SOLANO PROJECT BELOW MONTICELLO DAM 2017 WATERSHED SANITARY SURVEY Final Report June 2018 Prepared for Solano County Water Agency Solano Project Below Monticello Dam 2017 Watershed Sanitary Survey FINAL REPORT June 2018 Technical Committee: Solano County Water Agency Justin Pascual Alex Rabidoux 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 Solano Project Facilities ............................................................................................... 2-1 Lake Berryessa and Monticello Dam ................................................................. 2-1 Putah Creek, Lake Solano and Putah Diverson Dam ........................................ 2-1 Putah South Canal ............................................................................................ 2-3 Terminal Dam and Reservoir ............................................................................. 2-3 Watershed Description ................................................................................................. 2-3 Land Use ........................................................................................................... 2-3 Precipitation ....................................................................................................... 2-5 Water Treatment Plants ............................................................................................... 2-5 Gibson Canyon .................................................................................................. 2-6 Moose Lodge ..................................................................................................... 2-6 Pleasant Hills Ranch Estates............................................................................. 2-6 City of Vacaville ................................................................................................. 2-6 California Medical Facility .................................................................................. 2-6 North Bay Regional ........................................................................................... 2-7 Cement Hill ........................................................................................................ 2-7 Waterman .......................................................................................................... 2-7 Green Valley ...................................................................................................... 2-8 Fleming Hill ........................................................................................................ 2-8 Travis AFB ......................................................................................................... 2-8 City of Benicia .................................................................................................... 2-8 Section 3 – Water Quality Selected Constituent Review ....................................................................................... 3-2 Turbidity ............................................................................................................. 3-2 General Characteristics and Background ............................................... 3-2 Evaluation ............................................................................................... 3-2 Summary of Results................................................................................ 3-9 Microbial Constituents ..................................................................................... 3-10 General Characteristics and Background ............................................. 3-10 Evaluations ........................................................................................... 3-11 Cryptosporidium ............................................................................ 3-11 Solano Project Below Monticello Dam Watershed Sanitary Survey Page i Final Report E. coli ............................................................................................ 3-12 Fecal Coliform ............................................................................... 3-13 Total Coliform ............................................................................... 3-15 Summary of Results.............................................................................. 3-16 Total Organic Carbon ...................................................................................... 3-16 General Characteristics and Background ............................................. 3-16 Evaluation ............................................................................................. 3-16 Summary of Results.............................................................................. 3-19 Copper ............................................................................................................. 3-20 General Characteristics and Background ............................................. 3-20 Evaluation ............................................................................................. 3-20 Pesticides ........................................................................................................ 3-21 General Characteristics and Background ............................................. 3-21 Evaluation ............................................................................................. 3-21 Trihalomethanes and Haloacetic Acids ........................................................... 3-21 Evaluation ............................................................................................. 3-21 Section 4 – Watershed Contaminant Sources Review Spills ............................................................................................................................. 4-1 Background ....................................................................................................... 4-1 Related Constituents ......................................................................................... 4-1 Occurrence in Watershed .................................................................................. 4-1 Regulation and Management ............................................................................ 4-2 Summary of Findings for Spills .......................................................................... 4-2 Recreation .................................................................................................................... 4-3 Background ....................................................................................................... 4-3 Related Constituents ......................................................................................... 4-3 Occurrence in Watershed .................................................................................. 4-3 Stebbins Cold Canyon Reserve .............................................................. 4-3 Canyon Creek Resort ............................................................................. 4-4 Putah Creek Fishing Access Parks ......................................................... 4-4 Lake Solano County Park ....................................................................... 4-5 Summary of Findings for Recreation ................................................................. 4-5 Agriculture .................................................................................................................... 4-7 Background ....................................................................................................... 4-7 Related Constituents ......................................................................................... 4-7 Occurrence in Watershed .................................................................................. 4-7 Related Water Quality Issues and Data Review ................................................ 4-9 Regulation and Management............................................................................. 4-9 Source Water Protection Activities .................................................................. 4-10 Summary of Findings for Agriculture ............................................................... 4-10 Lateral Sources .......................................................................................................... 4-11 Background ..................................................................................................... 4-11 Occurrence in Watershed ................................................................................ 4-11 Source Water Protection Activities .................................................................. 4-13 Solano Project Below Monticello Dam Watershed Sanitary Survey Page ii Final Report Summary of Findings for Lateral Sources ....................................................... 4-13 Canal Cleaning ..........................................................................................................