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2-1 <br />DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. <br />Water Supply Alternatives Study-Draft Report.docx <br />Section 2 <br />Water Supply Options and <br />Alternatives <br />This section describes the approach for developing and screening potential water supply options to <br />result in a shortlist of alternatives for further evaluation. <br />2.1 Options Development and Initial Screening <br />BC worked closely with City staff to develop an inclusive list of potential water supply options. <br />Table 2-1 summarizes the list of options considered. <br />Table 2-1. Potential Water Supply Options for Screening <br />Category Option Description <br />Baseline <br />Project <br />PFAS Treatment and Wells 5, 6, & 8 <br />Rehabilitation Project <br />Design and construct a centralized PFAS treatment facility and rehabilitate the City’s <br />three existing wells. City Council suspended the baseline project on September 6, 2022, <br />to further evaluate water supply alternatives. <br />Modified PFAS Treatment (Well 8)Similar to the Baseline Project but involves adding PFAS treatment to Well 8 only (and <br />not Wells 5 and 6). <br />New City well(s) outside PFAS plume <br />(west part of the City)City-owned well(s), with or without treatment for other constituents (non-PFAS). <br />Zone 7 pump on City’s behalf a, b Zone 7 to pump from new well(s) outside PFAS plume (with or without treatment for other <br />constituents [non-PFAS]) <br />Regional PFAS Treatment Facility (at <br />Pleasanton’s Operations Services <br />Center) a, c <br />New facility constructed by Pleasanton (or jointly constructed by Pleasanton/Zone 7) and <br />operated and maintained by Zone 7 to produce regional water supply, including <br />Pleasanton’s GPQ. <br />Groundwater <br />Supply <br />Options <br />Blending/Dilution Blend existing well supply with water from Zone 7 to reduce PFAS concentration below <br />future maximum contaminant levels or lower, if possible. <br />100% purchases from Zone 7a Agnostic of source (i.e., assumed to include some combination of supply from the State <br />Water Project, groundwater, and future additions to Zone 7’s supply portfolio). <br />Purchases from another agency <br />Either wheeled through Zone 7’s system or direct connection to a wholesaler (e.g., San <br />Francisco Public Utilities Commission) or another retail water supplier (e.g., East Bay <br />Municipal Utility District). <br />Other Supply <br />Sources <br />Local alternative supplies Includes options such as desalination, stormwater capture, and/or satellite wastewater <br />treatment. <br />Expansion of non-potable system <br />Expand non-potable supply beyond what is already projected in the City’s 2020 Urban <br />Water Management Plan (~500 AFY), using recycled water and/or non-potable <br />groundwater.Demand <br />Management Long-term water use efficiency <br />(WUE) <br />Invest in permanent demand reduction measures (e.g., turf replacement), beyond <br />existing/planned WUE including state requirements to meet new standards-based water <br />use objectivesd. Does not include short-term conservation (i.e., behavioral changes). <br />a. Water supply options/alternatives involving Zone 7 require approval from Zone 7’s Board of Directors. <br />b. Zone 7 staff confirmed that existing infrastructure does not have adequate capacity to pump groundwater on the City’s behalf. <br />c. Zone 7 staff confirmed that expanding PFAS treatment at its Chain of Lakes or Stoneridge sites is not feasible. <br />d. New state requirements for WUE are established under 2018 water conservation legislation, including Assembly Bill 1668 (Friedman) <br />and Senate Bill 606 (Hertzberg).