Final Report New Hampshire Statewide Total Maximum Daily Load (TMDL)
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Final Report New Hampshire Statewide Total Maximum Daily Load (TMDL) for Bacteria Impaired Waters Final Report September, 2010 Final Report New Hampshire Statewide Total Maximum Daily Load (TMDL) for Bacteria Impaired Waters State of New Hampshire Department of Environmental Services P.O. Box 95 29 Hazen Drive Concord, New Hampshire 03302-0095 Prepared by: FB Environmental Associates, Inc. 97A Exchange Street, Suite 305 Portland, Maine 04101 Final Report New Hampshire Statewide TMDL for Bacteria Impaired Waters September 2010 TABLE OF CONTENTS 1. Introduction ...................................................................................................................................... 1 1.1. Background................................................................................................................................ 1 1.2. Purpose of Report ...................................................................................................................... 3 1.3. Report Format ............................................................................................................................ 5 2. Water Quality Standards for Bacteria ..............................................................................................13 2.1. Overview of Pathogens and Indicator Bacteria ..........................................................................13 2.2. Water Quality Standards for Bacteria in New Hampshire Waters ..............................................14 2.2.1. Classification and Designated Uses ........................................................................................14 2.2.2. Water Quality Criteria ...........................................................................................................16 2.2.3. Antidegradation Provisions ....................................................................................................18 2.3. Numeric Water Quality Target ..................................................................................................19 3. Bacteria Pollution Sources ...............................................................................................................20 3.1. Point Source Pollution ..............................................................................................................20 3.1.1 NPDES Non-stormwater (i.e., WWTFs, CSOs, CAFOs) ....................................................21 3.1.2 NPDES Stormwater (MS4GP, CGP, MSGP) .....................................................................23 3.1.3 Unauthorized Point Source Discharges of Untreated Wastewater (i.e., SSOs, Illicit Discharges, Boats) ...........................................................................................................................23 3.2. Non-point Source Pollution .......................................................................................................25 4. Bacteria Impaired Waters ................................................................................................................27 4.1. Data Collection and 303(d) Listing Process ...............................................................................27 4.2. Priority Ranking and TMDL Schedules .....................................................................................30 4.3. Watershed-Specific Bacteria TMDL Development Approach....................................................30 5. TMDL Development .......................................................................................................................33 5.1. Definition of a TMDL ...............................................................................................................33 5.2. TMDL Allocations ....................................................................................................................33 5.4. Margin of Safety .......................................................................................................................37 5.5. Seasonal Considerations ............................................................................................................38 5.6. Public Participation ...................................................................................................................38 5.7. Monitoring Plans ......................................................................................................................39 5.8. Reasonable Assurance ...............................................................................................................40 6. Implementation Plans ......................................................................................................................43 6.1. The Implementation and Restoration Process ............................................................................43 6.2. Types of Implementation Measures to Restore Impaired Waters ...............................................48 6.2.1. Stormwater ............................................................................................................................49 6.2.2. Illicit Discharges ................................................................................................................53 i Final Report New Hampshire Statewide TMDL for Bacteria Impaired Waters September 2010 6.2.3. Combined Sewer Overflows ..............................................................................................57 6.2.4. Septic Systems ...................................................................................................................60 6.2.5. Pet Waste ...........................................................................................................................63 6.2.6. Wildlife Waste ...................................................................................................................66 6.2.7. Agriculture.........................................................................................................................67 6.2.8. Beaches, Boats and Marinas ...............................................................................................72 7. Funding and Community Resources .................................................................................................78 8. Watershed-Specific Bacteria Data Summaries and Reduction Estimates ..........................................82 8.1 Wet/Dry Weather Analysis Methodology ......................................................................................82 8.2 Estimated Load Reduction Calculation Methodology ....................................................................83 9. Examples of Implementation Plans to Remove Bacteria Impairment ...............................................94 9.1 Furnace Brook Watershed-Based Restoration Plan ........................................................................94 9.2 Greenville IDDE Investigation Report ...........................................................................................95 References ..............................................................................................................................................96 LIST OF TABLES Table 1-1: Number of Bacteria Impaired Assessment Units in New Hampshire, by Waterbody Type. ...... 3 Table 1-2: Bacteria Impaired Waters Covered by the TMDL, Based on the NH 2008 303(d) List............. 7 Table 2-1: Designated Uses for New Hampshire Surface Waters............................................................. 15 Table 2-2: Ambient Bacteria Criteria for Contact Recreation ...................................................................16 Table 2-3: Fecal Coliform Criteria for Shellfish Consumption (NSSP, 2007). .........................................18 Table 5-1: WLAs and LAs for Freshwater (Primary Contact Recreation)* ..............................................35 Table 5-3: WLAs and LAs for Tidal Waters (Shellfishing)*.................................................................... 36 Table 5-2: WLAs and LAs for Tidal Waters (Primary Contact Recreation)*. ..........................................36 Table 5-4: Notes for WLA, LA Allocation Tables 5-1, 5-2 and 5-3. ........................................................37 Table 8-1: Summary of Estimated Percent Reductions for Bacteria Impaired Segments. .........................85 LIST OF FIGURES Figure 1-1: Map of Bacteria Impaired Waters in New Hampshire, by HUC 8 Watershed. ........................ 4 Figure 2-1: Relationship among Indicator Organisms (USEPA, 2001)..................................................... 14 Figure 4-1: Map of Bacteria Impaired Waters in New Hampshire, by HUC 8 Watershed. .......................32 Figure 6-1: Steps in the Watershed Planning and Implementation Process (USEPA, 2008). ....................45 Figure 6-2: Relationship between TMDLs and Watershed Management Plans (USEPA, 2008). ..............46 ii Final Report New Hampshire Statewide TMDL for Bacteria Impaired Waters September 2010 LIST OF APPENDICES Appendix A: Lower Androscoggin River Watershed Appendix B: Saco River Watershed Appendix C: Salmon Falls-Piscataqua River Watershed Appendix D: Pemigewasset River Watershed Appendix E: Winnipesaukee River Watershed Appendix F: Contoocook River Watershed Appendix G: Nashua River Watershed Appendix H: Merrimack River Watershed Appendix I: Upper Connecticut River Watershed Appendix J: Connecticut River Watershed from John River to Waits River Appendix K: Connecticut River Watershed from Waits River to White River Appendix