Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN APRIL 2026 / FINAL / CAROLLO CITY OF PLEASANTON 9 Table 3 Alternative 2 City Distribution System Improvements Improvement Number(1) Type of Improvement Size (inches) Length (lf) Cost Share (Percentage) Capital Cost, City Share ($)(2) TO-8 Turnout N/A N/A City (100%) 4,270,000(3) F-1 Pipe 24 5,250 City (100%) 3,810,000 F-2 Pipe 24 310 City (100%) 220,000 F-6 Pipe 16 3,800 City (100%) 2,090,000 F-7 Pipe 16 3,450 City (100%) 1,900,000 Notes: (1) The information presented in this table is from Akel’s Hydraulic Analysis Results Package No. 1 (Revised) (Akel, November 2025). (2) Costs provided in Akel’s Hydraulic Analysis Results Package No. 1 are from April 2023. According to Engineering News Record’s 20-City Cost Index, market escalation from April 2023 to January 2026 is 6.6 percent. The costs provided in this table are escalated to 2026 dollars and rounded to the nearest ten thousand. (3) The capital cost for TO-8 was estimated by Carollo as detailed in Appendix B and supersedes costs provided by Akel. 3.2.2 Joint Groundwater Supply Improvements The joint groundwater supply improvements include new groundwater production wells located at Tennis Park (5801 Valley Ave, Pleasanton, CA) and Hansen Park (5697 Black Ave, Pleasanton, CA), a transmission pipeline from the wells to the Hopyard Chloramination Facility, and improvements to the Hopyard Chloramination Facility to increase Chloramination capacity. As shown in Figure 5, Zone 7 and the City are considering two locations for the new well facilities within both Tennis Park and Hansen Park sites and will continue to evaluate the locations within both parks during final design. Selection of the well facility location will consider routine site access, special operations and maintenance (O&M) access (i.e., portable generators, equipment removal with cranes), storm drain capacity for pump-to-waste operation, ease of Pacific Gas and Electric (PG&E) service, and noise ordinance (construction and operation). In addition, architecture and landscaping requirements at both well facilities will be coordinated during final design to minimize visual impacts to park users and nearby residents. The well building facilities at both Tennis Park and Hansen Park will have an approximate footprint of 40 feet by 43 feet (1,720 square feet) and an approximate height of 25 feet. Equipment contained in each well building will include the following:  Wellhead and associated accessories.  Well pump and associated piping and appurtenances.  Water sampling station.  4160 volts medium voltage switchgear with integral transformer.  800 horsepower variable frequency drive.  Low voltage panelboards and transformer. As shown in Figure 5, most of the transmission pipeline is planned to be installed in Hopyard Road with a portion in Hansen Drive. The pipeline alignment was identified as the preferred alignment by the City during a meeting held on July 31, 2025. Approximately 2,920 lf of the transmission main is in