DRAFT Northeast Regional Mercury Total Maximum Daily Load Connecticut Department of Environmental Protection Maine Department of Environmental Protection Massachusetts Department of Environmental Protection New Hampshire Department of Environmental Services New York State Department of Environmental Conservation Rhode Island Department of Environmental Management Vermont Department of Environmental Conservation New England Interstate Water Pollution Control Commission April 2007 DRAFT Contents Contents .......................................................................................................................................................ii Tables ..........................................................................................................................................................iv Figures.........................................................................................................................................................iv Acknowledgements .....................................................................................................................................v Executive Summary ...................................................................................................................................vi Abbreviations ...........................................................................................................................................xiii Definition of Terms..................................................................................................................................xvi 1 Introduction..............................................................................................................................................1 1.1 Water Quality and Health Concerns...............................................................................................1 1.2 TMDL Requirements and Process ..................................................................................................1 2 Background Information.........................................................................................................................2 2.1 Fish Consumption Advisories ..........................................................................................................2 2.2 Section 319 Nonpoint Source Assessments and Categorization of Atmospheric Deposition as a Nonpoint Source......................................................................................................................................3 2.3 Massachusetts’ TMDL Alternative and EPA Justification for Disapproval ...............................4 2.4 Section 303(d) Listing for Mercury Impaired Waters – Category 5m.........................................5 2.5 Northeast Regional Commitment to Reducing Regional Sources of Mercury............................6 2.6 Control of In-State Sources not Sufficient to Meet Water Quality Standards............................7 3 Applicable Water Quality Standards and Fish Tissue Criteria...........................................................7 3.1 Assessment of Fish Contaminants ...................................................................................................8 4 Fish Tissue Mercury Concentrations .....................................................................................................8 4.1 Fish Tissue Monitoring Dataset.......................................................................................................8 4.2 Areas of Elevated Concentration...................................................................................................10 5 Northeast Regional Approach...............................................................................................................10 5.1 Impaired Waters .............................................................................................................................10 5.2 Selection of Existing Fish Mercury Concentration Based on Standard Size Fish.....................11 5.3 Target Fish Mercury Concentration.............................................................................................11 5.4 Proportionality of Mercury Reductions........................................................................................12 6 Source Assessment .................................................................................................................................12 6.1 Northeast States Emissions Inventory...........................................................................................12 6.2 Atmospheric Deposition Modeling ................................................................................................15 6.3 Point Sources to Water...................................................................................................................16 7 Development of a Regional Total Maximum Daily Load...................................................................17 7.1 TMDL Formulation ........................................................................................................................17 7.2 Calculation of Existing Total Source Load (TSL)........................................................................17 7.3 Reduction Factor (RF)....................................................................................................................19 7.4 TMDL Calculation..........................................................................................................................19 7.5 Wasteload Allocation (WLA).........................................................................................................19 7.6 Load Allocations..............................................................................................................................20 7.6.1 Load Allocation Calculations..................................................................................................20 7.6.2 Necessary Reductions to Meet LA..........................................................................................20 7.7 Margin of Safety..............................................................................................................................21 7.8 Seasonal Variation and Critical Conditions .................................................................................21 7.9 Daily Load........................................................................................................................................22 8 Final TMDL............................................................................................................................................22 9 Implementation ......................................................................................................................................22 9.1 State and Regional Implementation ..............................................................................................23 Northeast Regional Mercury TMDL – April 2007 ii DRAFT 9.1.1 Implementation of Wasteload Allocation ..............................................................................23 9.1.2 Adaptive Implementation of Load Allocation .......................................................................23 9.2 Adaptive National Implementation ...............................................................................................24 10 Reasonable Assurances........................................................................................................................25 10.1 State Level Assurances .................................................................................................................25 10.2 National and International Assurances.......................................................................................31 11 Public Participation .............................................................................................................................31 12 References.............................................................................................................................................33 Appendix A: Northeast Waters Impaired Primarily by Atmospheric Deposition of Mercury .........36 Appendix B: Necessary Reductions to meet Water Quality Standards in Maine and Connecticut..41 Northeast Regional Mercury TMDL – April 2007 iii DRAFT Tables Table ES-1 Summary of Northeast Regional Mercury TMDL………………………………………......viii Table 2-1 Summary of Statewide Fish Consumption Advisories for Freshwaters………………………...3 Table 3-1 Water Quality Criteria and Fish Consumption Advisory Values for Mercury…………..……...8 Table 4-1 Standard Lengths and Mercury Concentrations of Selected Freshwater Fish Species in the Northeast……………………………………………………………………………………………………9 Table 5-1 Northeast Waterbodies Impaired Primarily by Atmospheric Deposition of Mercury..........…...10 Table 6-1 1998 Northeast Regional Mercury Emissions Inventory…………...……………………….…14 Table 6-2 Modeled Mercury Atmospheric Deposition in 1998 and 2002 for the Northeast Region…………………………………………………………………………………………...………...15 Table 6-3 Mercury Point Sources to Water……………………………………………………………….16 Table 9-1 Northeast State Mercury Control Programs for Coal-Fired Utilities…………………………..23 Table 10-1 Comparison Between 1998 and 2002 Regional Mercury Emissions Inventories…………….27 Figures Figure 6-1 Breakdown of Major Sources of Northeast Regional Mercury Emissions……..…………….13 Northeast Regional Mercury TMDL – April 2007 iv DRAFT Acknowledgements This TMDL was developed by a