DRAFT TMDL Salt Fork Vermilion River Watershed Prepared for: Illinois Environmental Protection Agency July 2007 Spoon Branch (IL_BPJD-02): Dissolved oxygen Salt Fork Vermilion River (IL_BPJ-10): Nitrate, pH Salt Fork Vermilion River (IL_BPJ-08): Nitrate, pH Salt Fork Vermilion River (IL_BPJ-03): Nitrate, fecal coliform bacteria Ann Arbor, Michigan www.limno.com This page is blank to facilitate double sided printing. Draft TMDL July 2007 Salt Fork Vermilion River Watershed TABLE OF CONTENTS Introduction..........................................................................................................................1 1. Problem Identification .....................................................................................................3 2. Required TMDL Elements...............................................................................................5 3. Watershed Characterization...........................................................................................19 4. Description of Applicable Standards and Numeric Targets ..........................................25 4.1 Designated Uses and Use Support .........................................................................25 4.2 Water Quality Criteria............................................................................................25 4.3 Development of TMDL Targets ............................................................................26 5. Development of water quality modelS ..........................................................................29 5.1 QUAL2E Model.....................................................................................................29 5.2 Load Duration Curve Analysis ..............................................................................33 5.3 pH Approach..........................................................................................................37 6. TMDL Development......................................................................................................39 6.1 Dissolved Oxygen..................................................................................................39 6.2 Fecal Coliform TMDL...........................................................................................39 6.3 Nitrate TMDL ........................................................................................................43 6.4 pH TMDL ..............................................................................................................51 7. Public Participation and Involvement............................................................................55 8. Implementation Plan ......................................................................................................57 8.1 Existing Controls ...................................................................................................57 8.2 Implementation Approach .....................................................................................58 8.3 Implementation Alternatives..................................................................................59 8.4 Identifying Priority Areas for Controls..................................................................67 8.5 Reasonable Assurance ...........................................................................................73 8.6 Monitoring and Adaptive Management.................................................................75 9. References......................................................................................................................79 LimnoTech Page i Draft TMDL July 2007 Salt Fork Vermilion River Watershed LIST OF TABLES Table 1. Permitted Dischargers......................................................................................... 20 Table 2. Stage 2 sampling summary................................................................................. 21 Table 3. Listing Changes Since Stage 1 Report................................................................ 22 Table 4 QUAL2E Segmentation....................................................................................... 31 Table 5. Fecal Coliform Load Capacity (IL_BPJ-03) ...................................................... 40 Table 6. Required Reductions in Existing Loads under Different Flow Conditions (IL_BPJ-03) .............................................................................................................. 40 Table 7. Segment IL_BPJ-03 Permitted Dischargers and WLAs for Fecal Coliform......... 41 Table 8. Fecal Coliform TMDL for Segment IL_BPJ-03 Salt Fork Vermilion River1 .... 42 Table 9. Nitrate Load Capacity (IL_BPJ-03).................................................................... 43 Table 10. Required Reductions in Existing Loads under Different Flow Conditions (IL_BPJ-03) .............................................................................................................. 44 Table 11. Nitrate Load Capacity (IL_BPJ-08).................................................................. 44 Table 12. Required Reductions in Existing Loads under Different Flow Conditions (IL_BPJ-08) .............................................................................................................. 44 Table 13. Nitrate Load Capacity (IL_BPJ-10).................................................................. 45 Table 14. Required Reductions in Existing Loads under Different Flow Conditions (IL_BPJ-10) .............................................................................................................. 45 Table 15. Segment IL_BPJ-03 Permitted Dischargers and WLAs for Nitrate.................... 46 Table 16. Nitrate TMDL for Salt Fork Vermilion River (Segment IL_BPJ-03) .............. 47 Table 17. Segment IL_BPJ-08 Permitted Dischargers and WLAs for Nitrate.................... 48 Table 18. Nitrate TMDL for Salt Fork Vermilion River (Segment IL_BPJ-08) .............. 48 Table 19. Segment IL_BPJ-10 Permitted Dischargers and WLAs for Nitrate.................... 49 Table 20. Nitrate TMDL for Salt Fork Vermilion River (Segment IL_BPJ-10).............. 50 Table 21. Point Sources with a pH Limit for Salt Fork Vermilion River (Segments IL_BPJ-08 and IL_BPJ-10) ...................................................................................... 52 Table 22. Point Sources Expected to Discharge Fecal Coliform Bacteria........................ 62 Table 23. Point Sources with a pH Limit for Salt Fork Vermilion River (Segments IL_BPJ-08 and IL_BPJ-10) ...................................................................................... 63 Table 24. Permitted Dischargers....................................................................................... 73 LimnoTech Page ii Draft TMDL July 2007 Salt Fork Vermilion River Watershed LIST OF FIGURES Figure 1. Base Map of Salt Fork Vermilion River Watershed ......................................... 23 Figure 2. QUAL2E Calibration Spoon Branch................................................................. 33 Figure 3. Nitrate Load Duration Curve for Salt Fork Vermilion River (IL_BPJ-03) with Observed Loads (triangles)....................................................................................... 35 Figure 4. Nitrate Load Duration Curve for Salt Fork Vermilion River (IL_BPJ-08) with Observed Loads (triangles)....................................................................................... 36 Figure 5. Nitrate Load Duration Curve for Salt Fork Vermilion River (IL_BPJ-10) with Observed Loads (triangles)....................................................................................... 36 Figure 6. Fecal Coliform Load Duration Curve for Salt Fork Vermilion River (IL_BPJ- 03) with Observed Loads (triangles)......................................................................... 37 Figure 7. pH vs. Flow: Salt Fork Vermilion River (IL_BPJ-08)...................................... 38 Figure 8. pH vs. Flow: Salt Fork Vermilion River (IL_BPJ-10)...................................... 38 Figure 9. Areas with Steep Slopes .................................................................................... 69 Figure 10. Areas of Highly Erodible Land ....................................................................... 70 Figure 11. Potential Priority Areas for BMPs................................................................... 71 Figure 12. Potential Wetland Restoration Areas............................................................... 72 LIST OF ATTACHMENTS Attachment 1. Stage 1 Report Attachment 2. Stage 2 Report Attachment 3. QUAL2E Model Files Attachment 4. Nitrate Load Duration Worksheets Attachment 5. Fecal Coliform Load Duration Worksheets LimnoTech Page iii Draft TMDL July 2007 Salt Fork Vermilion River Watershed This page is blank to facilitate double sided printing. LimnoTech Page iv Draft TMDL July 2007 Salt Fork Vermilion River Watershed INTRODUCTION Section 303(d) of the 1972 Clean Water Act requires States to define impaired waters and identify them on a list, which is referred to as the 303(d) list. The State of Illinois has issued the 2006 303(d) list, which is available on the web at: http://www.epa.state.il.us/water/tmdl/303d-list.html. Section 303(d) of the Clean Water Act and EPA's Water Quality Planning and Management Regulations (40 CFR Part 130) require states to develop Total Maximum Daily Loads (TMDLs) for water bodies that are not meeting designated uses under technology-based controls. The TMDL process establishes the allowable loading