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CPAC Meeting 12-15-03


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CPAC Meeting 12-15-03

  1. 1. Water Quality Update Presented to CPAC January 12, 2003
  2. 2. Objectives of Presentation <ul><li>How tasks fit together to support the Long Term Control Plan </li></ul><ul><li>What has been accomplished </li></ul>
  3. 3. Tools to Understand CSO Impacts <ul><li>Flow Characterization </li></ul><ul><ul><li>System Characterization and Flow Metering </li></ul></ul><ul><li>Hydraulic Sewer Model </li></ul><ul><li>Water Quality Study </li></ul><ul><li>Water Quality Model </li></ul><ul><li>Long Term Control Plan </li></ul>
  4. 4. Consent Decree Requirements <ul><li>All study efforts required by consent decree </li></ul><ul><li>CD included specific items each study must include </li></ul><ul><li>Study work plans were approved April 7, 2003 </li></ul><ul><li>Reports for Flow Characterization and Water Quality Study are due in April 2004. </li></ul><ul><li>Long Term Control Plan Report due October 2005. </li></ul>
  5. 5. System Characterization
  6. 6. Flow Metering
  7. 7. Hydraulic Sewer Modeling
  8. 8. Water Quality Study
  9. 9. Water Quality Model
  10. 10. Long Term Control Plan
  11. 11. How Monitoring/ Models Are Used in Long Term Control Planning <ul><li>Monitoring </li></ul><ul><ul><li>Shows current conditions </li></ul></ul><ul><ul><li>Helps identify unusual operating conditions </li></ul></ul><ul><ul><li>Provide data to make sure models make sense </li></ul></ul><ul><li>Models </li></ul><ul><ul><li>Fill in the gaps where we can’t monitor </li></ul></ul><ul><ul><li>Predicts what will happen with different rainfall conditions </li></ul></ul><ul><ul><li>Allows evaluation of changes to the system </li></ul></ul>
  12. 12. 2003 Flow Metering Locations
  13. 13. 2003 Flow Metering Program <ul><li>Meter Installation </li></ul><ul><li>Meters Installed May through August </li></ul><ul><li>Site Visits – Site Check/Data Download weekly </li></ul>
  14. 14. Metering Locations – data set
  15. 15. Data Set <ul><li>1999 City-wide Flow Monitoring Study – 48 meters </li></ul><ul><li>SCADA data – 47 data collection locations </li></ul><ul><li>2003 Data – 36 metering locations </li></ul><ul><li>Point Place - __ metering locations </li></ul><ul><li>Overall – 130+ metering locations with consistent data analysis techniques </li></ul>
  16. 16. 2003 Metering Period Rain Events <ul><li>Several Rain Events Greater than One Inch </li></ul>88% 1.07 May 31, 2003 91% 3.57 September 1, 2003 73% 2.66 August 3, 2003 97% 1.58 July 7, 2003 97% 1.36 June 11, 2003 42% 2.01 May 9, 2003 Percentage of Meters Recording Data Amount of Rain (inches) Date of Wet Weather Event
  17. 17. Sanitary Area Flow Contributions <ul><li>Percent Capture – 1999 and 2003 </li></ul>
  18. 18. Sanitary Area Flow Contributions <ul><li>Peaking Factor – 1999 and 2003 </li></ul>
  19. 19. Sanitary Area Flow Contributions <ul><li>Separated portions of the sewer system will contribute significant flow in wet weather. </li></ul><ul><li>There are a number of very wet areas of the system where flow reduction work is encouraged </li></ul><ul><li>The sanitary flow rates during wet weather are important to consider in evaluating CSO control alternatives and the overall impact on the plant </li></ul>
  20. 20. Combined Area Flow Contributions <ul><li>Combined Area Flow (Hydrologic) Response </li></ul><ul><li>This is a critical parameter for modeling. </li></ul><ul><li>Values fall within typical ranges </li></ul><ul><li>73% of Combined Area Monitored </li></ul>
  21. 21. Estimated Capture Rates 2003
  22. 22. Combined Flow Summary <ul><li>Data collected to calibrate model </li></ul><ul><li>Ability of flow to be delivered to the interceptor varies significantly by regulator </li></ul><ul><ul><li>Variability in frequency of discharge </li></ul></ul><ul><ul><li>Overloading of interceptor system </li></ul></ul>
  23. 23. Windermere Pump Station 9/1/03 Response
  24. 26. System Hydraulics - observations <ul><li>The system backs up during wet weather events </li></ul><ul><li>The majority of the back up seems to start at the WWTP </li></ul><ul><li>Because of the backups, flow reverses direction in the sewers. More overflow to the waterways also occurs. </li></ul>
  25. 27. System Hydraulics - consequences <ul><li>Once the WWTP can process more flow </li></ul><ul><ul><li>System backup should be reduced </li></ul></ul><ul><ul><li>Less CSO discharge to the waterways </li></ul></ul><ul><ul><li>Less risk of basement backup </li></ul></ul>
  26. 28. Water Quality Study <ul><li>Instream (CSO Area) </li></ul><ul><ul><li>Dry weather sampling (2 events) </li></ul></ul><ul><ul><li>Wet weather sampling (2 events) </li></ul></ul><ul><li>Upstream Boundary (Watershed) </li></ul><ul><ul><li>Dry/wet, 17 weekly sampling events </li></ul></ul><ul><li>Intensive DO </li></ul><ul><ul><li>Monitoring </li></ul></ul><ul><ul><li>Two 2-week periods </li></ul></ul>
  27. 29. 2003 Sampling Locations
  28. 30. Wet Weather Event Monitoring <ul><li>May 1, 2003: </li></ul><ul><ul><li>Fast-moving spring storm (shown) </li></ul></ul><ul><ul><li>0.6” at Toledo Express </li></ul></ul><ul><ul><li>CSO duration ~ 2 hours </li></ul></ul><ul><li>September 1, 2003 </li></ul><ul><ul><li>Slower-moving late summer storm </li></ul></ul><ul><ul><li>2.6” at Toledo Express </li></ul></ul><ul><ul><li>CSO duration ~ 14 hours </li></ul></ul>
  29. 31. WW Monitoring Results - Bacteria <ul><li>Ottawa River: </li></ul><ul><li>WW1 – low concentrations, dominated by upstream </li></ul><ul><li>WW2 – high upstream + significant in-stream contribution </li></ul><ul><li>Decreased concentrations downstream due to Maumee Bay mixing </li></ul>Primary Contact Recreational Standard Primary Contact Recreational Standard
  30. 32. WW Monitoring Results – Dissolved Oxygen <ul><li>Maumee River </li></ul><ul><ul><li>WW1 – Aeration elevates DO </li></ul></ul><ul><ul><li>WW2 – CSOs also reduce downstream DO </li></ul></ul>
  31. 33. Consent Decree Requirements – Hydraulic Sewer Model <ul><li>Workplan, approved April 7, 2003 </li></ul><ul><li>Develop sewer model to predict: </li></ul><ul><ul><li>Flows </li></ul></ul><ul><ul><li>Hydraulic grade lines and capacities </li></ul></ul><ul><ul><li>CSO frequencies and volumes </li></ul></ul><ul><li>Use in conjunction with WQ model to support Long Term Control Plan </li></ul>
  32. 34. Hydraulic Model Coverage
  33. 35. Status of Hydraulic Model <ul><li>East Side model is operational </li></ul><ul><ul><li>Calibrated to 2003 metering data </li></ul></ul><ul><ul><li>Calibration is preliminary, pending: </li></ul></ul><ul><ul><ul><li>West Side and 10-Mile Creek calibrations - consistency </li></ul></ul></ul><ul><ul><ul><li>Runs with complete model - reasonableness </li></ul></ul></ul><ul><li>West Side calibration not far behind </li></ul><ul><li>10-Mile Creek to be calibrated in December </li></ul>
  34. 36. East Side Hydraulic Submodel
  35. 37. Calibration to 2003 Metering Data <ul><li>Also important to accurately estimate flows to interceptor (example: Eastside Interceptor) </li></ul>
  36. 38. Consent Decree Requirements – WQ Model <ul><li>Workplan, approved April 7, 2003 </li></ul><ul><li>Model shall be capable of: </li></ul><ul><ul><li>Accurately modeling WQ in the 3 streams </li></ul></ul><ul><ul><ul><li>Under wide range of conditions </li></ul></ul></ul><ul><ul><li>Assessing impacts of CSOs on WQ </li></ul></ul><ul><ul><li>Assessing changes in CSO impact due to Long Term Control measures under evaluation </li></ul></ul>
  37. 39. Summary <ul><li>Flow Characterization Study - close to completion </li></ul><ul><li>Water Quality Study - on schedule </li></ul><ul><li>Hydraulic Model - on schedule about ready to use </li></ul><ul><li>Water Quality Model – will build off of hydraulic model </li></ul><ul><li>Long Term Control Plan – will use the models as tools to develop alternatives </li></ul>
  38. 40. Next Steps <ul><li>Long Term Control Plan – begin evaluation of alternatives </li></ul><ul><li>Gather input from stakeholders and the general public </li></ul>