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EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN <br />APRIL 2026 / FINAL / CAROLLO <br />CITY OF PLEASANTON 15 <br />At both new wells, fluoridation and chloramination must be provided upstream of connections to the <br />City’s distribution system. As such, at Tennis Park Well and Hansen Park Well, fluoridation and <br />chloramination equipment will be housed inside a chemical building adjacent to the well buildings. Each <br />well chemical building will be approximately 20 feet wide by 42 feet long. Fluoridation equipment will be <br />separated from chloramination equipment, as required to meet safety requirements. Final sizing and <br />location for the chemical facilities will be coordinated with the City during final design. <br />Hydrofluorosilicic acid will be used for fluoridation. Sodium hypochlorite and liquid ammonium sulfate will <br />be used for chloramination. The three chemicals will be injected into the well discharge prior to <br />transmission into the City’s distribution system. Each well’s chemical building will house the following <br />process equipment: <br /> Hydrofluorosilicic acid dosing pumps. <br /> Sodium hypochlorite dosing pumps. <br /> Liquid ammonium sulfate dosing pumps. <br /> 400-gallon hydrofluorosilicic acid tank. <br /> 2,500-gallon sodium hypochlorite tank. <br /> 250-gallon liquid ammonium sulfate tank. <br />Table 6 summarizes the total project cost estimate for the City only groundwater supply improvements. <br />Details of the estimate are included in Appendix F. <br />Table 6 Alternative 3 City Only Groundwater Supply Improvements <br />Improvement Description Cost Share <br />(City Percentage) <br />Capital Cost <br />City Share ($)(1) <br />Two new groundwater supply wells (including chemical facilities) City (100%) 28,080,000 <br />Notes: <br />(1) The capital costs were estimated by Carollo as detailed in Appendix F. <br />SECTION 5 ALTERNATIVES EVALUATION <br />The purpose of this section is to evaluate and score the project alternatives based on the evaluation <br />criteria and weighting developed by Carollo and the City. <br />5.1 Evaluation Criteria and Weighting <br />Carollo and the City met on February 11, 2026, to discuss the criteria to evaluate Alternative 1, <br />Alternative 2, and Alternative 3 and weighting. The City and Carollo decided to evaluate the alternatives <br />based on the following criteria. <br />5.1.1 Water Supply Reliability <br />This criterion considers the following: <br /> The alternative's ability to deliver the City's annual GPQ (3,500 AFY) and assist in meeting max day <br />demands by providing max day supply of 4,400 gpm for both existing and future conditions.