FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION Division of Water Resource Management, Bureau of Watershed Management NORTHWEST DISTRICT • CHOCTAWHATCHEE RIVER BASIN TMDL Report Fecal and Total Coliform TMDL for Choctawhatchee River WBID 49F Richard Wieckowicz, Ph. D., P.E. Katrina Sanders Jessica Rich-Zeisler 9/12/2005 9:29 AM September 2005 ii Florida Department of Environmental Protection Acknowledgments This study could not have been accomplished without significant contributions from staff in the Department’s Watershed Assessment Section. Tricia McClenahan provided the basin delineations and land use aggregations. Editorial assistance was provided by Jan Mandrup- Poulsen, Daryll Joyner, and Linda Lord. Mr. Stan Shirley (ADEM) also provided valuable information related to wastewater facilities in the watershed. Map production assistance provided by Tricia McClenahan. For additional information on the watershed management approach and impaired waters in the Choctawhatchee River Basin, contact Richard Wieckowicz, Ph.D., P.E. Florida Department of Environmental Protection Bureau of Watershed Management Watershed Planning and Coordination Section 2600 Blair Stone Road, Mail Station 3565 Tallahassee, FL 32399-2400 [email protected] Phone: (850) 245-8468; Suncom: 205-8468 Fax: (850) 245-8356 Access to all data used in the development of this report can be obtained by contacting Katrina Sanders Florida Department of Environmental Protection Bureau of Watershed Management Watershed Assessment Section 2600 Blair Stone Road, Mail Station 3555 Tallahassee, FL 32399-2400 [email protected] Phone: (850) 245-8471; Suncom: 205-8471 Fax: (850) 245-8356 OR Jessica Rich-Zeisler Florida Department of Environmental Protection Bureau of Watershed Management Watershed Assessment Section 2600 Blair Stone Road, Mail Station 3555 Tallahassee, FL 32399-2400 [email protected] Phone: (850) 245-8441; Suncom: 205-8441 Fax: (850) 245-8356 iii Florida Department of Environmental Protection Contents Chapter 1: INTRODUCTION___________________________________1 1.1 Purpose of Report ________________________________________________1 1.2 Identification of Waterbody ________________________________________1 1.3 Background _____________________________________________________6 Chapter 2: DESCRIPTION OF WATER QUALITY PROBLEM ________7 2.1 Statutory Requirements and Rule-Making History _____________________7 2.2 Information on Verified Impairment__________________________________7 Chapter 3. DESCRIPTION OF APPLICABLE WATER QUALITY STANDARDS AND TARGETS ______________________11 3.1 Classification of the Waterbody and Criteria Applicable to the TMDL_____11 3.2 Applicable Water Quality Standards and Numeric Water Quality Target __11 Chapter 4: ASSESSMENT OF SOURCES_______________________13 4.1 Types of Sources________________________________________________13 4.2 Potential Sources of Coliform in the Choctawhatchee River Watershed __13 4.2.1 Point Sources ________________________________________________13 4.2.2 Land Uses and Nonpoint Sources ________________________________18 4.4 Source Summary________________________________________________26 4.4.1 Summary of the Coliform Loadings into Choctawhatchee River from the Various Sources___________________________________________26 Chapter 5: DETERMINATION OF ASSIMILATIVE CAPACITY_______28 5.1 Determination of Loading Capacity _________________________________28 5.1.1 Data Used in the Determination of the TMDL ________________________28 5.1.2 TMDL Development Process ____________________________________37 5.2.3 Critical Conditions/Seasonality ___________________________________45 Chapter 6: DETERMINATION OF THE TMDL ____________________46 6.1 Expression and Allocation of the TMDL _____________________________46 6.2 Load Allocation (LA) _____________________________________________47 6.3 Wasteload Allocation (WLA)_______________________________________47 6.3.1 NPDES Wastewater Discharges__________________________________47 6.3.2 NPDES Stormwater Discharges __________________________________49 6.4 Margin of Safety (MOS)___________________________________________49 iv Florida Department of Environmental Protection Chapter 7: NEXT STEPS: IMPLEMENTATION PLAN DEVELOPMENT AND BEYOND _____________________51 7.1 Basin Management Action Plan____________________________________51 References _______________________________________________52 Appendices _______________________________________________57 Appendix A: Background Information on Federal and State Stormwater Programs__________________________________________________________57 Appendix B: Summary of Land Use Loads by Category ___________________59 Appendix C: Summary of Permitted Point Source Loads and Decay Rates ___59 Appendix D: Summary of Measured External Loads and Decay Rates _______59 Appendix E: Summary of Effluent Data _________________________________59 Appendix F: Summary of Photos and News Articles ______________________59 Appendix G: Historical Summary of Choctawhatchee River Data ___________59 Appendix H: USGS Gage and Flow Data ________________________________59 Appendix I: Ground Water Data in the Choctawhatchee River Basin _________59 Appendix J: Modeling Studies in the Choctawhatchee River Basin __________59 List of Tables Table 1.1 List of WBIDs West and East of 49F ____________________________2 Table 1.2 TMDL Determinations in the Choctawhatchee River Planning Unit______________________________________________________3 Table 2.1. Verified Impaired Segments in the Choctawhatchee River Basin ______7 Table 2.2. Summary of Coliform Data____________________________________8 Table 4.1. Point Sources in the Choctawhatchee River Watershed ___________14 Table 4.2. Classification of Land Use Categories in the Choctawhatchee River Watershed __________________________________________18 Table 4.3. Estimation of Coliform Loading from Failed Septic Tanks ___________24 Table 4.3a Summary of Cattle Populations in Holmes County, 1993 - 2002______22 Table 4.3b Summary of Agricultural Animal Populations (Excluding Cattle) in Holmes County in 1997 ___________________________________22 Table 4.4. Average Daily Quantity of Internal Fecal Coliform Loading into Choctawhatchee River WBID 49F _____________________________ xx Table 4.5. Summary of External Loads to the Choctawhatchee River _________27 Table 5.1. Statistical Table of Observed Historical Data for Choctawhatchee River, WBID (49F) ___________________________31 v Florida Department of Environmental Protection Table 5.2. Statistical Table of Observed Recent Data from the Department’s Intensive Surveys for Choctawhatchee River, WBID (49F) ______________________________________________35 Table 5.3. Observed Data for Calculating Exceedances to the State Criterion for Choctawhatchee River WBID (49F) __________________40 Table 5.4. Flow Conditions under Which Exceedances Occurred _____________43 Table 5.5. Table for Calculating Needed Reduction of Coliform_______________44 Table 6.1. TMDL Components for the Choctawhatchee River, WBID (49F) _____47 Table 6.2. Maximum Coliform Loading From Permitted Facilities _____________48 Table 6.3. Estimated Decay Rates of Coliforms for Permitted Dischargers in Basin _________________________________________________50 List of Figures Figure 1.1: Location of Choctawhatchee River and Major Geopolitical Features in the Choctawhatchee River Basin ______________________ Figure 1.2. WBIDs in the Choctawhatchee River ___________________________5 Figure 4.2a. Principal Land Uses in the Choctawhatchee River Watershed _______20 Figure4.2b. Principal Land Uses in WBID 49F of the Choctawhatchee River Watershed _______________________________________________22 Figure 4.3. Population Density in Holmes County, Florida____________________23 Figure 5.1. Historical Monitoring Sites in Choctawhatchee River, WBID (49F) ___________________________________________________30 Figure 5.2. Chart of Historical Observations for Choctawhatchee River WBID (49F) ______________________________________________31 Figure 5.3. Department’s Intensive Monitoring Sites on the Choctawhatchee River______________________________________33 Figure 5.4. Chart of Recent Observations for Choctawhatchee River WBID (49F) ___________________________________________________34 Figure 5.5. Flow Duration Curve for USGS Gage 02365500 __________________38 Figure 5.6a. Load Duration Curve for Fecal Coliform in WBID (49F) with Line-of-Best-Fit (Exponential Curve) ___________________________39 Figure 5.6b. Load Duration Curve for Total Coliform in WBID (49F) with Line-of-Best-Fit (Exponential Curve) Figure 5.7. Loading Curve Showing Hydrologic Conditions___________________43 Web sites Florida Department of Environmental Protection, Bureau of Watershed Management TMDL Program vi Florida Department of Environmental Protection http://www.dep.state.fl.us/water/tmdl/index.htm Identification of Impaired Surface Waters Rule http://www.dep.state.fl.us/water/tmdl/docs/AmendedIWR.pdf STORET Program http://www.dep.state.fl.us/water/storet/index.htm 2004 305(b) Report http://www.dep.state.fl.us/water/docs/2004_Integrated_Report.pdf Criteria for Surface Water Quality Classifications http://www/dep.state.fl.us/legal/legaldocuments/rules/ruleslistnum.htm Basin Status Report for the Choctawhatchee River Basin http://www.dep.state.fl.us/water/tmdl/stat_rep.htm Water Quality Assessment Report for the Choctawhatchee River Basin http://www.dep.state.fl.us/water/tmdl/stat_rep.htm Allocation Technical Advisory Committee