Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN APRIL 2026 / FINAL / CAROLLO CITY OF PLEASANTON 6 booster pump station will be implemented as a future project only if needed, the cost analysis presented herein does not include the booster pump station. Figure 3 Example Turnout Schematic (provided by Zone 7) 2.3 Estimate of Cost to Purchase GPQ from Zone 7 Although no new water supply facilities are to be constructed by the City under this alternative, significant annual costs for the purchase of additional Zone 7 water supply at the whole sale rate are required to offset the GPQ loss. The City provided a letter from Zone 7 dated October 16, 2025, that summarizes the wholesale rates for the City to purchase water from Zone 7 in calendar year 2026. The cost of purchasing water from Zone 7 consists of two separate charges: fixed and volume-based rate. The fixed charge is based on a two-year rolling average of the City’s water use proportional to the total water use by retailers/customers who purchase water from Zone 7. In this alternative, where the City offsets its GPQ with additional Zone 7 wholesale purchases, the rolling average of use by the City is higher thus creating a higher proportional use fixed charge. The annual fixed cost shown in Table 2 reflects the “increase” in fixed charges under this alternative. The volume-based rate charge shown in Table 2 is the product of a unit cost of $2.47 per centum cubic foot and the GPQ water volume. Table 2 2026 Cost for City to Purchase GPQ of 3,500 AFY from Zone 7 Charge Type Cost ($) Annual Variable 3,765,762 Annual Fixed Increase 2,252,693 Total Annual 6,018,455