SOLANO PROJECT – WATERSHED SANITARY SURVEY BELOW MONTICELLO DAM FINAL REPORT OCTOBER 2006 PREPARED BY ARCHIBALD CONSULTING Solano Project – Watershed Sanitary Survey Below Monticello Dam FINAL REPORT October 2006 Solano County Water Agency David Okita Alex Rabidoux Solano Irrigation District Don Burbey Frank Morris Sue Murphy Carol Ramirez City of Fairfield Laura deAlbidress Gil Hernandez Scott Leland Doug Rogers City of Vacaville Tony Pirondini City of Vallejo Nancy Dodsworth City of Benicia Scott Rovanpera Prepared By: Elaine Archibald, Archibald Consulting Bonny Starr, Starr Consulting TABLE OF CONTENTS Page Number Section 1 – Introduction Background .................................................................................................................. 1-1 Solano Project Facilities ............................................................................................... 1-1 Lake Berryessa and Monticello Dam ................................................................. 1-1 Putah Creek, Lake Solano, and the Putah Diversion Dam ................................ 1-3 Putah South Canal ............................................................................................ 1-3 Terminal Dam and Reservoir............................................................................. 1-5 Water Treatment Plants ............................................................................................... 1-5 Gibson Canyon Water Treatment Plant............................................................. 1-5 City of Vacaville................................................................................................. 1-5 California Medical Facility.................................................................................. 1-7 North Bay Regional WTP .................................................................................. 1-7 Cement Hill WTP ............................................................................................... 1-7 Waterman WTP................................................................................................. 1-8 Green Valley WTP............................................................................................. 1-8 Fleming Hill WTP............................................................................................... 1-8 City of Benicia.................................................................................................... 1-9 Point of Entry Devices ....................................................................................... 1-9 Report Outline .............................................................................................................. 1-9 Section 2 – Potential Contaminating Activities Evaluation Introduction .................................................................................................................. 2-1 Agriculture/Pesticide Use ............................................................................................. 2-1 Constituents of Interest...................................................................................... 2-2 Presence in the Watershed ............................................................................... 2-2 Putah Creek and Lake Solano ................................................................ 2-2 Putah South Canal.................................................................................. 2-4 Regulation and Management ............................................................................ 2-6 Irrigated Lands Waiver............................................................................ 2-7 Erosion ................................................................................................................ 2-9 Constituents of Interest...................................................................................... 2-9 Presence in the Watershed ............................................................................. 2-10 Putah Creek and Lake Solano .............................................................. 2-10 Putah South Canal................................................................................ 2-10 Regulation and Management .......................................................................... 2-12 Grazing .............................................................................................................. 2-12 Constituents of Interest.................................................................................... 2-12 Presence in the Watershed ............................................................................. 2-13 Putah Creek and Lake Solano .............................................................. 2-13 Terminal Reservoir ............................................................................... 2-14 Regulation and Management .......................................................................... 2-14 Solano Project – Watershed Sanitary Survey Page i Below Monticello Dam Rangeland Research ............................................................................ 2-15 Recreation .............................................................................................................. 2-15 Constituents of Interest.................................................................................... 2-16 Presence in the Watershed ............................................................................. 2-16 Putah Creek and Lake Solano .............................................................. 2-16 Spills/Illegal Dumping................................................................................................. 2-18 Constituents of Interest.................................................................................... 2-18 Presence in the Watershed ............................................................................. 2-19 Putah Creek and Lake Solano .............................................................. 2-19 Putah South Canal................................................................................ 2-20 Regulation and Management .......................................................................... 2-20 Urban Runoff .............................................................................................................. 2-21 Constituents of Interest.................................................................................... 2-21 Presence in the Watershed ............................................................................. 2-21 Putah Creek and Lake Solano .............................................................. 2-21 Putah South Canal................................................................................ 2-21 Regulation and Management .......................................................................... 2-22 Growth............................................................................................................. 2-23 Wildfires .............................................................................................................. 2-24 Constituents of Interest.................................................................................... 2-24 Presence in the Watershed ............................................................................. 2-24 Putah Creek and Lake Solano .............................................................. 2-24 Putah South Canal and Terminal Reservoir.......................................... 2-24 Watershed Programs ................................................................................................. 2-25 Section 3 – Water Quality Evaluation Introduction .................................................................................................................. 3-1 Monitoring Programs.................................................................................................... 3-1 Water Quality Evaluation.............................................................................................. 3-2 Rainfall .............................................................................................................. 3-2 Turbidity............................................................................................................. 3-2 Temporal and Spatial Trends.................................................................. 3-2 Impact of Storm Events........................................................................... 3-5 Treated Water Turbidity ........................................................................ 3-10 Microbiological Contaminants.......................................................................... 3-10 Pathogens............................................................................................. 3-11 Total and Fecal Coliforms..................................................................... 3-11 Disinfection Byproduct Precursors................................................................... 3-20 Total Organic Carbon............................................................................ 3-21 Alkalinity................................................................................................ 3-23 Bromide ................................................................................................ 3-23 Trihalomethanes and Haloacetic Acids................................................. 3-24 Algal Blooms.................................................................................................... 3-24 Pesticides