Illinois Bureau of Water Environmental P. O. Box 19276 Protection Agency Springfield, IL 62794-9276 October 2006 IEPA/BOW/07-010 Wabash River Watershed TMDL Report Printed on Recycled Paper This page intentionally left blank Wabash River Nutrient and Pathogen TMDL Development FINAL REPORT September 18, 2006 Prepared for Illinois Environmental Protection Agency Indiana Department of Environmental Management Prepared by Tetra Tech, Inc. This page intentionally left blank Wabash River TMDL Development Final Report Table of Contents 1 Introduction..............................................................................................................................................1 2 Inventory and Assessment of Water Quality Information .......................................................................3 2.1 303(d) List Status............................................................................................................................3 2.1.1 Relationship Between Nutrients, Algal Growth, Dissolved Oxygen, and pH .........................3 2.1.2 Wabash River Impairment Status in Ohio ...............................................................................4 2.1.3 Thermal Modification Impairments.........................................................................................4 2.2 Applicable Water Quality Standards ............................................................................................13 2.2.1 Ohio Water Quality Standards...............................................................................................13 2.2.2 Indiana Water Quality Standards...........................................................................................14 2.2.3 Illinois Numeric Water Quality Standards.............................................................................16 2.3 Impairment Verification ...............................................................................................................17 2.3.1 E. coli.....................................................................................................................................19 2.3.2 Fecal Coliform .......................................................................................................................19 2.3.3 Nutrients/Organic Enrichment/Low DO/Excessive Algal Growth........................................19 2.4 Sources .........................................................................................................................................24 2.4.1 National Pollutant Discharge Elimination System (NPDES) Facilities that Discharge Directly to the Wabash River.................................................................................................25 2.4.2 Combined Sewer Overflows..................................................................................................26 2.4.3 Storm Water Phase II Communities ......................................................................................27 2.4.4 Confined Feeding Operations and Concentrated Animal Feeding Operations......................27 2.4.5 Significant Tributaries and Subwatersheds Draining Directly to the Wabash River.............27 3 Technical Approach...............................................................................................................................29 3.1 In-stream Model Selection............................................................................................................29 3.2 Derivation of Tributary Flows and Water Quality .......................................................................29 3.3 Model Calibration.........................................................................................................................30 4 TMDL ...............................................................................................................................................32 4.1 Baseline Conditions......................................................................................................................32 4.2 Loading Capacity..........................................................................................................................32 4.3 Wasteload Allocations (WLAs)....................................................................................................42 4.4 Load Allocations (LAs)................................................................................................................42 4.5 Margin of Safety...........................................................................................................................42 4.6 Seasonal Variation........................................................................................................................43 4.7 Critical Conditions........................................................................................................................43 5 Public Participation................................................................................................................................44 6 Implementation......................................................................................................................................45 6.1 NPDES Permitted Dischargers.....................................................................................................45 6.2 Storm Water General Permit Rule 13...........................................................................................45 6.3 Confined Feeding Operations and Confined Animal Feeding Operations ...................................45 6.4 Watershed Projects .......................................................................................................................45 6.5 Monitoring Plan............................................................................................................................46 6.6 Potential Future Activities............................................................................................................46 6.6.1 Vegetated Filter Strips ...........................................................................................................47 6.6.2 Nutrient Management Plans...................................................................................................47 6.6.3 Septic Systems .......................................................................................................................47 7 References..............................................................................................................................................49 Appendix A: E. coli Sampling Data..........................................................................................................A-1 Appendix B: Fecal Coliform Sampling Data............................................................................................B-1 Appendix C: Total Phosphorus Sampling Data .......................................................................................C-1 i Wabash River TMDL Development Final Report Appendix D: Nitrate + Nitrite Sampling Data ..........................................................................................D-1 Appendix E: Dissolved Oxygen Sampling Data....................................................................................... E-1 Appendix F: pH Sampling Data................................................................................................................ F-1 Appendix G: Temperature Sampling Data................................................................................................G-1 Appendix H: RIV1 Model Calibration Process and Results.....................................................................H-6 Appendix I: Individual WLAs and LAs.................................................................................................... I-1 Appendix J: Active Watershed Groups in Indiana.................................................................................... J-1 Appendix K: Responsiveness Summary..................................................................................................K-1 Figures Figure 2-1. Location of impaired Wabash River segments addressed by the TMDLs presented in this report...................................................................................................................................12 Figure 2-2. Water quality sampling stations along the Wabash River...................................................18 Figure 2-3. Verified nutrient impaired segments...................................................................................24 Figure 3-1. Location of RIV1 hydrologic and water quality calibration locations................................31 Tables Table 2-1. Indiana and Illinois Wabash River 2002 303(d) Listed Segments for E. coli, Impaired Biotic Communities, and Nutrients/pH/Low DO. ................................................................6 Table 2-2. Indiana and Illinois Wabash River 2004 303(d) Listed Segments for E. coli, Impaired Biotic Communities, and Nutrients/pH/Low DO. ................................................................7 Table 2-3. Indiana and Illinois Wabash River 2006 303(d) Listed Segments (Category 5) for E. coli, Impaired Biotic Communities, and Nutrients/pH/Low DO. .................................................8 Table 2-4. Fecal coliform and E. coli standards for Ohio. Standards only apply for the period May 1 through October 15. [Ohio Administrative Code 3745-1-07]............................................13