City of Sonoma Agenda Item Summary Meeting: City Council - Mar 05 2018 Department Staff Contact Public Works Colleen Ferguson, Public Works Director/City Engineer Agenda Item Title Discussion, Consideration, and Possible Action to Adopt a Resolution to Approve the Recycled Water Feasibility Analysis (RWFA) Prepared by GHD Inc. Summary Water Recycling Water is continually recycled in nature through the water cycle. Modern wastewater treatment replicates the natural recycling process to restore large quantities of water quickly and effectively. In Sonoma, water from sinks, toilets, and indoor plumbing travels through pipes to the Sonoma Valley County Sanitation District (SVCSD) wastewater treatment facility, where it is treated to remove bacteria and pollutants. Tertiary-treated recycled water undergoes extensive testing to ensure it meets the strict standards set by the State of California. In Sonoma Valley, recycled water is used to irrigate more than 2,000 acres of premium grapes in the Carneros appellation. Recycled water is also used for irrigation of dairy fodder crops. In other areas, recycled water is mainly used for irrigation of crops and large landscaped areas such as golf courses, athletic fields, commercial and industrial parks, and cemeteries. Recycled water is transported through a system of purple pipes, completely separate from drinking water and wastewater systems. Previous Reports and Analysis In 2005, the Sonoma County Water Agency (SCWA) prepared a Sonoma Valley Recycled Water Feasibility Study on behalf of SVCSD, the Valley of the Moon Water District (VOMWD), and the City, and in consultation with the Sonoma Ecology Center, to evaluate the feasibility of recycled water use in Sonoma Valley. The study was organized into the following sections: Engineering Evaluation, Environmental Review, and a Financial/Economic Evaluation. This study led to the conclusion that expanding the use of recycled water in Sonoma Valley could result in: “reduced discharges to waters of the United States; reduction of peak potable water demands on the VOMWD and the City’s distribution systems including Russian River and groundwater supplies; and potential reduction of groundwater pumping for agricultural and private municipal purposes.” The Sonoma Valley Recycled Water Feasibility Study can be accessed in three parts here: https://www.sonomacity.org/documents/sonoma-valley- recycled-water-feasibility-study-2005-part-1/, https://www.sonomacity.org/documents/sonoma-valley-recycled-water-feasibility-study-2005- part-2/, and https://www.sonomacity.org/documents/sonoma-valley-recycled-water-feasibility- study-2005-part-3/. In 2006, the Sonoma Valley County Sanitation District (SVCSD) prepared an Environmental Impact Report (EIR) for the Sonoma Valley Recycled Water Project. The purpose of this project is to reduce the discharge of treated wastewater to the waters of the United States and provide a reliable source of water to meet the current and future needs of users located in the Sonoma Valley by offsetting current potable water supplies with recycled water. The proposed project includes several pipeline alignments that can be seen on Figure 2 in the attached Recycled Water Feasibility Analysis. Then, in 2009, the SVCSD, as part of the North Bay Water Reuse Authority (NBWRA), prepared the North Bay Water Recycling Program EIR/Environmental Impact Statement (EIS). The 2009 EIR/EIS incorporates the 2006 EIR by reference. The North Bay Water Recycling Program EIR/EIS can be accessed here: http://www.nbwra.org/reports- documents/final-environmental-impact-report-eir-environmental-impact-statement-eis-2011/. Also in 2009, the SVCSD prepared the Recycled Water Financial/Economic Analysis that included the use of recycled water for irrigation at select City parks. The SVCSD Financial Analysis can be accessed here: https://www.sonomacity.org/documents/sonoma-valley- recycled-water-financial-economic-analysis-2009/. In 2016, the City adopted an updated Urban Water Management Plan (UWMP) to evaluate whether the City can meet the water demands of its water customers as projected over a 25- year planning horizon. The UWMP can be accessed here at the City’s website: https://www.sonomacity.org/documents/2015-urban-water-management-plan. The UWMP includes a section describing the potential recycled water uses. The plan states: “the City recognizes that recycled water will help increase the reliability of their water supply by offsetting groundwater pumping particularly in the southern end of Sonoma Valley. The City also recognizes the benefit of expanded recycled water use to offset agricultural pumping in the southern portion of the Sonoma Valley in terms of increasing the reliability of their groundwater supplies. Accordingly, the City is collaborating with the SVCSD to increase recycled water use for agricultural and other purposes that results in reduced groundwater pumping… Extension of recycled water pipelines to the City’s services area is anticipated to be a later phase of a regional project, taking time and considerable outside funding to bring a recycled water system to the City’s service area.” The UWMP includes a projected water supply of 55 acre-feet per year of recycled water, the amount expected to be used in the future at Sonoma Valley High School, Adele Harrison Middle School, and Sonoma Valley Oaks Park. The UWMD Supply and Demand Assessment states that the City’s combined projected water supplies are sufficient to meet projected demands during normal and multiple- year conditions. Construction Status of Recycled Water Infrastructure In 2012, the SVCSD completed construction of 1) a recycled water storage reservoir to the north of the SVCSD’s existing wastewater treatment facility (WWTF) located along Eighth Street East, and 2) a recycled water pipeline extending north from storage reservoir to Watmaugh Road near Shainsky Road. Then, in 2017, the SVCSD completed construction of the Fifth Street East Recycled Water Pipeline Project. The project included the construction of a recycled water pipeline that would send water from the SVCSD WWTF to Sonoma Valley High School and Adele Harrison Middle School. The recycled water is intended to help irrigate the playing fields at each school, thereby offsetting potable water used for irrigation. The pipeline route begins at Watmaugh and Shainsky roads, proceeds east to Fifth Street East, and then extends north for approximately a mile to Denmark Street. A short pipeline also extends from Denmark Street west along Engler Street, which was constructed for bringing recycled water for irrigation at the City’s Sonoma Valley Oaks Park in the future. The SVCSD also recently completed construction of a recycled water pumping and piping upgrades project at the recycled water storage reservoir. Current Recycled Water Supply Currently, approximately 50 acre-feet per year (AFY) of recycled water is available for use by the Sonoma Valley Unified School District (School District) at Sonoma Valley High School and Adele Harrison Middle School. Approximately 5 AFY is available for use by the City of Sonoma at the Sonoma Valley Oaks Park on Engler Street. None of this recycled water is currently being utilized for the reasons outlined below. Recycled water produced at the facilities maintained by the SVCSD generally meets the requirements for disinfected tertiary recycled water. However, even with the high quality of recycled water produced by SVCSD, there are many requirements for the use of recycled water for irrigation (see Appendix B [Recycled Water Use Requirements] to the attached RWFA). Because modifications are needed to comply with these requirements, recycled water is not currently being used at the schools or at the Sonoma Valley Oaks Park. A representative from the School District has stated they are currently in the process of preparing a master plan for their athletic fields, and they expect it to be several years until they are able to use recycled water for irrigation. The City would need to provide funding, prepare the design, and construct modifications to the irrigation system at the Sonoma Valley Oaks Park to start using recycled water at that location. The SVCSD also provides recycled water to a limited number of agricultural users, all of which are located at the southern end of the Sonoma Valley in the Carneros Region. The existing agricultural users are comprised of vineyards, dairies and pastureland. During May to October, the recycled water usage ranges from 1,000 to 1,200 AFY. Use of recycled water to meet agricultural water demand has the potential to offset use of private well water and local creek water. Planning to date by the SVCSD and the City has identified the potential for additional recycled water use in the City at the Plaza, Arnold Field, Depot Park, Veterans Cemetery, Field of Dreams, Armstrong Park, the Patch, and other landscaped areas within proximity to an extension of the recycled water pipeline. Irrigation demand for these areas was estimated to be between 64 AFY and 76 AFY. SVCSD has stated they could provide the City an additional amount of recycled water to meet this demand. Recycled Water Feasibility Analysis As part of the City Council’s goals in FY 15/16 and 16/17, the City Council set an initiative to explore opportunities to expand recycled water program/projects. The City retained GHD Inc. to prepare the City’s Recycled Water Feasibility Analysis (RWFA) to 1) identify a preferred alignment to extend recycled water to the northern portion of the City,