2015 UPPER MOKELUMNE RIVER WATERSHED SANITARY SURVEY FINAL DRAFT JULY 2016 PREPARED BY: PETERSON BRUSTAD INC. 1180 IRON POINT ROAD, SUITE 260 FOLSOM, CA 95630 916‐608‐2212 Table of Contents TABLE OF CONTENTS Table of Contents ................................................................................................................... i List of Figures ....................................................................................................................... iii List of Tables ........................................................................................................................ iii Introduction ................................................................................................................ 1 Background ....................................................................................................................... 1 Objectives ......................................................................................................................... 3 Report Organization ......................................................................................................... 3 Summary of Progress Since 2010 ................................................................................. 4 Watershed Description ................................................................................................ 8 Upper Mokelumne River Watershed ............................................................................... 8 Land Use ................................................................................................................................ 8 Natural Setting .................................................................................................................... 10 Water Supply Systems ............................................................................................... 13 CCWD West Point WTP .................................................................................................. 13 CPUD Jeff Davis WTP ...................................................................................................... 16 Potential Contaminant Sources ................................................................................. 19 Watershed Activities ...................................................................................................... 19 Wastewater Management .................................................................................................. 19 Solid Waste Disposal ........................................................................................................... 20 Urban Runoff ....................................................................................................................... 21 Transported Hazardous Materials ...................................................................................... 21 Agricultural Crop Land Use ................................................................................................. 21 Grazing Animals .................................................................................................................. 21 Concentrated Animal Facilities ........................................................................................... 21 Pesticide/Herbicide Use ...................................................................................................... 22 Wild Animals ....................................................................................................................... 22 Logging ................................................................................................................................ 22 Mine Runoff ........................................................................................................................ 22 Traffic Accidents/Spills ........................................................................................................ 23 Geologic Hazards ................................................................................................................. 23 Calaveras County Water District Calaveras Public Utilities District 2015 Upper Mokelumne River Watershed Sanitary Survey i Table of Contents Fires ..................................................................................................................................... 23 Body Contact Recreation .................................................................................................... 24 Off-Highway Vehicle Recreation ......................................................................................... 24 Significance of Potential Contaminant Sources ............................................................. 24 Anticipated Growth within the Study Area .................................................................... 25 Changes in Sources of Contamination ........................................................................... 25 Water Quality ........................................................................................................... 26 Microbial Water Quality ................................................................................................. 26 CCWD West Point WTP ....................................................................................................... 26 CPUD Jeff Davis WTP ........................................................................................................... 28 Disinfection By-Product Water Quality .......................................................................... 28 CCWD West Point WTP ....................................................................................................... 28 CPUD Jeff Davis WTP ........................................................................................................... 29 Trace Metals ................................................................................................................... 30 CCWD West Point WTP ....................................................................................................... 30 CPUD Jeff Davis WTP ........................................................................................................... 30 Organic Compounds ....................................................................................................... 30 CCWD West Point WTP ....................................................................................................... 30 CPUD Jeff Davis WTP ........................................................................................................... 30 Summary of Ability to Meet Water Quality Goals ......................................................... 31 Conclusions and Recommendations ........................................................................... 32 Conclusions..................................................................................................................... 32 Potential Watershed Contaminants.................................................................................... 32 Progress Since 2010 WSS Update ....................................................................................... 32 Water Quality ...................................................................................................................... 33 Recommendations ......................................................................................................... 33 References ................................................................................................................ 34 Calaveras County Water District Calaveras Public Utilities District 2015 Upper Mokelumne River Watershed Sanitary Survey ii Table of Contents LIST OF FIGURES FIGURE 1. UPPER MOKELUMNE RIVER WATERSHED ............................................................................... 2 FIGURE 2. SUB-WATERSHEDS OF THE UPPER MOKELUMNE RIVER WATERSHED ............................................... 9 FIGURE 3. LOCATION OF CCWD TREATMENT FACILITIES ............................................................................ 14 FIGURE 4. LOCATION OF CPUD SERVICE AREA ........................................................................................ 17 LIST OF TABLES TABLE 1. POLICY 1 - MAINTAIN AND IMPROVE WATER QUALITY GOALS, OBJECTIVES AND PERFORMANCE MEASURES .................................................................................................................................. 5 TABLE 2. AREA OF UPPER MOKELUMNE RIVER SUB-WATERSHEDS ................................................................ 8 TABLE 3. WEST POINT WTP RAW AND TREATED WATER TURBIDITY ........................................................... 27 TABLE 4. WEST POINT WTP RAW WATER COLIFORM .............................................................................. 27 TABLE 5. JEFF DAVIS WTP RAW WATER COLIFORM ................................................................................. 28 TABLE 6. WEST POINT WTP TTHM AND HAA5 ..................................................................................... 29 TABLE 7. JEFF DAVIS WTP TTHM AND HAA5 ........................................................................................ 29 Calaveras County Water District Calaveras Public Utilities District 2015 Upper Mokelumne River Watershed Sanitary Survey iii Introduction INTRODUCTION This report presents the findings of the 2015 Watershed Sanitary Survey (WSS) for the Upper Mokelumne River watershed. The WSS was conducted for Calaveras County Water District (CCWD) and Calaveras