Total Maximum Daily Load for Total Phosphorus Honeoye Lake Ontario County, New York August 2019 U.S. Environmental Protection Agency Region 2 290 Broadway New York, NY 10007 New York State Department of Environmental Conservation 625 Broadway, 4th Floor Albany, NY 12233 Table of Contents Background/Problem Statement .............................................................................................................. 4 Introduction .................................................................................................................................................. 4 Waterbody and Pollutants of Concern .............................................................................................. 4 Table 1- 2014 New York State 303(d) list Honeoye Lake Information ............................ 5 Applicable Water Quality Standards .................................................................................................. 5 Numeric Water Quality Target .............................................................................................................. 5 Lake Morphometry .................................................................................................................................... 5 Figure 1- Bathymetric Map of Honeoye Lake ............................................................................ 6 Table 2- Honeoye Lake Characteristics ....................................................................................... 6 Assessment of Phosphorus Sources ..................................................................................................... 7 Point Sources ............................................................................................................................................. 7 Nonpoint Sources ...................................................................................................................................... 7 Table 3- Land use in the Honeoye Lake watershed ............................................................... 7 Figure 2- Map of land use in the Honeoye Lake watershed. ............................................... 8 Figure 3- Annual Honeoye Lake Watershed phosphorus loads ......................................... 9 Fig. 4 - Honeoye Lake Sub-watershed Boundaries .............................................................. 10 Table 4 - Honeoye Lake – Phosphorus Load by Sub-watershed .................................... 11 Internal Loading ....................................................................................................................................... 11 Figure 5 - Phosphorus Sources to Honeoye Lake ................................................................. 12 Table 5 - Growing season modeled mean ChlA concentrations ...................................... 12 Phosphorus Loading Capacity Analysis ............................................................................................. 13 Table 6 – Simulated growing season mean ChlA concentrations ................................... 13 Table 7 - Phosphorus Total Maximum Daily Load (TMDL) for Honeoye Lake ........... 15 Critical Conditions ................................................................................................................................... 15 Seasonal Variation.................................................................................................................................. 15 TMDL Implementation................................................................................................................................ 16 Internal Loading ....................................................................................................................................... 16 Watershed Management ...................................................................................................................... 17 Recommendations for Watershed Residents............................................................................... 18 Recommendations for Municipalities ............................................................................................... 20 Recommendations for Town & County Highway departments .............................................. 22 2 References ..................................................................................................................................................... 23 Appendix A-CE-QUAL-W2 Model Setup and Calibration for Honeoye Lake ................................ 27 A1 Introduction ............................................................................................................................... 27 A2 Description of CE-QUAL-W2 ............................................................................................... 27 A3 Model Setup ............................................................................................................................... 27 A4 Model Calibration .................................................................................................................... 37 A5 Discussion of Model Results ................................................................................................... 45 A6 Conclusion ................................................................................................................................. 53 A7 References .................................................................................................................................. 54 Appendix B: Honeoye Lake CE-QUAL-W2 Model Temperature & Water Quality Profile Plots . 55 B1 Water Temperature Profile Plots ............................................................................................ 56 B2 Dissolved Oxygen Profile Plots .............................................................................................. 98 B3 Soluble Reactive Phosphorus Profile Plots ........................................................................ 140 B4 Total Phosphorus Profile Plots ............................................................................................ 170 B5 Chlorophyll-a Profile Plots ................................................................................................... 201 Appendix C: Numeric Endpoint Development for Potable Water Use .......................................... 231 C.1 Conceptual Model .................................................................................................................. 232 C.2 Derivation of Site-specific Ambient Water Quality Values (Criteria) ........................... 234 C.3 Model Development .............................................................................................................. 238 C.4 Model Application.................................................................................................................. 238 Appendix D: Update of the Hydrologic & Nutrient Budgets of Honeoye Inlet & Lake .............. 243 Appendix E: Thirty Years Monitoring the Fall Standing Crop Biomass ......................................... 244 Appendix F: Honeoye Lake Macrophyte Management Plan ............................................................. 245 3 BACKGROUND/PROBLEM STATEMENT INTRODUCTION Section 303(d) of the Federal Clean Water Act (CWA) requires US states and territories to identify waters within their boundaries that are not meeting state or territorial water quality standards. Section 303(d) further requires EPA, states, and territories to develop a Total Maximum Daily Load (TMDL) for any pollutant violating or causing violation of an applicable water quality standard for each impaired waterbody. A TMDL defines the maximum amount of a pollutant that a waterbody can receive while continuing to meet water quality standards. A TMDL also allocates the maximum allowable pollutant load between point and nonpoint sources of the pollutant. A TMDL provides a framework for EPA, states, and territories to establish and implement pollution control and management plans, with the goal described in Section 101(a)(2) of the CWA: “water quality which provides for the protection and propagation of fish, shellfish, and wildlife, and recreation in and on the water, wherever attainable” (USEPA, 1991a). This report presents a TMDL for total phosphorus for Honeoye Lake in Ontario County, New York. WATERBODY AND POLLUTANTS OF CONCERN Honeoye Lake (WI/PWL ID 0402-0032) is in Ontario County, New York, within the Towns of Richmond and Candice. Honeoye Lake is included on the 2014 New York State Section 303(d) List of Impaired/TMDL Waters (NYSDEC 2014). The List of Impaired/TMDL Waters is maintained by the New York State Department of Environmental Conservation (NYSDEC) and, as required by the Federal Clean Water Act, specifies which waterbodies in New York do not meet the state’s surface water quality standards. Waters on the List of Impaired/TMDL Waters require development of a Total Maximum Daily Load (TMDL) that addresses the pollutants causing nonattainment of water quality standards. A TMDL defines the pollutant loading capacity of a waterbody, or the maximum allowable amount of a pollutant that the waterbody can receive and still meet water quality standards. A TMDL also allocates the maximum allowable pollutant load between pollutant sources. The 2014 List of Impaired/TMDL Waters identifies phosphorus and oxygen demand as the pollutants causing nonattainment of water quality standards in Honeoye Lake, based on monitored values above the guidance value for Phosphorus.