Degradation of water quality at Wakulla Springs, Florida: assessment and recommendations Item Type conference_item Download date 26/09/2021 05:34:48 Link to Item http://hdl.handle.net/1834/18868 DEGRADATION OF WATER QUALITY AT WAKULLA SPRINGS, FLORIDA: ASSESSMENT AND RECOMMENDATIONS Report of the Peer Review Committee on the Workshop Solving Water Pollution Problems in the Wakulla Springshed of North Florida May 12–13, 2005 Tallahassee, Florida December 2005 PEER REVIEWERS David E. Loper, Ph. D., Chair Professor Emeritus Department of Geological Sciences and Geophysical Fluid Dynamics Institute 18 Keen Building, MC 4360 Florida State University Tallahassee, FL 32306-4320 William M. Landing, Ph. D. Professor of Environmental and Marine Chemistry Department of Oceanography, 325 OSB Florida State University Tallahassee, FL 32306-4320 Curtis D. Pollman, Ph. D. Principal Scientist Tetra Tech, Inc. Research & Development Division 408 W. University Ave., Suite 301 Gainesville, FL 32601 Amy B. Chan Hilton, Ph. D. Assistant Professor Florida A&M University–Florida State University College of Engineering Department of Civil and Environmental Engineering Associate, Geophysical Fluid Dynamics Institute 2525 Pottsdamer Street Tallahassee, FL 32310-6046 i CONTENTS Peer Reviewers................................................................................................................................. i ABSTRACT.................................................................................................................................... v EXECUTIVE SUMMARY ........................................................................................................... vi Introduction................................................................................................................................ vi Nutrient Loading ....................................................................................................................... vii Dark Water................................................................................................................................. ix Other Comments......................................................................................................................... ix Recommendations.........................................................................................................................x CHAPTER 1. Introduction and Background ................................................................................. 1 1.1 Purpose of this Report.......................................................................................................... 1 1.2 Other Reports ....................................................................................................................... 2 1.2.1. Nitrate Loading and Non-point Source Pollution in the Lower St. Marks–Wakulla Rivers Watershed.................................................................................................................................. 2 1.2.2. Woodville Recharge Basin Aquifer Protection Study, Phases I and II...................................... 5 1.2.3. A Strategy for Water Quality Protection: Wastewater Treatment in the Wekiva Springs Area......................................................................................................................................... 7 1.2.4. Florida’s Springs: Strategies for Protection & Restoration.................................................... 9 1.2.5. Protecting Florida’s Springs: Land Use Planning Strategies and Best Management Practices............................................................................................................................................. 10 1.3 Regulatory Framework ...................................................................................................... 10 1.4 Physical Setting .................................................................................................................. 11 1.4.1 Surface Water Features............................................................................................................. 13 1.4.2 Groundwater Features .............................................................................................................. 14 Chapter 2: Water Quality Problems in Wakulla Springs and River ............................................ 19 2.1 Nitrate Loading .................................................................................................................. 19 2.1.1 Nitrate and the Nitrogen Cycle................................................................................................. 19 2.1.2 Extent and Causes of Nitrate Contamination........................................................................... 19 2.1.3 Extent and Causes of Invasive Exotic Aquatic Plant Growth .................................................. 22 2.2 Extent and Causes of Loss of Water Clarity ...................................................................... 24 CHAPTER 3: Sources of the Problems ....................................................................................... 26 3.1 Summary and Evaluation of Nitrogen Limitation .............................................................. 26 3.2 Sources of Nitrate............................................................................................................... 26 ii 3.3 Wastewater Treatment Facilities. ...................................................................................... 29 3.3.1 Trend of Groundwater Flow...................................................................................................... 30 3.4 Nitrate Data........................................................................................................................ 31 3.5 Fertilizer and Livestock...................................................................................................... 37 3.6 Septic Systems .................................................................................................................... 37 3.7 Sources of Dark Water ....................................................................................................... 38 CHAPTER 4: Solutions to the Problems..................................................................................... 39 4.1 Mitigation Strategies for Nutrient Loading........................................................................ 39 4.1.1 Wastewater Treatment Facilities.............................................................................................. 40 4.1.2 Septic Systems........................................................................................................................... 41 4.1.3 Fertilizers and Livestock .......................................................................................................... 41 4.2 Mitigation Strategies for the Loss of Water Clarity........................................................... 41 ACKNOWLEDGMENTS ............................................................................................................ 42 References..................................................................................................................................... 43 Table 1: List of acronyms ............................................................................................................. 45 Web sites of interest...................................................................................................................... 46 APPENDICES .............................................................................................................................. 47 Appendix A: Questions for the Peer Review Committee.......................................................... 47. Appendix B: Key Peer Review Committee Questions and Answers......................................... 49 Appendix C. List of Reviewers.................................................................................................. 51 Appendix D. History of Hydrilla Removal Efforts at Wakulla Springs.................................... 53 E.1 The Case against N Limitation .................................................................................................... 55 E.2 The Case for N Limitation............................................................................................................ 55 E.3 The Case for Reducing Plant Growth by Limiting Nitrate Loading to the Springshed ............... 56 Appendix F: Phosphate in the Floridan Aquifer and Wakulla Springs ................................... 60 Appendix G. Specific Suggestions for Research on Nutrients and Biota................................. 67 Appendix H. Speculation on the Origin of Dark Water ........................................................... 68 Appendix I: Ongoing Programs, City of Tallahassee Water Utility ......................................... 69 iii LIST OF FIGURES Figure 1: Aerial photo of Wakulla Spring and River..................................................................... vi Figure 2: Average nitrate concentrations in ground water sampled from the SESF monitoring wells .......................................................................................................... 6 Figure 3: Nitrate data from 1986 to 2004 for the SESF well with the highest average nitrate concentrations................................................................................................... 6 Figure 5: Florida portion of the Wakulla–St. Marks watershed