 mgd of Level 4 reuse water. Install moveable filter, UV system, piping, and distribution system. Land to be determined. Justification: Implements Level 4 reuse so that thermal load is removed from the Willamette River, Project Driver: Expansion of dry weather effluent reuse programs, Current NPDES thermal load compliance. Project Trigger: Potential exceedance of NPDES thermal load limit, identification of dry weather water needs for potential clients. Type of Project 100% Performance Estimated Project Cost $2,100,000 (2004 Dollars): Phasing: Budgeted for FY2006/07 Project Name: Reline Lagoons at BMF - Phase 1 Description: Reline lagoons, Phase I - from existing MWMC CIP. Justification: Testing has indicated that the lagoons may be leakin9. Project Driver: Regulatory requirements and maintaining operational reliability. Project Trigger: Identification of temporary storage location for contents of lagoon and ~nstailation of temporary equipment required to transfer lagoon contents, Type of Project 100% Rehabilitation Estimated Project Cost $1,200,000 (2004 Dollars): Phasing: Budgeted for FY2006/07 Project Name: Headworks Expansion Description: Expand headworks so that ail of the 2025 wet weather peak flow receives preliminary treatment. Justification: New dry weather headworks that will be used in conjunction with the existing headworks (which will then be used for peak flow events) to provide preliminary treatment for a total peak wet weather flow of 277 mgd. Project Driver: increases in peak wet weather flows resulting from the elimination of sanitary sewer overflows. Project Trigger: Peak wet weather flows in excess of 210 mgd. Type of Project 100% Capacity Estimated Project Cost $12,800,000 (2004 Dollars): Phasing: Budgeted for FY2007/08 Project Name: Primary Sludge Thickening Outside of Clarifiers Description: Thin primary s~udge pumping and piping systems to thickeners, (covered for odor control), supernatant ovedlow pumping and piping, thickened sludge piping/pumping to digesters. See Odorous Air Treatment for treatment of odors. Justificatior~: One of the projects that increases capacity of existing primary clarifiers from approximately 103 mgd to 165 mgd. Project Driver: All peak wet weather flows must receive primary treatment prior to diversion and effluent blending to meet the current NPDES permit for total suspended solids. Project Trigger: Primary clariher surface overflow rates exceeding 1800 gpd/sf: Sustained wet weather flows through the primaries in excess of 103 mgd after baffling improvements are made. Type of Project 100% Capacity Estiroated Project Cost $3,600,000 (2004 Dollars): Phasing: Budgeted for FY2007/08 Project Name: Biocycle Farm Phase 3 Description: Final 120 acres of the Biocyc~e Farm - site preparation begins in 8/07; planting in 3/08 Justification: Land already purchased and provides additiona~ area adjacent to BMF for application of ~iquid and dewatered biosolids. Expansion of the BF provides MWMC with more flexibility and control of overall biosolids management program. Project Driver: ~ncreased solids production at the F_JS WPCF and currently storing an excess inventory of biosoiids in the lagoons. Project Trigger: BF Phase 1 and 2 loading limits for liquid and dewatered biosolids are reached. Also, might accelerate if loss of cooperative farming land application sites occur. Type of Project 100% Performance Estimated Project Cost $300,000 (2004 Dollars): Phasing: Budgeted for FY2007/08 Project Name: Conversion to Sodium Hypochlorite disinfection Description: Convert existing chlorine gas system to sodium hypochlorite for the base flow. Retain the existing chlorine contact bas~ns, install system with capability for high rate disinfection of PE diversion assuming high dosages of chlorine into a 72qnch pipe and small chlorine contact basin. Justification: Liquid sodium hypochlodte and sodium bisulfite system will replace the existing chlorine sulfur dioxide gas systems and increase the disinfection capacity from 175 mgd to 277 mgd. Project Driver: Operator and community safety issues. Project Trigger: Phasing with other related projects. Type of Project 50% Capacity; 50% Pedormance Estimated Project Cost $4,100,000 (2004 Dollars): Phasing: Budgeted for FY2007/08 Additional Odorous Air Treatment Part 2 Project Name: Description: Two 14-foot diameter, 30 foot tall biotowers for air collected from two primary clarifier centerwells and launders and new gravity thickener Justification: Primary clarifier weirs and launders as well as gravity thickeners are odor sources. Project Driver: Maintain MWMC's status as environmental stewards. Address neighborhood odor complaints and community concerns regarding odors. Project Trigger: Construction of gravity thickeners. Type of Project 100% Performance Estimated Project Cost $2,300,000 (2004 Dollars): Phasing: Budgeted for FY2008/09 Project Name: Parallel Primary/Secondary Peak Flow Management Description: Piping, pumping, and flow split boxes to enable primary and secondary treatment to be operated in parallel Justification: This project expands the peak wet weather treatment capacity to 277 mgd through flow management techniques. Project Driver: DEQ requirement that the peak wet weather flow (5-year, 24-hour rain event) be treated by the E/S WPCF and meet secondary effluent standards (diverted blended flow receives equivalent of primary treatment). Project Trigger: Elimination of sanitary sewer overflows by the year 2010. Type of Project 100% Capacity Estimated Project Cost $11,000,000 (2004 Dollars): Phasing: Budgeted for FY2008/09 Project Name: Filtration. (10 mgd) - Part 1 Description: Filtration: includes infrastructure/support facilities for 30 mgd of fi~ters; instatl filter cells sufficient for only 10 mgd. Justification: An estimated 30 mgd of filters is required by 2010 to meet dry season mass limits. Facility Plan proposes phasing filters in sooner to facilitate development of Level 3 and Level 4 reuse. Provides high quality secondary effluent and potential level 4 reuse water. Also, needed to assist with meeting wet season mass ~oad requirements during peak flow events (under all peak flow management alternatives). Project Driver: Performance reliability to meet the dry weather NPDES total suspended solids ~imits of less than 10 mg/L, reuse development, and compliance with peak flow management. Project Trigger: NPDES permit compliance for TSS: Dry weather maximum month flow in excess of 49 mgd. Also, initially to provide higher quality effluent so that reuse can be developed. Type of Project 25% Capacity; 75% Performance Estimated Project Cost $10,100,000 (2004 Dollars): Phasing: Budgeted for FY2008/09 Project Name: New Bankside Outfa~l Description: Bankside out[all to accommodate 117 mgd (277 mgd less 160 mgd which is the estimated capacity of the existing outfall system after secondary treatment modifications. Justification: New bankside outfall is required to pass the peak wet weather flow to the river. Project Driver: After secondary treatment modifications are made, a maximum peak flow of 160 mgd can pass through the existing outfa~ box without submerging the secondary cladfier weirs. Project Trigger: Peak wet weather flows in excess of 160 mgd. Type of Project t 00% Capacity Estimated Project Cost $1,500,000 (2004 Do~iars): Phasing: Budgeted for FY2009/10 Project Name: Level I! Reuse at the Biocycle Farm Description: Provide 1.5 mgd of level I1 reuse water at the Biocycle Farm. Installation of dedicated reuse irrigation pipeline and microspray system. Tota~ reuse of 3.75 mgd in July and August. Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $3,600,000 (2004 Dollars): Phasing: Budgeted for FY2009/10 Project Name: Reline Lagoons at BMF - Phase 2 Description: Reline lagoons, Phase 2 - from existing MWMC CIP. Justification: Testing has indicated that the lagoons may be leaking. Project Driver: Regulatory requirements and maintaining operational reliabi~ity~ Project Trigger: Identification of temporary storage location for contents of lagoon and installation of temporary equipment required to transfer lagoon contents. Type of Project 100% Rehabilitation Estimated Project Cost $1,100,000 (2004 Dollars): Phasing: Budgeted for FY2009/10 Project Name: Gienwood Pump Station Upgrade Description: Expand pump station capacity (from existing FY03/04 budget) Justification: Additiona~ pumping capacity is required to increase tota~ influent pumping capacity to 277 mgd. Project Driver: Systematic elimination of sanitary sewer ovedlows by the year 2010. Project Trigger: Collection system computer model estimates the current wet weather peak flow to plant to be 264 mgd. Overall existing peak flow capacity is 175 mgd so them is already a capacity deficit. Type of Project 100% Capacity Estimated Project Cost $500,000 (2004 Dollars): Phasing: Budgeted for FY2010/11 Project Name: Additional Digestion Capacity and Class A Biosolids Production Capacity Description: Add fourth digester and or convert to thermophi~ic digestion to achieve Class A. Justification: Project Driver: Project Trigger: Type of Project 66% Capacity; 34% Performance Estimated Project Cost $13,800,000 (2004 Dollars): Phasing: Budget for FY2010/11 Project Name: Additional Odorous Air Treatment - Part 3 Description: One 14-foot diameter, 30-foot tall biotower for air collected from headworks expansion and conversion of the existing air sources from biofilter to biotowers. Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $2,300,000 (2004 Dollars): Phasing: Budgeted for FY2010/11 Project Name: Reline lagoons at BMF - Phase 3 Description: Reline lagoons - phase 3. From existing MWMC CIP Justification: Project Driver: Project Trigger: Type of Project 100% Rehabilitation Estimated Project Cost $1,100,000 (2004 Dollars): Phasing: Budgeted for FY2010/11 Project Name: Facilities Plan Update Description: Update portions of the existing Facilities Plan Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $150,000 (2004 Dollars): Phasing: Budgeted for FY2010/11 Project Name: Reline ~agoons at BMF - phase 4 Description: Reline lagoons - phase 4. From existing MWMC CIP Justification: Project Driver: Project Trigger: Type of Project 100% Rehabilitation Estimated Project Cost $1,100,000 (2004 Do~ars): Phasing: Budgeted for FY2011/12 Project Name: Repair/partial replacement of biosolids forcemain Description: Repair/replace sections of the biosolids forcemain where struvite deposits limit pipe diameter and cannot be removed by acid wash. Justification: Project Driver: Project Trigger: Type of Project 100% Rehabilitation Estimated Project Cost $1,000,000 (2004 Dollars): Phasing: Budgeted for FY2011/12 Project Name: Permanent Level iV Reuse Description: Provide 2.5 mgd of permanent Level IV muse water to local greenspaces and community areas. Modify/install UV system capable of 3 mgd and modify/increase piping system installed in demonstration project. Total reuse of 5.25 mgd. Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $4,100,000 (2004 Dollars): Phasing: Budgeted for FY20t2/13 Project Name: Fiitration (10 mgd) - Part 2 Description: Additional 10 mgd of filter cells, for a total of 20 mgd. Justification: An estimated 30 mgd of filters is required by 2010 to meet dry season mass limits. Facility Plan preposes phasing filters in sooner to facilitate development of Leve~ 3 and Level 4 reuse. Provides high quality secondary effluent and potential level 4 reuse water. Also, needed to assist with meeting wet season mass load requirements during peak flow events (under all peak flow management alternatives). Project Driver: Performance reliability to meet the dry weather NPDES total suspended solids limits of less than 10 rog/L, reuse development, and compliance with peak flow managemenL Project Trigger: NPDES permit compliance for TSS: Dry weather maximum month flow in excess of 49 mgd. Also, initially to previde higher quality effluent so that reuse can be developed. Type of Project 25% Capacity; 75% Pedormance Estimated Project Cost $5,050,000 (2004 Dollars): Phasing: Budgeted for FY2013/14 Project Name: Comprehensive Facilities Plan Description: Comprehensive update to portions of the MWMC Facilities Plan Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $800,000 (2004 DoJlars): Phasing: Budgeted for FY2014/15 Project Name: North Aeration Basin Improvements Description: Add step-feed, anoxic selectors, and assume existing diffusers will be replaced in 15 years, main air header will not be replaced Justification: Project Driver: Project Trigger: Type of Project 50% Capacity; 50% Performance Estimated Project Cost $6,200,000 (2004 Dollars): Phasing: Budgeted for FY2015/16 Project Name: Level IV Reuse - Full Scale Operation Description: Provide 2.5 to 5.0 mgd of Level IV reuse, increase pumping capacity, reuse pipeline, and UV system. Total rouse capacity of 7.75 to 10.25 mgd. Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $9,800,000 (2004 Dollars): Phasing: Budgeted for FY2015/16 Project Name: Composting Facility Description: Expand composting facility at the Biosolids Management Facility (from existing MWMC CIP) Justification: Project Driver: Project Trigger: Type of Project 100% Pedormance Estimated Project Cost $650,000 (2004 Dollars): Phasing: Budgeted for FY2015/16 Project Name: Maintenance Facility Improvements Description: Update/upgrade the operations and maintenance facilities at the E-S WPCF Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $1,500,000 {2004 Dollars): Phasing: Budgeted for FY2017/18 Project Name: Filtration ('10 m§d) - Part 3 Description: Additional 10 mgd of filter ce~ls, for a total of 30 mgd~ Justification: An estimated 30 mgd of filters is required by 2010 to meet dry season mass limits. Facility Plan proposes phasing filters in sooner to facilitate development of Level 3 and Level 4 reuse. Provides high quality secondary effluent and potential level 4 reuse water Also, needed to assist with meeting wet season mass load requirements during peak flow events (under alt peak flow management alternatives). Project Driver: Performance reliability to meet the dry weather NPDES total suspended solids limits of less than 10 rog/L, reuse development, and compliance with peak flow management. Project Trigger: NPDES permit compliance for TSS: Dry weather maximum month flow in excess of 49 mgd. Also, initially to provide higher quality effluent so that reuse can be developed. Type of Project 25% Capacity; 75% Performance Estimated Project Cost $5,050,000 (2004 Dollars): Phasing: Budgeted for FY2018/19 Project Name: Facility Plan Update Description: Update of portions of the current Facilities Plan J ustification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $150,000 (2004 Dollars): Phasing: Budgeted for FY2019/20 Project Name: Comprehensive Facilibes Plan Description: Comprehensive update to portions of the MWMC Facilities Plan Justification: Project Driver: Project Trigger: Type of Project 100% Performance Estimated Project Cost $800,000 (2004 Dollars): Phasing: Budgeted for FY2023/24 8.0 Financial Strategy 8.1 Introduction This financial strategy presents MWMC's current financial status and policies, future financial needs, and discusses the strategy for meeting these needs. 8.2 Current Financial Status and Policies Financial Status - In 2003, MWMC adopted an update o£ its financial plan. A financ'ml consultant performed a review of MWMC's financial stattrs as part of the plan update. The consultant used a variety of financial ratios to quantify MWMC's £mancial soundness. Examples of these financial ratios are: Operating ratio: Operating and maintenance expenses, divided by the total operating expenses, Net take-down ratio: Net revenues~ divided by gross revenue a_nd income, Interest coverage ratio: Net revenues, divided by interest requirements for the period, Debt service coverage ratio: Net revenues, divided by principal and interest requirements £or the period, and Debt service safety margin ratio: Net revenues, less principal and interest requirements for the period, divided by gross revenue and income. On the basis of this analysis, the consultant found: MWMC is posit~oned well finandally. MWMC's current financial situation, with zero long-term debt, and the 10-year future debt-financing scenario result in performance on the quantitative measures that exceeds (in a good sense) the national medians and the financing industry~s guidelines (The consults review was based on a 10-year future debt-£mancing scenario). · Qualitative measures assessed indicate that MWMC is in a strong pom'tion with respect to its credit-worthiness. MWMC's sound financial management, long-term financial forecasting and planning, stable operations and a host of other qualitative indicators all indicate that MWMC would perform extremely well in any assessment by a credit rating agency or other financial body. Financlal Management PoIicies - MWMC Financial Policies are grouped into the following categories: · Financial Forecasting and Budgeting MWMC_8.0_REV5 DOC 8.1 MWMC FACILITIES PLAN Capital PlmmLng and Financing Sewer User Rates and System Development Charges Asset Management Financial Forecasting and Budgeting - Financial forecasts and budget policies are intended to guide the Commission in prudent financial forecasting and budget planning, and are included to ensure the financial security and bonding capacity of the Regional Wastewater Program (RWP), as well as meeting m/nimum legal budget requirements. This set of policies also addresses the Commission's legal and contractual commitments regarding the use of sewer revenues to pay for sewer expenses. The purpose of the RWP is to protect public health and safety and the environment by providing high-quality wastewater management services to the Eugene/Springfield metropolitan area. The MWMC and the regional partners are committed to providing these services in a manner that ks effective, efficient, and meets customer service expectations. In order to achieve its purpose, the Commission shall establish and maintain key outcomes upon which RWP work plans and budgets will be focused. 2. The Commission shall maintain annual budgets that balance operating expenses with user fees a_nd other current operating revenue. 3. The Commission will monitor revenues and expenditures, and ma/nta/n a balanced budget through an appropriate combination of cost-saving measures, budget transfers, supplemental budgets and/or user rate adjustments as needed. 4. The Commission shall maintain a multi-year financial forecast and cash-flow projection, which estimates service levels, operating expenses, capital needs, reserves, and debt service. 5. The Commission shall establish and maintain prudent minimum cash reserves, including but not lkrdted to: Working Capital Reserve, Operating Reserve, Capital Reserve, Equipment Replacement Reserve, and Rate Stability Reserve. a. The Working Capital Reserve shall be sufficient to fulfill operating and capital cash flow needs. b. The Operating Reserve shall be maintained to mi_nkn~e the impact of unantidpated revenue shortfalls. c. The Capital Reserve shall accumulate revenue to prov/de for future projects. The Capital Reserve shall be funded by annual contribulions from user rates. A portion of the Capital Reserve shall be kept on hand and designated for conlgngency needs. d. The Equipment Replacement Reserve shall provide for the timely replacement or rehabilitation of equipment and may also be borrowed agairrst to provide short-term financing of capital/mprovements. e. A Rate Stabffity Reserve shall be maintained as necessary to protect ratepayers from volatility in user rates and to enhance credit-worthiness. 8-2 MWMC_8 0_RE'q5 DOC 8 FINANCIAL STRATEGY 6. MWMC hands are dedicated for the exclusive benefit of the RWP including operatfiag expenses, debt service payments, and the associated capital program. Capital Planning and Fh~ancing - Capital planrfing and financing policies direct that necessary future capital improvements be identified together with the f~zmcia~ resources needed to complete them. These policies also direct that major capital costs be spread over time to stabilize user rates and to provide equity among current and future ratepayers for long-lived capital ~nprovements. 1. The Commission shall maintain a capital planning and ffnancfng system for use in preparing a mtdti-year capital improvement project (C/P) 1L~ for consideration and adoption by MWMC and ratification by the partner agencies' governing bodies as a part of the Commission's budget process. 2. The Commission shall establish and maintain a list of approved finance mechanisms. 3. The Commission shall utilize debt service professionals and Government Finance Officers Association (GFOA) guidance to struchare bond covenants. Commission debt should be structured to match the expected useful life of the assets to be banded, but in no case exceed 20 years. 5. Long-term bonding shall be structured to maxLmize its cost effectiveness. 6. Before seeking to incur new debt, all available grant programs shall be evaluated for their potential to offset targeted program costs. 7. Consideration shall be given to the overall level of debt financing that can be sustained over the long-term given the size of the ~ature capital programs, potent/al impacts on credit ratings, and other relevant factors such as intergenerationai rate equity, overlapping debt, and the types of projects appropriately financed with long-term debt. 8. Consideration shall be given to competing demands for use of the comm'ardty's overall debt financing capacity. 9. Capital ~eserves and system development charge (SDC) reserves on h~aad shall generally be used for projects with a total cost of under $1 million. These reserves shall also be used in the early stages of a multi-year project so that bond issuance can be delayed and aggregated. 10. The Commission shall annually target 2 percent of the RWP asset value for capital reinvestment. This includes the amounts to be budgeted for major rehabilita~on and equipment replacement. 11. The max/rotan bonded debt burden shall be determined by comparing the debt service to the user ~ate. Budgeted debt service shall not exceed 25 percent of budgeted user rate Sewer User Rates and System Development Charges - User rate and SDC policies are intended to guide the Commission in establishing annual rate structures and approving RWP capital improvement and operating budgets. MWMC_8 0_REV5 DOC MWMC FACILITIES PLAN 1. Monthly sewer user rates, which are the primary source of revenue for the RWP, are to be equitably allocated to all customers based on a cost of service assessment. 2. New customers to the RWP shall pay an SDC. The Commission shah maintain the SDC methodology within the constraints of state law. 3. Existing and new sewer customers shall equitabIy contribute to the cost of Lhe RWP. To implement f_his policy, user rate and SDC methodologies will consider wastewater quantity, quality, and strength, consistent with state law. 4. MWMC rate structures shah be sufficient to fully fund reserves, comply with bond covenants, and cover the costs of constructing, operating, rehabilitating, maintaining, and improving the MWMC assets. 5. The Commission will attempt to adopt user rates that provide multi-year stability. 6. Costs of existing and future capacity for new customers shall be recovered by SDCs that are based on the cost of existing and required new capacity. 7. Costs of services (direct and indirect) provided to any public or private organizations by the RWP shall be recovered through appropriate fees or charges. Asset Management - Asset management policies are intended to guide the Corvwnission in protecting and safeguarding the investment in regional facilities and equipment. Capital asse~s Shall be kept in sound working condition. Replacement, maintenance, and rehabilitation shall be provided for so that total system costs are minimized while reliable, high-quality service and high water quality standards are maintained. 1. MWMC assets shall be insured for replacement value so that, in the evev. t of a loss, plant and equipment could be restored to working condition. 2. The Commission shall maintain a fully-funded Equipment Replacement Reserve so equipment can be replaced or rehabilitated when needed without creating volatility in the operating budget. 3. Equipment provided for by the Equipment Replacement Reserve shall include all roiling stock, all computer equipment, and all other equipment with a historical cost between $10,000 and $200,000, a projected replacement cost between $10,000 and $200,000, axed with a useful life expectancy of between 1 and up to 20 years. 4. Major rehabilitation work shah be funded from the Capital Reserve and appropriated annually into a budget line item called Major Rehab. 5. The Major Rehab work shall be capitalized if it extends the useful life of the asset beyond the original estimate. If the Major Rehab work does not extend the life of the asset, but enables the asset to reach its originally estimated useful life, then it wilJ be considered major maintenance work and not capitalized. 84 MWMC_B.O~REV5 DOC FINANCIAL STRATEGY 8.3 Future Costs and Revenues 8,3.1 Operation and Maintenance Costs An estimate o~ O&M costs, including personnel, materials, and service costs, is presented in Table 8.2.1. As new fadlities are placed on-line throughout the 20-year planning per/od, these costs will be further refined. TABLE 8.2.1 MWMC Projected Personnel, Materials and Service Costs For Study Pedod MWMC Facilities Plan, Eugene-Springfield Personal Services $181,400,000 [~ateriais & Services $109,840,000 Capital Outlay $700,000 Total $351,940.000 8.3.2 Replacement Cost of Proposed System Equipment replacement purchases were budgeted at $1,026,630 in FY 03-04; rehabilitation was budgeted at $182,000 in FY 03-04. Annual Equipment replacement purchases and rehabilitation expenditures are projected to average $1,100,000 and $400,000, respectively, over the study period. 8.3.3 Capital Project Needs As recommended in Chapter 7.0, MWMC intends to proceed with implementation of the $144 million Alternative 5 - Parallel Pr/mary/Secondary Treatment. l_f DEQ does not approve Alternative 5, then MWMC intends to proceed with implementation of the $157 million Alternative 4 - High-Rate Clarification (assuming that DEQ is willing to approve Alternative 4 as the next best alternative). 8.3.4 Sources of Revenue In the past, MWMC has generated revenues from monthly sewer rates, SDCs, and special assessments on property taxes associated with the general obligation bonds that were issued for the construction of the original regional system in the 1980s. As was mentioned in section 8.2, the general obligation bonds have been paid off and the current sources of revenue are montl'dy sewer user fees and SDCs. it is assumed that these two methods will continue to be the primary sources of revenue through the study period. MWMC_B O_REV5 DOC 8-5 MW'MC FACiLiTiES PLAN Sewer user fee needs are assessed by MWMC on an annual basis as part of the budgetary process. MWMC policies regarding sewer user rates are described above. Table 8.3.4-1 describes current custozrter classes, numbers of accounts, annual discharges and projected revenue for FY 03-04. TABLE MWMC Sewer User Rate Data MWMC Facilities Plan, Eugene-Springfield Annua~ Sewer User Fee Classifications Discharge Projected (Strength based on tota~ pounds BeD and TSS) Accounts (1,000 ga~) Revenue Residential 65,600 3,924,400 $7,145,000 Low Strength (0 to 400) 5,410 2,703,700 3,589,000 Medium Strength (400 to 800) 73 167,400 301,000 High Strength (800 to 1,200) 320 229,500 596,000 Very High Strength (1,200 to 1,600) 0 0 0 Super High Strength (>1,600) 16 34,400 139,000 Septage 4000 381,000 MWMC recently approved an SDC methodology to comply with state statutes that will go Lute effect June 1, 2004. MWMC policies regarding sewer user rates are described above. Table 8.3.4-2 describes projected SDC revenue for FY 04-05. TABLE Projected SDC Revenue for FY 2004- 2005 MWMC Facilities Plan, Eugene-Springfield SDC Strength Based Development Classifications Projected (Strength based on total pounds BeD and TSS) Revenue Residential $1,214,092 Low Strength (0 to 400) 629,079 Medium Strength (400 to 800) 68,104 High Strength (800 to 1,200) 145,514 Super High Strength (>1,800) 503 Total $2,057,292 8-6 MWMC_80_REV5 DOC FINANCIAL STRATEGY 8.4 Evaluation of Local Funding Resources MWMC will rely on monthly wastewater rates and SDCs for revenue. Financing for capital projects w/il most likely be provided by revenue bonds, although MWMC would like to retain the option to use t. he State Revolving Loan Fund (SRF) program administered by DEQ. As stated in section 8.2, MWMC is in a strong position with respect to its credit-worth/ness. MWMC's sound financial management, long-term financial forecasting and planning, stable operations, and a host of other qualitative indicators all show that MWMC would per£orm extremely well in any assessment by a credit rating agency or other financhl body. 8.5 Evaluation of Federal and State Funding Resources In previous financial evaluations, MWMC staff evaluated potential federal and state funding resources for which MWMC might qual~. The SPd~ program was identified as the only realistic alternative, but was determined to be less cost-effective than funding projects through revenue bonds. MWMC would like to retain the option of accessing the SRF program and has developed this comprehensive Facilities Plan to be eligible for SRF monies ff that financing approach becomes more favorable than revenue bonds in the futvrre. 8.6 Recommended Financing Strategy 8.6.1 System Development Charges A thorough revision of the SDC methodology was recently completed for the MWIvIC regional wastewater system and was adopted by the Commission on April 1, 2004. The methodology was developed/n accordance with Oregon SDC legislation (ORS 223.297- 223.314), and with the guidance of a CAC appointed by MWMC. The MWMC SDC Methodology is based on a comb/ned reimbursement and improvement fee structure. In order to calculate the improvement fee portion of the SDCs, it is necessary to allocate the costs of capital projects as follows: Step 1: Allocate projects to facility process components (e.g., prima~ treatment, secondary treatment, etc.) Step 2: Allocate costs by components to system capacity parameters (e.g., average flow, peak flow, etc.) · Step 3: Allocate project costs to improvement type (capacity improvement, performance upgrade, or rehabilitation) ~ Step 4: Allocate costs to user type (existing customers or projected growth) These steps are applied to the $144 million 20-year project list (Alternat/ve 5 - Parallel Primary/Secondary Treatment). Steps 1 and 3 have to be developed on a case-by-case basis for the 20-year project list in question. Step 2 and 4 are inherent in the methodology and occur automatically once the allocations associated with Step 1 and 3 are determined. The basis for allocating projects in the proposed MWMC 20-year project list to the facility MWMC_8 0_REVS.DOC 8-7 MWMC FACILITIES PLAN process components (Step 1) and to an improvement type (Step 3) is discussed later in this section and is summarized in Table 8.6.1-1 (located at the end of this chapter). Then, combining Steps 1 and 3 with the allocations determined by the methodology (Steps 2 and 4), the resulting breakdown between growth (SDCs) and exis~g user rates ~ presented in Table 8.6.1-2 (located at the end of this chapter). In summary, approximately 40 percent ($57.8 million) of the 20-year project list is projected to be funded by SDCs, with the remainLng 60 percent ($86.2 million) funded by user rates. In Step 1 each future project is allocated to the following 12 facility components (Lqcluding 3 subcategories for biosolids): Collection system pipeline Collection system pump stations Prelirrfinary treahnent Primary treatment Secondary treatment Disinfection/ouffa~ Biosolids - General - Dewatering - Biocycle Farm Tertiary filters Reuse facilities Odor Control Peak flow management Support Facikities (Indirects) These facility process components are defined in the SDC Methodology as adopted by MWMC on April 1, 2004. In addition, an allocation of the projects to project type is also presented. The three project types are Capacity, Performance, and Rehabilitation, wb2ch are defined in the SDC Methodology. The majority of the projects are allocated to one project type; however, some projects will be split between capacity and performance types. Projects that have identical allocations and basis for allocations may be grouped together. The basis for allocating projects in the proposed MWMC 20-year project list to the facility process components (Step 1) and to an improvement type (Step 3) is discussed in the following paragraphs. 8-8 MW~C_80_REV5 DOC 8 FINANCIAL STP~TEGY 8.6.2 Collection System/lnfluent Pumping GJenwood Pump Station Upgrades, Wil~akenzie Pump Station Expansion, and Screw Pump Station Expansion Facility Component Allocation These projects expand the base pumping capacity of the respective pump stations. The peak flow capacity of MWMC's overall facilities is also increased as a result of these projects. The allocation is split equally between Collection System Pump Stations and Peak Flow Management. Project Type Allocation These projects expand influent purnp~g and peak flow capadty and are therefore allocated entirely to Capacity. River Avenue improvements Facility Component Allocation This project makes improvements to the roadway and is allocated entirely to Support Fadlities. Project Type Allocation This project re_habJlitates the roadway and is therefore allocated entirely to Rehabilitation. 8.6.3 Liquids Treatment Headworks Expansion Facility Component Allocation This project expands both preliminary treatment and peak flow capadty so the allocation is split equally between Preliminary Treatment and Peak Flow Manigement. Project Type Allocation This project expands capacity and is allocated enffrely to Capacity. Primary Clarifiet Enhancements and Primary Sludge Thickening Outside of Primary Clarifiers Facility Component Allocation These projects expand both the primary treatment and the overall peak flow capadty of the fadlity so the allocation is split equally between Primary Treatment and Peak Flow Management. Project Type Allocation These projects expand capadty and are allocated enfftely to Capacity. Additional Odorous Air Treatment Facility Component Allocation These improvements are allocated entirely to Odor Contzol. MWMC_8,0_REVS, DOC 8-9 MWMC FACILITIES PLAN Project Type Allocation These improvements, which are driven by increased community performance shandards, provide capacity/enhanced capability for both the growth Lncrement and for exLsting users and are therefore allocated entirely to Performance. Aeration Basin Uodificafions - South and North Facility Component Allocation The pr~nary purpose of these modifications zs to Lrnprove the capacity of the aeration basins and the performance of the overall secondary treatment system. A secondary benefit of these projects is to provide the WPCF with additional operational flexib~ty during peak flow events. These projects are allocated 90 percent to Secondary Treatment and 10 percent to Peak Flow Management. Project Type Allocation These projects expand capacity as well as improve the performance of the secondary treatment system to meet the new ammonia limit and more effectively and consistently meet the BOD and TSS limits moving forward. These projects are equally d~vided between Capacity and Performance. Secondary Clarifier Enhancements Facility Component Allocation This project is allocated equally between Secondary Treatment and ]?eak Flow Management because both the base capacity of the secondary treatment process as well as the peak flow capacity of the facil~ty are increased as a result of these ~nprovements. Project Type Allocation Tl~s project is split equally between Capacity and Performance because t_he modLfica~ions to these existing urdts increases the ]Squids treatment capacity of t_he facility and also improves the consistency/reliabffity of the effluent performance. 9th and l0· Secondary C~arifiers Facility Component Allocation Construction of these two additional units increases the base capacity of the secondary treatment system and the peak flow capacity of the overall facility and therefore the allocation is split equally between Secondary Treatment and Peak Flow Management. Project Type Allocation This project expands capacity and is allocated ert~Lrely to Capacity. Conversion to Sodium Hypoch~orite Disinfection Facility Component Allocation Approximately half of the cost of this project will provide the facilities to convert disinfection from chlorine to sodium hypochlorite for the base secondary effluent flow. The remaining half of the costs of this project are for providing disinfect]on to the high-rate clarification effluent ~ the case of peak flow management Alternative 4, or to the primary effluent in the case of peak flow management Alternative 5. Therefore, 50 percent is allocated to DisinfecQon/Ouffall and 50 percent to Peak Flow Management. 8-10 I~WMC_8 0_REV5 DOC 8 FtNANCL~L STRATEGY Project Type Allocation Providing disaffection for the peak flow management flow stream is additional capac2[y; replacing the exist~g chlorine disinfection system is the result of commurrity performance standards. Therefore, 50 percent is allocated to Capacity and 50 percent to Performance because this is the same breakdown between facffity components Peak Flow Management and Disinfection/Ouffall. Filtration Facility Component Allocation Filtration is a new unit process and is aliocated almost entirely to the new facility component, Tertiary Filters. It is anticipated that during peak flow events, a portion of the secondary effluent will be routed through the filters to assist with permit compliance so there ~ be some peak flow benefit. Therefore, 90 percent is allocated to Tertiary F~lters and 10 percent to Peak Flow Management. Project Type Allocation The filters will provide for more consistent/reIiab]e effluent performance ~xt the dry season to all users - existing and future. A primary driver of the fLlters is to provide an increased level o£ performance to enable MWMC to comply with existing mass load 1/m/ts as influent flows increase. Also, by removing loads/-rom the final effluent the f~lters in essence &ee up or create additional dry season capacity. The aliocafdon is assigned 25 percent to Capacity and 75 percent to Performance. Peak Flow Management Primary Secondary Alternative 5: Facility Component Allocation This project is allocated entirely to Peak Flow Management. Tbfis allocation would not change ff a different peak flow management alternative were ultimately J.mplemented. Project Type Allocation ThLs project will increase the peak flow capacity of the facility and is allocated entirely to Capacity. It should be noted that Lf MWMC is required to implement the more costly peak flow management approach (Alternative 3 - Full Primary Treatment or Alterrmttve 4 - High-Rate Clarification), other projects that have some peak flow management benefit such as primary clarff/er enhancements, secondary ctartfier enhancements, and the 9~ and 10ta secondary clattfiers will still be implemented. New Bankside Outfali Facility Component Allocation This project provides additional ba.~e ouffall capacity/performance and would also Ja2crease the peak flow capacity of the overall facffity. The project is allocated equally between Disinfection/Outfall and Peak Flow Management. Project Type Allocation This project expands the capacity of the discharge ouffa~ system to the Willamette Privet entirely to Capacity. and allocated MWMC_8 0_REV5 DOC 8-11 MWMC FAQLtTIES PLAN 8,6.4 Biosolids Waste Activated Sludge Thickening Facility Component Allocation This project is allocated entirely to Biosohds-General. Project Type Allocation This project would expand the capacity of WAS thickening and potentially defer construction of additional digestion capacity. The allocation is assigned to Capacity. Additional Digestion Capaci[y and Class A Capability Facility Component Allocation This project is allocated entirely to Biosolids-General. Project Type Allocation This project provides additional digestion capacity (approximately one-third of the cost) and would convert MWMC to a Class A biosolids program (remaining two-ffdrds of the cost), which would provide additional enhanced capability to address higher community performance standards. The aliocation is split one-third/two-thirds between Capacity and Performance. Digester Uixing Improvements Facility Component Allocation This project is allocated entirely to Biosolids-GeneraL Project Type Allocation This project improves the performance of the exisffng three digesters. Ln doing so a larger portion of the existing tankage can actually be used for digestion and therefore construction of additional digestion capacity can be deferred. The project is allocated 50 percent to Capacity and 50 percent to Performance. Biocyc~e Farm Phases 2 and 3 Facility Component Allocation These projects are allocated to the Biosolids-Biocycle Farm. Project Type Allocation The Biocycle Farm provides emhanced capability and reliability to IvFWMC's overall biosolids management program and is therefore allocated to Performance. Biocycle Farm Biosolids Distribution Equipment Facility Component Allocation This project is allocated to the Biosolids-Biocycle Farm component. Project Type Allocation The Biocycle Farm provides enhanced capability and reliability to MWMC's overall biosolids management program and is therefore allocated to Performance. 8-12 MWMC_8 0_REV5 DOC FINANCIAL STRATEGY Composting Facility ?acility Component Allocation Similar to the Biocycle Farm, this project would further develop MWMC's pilot composting program, which serves to enhance the capabJl/ty and reliability of MWMC's overall biosolids management program. This project is allocated to Biosolids-Biocycle Farm. Project Type Allocatio~ Composting serves a similar purpose as the Biocycle Farm and is therefore allocated to Performance. Re. Line Lagoons Phases t through 4 Facility Component Allocation This project is allocated entirely to Biosolids-Generat. Project Type Allocation This project replaces the existing liners in the biosolids storage lagoons at the Biosolids Management Facility and therefore is allocated to Rehabilitation. Repairs/Partial Replacement of Biosolids Force Main Facility Component Allocation This project would repair and/or replace certain sections of the biosolids force main, which conveys treated biosolids from the WPCF to the BMF. The project is allocated entirely to Biosolids-General. Project Type Allocation This project would rehabilitate the existing biosolids force main and is allocated entirely to Rehabilital2on. 8.6.5 Support Facilities Maintenance Facility Improvements and Fiber Optic Wiring Facility Component Aflocation These projects serve MIAAViC's overag efforts and are allocated to the Support Facffities (Indirects) component. Project Type Allocation These projects would benefit both the growth increment and existing users by enhancing staff's ability to operate and maintain MWMC's facilities. These projects are allocated to Performance. 8.6.8 Effluent Reuse Effluent Reuse Facility Componer~t Allocation This ongoing program to develop reuse to mitigate water quality impacts to the Wi~amette River is allocated entirely to Reuse Facilities. IViWMG_8.0_REVS. DOC 8-.13 MWMC FACILITIES PLAN Project Type Allocation Effluent reuse takes WPCF effluent out of the Willamette River. Potent-ia1 end uses include irrigation of landscaping and agricultural lands. Development of reuse will help MW-MC comply with existing and future thermal load limits, which may become more stringent. Reuse will also assist with future compliance with mass load limits. As reuse is expanded and effluent is used for irrigation or other uses instead of discharged to the Willamette River, capacity is essentially freed up for new users. Effluent reuse benefits both existing users and growth proportionate to their average flow contribution and is therefore allocated to Performance. 8.6.7 Other Projects Temporary Construction t~anagement, Facility Plan Update Projects, Wet Weather F~ow Management PLan Update, and Support Development of Private Lateral Program Facility Component Allocation These projects serve MWMC's overall efforts and are allocated to Support Fac~ties. Project Type Allocation These projects identify long-term planning approaches and/or enable MWMC to continue to operate the facilities in a manner that complies with local, state, and federal guidelines. It is assumed that these projects benefit both exis 'ting and the growth increment equally and are therefore allocated to Performance. Mixing Zone Study Update Facility Component Allocation The purpose of this study is to determine the characteristics of the mixing zone of the outfall to the Willamette Pdver and is therefore allocated to the Disinfectton/Outfall facility component. For the same rationale as the other study projects, this project is allocated to Performance. 8.6.8 Monthly Sewer Rates Assun4ng that the $144 million Alternative 5 is implemented, three rate scenarios were developed for the next 10 years. All three scenarios assume the approximate 40/60 split for funding the 20-year project List between SDCs and user rates so that roughly $86.2 million of the $144 million would be funded by rates. The rate scenario evaluation demonstrated that MWMC has various options available to phase in increased rates to provide revenue adequacy. 8.6.9 impact of Implementing Alternative 4 If DEQ does not approve Alternative 5 - Parallel Primary/Secondary Treatment ($144 million), and Alternative 4 - High-Rate Clarification ($157 million) is implemented instead, an additional $13 mJllion will have to be spent on capital investments. The allocation between growth impact fees (SDCs) and existing users (user rates) for this additional expenditure w~ be identical to the allocation for the Parallel Primary/Secondary Treatment project in the 20-year project list. Based on Table 8.6.1-2, 29 percent of this 8-t4 MWMC_8 0_REV5 DOC 8 FINANCIAL STRATEGY addiQonal expenffiture or $3,770,000 will be funded by SDCs, with the remaining 71 percent or $9,230,000 being funded by user rates. This represents roughly a 6.5 percent increase ($57.8 million to $61.6 rv~lI~on) in the portion of the 20-year project l/st that would be funded by SDCs and roughly an I1 percent increase ($86.2 million to $95.4 million) in the port/on of the 20-year project list that would be funded by rates. If MW1V~C implements Alternative 4 versus Alternative 5, an adjustment to the SDCs and user rates roughly in proportion to the 6.5 and ll percent increases for SDCs and user tares, respectively, would have to be implemented. However, the overall financing strategy of issuing revenue bonds to fund the capital improvements would not change. t~WMC_8 0_REV5 DOC 8-15 TABLE 8.6.1-2 Summary of 20-Year Project List Allocations for Improvement Fee MWMC Facilities Plan, Eugene-Spnngfield Allocation Summary Growth Portion Existing User (in 2004 Portion (in Existing PROJECT dollars) Growth % 2004 Dollars) Users % Total Collection Systemllnfluent Pumping WiIlakenz=e Pump Station F. xpanston $2,294,118 38% $3,705,882 62% $6,000,000 Screw Pump Station Expansion $650,000 38% $1,050,000 62% $1 Glenwood Pump Stabon Upgrade $191,176 38% $308,824 52% $500,000 R~ver Avenue Improvements $0 0% $330,000 100% $330,000 Subtotal Collection System/Influent Pumping $3,135,294 37% $5,394,706 63% $6,530,000 Liquids Treatment Headworks Expansion $4,894,118 36% $7,905,682 62% $12,800,000 Pnmary clan/let enhancements $776,471 §5% $423,529 35% $1,200,000 Pnmary sludge thickening outside of pnmary clanflers $2,329,412 65% $1,270,588 35% $3,600,000 Addlbonal odorous a~r treatment St ,797,019 25% $5,102,981 74% $6,900,000 South aerabon basin ~mprovements $4,051,880 59% $2,848,120 41% $6,900,000 North aerabon basra ~mprovements $3,640,820 59% $2,559,18,0 41% $6,200,000 Secondary clanfler enhancements $2,203,026 42% $3,095,974 58% $5,300,000 9th and 10th secondary clardiers $4,976,471 65% $2,223,529 35% $6,300,000 Conversion to sodium hypochlonte dlsinfecbon $1,044,878 25% $3,055,122 75% $4, t00,000 F~ltrat~on $8,412,649 42% $11,787,351 58% $20,200,000 Parallel Primary Secondary $3,235,294 29.4% $7,764,706 70.6% $11,000,000 New Oanks~de Outfall $573,529 38% $925,471 62% $1,500,000 Subtotal Liquids Treatment $37,035,566 43% ~48,984,434 57% $86,000,000 Treatment - Biosolids Waste Activated Sludge Thickening $2,500,000 100% $0 0% $2,500,000 D~gesbon Expansion/Class A Capabdlty $7,469,780 54% $6,310,220 48% $13,800,000 D~gestlon M~xlng Improvements $1,317,519 56% $682,481 34% $2,000,000 B~ocycle Farm Phase 2 $66,528 22% $233,472 78% $300,000 B~ocycle Farm Phase 3 $86,528 22% $233,472 78% $300,000 B~ocyle Farm Distribution Equipment $57,658 22% $202,342 78% $260,000 Compostmg fac~hty $144,145 22% $505,855 78% $650,000 Blosolids Management Facility (BMF) - Line lagoons phase I $0 0% $1,200,000 100% $1,200,000 BMF - Line lagoons phase 2 $0 0% $1,100,000 100% $1,100,000 BMF - Line lagoons phase 3 $0 0% $1,100,000 100% $1,100,000 BMF - Line lagoons phase 4 $0 0% $1,100,000 100% $1,100,000 Repairs/Partial Replacment of B~osolids Forcema~n $0 0% $1,000,000 100% $1,000,000 Subtotal aiosolids $11,042,158 46% $13,667,842 54% $25,310,000 Support Facilities Maintenance Facility Improvements $315,156 21% $1,184,844 79% $1,500,000 Fiber Opbc W~nng $2,10t 21% $7,899 79% $10,000 Subtotal Support $317,257 21% $1,t92,743 79% $I,510,000 Total Treatment Effluent Reuse $5,2t2,5t2 2;6% $14,787,488 74% $20,000,000 MWMC_Tal TABLE 8,6.1-2 Summary of 20-Year Project List Allocations for Improvement Fee ~WMC Fac~lfl~es Plan, Eugene-gprmgfield Ailo~tion Summa~ Gro~ Po~on Existing User (in 20~ Potion (in Existing PROJECT doilam) Gro~h % 20~ Dollars) Usem % Total ~her P~ojec~ Tem~m~ Construction Mana~ment Factories $21,010 21% $78,990 79% Mixing Zone Study u~ate $21,9~ ~5% $128,042 85% Pa~al fadhty plan u~ate (2010} $31,516 21% $118,4~4 79% $1~,~ Compmhensl~ fac~hty plan (2015) 5168,083 21% $631,917 79% Pa~al fa~lsty plan u~ate (2020) $31,516 21% S118,4~ 79% $150,~0 Comprehensive facility plan (2025) $168,083 21% $631,917 79% $~00,~0 Wet Weather Flow Manag~ent Plan Update $27,076 11% $222,924 ~/o $2~,~0 Suppod development of pevate lateral pr~ram $0 0% $2~,000 100% $2~,~0 Subtotal Other Proj~ ~69,241 ~ 8% $2,180,759 82% $2,6~,~0 TOT~ $57,812,027 40% $86,~87,973 6~/0 MWMC_Ta 1 xls 9.0 Environmental Report 9.1 introduction This chapter describes potential environmental impacts associated with alternatives for the construction and operation of expanded MWMC facilities. The analysis includes a description of potential impacts to the physical, biological, and human environment in the immediate vicinity of the expanded facilities, as well as impacts to the receiving waters of the Willamette River at the WPCF ouffall. The alternatives include MWMC's preferred alternative (System1 Alternative 5) Parallel Primary/Secondary Treatment, and the agency's next best alternative (System Alternative 4) High-Rate Clarification. To compare the project alternatives and potential environmental impacts that could occur if the facilities are not expanded, the analysis also includes a third alternative, the No Action Alternative (System Alternative 1). Because of insu_rmountable technical difficulties, Alternatives 2 and 3 were considered and eliminated as viable altematives in this Facilities Plan (see Chapter 7.0). Therefore, an analysis of these alternatives is not included in this Environmental Report. To provide a basis for identifying how the physical layout of the current facilities will differ from potential lucre expansions and upgrades, a brief description of MWMC's main facilities is provided below. 9.1.1 Current Process Overview Currently, wastewater is channeled to the WPCF via 800 miles of Eugene-Springfield sanitary pipes and 47 pump stations (MWMC, 2004). At the WPCF, influent undergoes primary and secondary treatment. Biosolids are pumped to facultative sludge lagoons at the BMF and wastewater is disinfected before being discharged into the Willamette River. Water Pollution Contro~ Facility (WPCF) Wastewater entering the WPCF undergoes four treatment phases prior to discharge into the Willamette River. These phases (preliminary, primary, secondary, and disinfection), as well as biosohds management at the facility, are described below. Preliminary Treatment. Preliminary treatment consists of receiving wastewater from the regional collection system, removing sand and debris, reducing the size of solids, and injecting air (aeration) to remove odorous gases (City of Eugene, 2004). The facihty has available four grit removal chambers (each with a volume of 101,000 gallons) and four preaeration chambers (each with a volume of 152,000 gallons) - these are used according to 1 The Facilities P~an identifies various component altematlves and makes specific recommendations for these alternatives. The Environmental Report consists of a review of potential impacts for the entire system that makes up the WPGF. Therefore, to avoid confusion in how the term "alternative" ~s used, the two project alternatives in the Environmental Report and the No Action Alternative are described as System Attemat~ves 1, 4, and 5. hIWI~C_~ 0_REV14.DOC 9-1 MWMC FACILr~Es PLAN the influent flow requirements. A biofilter is used to remove air odors at 13,000 ff3/mJn 2(City of Eugene, 2004). The current capacity of the prelkninary treatment facilities ranges from 175 to 210 mgd, and is 1Lrrfited by the influent screening capacity (see "Peak Flow Management Alternatives" technical memorandum in the appendix). Primary Treatment. During primary treatment, solids and scum are removed through settling and skimming (City of Eugene, 2004). Prh~ary clarifiers thicken the sludge to 4 to 6 percent solids. The thickened sludge is pushed by rake arms into a hopper, where the sludge is transferred by air-operated diaphragm pumps to the primary (anaerobic) digesters (Management Plan for a Dedicated Biosolids Land Application Site [CH2M HILL, 2003]). The effective peak flow pr/mary treatment capacity is approximately 90 mgd with all four primary clarffiers in service, although the facility moves in excess of 200 mgd through the clarffJers during peak flow events. Socor~dt~ry Troatmor~L Secondary treatment at the WPCF consists of aerating and recycling bacteria, and converting fine particles and dissolved orgardc matter izzto settleable solids (City of Eugene, 2004). Secondary treatment facilities consist of eight aeration basins and eight secondary clarffiers. During secondary treatment, sludge can be thickened in one of two ways, co-thickened by rrdxing WAS with primary influent and settled in primary clarifiers or tl-dckened directly at the GBT. The activated sludge flow can be routed to the grit channels to be mixed with primary influent or the WAS is combined with polymer and applied to the gravity filter belts, then thickened to 4 percent dry solids. After thickening, the waste activated sludge is pumped to the anaerobic digestion process. During the anaerobic digestion process, sludge is inoculated with bacteria and heated to approximately 36°C. Bacteria reduce the organic material to water, carbon dioxide, and methane gas. The process takes 15 to 35 days, depending on the amount of sludge pumped into the digesters. The methane gas is used to produce heat and electr/cal energy, which is used in the operation of the Regional Treatment Facility. The current peak flow secondary treatment capacity is estimated at 103 mgd and is l~ted by secondary clarffication. PE flows over 103 mgd are diverted around secondary treatment through a diversion conduit and recombined with the SE prior to disinfection. Di$[tlfoctiori. Disinfection, the final wastewater treatment stage at the WPCF, consists of disinfection by chlorine, followed by addition of sulfur dioxide to dechlorinate. Dish'dection facilities consist of gaseous chlorine, four chlorine contact basins, and gaseous sulfur dioxide. The peak flow disinfection capacity, estimated at 215 mgd, typically is lkmited by the chlorinators, although hydraulic restrictions based on river level may liner capacity to 175 mgd. 2 The blofilter has a peak capac~ of 18,000 cfm. 9-2 MWMC_90...REVI~ 4.DOC 9 ENVIRONMENTAL REPORT Biosolids Management Facility (BMF) Digested biosol/ds holding are pumped through a from the tanks 5.5-m~e force main into one of four, 6.25-acre facultative sludge lagoons at the BMR The lagoons are designed to maintain an aerobic layer free of scum or membrane-type film buildup. The aerobic layer is maintained by controlling annual organic lagoon loading at or below a crihcal area loading rate, and through use of surface mixers to agitate and mix the aerobic surface layer. The aerobic surface layer of the lagoons usually is between 1 and 3 feet deep and supports a dense population of algae. Dissolved oxygen is supplied to this layer by algal photosynthesis, by direct surface transfer from the atmosphere, and by the surface mixers. Sludge bacteria use the oxygen to aerobically degrade organic matter. Digested sludge solids settle to the bottom of the lagoons and continue decomposing anaerobically. Supernatant flows via 10-inch-diameter pipes to a sanitary sewer and is then conveyed to the WPCF (Management Plan for a Dedicated Biosolids Land Application Site [CH2M HILL, 2003]). Seasonal industrial Waste Facility The SIWF is a 290-acre site with 190 acres of irrigated cropland and 25 acres of non-irrigated cropland. The total farmable area is approximately 215 acres. The site is located approximately 1 mile northeasterly from the BMF and 5 miles north of Eugene. It is currently developed with three 60-acre circles and one 16-acre circle of grass. The irrigation system consists of 1996 Pierce center pivots. A 14-acre, 57-MG storage lagoon is also located at the S1WF site. The lagoon no longer receives influent cannery waste but still contains residual waste from prior years infiuent. Potential future uses for the lagoon include effluent equalization/storage, BFP filtrate storage, and facuttative sludge lagoon supematant equalization/storage/treatment. The SIWF was built in 1983 to avoid high-strength orgardc waste loads into the WPCF on a seasonal basis. Since the purchase of the land by Eugene-Springfield, the SIWF has not been used for any land application or liquid storage of non-cannery wastewaters, as the site has been dedicated solely to Lrrigation of cannery wastewater. The land has been leased to a local farmer and forage producer to ensure that the site is continuously farmed using sound farm management practices. Biosolids Disposa~ - Biocycle Farm (Poplar Farm) The Biocyde Farm currently is in development. This facility is located next to the BMF and along Highway 99 between Awbrey Lane and Meadowview Road. The Biocycle Farm will provide IVI-WMC with a land application site for beneficial recycling of biosolids. It is scheduled to be constructed in three phases and completed by 2008. Phase I will involve planting 160 acres of poplar trees and is scheduled to be operational by Surnmer 2004. Stabilized dewatered shidge from the BMF lagoons will be applied to the Biocycle Farm to provide the necessary nutrients for the poplar trees. This is anticipated to be the preferred method of biosolids reuse over the current practice of hauling to cooperative farms. Additionally, the Biocyde Farm will provide the flexibility to pump stabilized l/quid sludge directly from the BMF lagoons to the Biocyde Farm for land application of liquid biosolids. MWMC_90_REV14 DOC ~3 MWMC FACILITIES PLAN Ultimately, the three phases of the Biocycle Farm will occupy 595 acres, of which 400 acres wffi grow poplar trees. 9.1.2 Analysis of Alternatives Descriptions of modifications associated the three system alternatives, along with a more detailed analysis of the potential fl-npacts associated with each alternative, Ls provided sections 9.3, 9.4, and 9.5. The alternatives analysis presented below focuses on potential impacts associated with construction and operational activities that have not been analyzed under an existing or previous facilities plan or other environmental review conducted by MWMC. For this reason, an analysis of potential impacts associated with the Biocycle Farm is not included in this Environmental Report. The Facilities Plan also includes descriptions and recommendations on selected components of the MWMC system that either specify no change in the physical layout or operational procedures at these facilities, or the impact associated with the component is already incorporated in the environmental impact analysis for the project alternatives described below. For this reason, an impacts analysis for proposed modifications at the BMF are not included in this Environmental Report. Finally, the Facilities Plan recommends that MWMC's SIWF be put into service for biosolids and effluent reuse. It Ls anticipated that this activity would result in a net environmental benefit to the Eugene-Springfield metropolitan area. These benefits could be substantially sflnilar to the potential benefits associated with the use of the Biocycle Farm. However, because of the scale of the potential operation--the S1WF facility includes a 290-acre site with a total farmable area of appro/6mately 215 acres and a 14-acre, 57-MG treatment pond--a more detailed analysis of the environmental issues associated with fids site is beyond the scope of th~s Enviror~mental Report. It is assumed that further review of the environmental characteristics of this site along with an assessment of environmental affects associated with biosolids and effluent reuse will be performed at a later date pending MWMC's decision on the future of the facility. 9.2 Purpose and Need The MWMC Facility l~lan proposes a preferred alternative for expanding and upgrading its facilities to meet the future growth needs and regulatory requirements for water quality/n the MWMC service area. By providing additional capacity when needed, the expanded a_nd upgraded MWMC facLIifies would help to preserve water quality in the Eugene-Spr~gfield area and protect public health and safety for future generations. In addition, upgraded facilities will allow MWMC to meet applicable state and federal regulations and satisfy service contracts with the cities of Eugene and Springfield. The purpose and need for this section is to identify the potential environmental effects associated with development of MWMC's preferred alternative (System Alternative 5), System Alternative 4, and System Alternative 1. The existing MWMC treatment system is running out of capacity. It is anticipated that sufficient dry weather treatment capacity exists to meet short-term growth through 2005; however, peak wet weather flows currently constrain the life span of the plant's design capacity. In addition, new regulatory 9,-4 MWMC_90_REV'~4 DOC 9 ENVIRONMENTAL REPORT requirements, changes in regulatory policy, and new treatment technologies drive the need for upgrades and expansion of the existing MWMC treatment facilities. 9.3 System Alternative 1--No Action 9.3.1 Affected Environment Although the entire Eugene-Springfield area could be indirectly impacted by the implementation of System Alternative 1, the area of greatest impact would likely occur in the vic~ity of the present location of the WPCF, as welt as areas in the Willamette River downstream from the WPCF outfall. In System Alternative 1, implementation of MWMC's preferred alternative (System Alternative 5) and the agency's next best alternative (System Alternative 4) would not occur. MWMC facilities would remain in their current operating configuration and the footprint of the facilities would remain unchanged. Upgrades and replacement of facilities and equipment that take place because of normal maintenance would continue to occur. Changes to equipment and operating procedures during normal maintenance would not constitute a major expansion or overhaul to the MWMC facilities. However, technological advances associated with these modifications could result in greater efficiencies and higher flow capacity. 9.3.2 Water Quality System Alternative I would result in significant potential impacts to water quality in the Willamette River and other local waterways. Impacts from the No Action Alternative would be greater than impacts from System Alternatives 5 and 4. If MWMC facilities are not upgraded or expanded, flows from all parts of the MWMC service area would continue to increase in conjunction with population growth and increasing industrial expansion in the Eugene-Springfield area. These flows would continue to go to the existing facilities, and the increasing volume would ultimately exceed the capacity of the treatment plant and conveyance system to treat the wastewater. There would be a strong likelihood that wastewater would overflow into the local environment whenever volumes exceeded the capacity of the treatment plant and conveyance system, thereby greatly increasing the risk of environmental health hazards and the potent-iai for degrading the water quality in the Willamette River and other waterways. This situation would put MWMC out of compliance with its NPDES permit and violate the Clean Water Act and possibly other laws. Although No Action would provide no new capacity for existing facilities to treat flows from the service area, other MWMC programs and projects could be implemented under System Alternative 1. This could include continuation of programs to control the amom~t of I/I (groundwater and stormwater) that enters the conveyance pipelines through cracked pipes, leaky joints, manhole covers, and illegal connections such as storm and roof drains. MWMC and a CAC (Citizen's Advisory Committee) studied several methods of managing wet weather flows within the Wet Weather Flow Management Plan (WWFMP) (CH2M HILL, 2000). The recommended cost-effective solution by the CAC and governing bodies is to and treat" solution that includes pipe rehabilitation of the collection implement a "convey NIWI~IC_9.0_RE¥ 14.DOC MW'MC FACILITIES PLAN system and WPCF wet weather treatment improvements. The WWFMP s~ady determined that collection system rehabilitation programs alone cou_ld not cost-effectively reduce WPCF influent flows to the point that additional treatment capacity would not be required. If the WPCF is not improved for wet weather, MWMC facilities would still experience capacity issues and be at risk of sanitary sewer overflows. Other, more dramatic actions could include enacting new regulations that would restric~t water use in the metropolitan area, or implementation of zoning changes and building moratoriums throughout the MWMC service area. To protect public and env~_ronmental health, these restrictions would need to be in place to constrain population and industrial growth in the area, thus slowing the increase in wastewater flow to the ~reatment facffities. While these programs would help to maintain the wastewater system and provide additional environmental protection over the short-term, they would not eliminate the eventual need to construct additional conveyance and treatment capacity for predicted long- term increases in wastewater flows in the MWMC service area. An additional option could include construction of new treatment fadl~ties in an undisclosed location in the Eugene-Springfield metropolitan area. However, the construction of additional treatment capacity would require sizable funding, site acquisition, design, permitting, and construction. These activities would requite time to complete and during this period MWMC facilities would be at maximum capacity and at risk of overflow and violation of NPDES penrdt conditions. 9.3.3 Biological Resources System Alternative 1 would result in impacts to biological resou_rces in the Willamette Pdver. Impacts from the No Project Alternative would be greater than Lmpacts from System Alternatives 5 and 4. As noted above, System Alternative I would increase the potential for the discharge of untreated wastewater into the Willamette River and other area waterways. Th/s, in turn, would impact water quality and would likely result in significant degradation of the biological resources in the river downstream of the WPCF outfall. The discharge of untreated wastewater would also likely result in increased potential to harm public health. 9.3.4 Air Quality, Odor, and Noise System Alternative I would result in impacts to air quality, odor, and noise. Impacts from System Alternative 1 would be greater than impacts from System Alternatives 5 and 4. As the current MWMC facilities reach their capacity, increased flows during wet and dry weather conditions will result in increased releases of fugitive odors. In general, the proposed changes under System Alternatives 5 and 4 will improve odor control by capturing more fugitike odors and using odor-reducing technologies. These changes in odor control tedmolo~ will greatly improve odor control in comparison to cn. trrent and future operating conditions under System Alternative 1. With System Alternative 1, noise and air quality could also be impacted if the flow tb~ough the facilities approaches full capacity. Increased facility loading could mean changes in ENVIRONMENTAL REPORT operation hours and increased noise and emissions and potential violations o~: air quality permit conditions. 9.3.5 Energy Management and Consumption System Alternative 1 would result in impacts to energy consumption. Impacts from System Alternative 1 would be less than impacts from System Alternatives 5 and 4. However, it is anticipated that energy consumption at MWMC facilities will still increase under System Alternative 1. Energy consumption is tied to volume of treated material processed throughout the MWMC system. Flows and loadings processed through the facility are, in turn, driven by various factors including population and industrial growth, seasonal precipitation, and equipment efficiencies. As noted above, replacement of equipment during normal maintenance procedures would likely incorporate new technology. The corresponding equipment efficiencies would reduce energy demand. However, even with increased equipment efficiencies, anticipated increases in flows and loadings would likely result in energy demands that exceed current levels. 9.3.6 Floodplains and Soils System Alternative 1 will have no anticipated impact on the floodplain because no changes will be made that affect flow in the river channel. Construction activities would not occur and there would be no disturbance of surface soils at MWMC facilities. 9.3.7 Land Use and Zoning System Alternative 1 would avoid land use artd zoning impacts. Because the MWMC facilities would remain in their cvxrent configuration, potential impacts related to land use compatibility would not occur. System Alternative 1 could result in secondary (indirect) land use and zoning impacts. To reduce wastewater flows, the cities of Eugene and Springfield could consider zoning changes and building moratoriums as a method to constrain population and industrial growth in the metropolitan area. Under this scenario, impacts associated with land use and zoning could be greater than System Alternatives 5 and 4. In addition, violations of permit requirements tied to growth in flow and loadings to the treatment facilities could result in enforcement actions by the State, including moratoriums on future development and hookups to t~he sal~Jtary collection system until the problems are resolved. 9.3.8 Transportation System_ Alternative 1 would avoid impacts to transportation/circulation_ in the vicinity of MWMC facilities. This alternative would not contribute to short-term construction-related impacts resulting from additional truck and construction vehicle traffic. This alternative also would not result in vehicular increases on the surrounding street system- Impacts associated with transportation/circulation would be less than impacts associated with System Alternatives 5 and 4. NtWMC_90_REV14 DOC 9-7 M~C FAC~Lr~E$ PLAN 9.3,9 Cultural Resources System Alternative 1 will have no anticipated impact on cultural resources. Co~_struction activities would not occur at MWMC facilities and there would be no poten[ial to disturb culturally significant resources. 9.3,10 $ocioeconomics System Alternative 1 could result in negative impacts to the econom/c growth in the Eugene-Springfield metropolitan area. Expansion and upgrades to MWMC facilities would result in an increase in temporary construction and construction-related employment in the Eugene-Springfield metropolitan area. In addition, it is anticipated that the local market would benefit from the sale of construction materials, thus increasing the level of economic activity during construction periods. Construction activities would not occur under the no action altemative and this alternative would not provide the same level of economic benefits to the local economy as System Alternatives 5 and 4. As the current MWMC facilities reach their capacity, the increasing volume would ultfl-nately exceed the capacity of the treatment plant and conveyance system to treat the wastewater. There would be a strong likelihood that wastewater would overflow into the local environment. As noted in sections 9.3.2 and 9.3.3, these wastewater overflows could seriously degrade water quality and biological resources in the Willamette River downstream from the WPCF ouffall, and in other local waterways. Impacts to water quality and biological resources could, in barn, have a negative impact on property values, recreational resources, and human health downstream from the ouffall. These impacts could negatively affect economic activity in the area by lowering property values, reducing recreational opportunities, and increasing the potential for proliferation of water-borne illnesses in the area. As noted in sect/on 9.3.4, increased flours and loadLngs during wet and dry weather conditions will result in increased releases of fugitive odors. Increased fugitive odors could, in turn, affect property values and have a potential negative impact on human health in the vicinity of the MWMC facilities. 9.4 System Alternative 5 - MWMC Preferred Alternative: Parallel Primary/Secondary Treatment 9.4.1 Affected Environment Upgrading the WPCF could result in two types of impacts: temporary, construction-related impacts, and environmental impacts not related to construction processes. Similar to System Alternative 1, the affected environment associated with System Alternative 5 includes areas where both direct and indirect impacts could occur, such as in the viciv5ty of the present location of the WPCF and areas in the Willamette River downstream from the WPCF ouffall (direct impacts), and the entire Eugene-Springfield area (indirect impacts). MWMC_~ 0_RE¥14 DOC ENVIRONMENTAL REPORT To provide a basis for comparison to System Alternative 1 and System Alternative 4, the features that would be added to the WPCF and the wastewater treatment process are described below. An analysis of the types of potential environmental impacts .under MWMC's preferred alternative are presented in sections 9.4.2 through 9~4.10. Water Pollution Control Facility Under the parallel primary/secondary treatment alternative (P?/ST), the peak wet weather flow capacity of the WPCF would increase from approximately 160 mgd to 300 mgd. All wastewater entering the plant would receive prelLminary treatment (grit removal, etc.). Additionally, a new tertiary treatment system would be added with capacity to treat 30 mgd of secondary-treated wastewater. Under this alternative, wastewater treatment would vary depending on plant influent flows, as follows. o 0-137 mgd: Total influent flows to the plant of 0-137 mgd would undergo the same series of treatment processes currently used to treat plant flows: preliminary screening followed by primary treatment, secondary treatment, and disinfect/on prior to discharge. · 137-160 mgd: With plant influent flows of 137-160 mgd, preliminary-treated wastewater (0-23 mgd) would bypass primary treatment and go directly to secondary treatment. 160-300 mgd: When plant irLfluent flows totaled 160-300 rngd, 23 mgd would bypass primary treatment and go directly to secondary treatment, as described above. The rest of the flow above 160 mgd (0-140 mgd) would undergo primary treatment and bypass secondary treatment, heading to high-rate disinfection. Table 9.4.1-1 describes how the irffiuent would be routed under this project alternative. TABLE 9.4.14 Parallel Primary and Secondary Treatment Flow Strategy MWMG Facilities Plan, Eugene-Springfield P~ant Total Flow Through Preliminary Treated Primary Treated Primary Treated Effluent Influent Secondary Effluent to Secondary Effluent to Secondary Diverted Around Flow (mgd) Treatment Treatment Treatment Secondary Treatment 0-137 0 increasing to 137 0 0 increasing to 137 0 137-160 137 increasing to 160 0 increasing to 23 137 0 160-297 160 23 increasing to 160 137 decreasing to 0 0 increasing to 137 297-300 160 160 0 137 increasing to 140 The diverted primary effluent and secondary treated effluent would be disinfected in separate flow streams and blended together prior to being discharged into the W/Jlamette River. Implementing PP/ST at the WI>CF would involve constructing t_he following features (Figure 9.4.1-1): e Pretreatment expansion MWN~C_90_REV14.DOC ¢9 MWMC FACILITIES PLAN Primary diversion pump station Secondary diversion pump station Clarifier upgrades: primary clarifier baffles, primary clarifier blending structure, secondary clarifier baffles Two new secondary clarifiers New high-rate disinfection basin New effluent blending and outfall structure New tertiary filtration system New bank outfall New bioscrubbers for odor control New reuse disinfection facility New digester WAS thickening building expansion BAFFLED TREATMENT BAFFLED TWO NEW P~MARY ' O~VERSION P~P SEC~DARY CLARIFIERS ~ STAT~O~ CLARIRERS STRUCTURE ~ Normal SecondaryTreatm~t Flow Paths ~ New Dr,/and Wet Weather Dual Uae Facihflea ~ New Wet Weather Peak Flow Fac~ht~ea FIGURE 9.4.1-1 Proposed Layout for System Alternative 1 - Parallel Pdmary and Secondary Treatment MWMC Facilities Plan, Eugene-Springfield 9,4,2 Water Quality Compared to System Alternative 1, System Alternative 5 could result in potential ne§alive impacts to water quality in the Willamette River. These potential impacts would be temporary and would be related to project construction activities. However, compared to System Alternative 1, the implementation of System Alternative 5 during the operational 9-10 MWMC_CJ 0_REVI4 DOC ENVIRONMENTAL REPORT period could improve water quality in effluent discharge, thus reducing the potential for adverse affects to wfldt/~e, fish, and habitat in the river. Construction Period Construction impacts would be temporary and would be primarily related to the installation of a third (bank) ouffall on the Willamette River. Excavation and construction activities at the ouffall site could increase the potential for erosion and the discha~e of sediment into the river. Accidental spills of petroleum product and hazardous material and releases of debr/s and other mater/als used for site construction activities could also occur during the construction period but sound practices would reduce/el/minate river Lmpacts. Operational Period Compared to System Alternative 1, Lmplementation of System Alternative 5 would Iff<ely result in a net beneficial impact to water quality in the Willamette R/ver. The quality of effluent discharged to the Willamette River, and thus water quality in the Willamette River, would be higher under System Alternative 5 than under System Alternative 1. Implementation of System Alternative 5 would reduce the potential for untreated sewage discharges to the river during peak flow periods. Additionally, under System Alternative 5, water discharged from the WPCF would meet NPDES requirements for TSS and CBODs. Table 9.4.2-1 compares NPDES permit limits for TSS and CBODs with predicted discharges in treated effluent under System Alternative 5. TABLE 9.4.2-1. Comparison of WPCF NPDES Permit Conditions with Predicted Conditions Under System Alternative 5 (Parallel Primary/Secondary Treatment) MWMC Facilities Plan, Eugene-Springfield Permit Limit/Removal Predicted Discharge/Removal Parameter Requirements Efficiency Maximum Week TSS 26,000 lb/day 20,550 lb/day Maximum Week CBODs 24,000 lb/day 14,1~ lb/day Maximum Month TSS Removal 85 percent 87.6 percent Maximum Month CBQDs 85 percent 86.5 percent Removal Uifigation Construction best management practices (BMPs), including spill prevention, control, and countermeasures (SPCC) planning and sediment and erosion control practSces, wilt be implemented to w2nimize and avoid erosion and the discharge of sediment, petroleum products, hazardous materials, and construction debris from the project site. 9,4.3 Biological Resources Wetland and r/parian areas are the primary habitat types of concern in the vicin/ty ot: the WPCF. Compared to System Alternative 1, System Alternative 5 could result in temporary, MWMC_9 0_REV14 DOC 9-tt MW'MC FACILFRES PI.Afl construction-related impacts to biological resources and permanent habitat alteration in the vicinity of the WPCF outfall. However, no direct wildlife mortality is antidpated from implementing WPCF upgrades. Construction Period Temporary (Construction-Related) impacts Wetland h~.bitat in the vicinity of the WPCF is found along the Willamette River (see Figure 2.2.7-3). Wetlands in the Eugene area support a variety of wildlife and plant species, including at least eight species designated as Endangered, Threatened, Sensitive, or Species of Concern (see Table 2.2.7-2). Riparian habitat along the Willamette River also supports a variety of mammals, birds, reptiles, amphibians, and plants. Temporary disturbance of a limited area of riverbank is expected as a result of construction of a third outfall at the WPCF. Distttrbance resulting from movement of construction equipment, excavation, and installation of the outfall would be limited to the direct area of construction activity. Sediment and erosion would be prevented by following construction BMPs and sediment and erosion control practices. In-stream or riverbank impacts to wildlife or habitat in the vicinity of the WPCF would be minimal. Project construction activities at the WPCF will generate noise and dust. Most species potentially using habitat near the WPCF for feeding, roosting, breeding, and migration (e.g., birds such as bald eagles, great blue herons, red-winged blackbirds, and warblers, and mammals such as bats, raccoons, and fox) likely would avoid the area immediately surrounding the WPCF during periods of construction activity. Therefore, impacts on wildlife from noise and dust during construction would be minimal. Operafiona~ Period Biological impacts Compared to System Alternative 1, it is anticipated that System Alternative 5 would result in a net benefidal impact to biological resources in the vicinity of the WPCF. Relative to the no action alternative, Parallel Primary/Secondary Treatment wotfld reduce the potential for discharge of untreated sewage into the Willamette River and ensure achievement of NPDES permit effluent limitations. Thus, the potential for adverse affects to wildlife, fish, and habitat resulting from reduced water quality would be lower under System Alternative 5. Habitat Alteration Habitat alteration in the vicinity of the WPCF could result from changes in water quality or habitat character, or from habitat loss. As noted in section 9.4.2, water discharged from the WPCF will meet NPDES permit requirements for TSS and CBODs, and water in the Willamette River will experience minimal project-related erosion and sedimentation. For these reasons, impacts to habitat or wildlife in the area as a result of impaired water quality are not anticipated. No permanent habitat loss or alteration is expected to result from System Alternative 5, with the exception of potential perma2ent streambank or wetland habitat losses associated w~th installation of the third outfall. 9-t2 ~. ENVIRONMENTN_ REPORT ~itigation Wetland losses would be mitigated following U.S. Army Corps of Engineers (USACE) and Oregon Division o£ State Lands (DSL) grddance, and could involve direct or/ndirect mitigation. D~red rrfitigation includes options such as creating replacement wetlands on site or off site, or preserving e×isting wetlands in the project area. Indirect n'fitigation activities include purchasing "credits" from a wetland mitigation bank (credits are used to preserve the wetland area at which the bank is established), or conserving other wetland areas. 9.4.4 Air Quality, Odor, and Noise Compared to System Alternative 1, System Alternative 5 will have a beneficial/mpact on odor. However, System Alternative 5 will result h~ temporary, negative impacts to alt quality and noise during the construction period. Because of increased treatment capacity, a~r quality and noise impacts ~ander System Alternative 5 are expected to remain essentially unchaxtged during the operational period from the impacts described under System Alternative 1. In general, the proposed changes will improve odor control by capbaring more fugitive odors and using odor-reducing technologies. Construction Period Odor. Odor em/ssions during construction are not anticipated to c~ange. Construction work on expansion to the liquids processes will not affect the odor control processes. Air Quality. Air quality impacts from engine and dust emissions would occur during the construction period. However, these emissions would be temporary and limited to hours when corrstruction activities occtrr. NOise. Noise impacts to nearby residential neighborhoods and comanercial areas from construction traffic, engines, and construction activities would occur during the construction period. However, these impacts would be temporary and limited to hours when construction activities occur. Operational Period Odor. The proposed changes to the WPCF will increase the capacity of the wet weather treatment processes. Changes to wet weather processes will have mirdmal impacts on odor because odor emissions are largely driven by dr), weather conditions such as low flows and high temperatures. However, modifications to the system will improve odor control durkng dry weather conditions. Proposed changes involve increasing the odor control by covering existing and new process areas. Proposed odor control tec2mologies will also improve the efficiency of the odor control system. Using bio-scrubbers will greatly improve odor corttrol because of the increased odor reductior~ and the increase in mixing/dilution capacity of f. he bio-scrubber tower. MWMC_9 0_REV14 DOC 9--13 MW/~lC FACILmES PLAN 9.4.5 Energy Management and Consumption Information regarding energy managemenlc and consumption/s unavailable at this time; however, it is assumed that System Alternative 5 wRl use more energy than is currently consumed by the WPCF. It is also assumed that energy consumption under System Alternative 5 would be greater than energy use under System Alternative 1. It is anticipated that the amount of energy consumed by expanded facilities would be proportional to the mount of energy used by the current facility. Although data are unavailable at this time, the upgrades and expansions proposed in the Facilities Plan would double the size of the current facility. Therefore, it is assumed that a maxLmum capacity energy use would increase relative to the amount that the facility is c~rrrently using. 9.4,6 Floodplains and Soils With the exception of softs disturbed during project construction activities, knpacts to floodplains and softs are not anticipated. Construction of project ouffalls would not impede flow in the Willamette Privet or affect the floodplain in the project area. 9.4.7 Land Use and Zoning Construction Period Project construction and operations will not impact land use and zoning in the/mmediate vicinity of the WPCF. Construction of either system alternative would likely require staging areas, an excess materials storage area, or similar temporary land uses associated with a major municipal or industrial-style construction project. It is anticipated that such uses during the construction period and planned expansions and upgrades at the WPCF wilt not require additional land beyond the current perimeter of the facility boundary and thus would not affect overall land use or supply in the project area. Operational Period On a regional basis, planned expansions and upgrades at the WPCF will increase MWMC's wastewater treatment capacity. This increased capacity would indirectly affect long-term land use and zoning activities by providing land use planners with additional flexibility to incorporate projected residential, commercial, and industrial growth fit the Eugene- Springfield metropolitan area. 9.4.8 Transportation Impacts to the transportation system could include temporary traffic delays ~ the project area. Impacts would be primarily caused by the delivery of construction-related equipment and materials. Peak hours for workforce transport (commuting) dttrfftg project construction periods could also contribute to temporary traffic delays. Although unlikely, it is conceivable that construction activities may result ~ some visible damage to the roadway surface on River Avenue that is scheduled for street replacement in the summer of 2005. Impacts to the transportation system are not expected to occur after project completion. It is assumed that once construction is complete, the WPCF could require additional employees and materials for project operations. However, employment and supply needs would be 9-14 MWMC_9.0_REV14 DOC 9 ENVIRONMFNTAL REPORT small, and in relation to daily traffic loads in the area, impacts to the local transportation corridor from these activities wotdd be similar conditions substantially to that occur under current operations. Affected Environment The site is bordered to the east by the W/llamette River, to the south and west by the River Road residential neighborhood, and to the north by River Avenue. Commercial property and Beltline Highway are located to the north of River Avenue. Major roads in the immediate vicinity of the WPCF include Beltline Highway to the north and River Road to the west. Major roads and highways leading to Beltline Highway include Delta Highway and Interstate 5 (I-5) to the east, River Road, Northwest Expressway and Highway 99 to the west, and West llth Avenue (State Highway 126) to the south. Most of the traffic volume in the immediate vicinity of the eZPCF is handled by Beltline Highway. Other roads in the immediate area of the facility that carry signff4cant traffic volume inolude Delta Highway and River Road. Transportation Corridors The property is accessed via River Avenue. Beltline Highway will be the pr/mary roadway to and from the project site. Most construction traffic is expected to enter and leave the site via the Beltline/River Avenue on and off ramps. Construction traffic could also enter the site via the Beltline/River Road/River Avenue interchange. Construct/on traffic traveling along Beltline Highway from the east will likely originate from Delta Highway and I-5. Construction traffic traveling along Beltline Highway from the west will likely originate from Highway 99 and State Highway 126. It/s anticipated that the majority of the construction traffic will originate from the Eugene- Springfield area, reaching the project site via the Beltline Highway. It is expected that the majority of the construction workers required to build the project would likely access the site from within a 75-mile radius. Impacts from Construction Activities Construction activities could result in temporary traffic delays on River Avenue, River Road, and Beltline Highway. These impacts would most likely occur during peak traffic periods. As mentioned above, it is conceivable that construction activities may result irt some visible damage to the existing roadway surface on River Avenue that is scheduled for replacement/n Spring/Summer 2005. However, the del/very of construction materials and equipment is not expected to significantly degrade existing conditions. Impacts from veh/cle parking are not expected to occur. Workers traveling to the project site will most likely park their vehicles at the WPCF. It is assumed that the WPCF site is large enough to accommodate a worker parking area as well as a materials and equipment staghng area. Construction Activities Con._struction activities at the WPCF will occur during phased operations through the year 2025. Construction-related traffic increases will consist of workforce transport and deliveries project equipment and construction materials (such as concrete and steel) by truck. of MWMC_O.0_REV14 DOC 9-15 MWMC FACILITIES PLAN Workforce transport is anticipated to occur between 7:00 a.m. and 5:30 p.m. and truck deliveries are anticipated to occur between 8:00 a.m. and 4:30 p.m. on .w.eekclays. It is anticipated that truck deliveries will/nclude: Major equipment (components of the WPCF) Gravel, concrete, and reirdorcing steel Mechanical equipment Electr/cal equipmer~t and hinter/al Miscellaneous steel, roofing, and siding Const-ruction consumables Contractor mobilization and demobilization Construction equipment del/very and pickup It is premature to provide accurate schedules for construction per/ods and peak hour traffic times, as well as the size of the onsite peak workforce and estimates of the types and number of vehicles and round trips needed during project construction. However, it is reasonable to assume that construction period, delivery vehicles (e.g., gravel, concrete, steel hnacks, materiaks/equipment) will make multiple round trips and deliver construction materials to the site on a frequent basts. It is assumed that one round trip will be required for heavy equipment that will be needed at the site durhng the various project construction phases. Heavy equipment will remain at the site for the duration of the construction phase. Table 9.4.8-1 is a general list of the types of vehicles and equipment to be used at the project site during construction periods, their approximate gross vehicular weights (GVWs), and capacities and the nature of trips planned for the vehicles and equipment. 'tABLE 9.4.8-1 Specifications of Vehicles and Equipment Used During Typical Project Construction Activities MWMC Facilities Plan, Eugene-Springfield VehicleJ Approximate Equipment Us~Locaflon GVW (pounds) Capacity Nature of Trips Gravel trucks Haul mad fill 80,000 22 yards Ongoing during construction with trailer matedat gravel Concrete Concrete deliver/ 80,000 8 yards Ongoing dudng construction trucks concrete Water trucks Compaction; erosion 60,000-80,000 5,000 gallons Ongoing dudng construction and dust control water Ratbed Miscellaneous -- Variable Ongoing during construction trucks equipment Pickup General use and 5,000 Passengers Ongoing during construction trucks minor equipment and smalt hauling equipment Bulldozers Leveling/earth D8:100,000 N/A Brought once to site; at site for moving D9:400,000 duration of construction Cranes Bioscrubber, etc. 80,000 N/A Brought once to site; at site for construction duration of construction 9 ENVIRONMENTAL REPORT TABLE 9.4.8d Specifications of Vehicles and Equipment Used Dunng Typical Project Construction Activities MWMC Facilities Plan, Eugene-Springfield Vehicle/ Approximate Equipment Use/Location GVW (pounds) Capacity Nature of Trips Backhoe Digging trenches -- N/A Brought once to site; at site for duration of construction Hydraulic Loading and 80,000 + bb'A Brought once to site; at site for forklifts unloading equipment duration of ccmstruction Note: Materials will be transported to the site on a schedule that wilJ be determined at a ~ater date based on construction contracts and project needs. As the primary access route to the site, Belfline Highway and River Avenue will likely experience the greatest traffic impacts from construct/on vehicles and workforce transport. As previously noted, most construction traffic is expected to enter and leave the site via the Beltline/River Avenue on and off ramps. Conshnaction traffic could also enter the site via the Beltline/River Road/River Avenue interchange. Therefore, the Beltline/River Road/River Avenue area could also experience traffic impacts from the construction vehicles and workforce transport. As noted above, trucks will be used to dehver construction equipment and materials. Some of these trucks will have a GVW of the legal load limit of 80,000 pounds. Heavy equipment will be transported to the project site using a semi-truck and lowboy transporter designed for loads (i.e., axles). The vehicles would be D8 and D9 heavy rnultiple largest likely bulldozers weighing approxhnately 100,000 and 400,000 pounds, respectively. These vehicles exceed the legal load limit and would require a permit. Cranes would be required to install new equipment at the WPCF. Cranes would be within the legal load lindt of 80,000 GVW. They would be brought in on six axles with robber tires and would drive on the highway. Movement of the heavy equipment transporters will have a short-term impact on traffic along the Beltline Highway and other roadways used along the transporter route. Construction Accidents Although the additional vehicular and construction traffic attributable to the project could increase the risk of accidents, it is anticipated that the overall accident rate or pattern would be similar to ex~sting conditions. Mitigation Traffic control would be written into contract specifications, which would address traffic safety. Flaggers would be used for equipment transporter access and turn-around on an as- needed basis. 9.4.9 Cuitura Resources According to the Eugene Cultural Resource Inventory Program (Eugene Planning and Development Department, 2003), the River Road area in Eugene has not been surveyed for historical resources. However, the MWMC project site is highly disturbed from previous klWMC_9.0_REV14.DOC 9-t7 MWMC FACIL~ES PLAN construction activities and it is unlikely that cultural resources exist at the project site. Additionally, proposed upgrades under System Alternative 5 would not expand the footprint of the facility; therefore, impacts to cultural resources from project activities are not anticipated. 9.4.10 Soc[oeconomics Construction Period Socioeconomic impacts during periocl_s of project constructiort include changes in t-ravel patterns and accessibility that affect nearby residential and commercial neighborhoods, impacts on highway and overall public safety, and noise and emissions impacts that affect property values and quality of life ir~ [he area. Socioeconomic impacts during cortstruction phases also include indirect impacts such as construction-related employment and materials sales. Compared to System Alternative 1, project construction associated with System Alternative 5 could result in potential negative impacts to quality o£ life in nearby residential and commercial neighborhoods. These impacts would result from increased dust, air pollutq, on, and noise from truck and equipment traffic and site construction activities. Increased truck traffic may also have limited impacts on accessibility and public safety along access and egress corridors to the project site. However, the impacts noted above would be temporary and limited to the construction period and the time of day when construction activities Occur. Construction for expansion and upgrades to MWMC facilities would result in beneficial indirect impacts such as an increase in temporary construction and construction-related employment in the Eugene-Springfield metropolitan area. Furthermore, it is anticipated that the local market would benefit from the sales of construction materials, thus increasing the level of economic activiCf during construction periods. Operational Period Socioeconomic impacts durinl5 the operational period primarily consist of impacts to qxxality of life in residential neighborhoods and commercial areas related to changes in water quality and biological resources (primarily in the Willamette River); and odor, air emissions, and noise in the area. Compared to System Alternative 1, operation of the upgraded facilities under System Alternative 5 will have a direct net beneficial impact to the quality of life in nearby residential neighborhoods, and will benefit recreational resources in the Willamette River. Indirect impacts could include the preservation or enhancement of property values in the adjacent area. These impacts would occur by reducing the potential for discharge of fugitive odor emissions, and of untreated wastewater into the Willamette River. 9-18 MWMC_9.O_REV14.DOC B ENVlRONIV/ENTAL REPORT 9.5 System Alternative 4 - High-Rate Clarification 9.5.1 Affected Environment As with System Alternative 1 and Alternative 5, the affected environment associated with Alternative 4 includes areas where direct and indirect impacts could occur. Similar to the other alternatives, m~pacts could occur in the vicinity of the WPCF and along the Willamette River downstream from the WPCF outfall. The larger Eugene-Springfield area could experience indirect effects, such as noise or air quality impacts. The features that would be added to the WPCF under Alternative 4, and the wastewater treatment process under this alternative, are described below. Potential environmental impacts under this alternative are discussed in sections 9.5.2 through 9.5.10. Water Pollution Control Facility Under the High-Rate Clarification (HRC) alternative (System Alternative 4), as with the Parallel Primary/Secondary Treatment alternative (System Alternative 5), the peak wet weather flow capacity of the WPCF would increase from approximately 160 mgd to 300 mgd. Following preliminary treatmenb infiuent to the plant J_n excess of 160 mgd (up to 140 mgd) would be diverted around the existing primary clarifiers to a new HRC facility. Primary-treated wastewater from the HRC will be blended with secondary-treated wastewater that has passed through the existing primary and secondary treatment stages, before discharge to the Willamette River. Additionally, as with System Alternative 5, a new tertiary filtration system would be built to treat 30 mgd of plant effluent prior to disinfection. The influent flow-dependent treatment steps for wastewater entering the WPCF are described below for Alternative 4. * 0-160 mgd: Total influent flows to the plant of 0-160 mgd would undergo preliminary screening, primary treatment, secondary treatment (with two new secondary clarifiers; 10 total), and disinfection prior to discharge. 160-300: With plant kdluent flows of 160-300 mgd, preliminary-treated wastewater (0- 140 mgd) would bypass the existing primary treatment system and be treated in a new, HRC facility. Implementing System Alternative 4 at the WPCF would involve constructing the foltow~ng features (Figure 9.5.1-1): Pretreatment expansion Clarifier upgrades: primary clarifier baffles, primary darifier blending structure, secondary clarifier baffles Two new secondary darifiers Bypass pump station high rate clarifier High rate clarifier (HRC) facility New high-rate disinfection basin New effluent blending and outfall structure New bioscrubbers for odor control New tertiary filtration system MWMC_9 0_REV14 DCC 9-19 MWMC FACILITIES PLAN New bank outfall New reuse disinfection facility New digester WAS thickening building expansion BAFFLED MODIFIED } BAFFLED TWONEW PR[MARY ;, AERATION ISECONDARYi SECONDARY =LARIF~ERS BASINS ] CLARIFIERS C~RIFIERS aa~,a¢~ Normal Secondary Treatment Flow Paths ~ New Dry and Wet Weather Dual Uae Facilities ~ Ne~v Wet Weather P~k Fl~w Fscilit~ee FIGURE 9.5.1-1 Proposed Layout tot System Alternative 2 - High-Rate Clarification MWMC Facilities Plan, Eugene-Springfield 9.5,2 Water Quality Impacts under System Alternative 4 would be substantially similar to water quality impacts under System Alternative 5; that is, the quality of treated effluent discharged to the Willamette River would be higher than under System Alternative 1. Similar to System Alternative 5, effluent discharge under System Alternative 4 would meet NPDES requirements for TSS and CBODs. However, compared to Alternative 5, the High- Rate Clarification alternative would slightly improve TSS and CBODs removal (Table 9.5.2-1). 9-20 MWMC_90_REV14 DOC 9 ENVIRONMENTAL REPORT "tABLE 9.5.2 d. Comparison of WPCF NPDES Permit Conditions with Predicted Conditions Under System Alternative 4 (Hiqh Rate Clarification) MWMC Facilities Plan, Eugene-Spnngfield Permit Limit/Removall Predicted Discharge/Removal Parameter Requirements Efficiency Maximum Week TSS 28,000 Ih/day 18,820 lb/day Maximum Week CBODs 24,000 lb/day 13,908 lb/day Maximum Month TSS Removal 85 percent 88.0 percent Maximum Month CBOD5 Remova~ 85 percent 86,5 percent Mitigation planning would be the same as that in System Alternative 5. Sediment and erosion control BMPs and SPCC planning would be implemented during construction activities. These practices would eliminate, reduce, or avoid the potential for discharge of sediment, petroleum products, hazardous materials and debris to the Willamette River during the construction period. 9.5.3 Biological Resources Potential impacts to biological resources in the vicinity of the WPCF trader the High- Rate Ctarificahon alternative would be limited and essentially identical to those under the Parallel Primary/Secondary Treatment alternative (see section 9.4.3). Temporary, construction-related impacts on wildlife and habitat (e.g., from noise and dust generation) would be minhnal, because animals likely would avoid areas near construction activity. Temporary riverbank disturbance from construction of the third outfall would be limited to the immediate construction area and would be mivJm2ed through Lmplementation of construction BMPs and sedimentation and erosion control measures. Potential permanent wetland losses resulting from 'installation of the third outfall would be mitigated through direct measures (e.g., creation of replacement wetlands) or indirect measures (e.g., purchase of credits from a mitigation bank). No direct wildlife mortality or other permanent habitat alterations or losses are expected under System Alternative 4. 9.5.4 Air Quality, Odor, and Noise Impacts to air quality, odor, and noise under System Alternative 4 will be similar to impacts under System Alternative 5 (see section 9.4.4.). 9.5.5 Energy i anagement and Consumption Similar to System Alternative 5 (see section 9.4.5), it is assumed that the WPCF would consume more energy under System Alternative 4 than is currently consumed, as well as more energy than would be consumed under System Alternative 1. As described for System Alternative 5, the proposed upgrades would roughly double the capacity of the facility; therefore, it could be assumed that under System Alternative 4 energy consumption would increase relative to the amount of energy cttrrently used. MWMC_9.0.,REV14.DOC 9-21 MWMC FACILfflES P~N 9,5.6 Floodplains and Soils Similar to System Alternative 5 (see section 9.4.6), System Alternative 4 would not affect area floodplains and would result in soil disturbance only during proiect construction activities. 9.5.7 Land Use and Zoning As with System Alternative 5 (see section 9.4.7) construction activitSes, System Alternative 4 would not require ~ase of additional land beyond the current facihty boundaries, and thus would not affect land use or zoning in the project area. Regionally, upgrades planned under System Alternative 4 (as with System Alternative 5) would increase the treatment capacity of the WPCF, and thus would facilitate resident-iai, industrial, and commercial growth in the Eugene-Springfield metropolitan area. 9.5.8 Transportation Transportation issues ~mder System Alternative 4 would be similar to those under System Alternative 5 (see section 9.4.8). 9.5,9 Cultura~ Resources As with System Alternative 5 (see section 9.4.9), the footprint of the WPCF would not expand under System Alternative 4. Therefore, although cultural resources have not been surveyed in the River Road area (Eugene Planning and Development Department, 2003), it is unlikely that project activities within the already-disturbed facility boundary would affect cultural resources. 9.5.10 Socioeconomics Socioeconomic impacts under System Alternative 4 would be similar to those under System Alternative 5 (see section 9.4.10). Construction activities could result in increased traffic in the project area, and thus increases in noise, emissions, dust and traffic congestion on area roads. Conversely, project construction would be expected to benefit the local economy through job creation and materials sales. Ft't,/MC_g.0_REV14 DOC 10,0 References Allen, J.E. and M. Bums with S.C. Sargent 1986. Cataclysms on the Colttmbia: A layman's guide to the features produced by the catastrophic Bretz floods tn the Pacific Northwest. TimberPress: Portland, OR. 211. Andrus, C. 2000. Spring and Summer Fish Assemblages of the Willamette River near Eugene, Unpublished Report. Andrus, Chip (Water Work Consulting) and Jenny Walsh (Upstream Connection), 200Z Aquatic and Riparian Habitat Assessment for the Eugene-Springfield Area. September 2002. [onnne.] Biosohds Hauler Spill Response Procedure-CWEA Manual of Good Practice for Agricultttral Land Application of Biosolids, 1998. Brown & Caldwell, 1999. 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