Total Maximum Daily Loads for Total Phosphorus and Total Suspended Solids in the Rock River Basin Columbia, Dane, Dodge, Fond du Lac, Green, Green Lake, Jefferson, Rock, Walworth, Washington, and Waukesha Counties, Wisconsin July 2011 Prepared for: U.S. Environmental Protection Wisconsin Department of Agency Natural Resources Region 5 101 S. Webster Street, PO Box 7921 77 W. Jackson Blvd. Madison, Wisconsin 53707-7921 Chicago, IL 60604 Prepared by: Rock River TMDL – Final Report TABLE OF CONTENTS 1.0 INTRODUCTION .......................................................................................................... 1 1.1. Background ................................................................................................................................ 1 1.2. Problem Statement ..................................................................................................................... 1 2.0 WATERSHED CHARACTERIZATION .................................................................... 10 2.1. Watershed Characteristics ........................................................................................................ 10 2.2. Water Quality .......................................................................................................................... 14 3.0 APPLICABLE WATER QUALITY STANDARDS ..................................................... 17 3.1. Designated Uses ....................................................................................................................... 17 3.2. Narrative Water Quality Criteria ............................................................................................ 17 3.3. Numeric Water Quality Criteria ............................................................................................. 18 4.0 SOURCE ASSESSMENT ............................................................................................... 21 4.1. Spatial Framework ................................................................................................................... 21 4.2. Analysis of Phosphorus and Sediment Loading ....................................................................... 23 4.3. Summary of Sources of Phosphorus and Sediment Loading .................................................... 32 5.0 POLLUTANT LOADING CAPACITY ...................................................................... 39 5.1. Linking Pollutant Loading to Concentration .......................................................................... 39 5.2. Critical Conditions .................................................................................................................. 43 6.0 POLLUTANT LOAD ALLOCATIONS ...................................................................... 44 6.1. TMDL Equation ...................................................................................................................... 44 6.2. Load Allocation Approach ...................................................................................................... 44 6.3. Load Allocation ....................................................................................................................... 44 6.4. Wasteload Allocation ............................................................................................................... 45 6.5. Margin of Safety ....................................................................................................................... 45 6.6. Reserve Capacity ...................................................................................................................... 45 6.7. Seasonal Variation .................................................................................................................... 46 7.0 IMPLEMENTATION .................................................................................................... 47 7.1. Reasonable Assurance for Implementation .............................................................................. 47 7.2. Implementation Plan Development ......................................................................................... 47 7.3. Follow-up Monitoring ............................................................................................................. 55 8.0 Public Participation ......................................................................................................... 55 9.0 REFERENCES ................................................................................................................ 57 i Rock River TMDL – Final Report APPENDIX A. MODEL DESCRIPTION ............................................................................. 59 APPENDIX B. PHOSPHORUS CYCLING IN LAKES....................................................... 65 APPENDIX C. FLOWCHART OF LOAD ALLOCATION APPROACH ....................... 66 APPENDIX D. ORGANIZATIONS AND INITIATIVES THAT MAY CONTRIBUTE TO IMPLEMENTATION OF THE TMDL ......................................................................... 67 APPENDIX E. POTENTIALLY RESTORABLE WETLANDS ANALYSIS ...................... 74 APPENDIX F. SWAT SUB-BASINS ...................................................................................... 88 APPENDIX G. Growing‐Season Median Total Phosphorus Concentrations After TMDL Implementation Using SWAT‐Simulated Flows for 1989 ‐ 1998 ............................................. 91 APPENDIX H. Required Percent Reduction of TP from Annual Baseline Load ................... 93 APPENDIX I. Required Percent Reduction of TSS from Annual Baseline Load.................... 95 APPENDIX J. Daily Total Phosphorus Allocations ............................................................... 97 APPENDIX K. Daily Total Suspended Solids Allocations .................................................... 114 APPENDIX L. Agricultural/Non‐Permitted Urban TP Load Summary ‐‐ Baseline Loads, Load Allocations, and Percent Reductions ............................................................................. 131 APPENDIX M. Agricultural/Non‐Permitted Urban TSS Load Summary ‐‐ Baseline Loads, Load Allocations, and Percent Reductions ............................................................................. 135 APPENDIX N. MS4 TP Load Summary ‐‐ Baseline Loads, Load Allocations, and Percent Reductions .............................................................................................................................. 139 APPENDIX O. MS4 TSS Load Summary ‐‐ Baseline Loads, Load Allocations, and Percent Reductions .............................................................................................................................. 143 APPENDIX P. Monthly Total Phosphorus Allocations by Wastewater Treatment Facility ................................................................................................................................... 147 APPENDIX Q. Monthly Total Suspended Solids Allocations by Wastewater Treatment Facility ................................................................................................................................... 149 APPENDIX R. Daily Total Phosphorus Allocations by Wastewater Treatment Facility .... 151 APPENDIX S. Daily Total Suspended Solids Allocations by Wastewater Treatment Facility ................................................................................................................................... 153 APPENDIX T. Daily Total Phosphorus Allocations by MS4 ............................................... 155 APPENDIX U. Daily Total Suspended Solids Allocations by MS4 ...................................... 158 APPENDIX V. Annual Wasteload Allocations by MS4 ........................................................ 161 APPENDIX W. Baseline Discharge Information for Wastewater Treatment Facilities ........ 166 ii Rock River TMDL – Final Report LIST OF FIGURES Figure 1. Map of the Rock River Basin Showing Impaired Waters. .................................................4 Figure 2. Map of major sub-basins of the Rock River Basin. .......................................................... 11 Figure 3. Summary of land cover from WISCLAND in the Rock River Basin. ............................ 12 Figure 4. Land use/land cover from WISCLAND in the Rock River Basin. ................................. 13 Figure 5. Median growing-season total phosphorus concentrations at 93 sampling stations in the Rock River Basin. ........................................................................................................................... 15 Figure 6. Median annual total suspended solids concentrations at 63 sampling stations in the Rock River Basin. .................................................................................................................................... 16 Figure 7. Sub-basins in the Rock River Basin. ................................................................................ 22 Figure 8. Location of municipal and industrial WWTFs and CAFOs in the Rock River Basin ..... 30 Figure 9. Location of MS4s in the Rock River Basin. ..................................................................... 31 Figure 10. Average monthly pattern in TP and TSS loading in the Rock River Basin. .................. 33 Figure 11. Average annual distribution of baseline TP sources in the Rock River Basin. .............. 34 Figure 12. Average annual distribution of baseline TSS sources in the Rock River Basin. ............. 34 Figure 13. Average monthly distribution of baseline TP sources in the Rock River Basin.