System Characterization and Monitoring Activities

1. System Characterization and Monitoring Activities Julia Moore, P.E. Limno-Tech, Inc.

2. Expectations of the CSO Policy The purpose of system characterization [and] monitoring… is initially to assist the CSO community with implementation of the NMCs, and, if necessary, to support development of a LTCP. System Characterization and Monitoring Activities

3. Objectives • Develop an understanding of the combined sewer system (CSS) and receiving waters • Assess CSS design and operating conditions • Characterize combined sewage and CSO impacts on receiving waters • Identify gaps in existing information and plan activities to address them • Assist with implementation of the NMC System Characterization and Monitoring Activities

4. Three Components of System Characterization • Physical characterization of CSS • Characterization of combined sewage and CSOs • Characterization of receiving waters System Characterization and Monitoring Activities

5. Physical Characterization • Key sources of existing information • Sewer maps, design specifications, as-built drawings • CSS, pump station, and WWTP flow records • National Climate Data Center (NCDC) rainfall records http://www.ncdc.noaa.gov/oa/ncdc.html System Characterization and Monitoring Activities

6. Physical Characterization • Additional sources of existing information • WWTP facilities plans • Pump station and WWTP performance data (e.g. stress test results) • Treatment plant upgrade reports • Infiltration/inflow (I/I) studies • Sewer system evaluation surveys (SSES) • Storm water master plans • GIS databases System Characterization and Monitoring Activities

7. Physical Characterization • LTCP development typically includes: • Delineation of CSS area and sewersheds • Location of CSO outfalls and regulator structures, the WWTP, and pump stations • Description of CSO receiving water • Land use and estimated impervious cover, by sewershed • Layout of major interceptors • Hydraulic capacities for the WWTP, CSO regulators, and pump stations System Characterization and Monitoring Activities

8. Physical Characterization of Springfield, USA Separate Sewer Area • Delineation of CSS area • CSO outfall locations • Receiving waters CSS Area Lazy River Babbling Brook Satellite Community System Characterization and Monitoring Activities

9. CSO Area CSO Area #2 (250 acres) CSO Area #1 (300 acres) Lazy River CSO #1 CSO #2 CSO Area #3 (150 acres) Babbling Brook CSO #4 Pump station relief CSO #3 9

10. Physical Characterization • Layout of major interceptors • Location of: • WWTP • CSO regulators • Pump station WWTP System Characterization and Monitoring Activities

11. Physical Characterization • General land use and estimated impervious cover • Land use categories include: • Parkland or open space (<5% impervious) • Low density development (5-35% impervious) • Medium density development (35-70% impervious) • High density development (>70% impervious) System Characterization and Monitoring Activities

12. High Density Medium Density Low Density Open Space 12 System Characterization and Monitoring Activities

13. Land Use Tabulation System Characterization and Monitoring Activities

14. Impervious Cover Calculation Example:CSO Area #1includes: System Characterization and Monitoring Activities

15. Physical Characterization • Hydraulic analysis should be sufficient to: • Establish capacities for WWTP, pump stations and CSO regulators • Quantify dry weather and wet weather flows, including flows to CSS from neighboring communities • Describe any existing flow metering • Permanent system meters and monitors such as SCADA (Supervisory Control And Data Acquisition) • Metering/flow monitoring from previous studies • Identify problem areas and bottlenecks System Characterization and Monitoring Activities

16. Pump Station and WWTP Capacities (MGD) System Characterization and Monitoring Activities

17. CSS Capacities (MGD) System Characterization and Monitoring Activities

18. Flow BalanceQwet = CiA C = runoff coefficient (% imperviousness) i = rainfall intensity A = area System Characterization and Monitoring Activities

19. Flow Balance Diagram 19

20. Flow Balance Diagram 20

21. Problem Areas and Bottlenecks • Compare capacity at key locations in the collection system with peak wet weather flow rates • Intersections of major interceptors • Regulators • Pump stations • Cross connections • Additional study may be required in areas that often flood during wet weather System Characterization and Monitoring Activities

22. Example—Bottleneck • Pump station capacity should equal or exceed capacity of interceptors delivering flow From CSO #2 Max. flow = 2 MGD P.S. capacity 6 MGD to WWTP From CSOs #1 and #3 Max. flow = 5.5 MGD System Characterization and Monitoring Activities

23. Characterization of Combined Sewage and CSOs • Sources of existing information: • General WWTP operating data • Discharge monitoring reports (DMRs) • Pretreatment program data • Facility planning studies • GIS databases • Other local CSO studies • Literature System Characterization and Monitoring Activities

24. Characterization of Combined Sewage and CSOs • LTCP should include estimates of central tendency (median, EMC) and ranges of concentration for pollutants of concern • Most often: Bacteria, TSS, BOD • Sometimes: Nutrients • Less often: Metals and toxics System Characterization and Monitoring Activities

25. Average Pollutant Concentrations in Municipal Discharges System Characterization and Monitoring Activities

26. Average Pollutant Concentrations in Municipal Discharges System Characterization and Monitoring Activities

27. Average Pollutant Concentrations in Municipal Discharges System Characterization and Monitoring Activities

28. Characterization of Receiving Waters • Sources of existing information: • Applicable state water quality standards • USGS streamflow data http://waterdata.usgs.gov/nwis/sw • EPA STORET and BASINS Programs • State 305(b) Water Quality Assessment Reports • State 303(d) lists of impaired waters • Other local water quality assessments System Characterization and Monitoring Activities

29. Characterization of Receiving Waters • LTCP should document the following: • Designated uses for each CSO-impacted water • Available water quality, sediment, and biological data • Flow conditions in the CSO receiving water(s) • Known impairments • Location of sensitive areas • Planned or ongoing TMDL studies System Characterization and Monitoring Activities

30. Example Designated Use • Lazy River • Secondary Contact Recreation – Used for power boating, sail boating, canoeing and rowing for recreational purposes when surface water flow or impoundment conditions allow • Nontrout Water – Suitable for propagation and survival of fish System Characterization and Monitoring Activities

31. Example Water Quality Criteria • Lazy River • Dissolved Oxygen –the minimum daily average shall not be less than 5.0 mg/L, and at no time shall the DO concentration be less than 4.0 mg/L • Bacteria – the monthly geometric mean, from a minimum of five examinations, shall not exceed 200 MPN/100 mL during all periods when disinfection is practiced • pH – from 6.5 to 8.5, inclusive • Garbage and other refuse – none in any amounts System Characterization and Monitoring Activities

32. Example Summary of Available Water Quality Data Water Body – Lazy River System Characterization and Monitoring Activities

33. Example Designated Use • Babbling Brook • Potable Water Supply – Used, after conventional treatment, for drinking, culinary and other domestic purposes, such as inclusion into foods, either directly or indirectly • Primary Contact Recreation – Used for swimming and other full-body contact activities • Trout Water – Suitable for propagation and survival of fish, including trout System Characterization and Monitoring Activities

34. Example Water Quality Criteria • Babbling Brook • Dissolved Oxygen – the minimum daily average shall not be less than 6.0 mg/L, and at no time shall the concentration be less than 5.0 mg/L • Bacteria – the monthly geometric mean, from a minimum of five examinations, shall not exceed 200 MPN/100 mL • pH – from 6.5 to 8.5, inclusive • Garbage and other refuse – none in any amounts System Characterization and Monitoring Activities

35. Example Summary of Available Water Quality Data Water Body—Babbling Brook System Characterization and Monitoring Activities

36. Example Summary of Flow Conditions System Characterization and Monitoring Activities

37. Example Summary of Flow Conditions 37

38. What if Local Flow Data are Not Available? • Options for estimating flow: • Scale down/up from gage elsewhere in the watershed • Use data from similar local watershed with gage • Estimate flow using Q=CiA System Characterization and Monitoring Activities

39. Example Scale Up from Another Gage Shelbyville Gage on Babbling Brook SpringfieldCSO Area X 39

40. Babbling Brook at Shelbyville Drainage Area 13.9 mi2 Annual Average Flow 9.9 cfs Babbling Brook at Springfield Drainage Area 17.2 mi2 Annual Average Flow 17.2 mi2 = BB flow 13.9 mi2 9.9 cfs BB flow = 12.2 cfs Example – Scale Up from Another Gage System Characterization and Monitoring Activities

41. Example Summary of Known Impairments The State 303(d) list includes water bodies where existing pollution control activities are not sufficient to attain applicable WQ standards. The list includes several water bodies that pass through Springfield. • Lazy River within Springfield is listed for dissolved oxygen/ oxygen demand, pH, and floatables (NOT bacteria). • Babbling Brook from the county line to its mouth at the Lazy River is listed for bacteria and floatables. Upstream portions of the brook are also listed for bacteria. System Characterization and Monitoring Activities

42. Characterization of Receiving Waters • Sensitive areas per CSO Policy include: • Outstanding National Resource Waters • National Marine Sanctuaries • Waters with threatened and endangered species and their habitat • Primary contact recreation waters, such as beaches • Public drinking water intakes • Shellfish beds • Sensitive area descriptions should include locational information (e.g., river mile or narrative based on known upstream/downstream distance) System Characterization and Monitoring Activities

43. Example Identification of Sensitive Area Babbling Brook has a designated use of primary contact recreation. • Jebediah Springfield Beach is located on the northeast shore of the brook, approximately 0.3 miles downstream of CSO #1 and 0.1 miles above the confluence with the Lazy River. • Jebediah Springfield Beach is open to the public for swimming and wading weekends from Memorial Day to Labor Day. System Characterization and Monitoring Activities

44. Monitoring Program • Builds on the system characterization • Designed to obtain missing, but necessary, information about the CSS operating conditions and CSO impacts • Supports implementation of both the NMC and an LTCP System Characterization and Monitoring Activities

45. Expectations of the CSO Policy The permittee should develop a comprehensive, representative monitoring program that measures the frequency, duration, flow rate, volume and pollutant concentration of CSO discharges and assesses the impact of CSOs on the receiving water… System Characterization and Monitoring Activities

46. MonitoringGoals and Objectives • Typical objectives: • Define hydraulic response of the CSS to rainfall • Determine CSO impacts on receiving water(s) • Establish baseline conditions to characterize long-term effects of CSO controls • Evaluate effectiveness of the NMC System Characterization and Monitoring Activities

47. Monitoring Program Documentation • Identify monitoring goals and objectives • Identify data needs • Demonstrate that sampling program addressed data needs • Document method for data management and analysis System Characterization and Monitoring Activities

48. Monitoring—Data Needs • Data needs are very site specific • Closely linked to short and long-term control objectives • Data needs are dependent on the amount of existing information available • Prioritization often required as data needs are typically greater than available budget • Monitoring should be conducted in a manner consistent with applicable state water quality standards System Characterization and Monitoring Activities

49. Monitoring - Costs • Usually only 20 to 50 percent of CSOs need full monitoring in a system • Cover range of land use • Pick largest and/or unique CSOs • Monitoring is expensive • Models “stretch” the value of monitoring System Characterization and Monitoring Activities

50. Monitoring—Sampling Program • Types of monitoring: • Rain gage • CSS flow • Dry weather • Wet weather • CSO volume, frequency and pollutant concentrations • Receiving water monitoring • Upstream • CSO impacted zone System Characterization and Monitoring Activities