San Pitch River Watershed Water Quality Management Plan
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SSaann PPiittcchh RRiivveerr WWaatteerrsshheedd Water Quality Management Plan Prepared by Millennium Science and Engineering Prepared for Utah Department of Environmental Quality/Division of Water Quality James A. Harris Harry Lewis Judd Project Manager Project Supervisor EPA Approval: November 18th , 2003 SAN PITCH RIVER WATERSHED WATER QUALITY MANAGEMENT PLAN TABLE OF CONTENTS 1.0 INTRODUCTION .................................................................................................... 1 1.1 The TMDL Process ........................................................................................ 2 1.2 Utah’s Watershed Approach .......................................................................... 3 2.0 WATERSHED DESCRIPTION ............................................................................... 5 2.1 Historic Perspective ....................................................................................... 5 2.2 Climate........................................................................................................... 6 2.3 Geology / Soils............................................................................................... 7 2.4 Land Use / Land Cover ................................................................................ 11 2.5 Surface Water Hydrology ............................................................................. 13 2.5.1 Middle San Pitch River - Water Budget for Typical Year................. 14 2.5.2 Lower San Pitch River - Water Budget for Typical Year.................. 16 2.6 Groundwater Hydrology ............................................................................... 17 3.0 CURRENT MONITORING PROGRAM ................................................................ 20 3.1 STORET Locations ...................................................................................... 21 3.2 STORET Sampling Frequency..................................................................... 24 3.3 STORET Sampling Parameters ................................................................... 26 3.4 USGS gage stations..................................................................................... 26 4.0 WATER QUALITY................................................................................................ 27 4.1 Designated Segments and Beneficial Uses ................................................. 27 4.2 Applicable Water Quality Standards............................................................. 27 4.3 303(d) Listing Criteria................................................................................... 29 4.4 Water Quality Assessment........................................................................... 30 4.4.1 Surface Water ................................................................................. 30 4.4.2 Groundwater ................................................................................... 34 4.5 Flow Characterization .................................................................................. 36 4.5.1 Surface Water and the San Pitch River........................................... 36 4.6 Pollutant Sources and Linkages................................................................... 39 4.6.1 Point Sources.................................................................................. 39 4.6.2 Nonpoint Sources............................................................................ 40 4.7 Load Calculations......................................................................................... 42 4.7.1 TMDL Equations and Terminology.................................................. 42 4.7.2 Approach and Assumptions ............................................................ 42 Load Calculation Alternatives...................................................... 43 Selection of STORET Stations.................................................... 44 TMDL Measurement Points ........................................................ 46 Critical Period.............................................................................. 46 Water Quality Target................................................................... 47 i 4.7.3 Middle San Pitch River.................................................................... 47 Point Source Load (Waste Load Allocation) ............................... 47 Nonpoint Source and Background Load (Load Allocation) ......... 47 Target Load................................................................................. 50 TMDL Load ................................................................................. 52 4.7.4 Lower San Pitch River..................................................................... 53 Point Source Load (Waste Load Allocation) ............................... 53 Nonpoint Source and Background Load (Load Allocation) ......... 53 Target Load................................................................................. 54 TMDL Load ................................................................................. 56 4.8 Source Loads and Load Allocation............................................................... 57 4.8.1 Middle San Pitch River Watershed.................................................. 57 4.8.2 Lower San Pitch River Watershed .................................................. 58 Natural Sources of TDS .............................................................. 58 Site-Specific Criteria ................................................................... 59 4.9 Best Management Practices ........................................................................ 61 5.0 TMDL.................................................................................................................... 64 6.0 PROJECT IMPLEMENTATION PLANS .............................................................. 82 6.1 Statement of Need ....................................................................................... 82 6.1.1 Project Water Quality Priority .......................................................... 82 6.1.2 Project Goals................................................................................... 83 6.1.3 Objectives and Tasks...................................................................... 84 6.1.4 Permits............................................................................................ 87 6.1.5 Lead Sponsor.................................................................................. 87 6.1.6 Assurance of Project Operation and Maintenance .......................... 87 6.2 Coordination Plan......................................................................................... 88 6.2.1 Lead Project Sponsor...................................................................... 88 6.2.2 Local Support .................................................................................. 88 6.2.3 Coordination and Linkages.............................................................. 88 6.3 Evaluation and Monitoring Plan ................................................................... 89 6.3.1 Sampling and Analysis Plan............................................................ 89 6.3.2 General Design and Parameters..................................................... 91 6.3.3 Data Management, Storage, and Reporting.................................... 92 6.3.4 Models used.................................................................................... 92 6.3.5 Long-Term Funding Plans for Operation and Maintenance............. 92 6.4 Public Involvement....................................................................................... 93 7.0 FUTURE LAND USE............................................................................................ 94 8.0 CONCLUSIONS AND RECOMMENDATIONS .................................................... 95 9.0 REFERENCES ..................................................................................................... 98 ii SAN PITCH RIVER WATERSHED WATER QUALITY MANAGEMENT PLAN LIST OF TABLES Table 2.1 Climate and Precipitation............................................................................. 6 Table 2.2 Climatic Zones............................................................................................. 7 Table 2.3 Division of Water Rights Diversions .......................................................... 14 Table 2.4 Source of Groundwater Recharge............................................................. 18 Table 2.5 Sources of Groundwater Discharge .......................................................... 18 Table 3.1 STORET Sites in the San Pitch River Watershed ..................................... 21 Table 3.2 STORET Sites Without TDS or Specific Conductivity Data....................... 22 Table 3.3 Summary of TDS Data Available in the San Pitch River Database ........... 23 Table 3.4 STORET Sampling Frequency .................................................................. 25 Table 3.5 USGS Stream Gaging Stations in the San Pitch River Watershed............ 26 Table 4.1 Utah Water Quality Criteria for Class 4 Waters ......................................... 28 Table 4.2 303 (d) Criteria for Assessing Agricultural Beneficial Use Support............ 29 Table 4.3 Summary of TDS Data Available for the Upper San Pitch River (1995 - 2000) ............................................................................................ 31 Table 4.4 Summary of TDS Data Available for the Middle San Pitch River (1995 - 2000) ...........................................................................................