LAKE BERRYESSA 2018 WATERSHED SANITARY SURVEY Final Report October 2018 Prepared for Napa County Flood Control Water Conservation District and Solano County Water Agency Lake Berryessa 2018 Watershed Sanitary Survey FINAL REPORT October 2018 Technical Committee: Napa County Flood Control Water Conservation District Annamaria Martinez Phillip Miller Solano County Water Agency Justin Pascual Prepared By: Leslie Palencia, Palencia Consulting Engineers PREPARED BY TABLE OF CONTENTS Page Number Section 1 – Introduction Introduction .................................................................................................................. 1-1 Objectives of the Update .............................................................................................. 1-1 Constituents and Potential Contaminating Activities Covered in the Current Update ... 1-2 Report Organization ..................................................................................................... 1-3 Section 2 – Watershed and Water Supply Systems Background .................................................................................................................. 2-1 Watershed Description ................................................................................................. 2-2 Land Use ........................................................................................................... 2-2 Precipitation ....................................................................................................... 2-2 Water Treatment Plants ............................................................................................... 2-3 Lake Berryessa Resort Improvement District .................................................... 2-3 Napa Berryessa Resort Improvement District.................................................... 2-4 Section 3 – Water Quality Selected Constituent Review ....................................................................................... 3-1 Turbidity ............................................................................................................. 3-1 General Characteristics and Background ............................................... 3-1 Evaluation ............................................................................................... 3-2 Summary of Results................................................................................ 3-3 Microbial Constituents ....................................................................................... 3-4 General Characteristics and Background ............................................... 3-4 Evaluations ............................................................................................. 3-5 Cryptosporidium .............................................................................. 3-5 E. coli .............................................................................................. 3-5 Total Coliform ................................................................................. 3-7 Summary of Results................................................................................ 3-7 Total Organic Carbon ........................................................................................ 3-8 General Characteristics and Background ............................................... 3-8 Evaluation ............................................................................................... 3-8 Summary of Results................................................................................ 3-9 Cyanotoxins ....................................................................................................... 3-9 General Characteristics and Background ............................................... 3-9 Evaluation ............................................................................................. 3-10 Summary of Results.............................................................................. 3-10 Section 4 – Watershed Contaminant Sources Review Spills ............................................................................................................................. 4-1 Lake Berryessa Watershed Sanitary Survey Page i Final Report Background ....................................................................................................... 4-1 Related Constituents ......................................................................................... 4-1 Occurrence in Watershed .................................................................................. 4-1 Regulation and Management ............................................................................ 4-4 Summary of Findings for Spills .......................................................................... 4-4 Recreation .................................................................................................................... 4-5 Background ....................................................................................................... 4-5 Related Constituents ......................................................................................... 4-5 Occurrence in Watershed .................................................................................. 4-5 Putah Canyon Recreation Area .............................................................. 4-7 Berryessa Point Recreation Area ............................................................ 4-8 Spanish Flat Recreation Area ................................................................. 4-8 Steele Canyon Recreation Area ............................................................. 4-8 Pleasure Cove Marina ............................................................................ 4-8 Markley Cove Resort .............................................................................. 4-8 Eticuera Day Use Area ........................................................................... 4-9 Smittle Day Use Area.............................................................................. 4-9 Oak Shores Day Use Area ...................................................................... 4-9 Dufer Point Visitor Center ..................................................................... 4-10 Capell Cove Boat Launch ..................................................................... 4-10 Olive Orchard Day Use Area ................................................................ 4-10 EcoCamp Berryessa ............................................................................. 4-10 Regulation and Management .......................................................................... 4-10 Source Water Protection Activities ................................................................. 4-11 Summary of Findings for Recreation ............................................................... 4-12 Agriculture .................................................................................................................. 4-13 Background ..................................................................................................... 4-13 Related Constituents ....................................................................................... 4-13 Occurrence in Watershed ................................................................................ 4-13 Related Water Quality Issues and Data Review .............................................. 4-15 Regulation and Management........................................................................... 4-16 Source Water Protection Activities .................................................................. 4-17 Summary of Findings for Agriculture ............................................................... 4-17 Wastewater ................................................................................................................ 4-18 Background ..................................................................................................... 4-18 Seasonal Patterns ........................................................................................... 4-18 Occurrence in Watershed ................................................................................ 4-18 Middletown ............................................................................................ 4-19 Hidden Valley Lake Community Services District ................................. 4-20 Lake Berryessa Resort Improvement District ........................................ 4-21 Spanish Flat Water District, Berryessa Pines ....................................... 4-23 Spanish Flat Water District ................................................................... 4-25 Napa Berryessa Resort Improvement District ....................................... 4-25 Turtle Rock Motel and Boat Storage WWTF ......................................... 4-27 Capell Valley Mobile Home Park .......................................................... 4-27 Circle Oaks County Water District ........................................................ 4-28 Lake Berryessa Watershed Sanitary Survey Page ii Final Report Reclamation Administrative Center and Day Use Areas ....................... 4-29 Pleasure Cove Marina .......................................................................... 4-29 Markley Cove Resort ............................................................................ 4-30 Other Recreation Area .......................................................................... 4-30 Regulation and Management..........................................................................