Mattaponi River Watershed TMDL Implementation Plan Prepared by Virginia Department of Environmental Quality Streams Tech, Inc. March 2020 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................................ i LIST OF FIGURES .................................................................................................................................................. iv LIST OF TABLES .................................................................................................................................................... vi Acknowledgements .................................................................................................................................................... x Executive Summary .................................................................................................................................................. xi Overview ............................................................................................................................................................... xi Review of the TMDL ........................................................................................................................................... xii Public Participation ............................................................................................................................................. xiii Recommended Management Measures............................................................................................................... xiii Benefits ............................................................................................................................................................... xiv 1 Introduction ........................................................................................................................................................ 1 2 Federal and State Requirements......................................................................................................................... 5 2.1 Requirements for Section 319 Funding Eligibility .................................................................................... 5 3 Mattaponi River Watershed TMDL Review and Update .................................................................................. 7 3.1 Overview .................................................................................................................................................... 7 3.2 Study Area ................................................................................................................................................. 7 3.3 Land Use .................................................................................................................................................. 12 3.4 Source Assessment ................................................................................................................................... 14 3.4.1 Population and Number of Households ........................................................................................... 14 3.4.2 Point Sources ................................................................................................................................... 17 3.4.3 Septic Systems ................................................................................................................................. 19 3.4.4 Livestock .......................................................................................................................................... 22 3.4.5 Wildlife ............................................................................................................................................ 27 3.4.6 Pets ................................................................................................................................................... 29 3.4.7 Biosolids .......................................................................................................................................... 30 3.5 Water Quality Conditions ........................................................................................................................ 30 3.6 Modeling Update ..................................................................................................................................... 37 4 Public Participation .......................................................................................................................................... 40 4.1 Initial Public Meeting .............................................................................................................................. 40 4.2 Agricultural Workgroup Meeting ............................................................................................................ 41 4.3 Residential Workgroup Meeting .............................................................................................................. 42 4.4 Steering Committee Meeting ................................................................................................................... 43 4.5 Final Public Meeting ................................................................................................................................ 44 5 Implementation Actions ................................................................................................................................... 45 5.1 Agricultural Implementation Needs ......................................................................................................... 47 i 5.1.1 Livestock Exclusion Fencing ........................................................................................................... 47 5.1.2 Pasture and Cropland ....................................................................................................................... 54 5.1.3 Equine Management ........................................................................................................................ 61 5.2 Residential Implementation Needs .......................................................................................................... 65 5.2.1 Septic Systems ................................................................................................................................. 65 5.2.2 Pet Waste ......................................................................................................................................... 69 5.2.3 Stormwater ....................................................................................................................................... 71 5.3 Education and Outreach ........................................................................................................................... 74 5.3.1 Implementation Actions ................................................................................................................... 74 5.4 Technical Assistance ................................................................................................................................ 76 5.5 Summary of Recommended Implementation Actions ............................................................................. 76 6 Cost of Implementation ................................................................................................................................... 78 7 Benefits ............................................................................................................................................................ 79 7.1 Agricultural Practices ............................................................................................................................... 79 7.2 Residential and Developed Land Practices .............................................................................................. 80 7.3 Education and Outreach ........................................................................................................................... 81 8 Measurable Goals and Milestones for Attaining Water Quality Standards ..................................................... 82 8.1 Prioritizing Agricultural Actions ............................................................................................................. 99 8.2 Prioritizing Non-Agricultural Actions ................................................................................................... 100 9 Water Quality Monitoring.............................................................................................................................. 101 9.1 DEQ Monitoring .................................................................................................................................... 101 9.2 Citizen Monitoring ................................................................................................................................. 102 9.3 Additional Monitoring ........................................................................................................................... 102 10 Stakeholder Roles and Responsibilities ......................................................................................................... 104 10.1 Agricultural and Residential Landowners .............................................................................................. 104 10.2 Local Soil and Water Conservation Districts (SWCDs) and USDA Natural Resources Conservation Service (NRCS) staff ..................................................................................................................