Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN APRIL 2026 / FINAL / CAROLLO CITY OF PLEASANTON 4 Table 1 Alternative 1 City Distribution System Improvements Improvement Number(1) Type of Improvement Size (inches) Length (lf) Cost Share (City 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: lf – linear feet. (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. The City and Akel identified that a new turnout (Turnout 8) is required to connect to Zone 7’s transmission system to meet future demand conditions and provide improved reliability to existing Turnout 5. The capacity of Turnout 8 is assumed to match the capacity of Turnout 5, which is up to 7,000 gallons per minute (gpm) and would be located on City-owned property near the intersection of Vineyard Avenue and Bernal Avenue as shown in Figure 2. The turnout will be located downstream of a tee connection to Zone 7’s existing 36-inch water main in Vinyard Ave. The turnout consists of a below ground concrete vault containing a flow control valve, flow meter, check valve, and isolation valves as shown in Figure 3. This vault will be owned and operated by Zone 7, but the City is responsible for the cost of its construction. Downstream of the turnout, the water main becomes City property. The example schematic layout and configuration of the turnout, shown in Figure 3, was provided by Zone 7. Connection to the City’s distribution system will be located downstream of the turnout vault at an existing 18-inch stub out as shown in Figure 2. The turnout will also need to include fluoridation facilities owned and operated by the City. The fluoridation chemical storage and pumping equipment will be located in a concrete masonry unit building adjacent to the turnout. The property identified for Turnout 8 is currently zoned Planned Unit Development with Residential Design (residential). To construct the new turnout, the City’s planning department recommends rezoning the property to public facilities. The City has determined it is feasible to rezone the property but would require approval by the Planning Commission and City Council. The City estimates the rezoning process would require 4 months.