Rice Brook and Clay Brook Water Quality Remediation Plan
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SUMMIT VENTURES NE, LLC SUGARBUSH RESORT Warren, Vermont WATER QUALITY REMEDIATION PLAN CLAY BROOK AND RICE BROOK WATERSHEDS October 15, 2008 SUMMIT VENTURES NE, LLC SUGARBUSH RESORT WATER QUALITY REMEDIATION PLAN CLAY BROOK AND RICE BROOK WATERSHEDS October 2008 TABLE OF CONTENTS EXECUTIVE SUMMARY ........................................................................................................ I 1.0 INTRODUCTION ......................................................................................................... 1 1.1 Background ............................................................................................................... 1 1.2 Water Quality Remediation Plan Overview ........................................................ 2 1.2.1 Watershed Delineation ...................................................................................... 4 1.2.2 Wash‐off Sediment Load Analysis .................................................................. 5 1.2.3 Hydrologic Modeling ........................................................................................ 5 1.2.4 Instream Survey and Reconnaissance ............................................................. 6 1.3 Water Quality Remediation Plan Components ................................................... 7 2.0 CLAY BROOK AND RICE BROOK WATERSHEDS .............................................. 8 2.1 Regional Setting ........................................................................................................ 8 2.2 Land Use / Land Cover ........................................................................................... 8 2.3 Existing Environmental Permits ........................................................................... 11 2.3.1 Umbrella Federal Permits ............................................................................... 11 2.3.2 Existing Stormwater and Stream Restoration Activities ............................ 11 2.3.3 Water Supply and Wastewater Disposal System ........................................ 12 3.0 ATTAINMENT WATERSHED ................................................................................. 14 3.1 Regional Setting ...................................................................................................... 14 3.2 Land Use / Land Cover ......................................................................................... 15 3.3 Existing Environmental Permits .......................................................................... 16 4.0 SEDIMENT LOADING ANALYSIS ......................................................................... 16 4.1 Sediment Loading Analysis Information ........................................................... 16 4.2 Sediment Loading Analysis Results .................................................................... 19 4.2.1 Clay Brook Watershed..................................................................................... 19 4.2.2 Rice Brook Watershed ..................................................................................... 20 Table of Contents Page 2 4.2.3 Chase Brook Watershed .................................................................................. 21 5.0 HYDROLOGIC MODELING ANALYSIS ............................................................... 22 5.1 Hydrologic Modeling Information ...................................................................... 22 5.1.1 Channel Protection Volume (CPv) Standard ............................................... 24 5.2 Hydrologic Modeling Results .............................................................................. 24 6.0 IDENTIFIED IMPACT AREAS ................................................................................. 25 6.1 Existing Land Uses and Erosion .......................................................................... 25 6.1.1 Clay Brook ......................................................................................................... 26 6.1.2 Rice Brook ......................................................................................................... 27 6.2 Sources of Iron ........................................................................................................ 27 6.2.1 Clay Brook ......................................................................................................... 28 6.2.2 Rice Brook ......................................................................................................... 29 6.3 Channel Processes .................................................................................................. 31 6.3.1 Clay Brook ......................................................................................................... 31 6.3.2 Rice Brook ......................................................................................................... 33 6.4 Water Chemistry .................................................................................................... 36 6.4.1 Clay Brook ......................................................................................................... 36 6.4.2 Rice Brook ......................................................................................................... 37 6.5 Aquatic Biota .......................................................................................................... 38 6.5.1 Clay Brook ......................................................................................................... 38 6.5.2 Rice Brook ......................................................................................................... 39 7.0 REMEDIATION STRATEGIES ................................................................................. 42 7.1 Clay Brook Watershed........................................................................................... 42 7.1.1 Existing .............................................................................................................. 42 7.1.2 Proposed .................................................................................................................. 43 7.1.3 Future ................................................................................................................. 44 7.2 Rice Brook Watershed ........................................................................................... 45 7.2.1 Existing .............................................................................................................. 45 7.2.2 Proposed ............................................................................................................ 46 7.2.3 Future ................................................................................................................. 47 8.0 SCHEDULE OF IMPLEMENTATION ..................................................................... 47 8.1 Implementation of Remedial Measures .............................................................. 48 8.2 Proposed Water Quality Targets ......................................................................... 48 8.3 Water Quality Monitoring Plan ........................................................................... 49 8.3.1 Water Quality Monitoring Locations and Parameters ............................... 49 8.3.2 Water Quality Monitoring Schedule and Reporting ................................... 50 8.3.3 Meeting Water Quality Targets...................................................................... 51 8.3.4 Water Quality Remediation Plan Revisions ................................................. 51 SUMMIT VENTURES NE, LLC SUGARBUSH RESORT WATER QUALITY REMEDIATION PLAN CLAY BROOK AND RICE BROOK WATERSHEDS October 2008 EXECUTIVE SUMMARY To address existing water quality impairments, VHB Pioneer (VHBP) has prepared a Water Quality Remediation Plan (WQRP) for the Clay Brook and Rice Brook watersheds in Warren, Vermont. Both of these streams are listed by Vermont Department of Environmental Conservation (VT DEC) on the 2006 Section 303(d) as not meeting Vermont Water Quality Standards (VWQS) due to aquatic life support, which has been documented through macroinvertebrate surveys in the subject streams conducted over many years. The designated cause of the impairment is principally stormwater runoff. This WQRP is structured to meet the required elements for Category 4(b) waters, as presented in the 2006 U.S. Environmental Protection Agency (EPA) integrated listing guidance. The specific elements of this WQRP are: 1. Quantification of historic stormwater pollutant impacts to Clay Brook and Rice Brook 2. Identification and quantification of water quality improvements resulting from the measures implemented since 2003 pursuant to existing permits and authorizations 3. Determination of additional measures that may be warranted now and in the future, to assure attainment of VWQS in these watersheds. The analyses presented herein are based on sediment washoff loading, and utilize the concept of an attainment watershed as the basis for the determination that standards will be achieved. The loading analyses have demonstrated that overall watershed SUGARBUSH RESORT –WATER QUALITY REMEDIATION PLAN CLAY BROOK AND RICE BROOK WATERSHEDS ii sediment washoff loads have been reduced by four (4) percent in the Clay Brook watershed and 45 percent in the Rice Brook watershed, due to previously completed improvements, with as much as an 80 percent reduction on the subwatershed scale. Substantial reductions in both sediment washoff and peak runoff rates from existing developed areas on parcels