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1-1 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Water Supply Alternatives Study-Draft Report.docx Section 1 Introduction The City of Pleasanton (City) is a water retailer, meaning it sells water directly to individual water users. The City receives its potable water (i.e., drinking water) supply from two sources: •Wholesale water purchases from Zone 7 Water Agency (Zone 7). Zone 7 treated water purchases have typically accounted for approximately 11,000 acre-feet/year (AFY), which is about 80 percent of the City’s potable (i.e., drinking) water supply. Zone 7 also sells treated water supply to three other retailers: California Water Service, City of Livermore, and Dublin San Ramon Services District (DSRSD). •Local groundwater. Groundwater has typically been about 20 percent of the City’s potable water supply. Groundwater use is limited by the City’s groundwater pumping quota (GPQ) of 3,500 AFY. Until recently, the City has pumped groundwater from three wells that the City owns and operates (Well 5, Well 6, and Well 8) to meet peak demands and provide redundancy in the City’s water system. The City owns and operates facilities to store and deliver potable water to its residents and commercial customers, as well as approximately 250 customers in unincorporated Alameda County. The City also owns and operates a separate storage and pipeline system for recycled water. Recycled water is highly treated wastewater that can be used for non-potable purposes. The City delivers recycled water to a portion of customers within its service area, mainly for landscape irrigation. Recycled water deliveries are approximately 1,200 AFY. 1.1 Background Per- and polyfluoroalkyl substances (PFAS) in drinking water is a serious national issue. Also found in non-stick cookware, firefighting foam, water resistant materials, and many other products, PFAS have leached into the region’s groundwater for more than half a century, and new regulatory requirements are forcing the City to either build a treatment system or remove the wells from service (City of Pleasanton, 2019). In the meantime, the City has decided to shut off its wells and authorized use of Wells 5 and 6 only on an emergency basis. Zone 7 has agreed to supply Pleasanton with additional water, as available in the interim; however, the ability of Zone 7 to meet Pleasanton’s long-term demands is uncertain. Starting in September 2020, the City initiated the PFAS Treatment and Wells Rehabilitation Project (PFAS Treatment Project) with the goal of extending the life of existing groundwater facilities and providing PFAS treatment. The scope of the PFAS Treatment Project includes: •Replacing Well 5 with a new Well 9 at Amador Park •Rehabilitating Well 6 (renamed as Well 10) •Rehabilitating Well 8 •Constructing and operating a new centralized treatment facility for PFAS treatment, disinfection, and fluoridation •Constructing a new raw water transmission pipeline and improving treated water distribution piping