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ES-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 Executive Summary 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: about 80 percent of its potable supply is purchased wholesale supply from Zone 7 Water Agency, while the City typically relies on groundwater for the remaining 20 percent of its supply. 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. 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 As of September 2022, the City had progressed its PFAS Treatment Project through 50 percent design, and the project was in its final phase of design; however, given the increasing costs of PFAS treatment, regulatory uncertainty, and long-term operational commitments, the City decided to pause and consider other water supply alternatives before proceeding with the PFAS Treatment Project. On September 6, 2022, the City Council authorized staff to suspend the PFAS Treatment Project, and in October 2022, the City Council established the Water Supply Alternatives Study (Study) as a new capital improvement project and contracted Brown and Caldwell (BC) to support City staff in conducting the Study. The Study's purpose is two-fold, including: •Identify and evaluate alternatives relative to the PFAS Treatment Project for the portion of water supply that has been obtained using the City’s GPQ of 3,500 AFY and is critical for meeting peak monthly/daily demands. •Inform the path forward, including whether the City should proceed with the PFAS Treatment Project or pursue an alternative to produce 3,500 AFY of potable water supply and meet peak monthly/daily demands.