Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN APRIL 2026 / FINAL / CAROLLO CITY OF PLEASANTON 11 Table 4 Alternative 2 Joint Groundwater Supply Improvements Improvement Description(1) Capital Cost, Total Project ($)(2) Cost Share (City Percentage) Capital Cost, City Share ($) Two new groundwater supply wells, transmission pipeline from the wells to the Hopyard Chloramination Facility, and upgrade of the Hopyard Chloramination Facility 42,100,000(3) City (36%) 15,156,000 Notes: (1) The information presented in this table is from the Regional Groundwater Facilities Feasibility Study prepared by LSCE and Carollo in December 2025. (2) Costs provided in the Regional Groundwater Facilities Feasibility Study are from May 2025. According to Engineering News Record’s 20-City Cost Index, market escalation from May 2025 to January 2026 is 2 percent. The costs provided in this table are escalated to 2026 dollars and rounded to the nearest ten thousandth place. (3) Total project capital cost is lower than the total estimated project cost presented in the Regional Groundwater Facilities Feasibility Study ($42,308,000), prepared by LSCE because the actual market escalation was less than the escalation rate used when the Feasibility Study was prepared. SECTION 4 ALTERNATIVE 3 – CITY ONLY PROJECT 4.1 Project Overview Alternative 3 assumes the City will construct, own and operate two new groundwater wells located at Hansen Park and Tennis Park with new chloramination and fluoridation facilities at each site. In addition, City distribution system improvements are required to convey water from the wells to customers. For this alternative, the City will produce and manage its GPQ independently of Zone 7, assuming full responsibility for capital costs, operations, and long-term maintenance of all facilities. Figure 7 provides an overview of improvements in this alternative.