Evaluation of CSO Control Alternatives in Small Communities

1. Evaluation of CSO Control Alternatives in Small Communities Michael SullivanLimno-Tech, Inc.

2. Elements of an LTCP for Small CSO Communities Required in CSO Control Policy: • Consideration of sensitive areas • Public participation • Evaluation of CSO control alternatives Useful or likely to be required: • Characterization (not necessarily monitoring and modeling • Maximization of treatment at the POTW • Post-construction compliance monitoring Evaluation of CSO Control Alternatives

3. Most Widely Used CSO Controls Evaluation of CSO Control Alternatives

4. CSO Controls for Small Community Consideration • Maximization of treatment at the POTW. • Inflow control. • Sewer separation. • Storage. Emphasis placed on these controls, but there are many other types of controls available. Evaluation of CSO Control Alternatives

5. 1. Maximization of Treatment at the POTW • Take advantage of existing infrastructure • Increase conveyance and pumping capacity where excess POTW treatment capacity is available • Increase POTW treatment capacity where conveyance is available Evaluation of CSO Control Alternatives

6. Build on Existing Infrastructure: Increase Pump Station CapacityWilmington, DE 6 Evaluation of CSO Control Alternatives

7. Add Wastewater Treatment Capacity Evaluation of CSO Control Alternatives

8. Increase POTW CapacityCity of Frankfort, KY (pop 27,750) • In Frankfort the 2001 expansion increased the POTW capacity from a 6.6 MGD facility to a 9.9 MGD facility.  Evaluation of CSO Control Alternatives

9. 2. Inflow Reduction Various techniques used to reduce the amount of water that enters a CSS through: • Roof leaders • Area drains • Foundations drains • Basement sump pumps Evaluation of CSO Control Alternatives

10. Find and Eliminate Downspouts Evaluation of CSO Control Alternatives

11. Downspout Extension and RedirectionMilwaukee Metropolitan Sewer District Evaluation of CSO Control Alternatives

12. Rain Gardens Evaluation of CSO Control Alternatives

13. Typical Basement Sump Pump Evaluation of CSO Control Alternatives

14. Rain Garden Solution:Downspout and Basement Sump RedirectionSweetwater Alliance, Duluth, MN Evaluation of CSO Control Alternatives

15. Smoke Testing:Identify and Eliminate Area Drains Evaluation of CSO Control Alternatives

16. Inflow ReductionSouth Portland, ME (Pop: 23,200) • CSS covers 5,250 acres • Surveyed 6,000 residential buildings. • Found 380 roof leaders connected to CSS. • Notified property owners and established rebate program: • $75 for roof leader diversion* • $400 for basement sump pump diversion* • Achieved substantial reduction in CSO discharge for relatively low cost. * 1995 dollars Evaluation of CSO Control Alternatives

17. Inflow ReductionBurlington, IA (Pop 26,800) • Inspected 1,300 manholes (GPS opportunity). • Smoke testing on 300,000 lf sewer line. • Surveyed 4,500 homes • Disconnected all but 50 of 1,400 roof leaders. Evaluation of CSO Control Alternatives

18. 3. Sewer Separation A widely used CSO control – especially in small communities. Can be expensive and disruptive. Often implemented with other projects – road work, utility work, and redevelopment. Solves CSO problem, but adds to storm water problem. Evaluation of CSO Control Alternatives

19. Sewer Separation 19 Evaluation of CSO Control Alternatives

20. Sewer Separation Evaluation of CSO Control Alternatives

21. Sewer Separation: Onondaga County, NY Tallman and Onondaga Avenue Areas Sub Areas Acres Taylor Street 10 Tallman Street West 12 Onondaga Avenue 1 15 Onondaga Avenue 2 16 53 Evaluation of CSO Control Alternatives

22. Onondaga County, NYDetails • New sanitary sewers constructed. • Old sewers become storm sewer. • Cost is $90,000 per acre • 70% funding from Corps of Engineers Evaluation of CSO Control Alternatives

23. Onondaga County, NYAdditional Improvements • Replacing sewer laterals from street to curb line. • Making spot repairs to existing combined sewer. • Replacing active lead or galvanized iron water lines from water main to curb stop. • Gas utility replacing gas main in some portions of work areas. Evaluation of CSO Control Alternatives

24. Onondaga County, NYDisruption Considerations • Development of traffic plan. • Construction done during normal work hours. • Advance notification of water service disruption and alternative water source provided. • Minimization of gas service interruptions. Evaluation of CSO Control Alternatives

25. Sewer Separation Example Randolph, VT (Pop: 2,270) • Separated 44 of 52 catch basins. • Cost to date is $2.7M • 25% State grant • 50% State revolving fund loan • 25% City of Randolph • CSOs reduced but not eliminated. • Achieving full separation is difficult. • Planning to spend another $0.5M. Evaluation of CSO Control Alternatives

26. 4. Storage FacilitiesMany possibilities for small communities • In-line storage—oversized conduits and regulators; in-line tanks; parallel relief sewers. • Off-line storage—retention basins/tunnels to store wet weather flow for subsequent treatment. • On-site storage / flow equalization—storage at WWTP to manage excess wet weather flow. Evaluation of CSO Control Alternatives

27. In-Line Storage: Inflatable Dam Evaluation of CSO Control Alternatives

28. Off-Line StorageExcavation of Retention BasinMassachusetts Water Resources Administration, MA Evaluation of CSO Control Alternatives

29. On-Site Storage - Flow Equalization Basin Evaluation of CSO Control Alternatives

30. On-Site Storage Example Oakland, ME (Pop: 6,000) Restoration of unused flow equalization basin: • Had sufficient conveyance capacity. • Needed additional wet weather capacity. • Restored unused flow equalization basin from closed textile mill. • New storage volume is 0.2 MG • Cost was $27,600 (14 cents per gallon) Evaluation of CSO Control Alternatives

31. On-Site Storage Example South Paris, ME (Pop: 2,237) Restoration of unused pretreatment facility: • Wastewater treatment system designed with two pretreatment facilities – tannery and cannery. • Tannery closed in 1985. • Tannery pretreatment facility brought back on line in mid-1990s. • New storage volume is 1.5 MG • Cost was $110,000 (7 cents per gallon) Evaluation of CSO Control Alternatives

32. CSO Technology References • Report to Congress on Impacts and Control of CSOs and SSOs http://www.epa.gov/npdes/pubs/csossoRTC2004_AppendixL.pdf • EPA Municipal Support Division Fact Sheets www.epa.gov/owm/mtb/mtbfact.htm • Rouge River National Wet Weather Demonstration Project (MI) www.wcdoe.org/rougeriver/ • Columbus Water Works National Demonstration Program (GA) www.cwwga.org/NationalPrograms/Index.htm Evaluation of CSO Control Alternatives

33. Screening and Evaluation of CSO Controls The screening and evaluation of controls should: • Include WQ considerations • Consider site specific control needs • Address performance of control technologies • Describe implementation issues • Explain reasons for selecting CSO control alternatives • Explain reasons for rejecting other controls Note: Looking for logical decision-making process Evaluation of CSO Control Alternatives

34. Selecting the Best CSO Control Alternatives • Will water quality and designated uses be protected? • Have sensitive areas been considered? • Has a reasonable range of CSO control alternatives been considered? • Has public input been obtained and used? • Has financial capability been assessed? Evaluation of CSO Control Alternatives

35. Final Selection of CSO Control Alternatives • Should be based on: • Control priorities • Site specific conditions • Protection of WQS and designated uses • Public input • Cost-effectiveness of controls • Financial capability • Other considerations Evaluation of CSO Control Alternatives

36. CSO ControlWest Lafayette, IN (Pop 28,900) The 20 Year plan for CSO control that began in mid-1990s includes: • An $18 million upgrade to the POTW • A $2.2 million foundation drain disconnect program in the BarBarry neighborhood (1999) • Construction of the $2.3 million North River Road lift station (1999). • The $1.9 million rehabilitation of the Happy Hollow interceptor (2001). • Construction of the $5.9 million wet weather treatment facility to reduce CSO impacts on the Wabash River (2003). Evaluation of CSO Control Alternatives

37. CSO Control: Auburn, IN (Pop 12,000) Evaluation of CSO Control Alternatives

38. CSO ControlSaltsburg Borough, PA (Pop. 955) Small population and limited budget required emphasis on NMCs: • Proper O&M of existing sewer system. • Installed baffles to control floatables in catch basins. • Notification signs at CSOs • Community bulletin board for education abut CSOs. • Limited monitoring of CSO volume and freq. Evaluation of CSO Control Alternatives

39. CSO ControlSouth Portland, ME (Pop: 23,200) Achieved 90 percent reduction in CSO volume • Wet weather primary capacity expanded from 12 mgd to 56 mgd • Adjusted weir heights • Upgraded pump stations • Inflow reduction (roof leaders and sump pumps) • Select sewer separation • Eliminated 25 of 30 CSO outfalls Evaluation of CSO Control Alternatives

40. CSO ControlBangor, ME (Pop: 31,500) • Sewer separation – 23 projects – $6.3M. • Increased primary treatment by 13 MGD. • Eliminated 33% of CSO outfalls. • Built 1.2 MG off-line storage beneath parking lot for $2.3M ($1.92 per gallon) Evaluation of CSO Control Alternatives