Calaveras River 2016 Watershed Sanitary Survey Prepared for Calaveras County Water District Stockton East Water District Karen E. Johnson Water Resources Planning October 12, 2016 CALAVERAS RIVER 2016 WATERSHED SANITARY SURVEY PREPARED FOR STOCKTON EAST WATER DISTRICT & CALAVERAS COUNTY WATER DISTRICT October 2016 Prepared by: Karen E. Johnson Water Resources Planning TABLE OF CONTENTS Executive Summary ....................................................................................................................................................... ES-1 Section 1 Introduction ................................................................................................................................................... 1-1 Regulatory Requirement for a Watershed Sanitary Survey ............................................................... 1-1 Stanislaus/Calaveras River Group ................................................................................................................ 1-1 Survey Methods .................................................................................................................................................... 1-1 Report Organization ........................................................................................................................................... 1-2 Abbreviations and Acronyms ......................................................................................................................... 1-3 Section 2 Watershed Characteristics and Infrastructure ........................................................................... 2-1 Watershed Study Area and Water Supply System ................................................................................. 2-1 Calaveras River Watershed Sanitary Survey Study Area Description ........................................... 2-4 Hydrology ................................................................................................................................................ 2-4 Topography ............................................................................................................................................ 2-4 Geology ..................................................................................................................................................... 2-4 Vegetation ............................................................................................................................................... 2-5 Land Use .................................................................................................................................................. 2-5 Urban/Residential/Commercial .................................................................................................... 2-5 Calaveras River Water Supply Systems ...................................................................................................... 2-5 White Pines Lake .................................................................................................................................. 2-6 Sheep Ranch Water Treatment Plant .......................................................................................... 2-6 New Hogan Dam ................................................................................................................................... 2-6 New Hogan Reservoir ........................................................................................................................ 2-6 Jenny Lind Water Treatment Plant ............................................................................................... 2-7 Dr. Joe Waidhofer Water Treatment Plant ................................................................................ 2-8 Section 3 Potential Contaminant Sources ........................................................................................................... 3-1 Watershed Counties and Subwatersheds .................................................................................................. 3-1 Water Quality Parameters of Concern ........................................................................................................ 3-3 Microorganisms .................................................................................................................................... 3-3 Disinfection By-Product Precursors ............................................................................................ 3-3 Turbidity .................................................................................................................................................. 3-3 SOCs, VOCs, Herbicides, Pesticides, and Metals ....................................................................... 3-4 Forestry Activities ............................................................................................................................................... 3-4 Concern .................................................................................................................................................... 3-5 Potential Contaminant Sources ...................................................................................................... 3-5 Watershed Management ................................................................................................................... 3-5 Irrigated Agriculture and Pesticides ............................................................................................................ 3-6 Concern .................................................................................................................................................... 3-6 Potential Contaminant Sources ...................................................................................................... 3-7 Irrigated Agriculture ........................................................................................................... 3-7 Pesticides and Herbicides ................................................................................................. 3-8 Watershed Management ................................................................................................................... 3-8 Livestock................................................................................................................................................................ 3-10 Concern .................................................................................................................................................. 3-10 Potential Contaminant Sources .................................................................................................... 3-11 Watershed Management ................................................................................................................. 3-11 Mining ..................................................................................................................................................................... 3-12 Concern .................................................................................................................................................. 3-12 Potential Contaminant Sources .................................................................................................... 3-12 Watershed Management ................................................................................................................. 3-13 Active and Inactive Mines ............................................................................................... 3-13 Methyl Mercury ................................................................................................................... 3-14 CALAVERAS RIVER 2016 WATERSHED SANITARY SURVEY TABLE OF CONTENTS Recreation ............................................................................................................................................................. 3-14 Concern .................................................................................................................................................. 3-14 Potential Contaminant Sources .................................................................................................... 3-14 Calaveras Big Trees State Park ..................................................................................... 3-15 White Pines Lake ................................................................................................................ 3-15 New Hogan Reservoir ....................................................................................................... 3-15 Less Formal Recreation Areas ...................................................................................... 3-16 Unauthorized Uses ............................................................................................................. 3-16 Watershed Management ................................................................................................................. 3-16 Solid and Hazardous Waste Disposal ........................................................................................................ 3-17 Concern .................................................................................................................................................. 3-17 Potential Contaminant Sources .................................................................................................... 3-17 Landfills .................................................................................................................................