Amendment to the Upper Delaware Water Quality Management Plan and Sussex County Water Quality Management Plan Total Maximum Daily Loads for Phosphorus to Address Four Impaired Assessment Units in the Pequest River Watershed Northwest Water Region Watershed Management Area 1 Pequest River, Beaver Creek and Bear Creek Watersheds Drainage Area Identifications: HUCs 02040105090020-01, 02040105090030-01, 02040105090010-01, 02040105070060-01 Proposed: June 7, 2010 Established: September 9, 2010 Approved: September 29, 2010 Adopted: June 20, 2011 New Jersey Department of Environmental Protection Bureau of Environmental Analysis & Restoration 1 1.0 Executive Summary...................................................................................................................... 4 2.0 Introduction................................................................................................................................... 5 3.0 Pollutant of Concern, Applicable Surface Water Quality Standards and Area of Interest........... 7 3.1 Pollutant of Concern.............................................................................................. 7 3.2 Applicable Surface Water Quality Standards........................................................ 9 3.3 Area of Interest.................................................................................................... 10 4.0 Water Quality Analysis.............................................................................................................. 12 5.0 Source Assessment .................................................................................................................... 15 5.1 Assessment of Point Sources............................................................................... 15 5.2 Assessment of Nonpoint Sources........................................................................ 18 6.0 TMDL Calculations.................................................................................................................... 19 6.1 FIRE method to estimate Land Use Load Percent Reduction:............................ 20 6.2 Mass Balance Calculation to Determine the WLA for the Wastewater Treatment Discharges........................................................................................................... 23 6.3 Summary of TMDL Allocations ......................................................................... 26 6.4 Seasonal Variation, Critical Conditions and Margin of Safety (MOS)............... 31 6.5 Reserve Capacity................................................................................................. 31 7.0 Follow-up Monitoring................................................................................................................ 32 8.0 Implementation Plan................................................................................................................... 32 8.1 Stormwater Measures.......................................................................................... 33 8.2 Agricultural and Other Measures ........................................................................ 35 9.0 Reasonable Assurance................................................................................................................ 38 10.0 Public Participation..................................................................................................................... 39 References: ............................................................................................................................................. 51 2 Appendices: ............................................................................................................................................ 53 Appendix A Database of Phosphorus Export Coefficients...................................................... 53 Table A-1 Phosphorus Export Coefficient Used with 2002 Land Use Coverage to derive land use loads...................................................................................................... 53 Appendix B Assessment Units Addressed Under the TMDL or the TMDL Implementation Plan ..................................................................................................................... 58 Appendix C Municipal Stormwater Permits and Identification of Tier A or B Classification for the Pequest River Watersheds....................................................................... 59 Appendix D Mass Balance Calculation ................................................................................... 60 Appendix E Flow-Integrated Reduction of Exceedances (FIRE) method .............................. 62 Appendix F Data Sources........................................................................................................ 71 Appendix G Water Quality Data.............................................................................................. 72 Table of Figures: Figure 1 Spatial Extent of TP Impaired HUC 14s within Pequest River Watershed ............................. 8 Figure 2 2002 Land Uses / Land Cover for the Pequest River Watershed........................................... 11 Figure 3 Total Phosphorus Concentrations at the Sites Monitored by HydroQual Under Low Flow Condition................................................................................................................................ 14 Figure 4 Current Land Use Load distribution at Pequest River at Pequest.......................................... 19 Figure 5 Loading Capacity Distribution at Pequest at Pequest for the Summer Months..................... 30 Figure 6 Category One Waterways in the Pequest River Watershed................................................... 35 Table of Tables: Table 1 Assessment Units Listed as Impaired for TP on 2008 Integrated List of Waters Addressed in this TMDL Report.................................................................................................................... 5 Table 2 Summary of 2002 Land Uses and Land Covers contributing land use loads to the Study Area ................................................................................................................................................ 12 Table 3 Summary of the Data Collected by Different Groups along the Pequest River..................... 13 Table 4 NJPDES Permitted Wastewater Discharges Located within the Impaired Assessment Units Addressed in This Report....................................................................................................... 17 Table 5 Summary FIRE Output for Exceedances at Pequest River at Pequest, Station ID No. 01445500................................................................................................................................ 20 Table 6 Summary of FIRE Output for Exceedances at Pequest River at Townsbury (Station ID 01445430) .............................................................................................................................. 22 Table 7 Allocation of Land Use Loads at Pequest River at Pequest................................................... 23 Table 8 Distribution of WLAs and LAs Among Land Use Source Categories .................................. 27 Table 9 Overall Loading Capacity at Pequest River at Pequest.......................................................... 28 Table 10 C1 Designated Waterbodies in the Pequest River Watershed................................................ 34 Table 11 Nonpoint Source Management Measures .............................................................................. 36 3 1.0 Executive Summary In accordance with Sections 305(b) and 303(d) of the Federal Clean Water Act (CWA), the State of New Jersey, Department of Environmental Protection (Department) developed the 2008 New Jersey Integrated Water Quality Monitoring and Assessment Report assessing the overall water quality of the State’s waters and, in Sublist 5 of the Integrated List of Waters, identifying the list of impaired waters by pollutant in each Hydrologic Unit Code (HUC) 14 assessment unit. Sublist 5 constitutes the list of Water Quality Limited Waters required under Section 303(d) of the CWA. A Total Maximum Daily Load (TMDL) is required to be prepared for those waters on the 303(d) list. A TMDL is developed to identify all the contributors of a pollutant of concern and the load reductions necessary to meet the Surface Water Quality Standards (SWQS) relative to that pollutant. The Department adopted and the Environmental Protection Agency (EPA) approved the 2008 Integrated List of Waters, which formed the basis for the initial analysis of phosphorus impairment in the Pequest River watershed. Table 1 shows the phosphorus impairments, as indicated by the presence of total phosphorus (TP) concentrations in excess of the numeric criterion, as they appear on the 2008 Integrated List of Waters for the Pequest River watershed. This report addresses these impairments. Specifically, this report adopts TMDLs to address the phosphorus impairments upstream of and including HUC 14 No. 02040105090030-01 (i.e., Pequest River, Furnace Brook to Cemetary Road). The Pequest River below Furnace Brook (02040105090060-01), the only remaining HUC 14 listed for TP impairment within the Pequest Watershed, will be addressed in a subsequent TMDL study because additional evaluation of sources is needed. Other listed impairments within the Pequest River watershed will be addressed in subsequent TMDL evaluations. The target for the TMDL calculations is