Connecticut Statewide Total Maximum Daily Load (TMDL) for Bacteria-Impaired Waters Connecticut Statewide Total Maximum Daily Load (TMDL) for Bacteria Impaired Waters Connecticut Department of Energy and Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Prepared by: FB Environmental Associates, Inc. 97A Exchange Street, Suite 305 Portland, Maine 04101 Connecticut Statewide Bacteria TMDL – FINAL September 2012 Table of Contents LIST OF ACRONYMS .......................................................................................................................... vii 1. Introduction ............................................................................................................................................ 1 2. Background ............................................................................................................................................ 3 2.1 Pathogens & Indicator Bacteria ........................................................................................................... 3 2.2 Bacteria Pollution Sources ................................................................................................................... 4 2.2.1 Point Source Pollution .................................................................................................................. 4 2.2.2 Non-Point Source Pollution ........................................................................................................ 14 3. Water Quality Standards for Bacteria .................................................................................................. 18 3.1 Classification and Designated Uses ................................................................................................... 18 3.2 Water Quality Criteria for Bacteria .................................................................................................... 20 3.3 Antidegradation Provisions ................................................................................................................ 22 3.4 Numeric Water Quality Target........................................................................................................... 23 4. Bacteria-Impaired Waters .................................................................................................................... 24 4.1 Monitoring for Compliance with Water Quality Standards & Source Identification ........................ 24 4.2 Waterbody Descriptions and Priority Ranking .................................................................................. 25 5. TMDL .................................................................................................................................................. 36 5.1 TMDL Definition ............................................................................................................................... 36 5.2 Loading Capacity, MOS, and Allocations ......................................................................................... 36 5.2.1 Concentration TMDLs ................................................................................................................ 37 5.3 Seasonal Considerations .................................................................................................................... 44 5.4 Future TMDL Applicability ............................................................................................................... 44 5.5 NPDES Regulated stormwater discharges ......................................................................................... 44 5.5.1 MS4 GP discharges ..................................................................................................................... 44 5.5.2 Industrial GP discharges ............................................................................................................. 45 5.5.3 Commercial GP discharges ........................................................................................................ 45 5.5.4 Construction stormwater discharges .......................................................................................... 46 5.5.5 Non-regulated MS4 discharges .................................................................................................. 46 i Connecticut Statewide Bacteria TMDL – FINAL September 2012 5.6 Monitoring Plans ................................................................................................................................ 46 5.7 Reasonable Assurance ........................................................................................................................ 49 5.8 Public Participation ............................................................................................................................ 50 5.9 Response to TMDL goals................................................................................................................... 50 6. Implementation Plans ........................................................................................................................... 50 6.1 The Implementation and Restoration Process .................................................................................... 51 6.1.1 Watershed Management Plan Examples and Resources ............................................................. 55 6.2 Best Management Practices ............................................................................................................... 58 6.2.1 Developed Area Stormwater Runoff ........................................................................................... 59 6.2.2 Subsurface Sewage Disposal Systems ........................................................................................ 65 6.2.3 Agriculture .................................................................................................................................. 69 6.2.4 Illicit Discharges ......................................................................................................................... 72 6.2.5 Combined Sewer Overflows (CSOs) .......................................................................................... 76 6.2.6 Pets .............................................................................................................................................. 78 6.2.7 Wildlife ....................................................................................................................................... 79 6.2.8 Boats and Marinas ....................................................................................................................... 80 7. Funding and Community Resources .................................................................................................... 83 8. Connecticut’s Drainage Basins and Bacteria-Impaired Segments ....................................................... 92 8.1 Watershed-Specific Bacteria Data Summaries .................................................................................. 93 8.1.1 Wet/Dry Weather Analysis Methodology ................................................................................... 96 8.1.2 Estimated Bacteria Reduction Calculation Methodologies......................................................... 96 9. References .......................................................................................................................................... 110 List of Tables Table 2-1: Combined Sewer Overflow (CSO) Regulator Status. .................................................................. 7 Table 2-2: Description of system type and jurisdictions…………………………………………………..15 Table 3-1: Applicable Designated uses by Waterbody Class. ..................................................................... 20 Table 3-2: Numeric Criteria for Indicator Bacteria by Waterbody Class and Designated Use in Connecticut. ...................................................................................................................................................................... 22 ii Connecticut Statewide Bacteria TMDL – FINAL September 2012 Table 5-1: Bacteria (E. coli) TMDLs, WLAs, and LAs for Fresh Water (not drinking water supply). ...... 39 Table 5-2: Bacteria (Enterococcus) TMDLs, WLAs, and LAs for Estuarine and Marine Waters (non- shellfish harvesting areas). ........................................................................................................................... 40 Table 5-3: Bacteria (Fecal Coliform) TMDLs WLAs, and LAs for Shellfish Harvesting Areas. ............... 42 Table 5-4: Bacteria (Total Coliform) TMDLs, WLAs, and LAs for Drinking Water Supply. .................... 43 Table 8-1: Connecticut Major Watersheds and Long Island Sound Divisions with Number of Bacteria- Impaired Segments Indicated. ...................................................................................................................... 93 Table 8-2: Summary of Estimated Percent Reductions for Bacteria-Impaired Waterbodies. ..................... 99 List of Figures Figure 2-1: Relationship among Indicator Organisms (USEPA, 2001). ........................................................ 4 Figure 2-2: CSO Communities in Connecticut .............................................................................................. 7 Figure 4-1: of Bacteria-Impaired Waterbodies and Major Watersheds in Connecticut. .............................. 26 Figure 6-1: Steps in the Watershed Planning and Implementation Process (USEPA, 2008). ....................