Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

REGIONAL GROUNDWATER FACILITIES PROJECT FEASIBILITY STUDY 12 Zone 7 Water Agency December, 2025 sites to the HCF. The park is large, with tennis and basketball courts providing well pump station siting flexibility. Two potential well and pump station siting concepts within the park were identified, including locations near Valley Avenue and Hopyard Road and alternative locations accessed from existing parking areas, each offering different tradeoffs related to visual impacts, proximity to residences, and pipeline connection locations. Tennis Park also demonstrated the highest estimated yields from aquifer testing. Alternative 1 consists of one well at Tennis Park, with raw water conveyed to the HCF for chloramination via approximately 1,400 lineal feet (LF) of 18-inch diameter pipeline. While it is the lowest-cost alternative, it cannot meet Zone 7’s 7,000 AFY drought-year production target on its own. The proposed well pump station location (with an estimated well pump motor size requirement of 700 hp) and associated pipeline alignment are shown in Figure 4. 3.2.2. Alternative 2 – Tennis and Hansen Park Wells Hansen Park is located along Hansen Drive. Two potential well and pump station siting concepts were identified within the park. These siting concepts were evaluated to minimize impacts on park use while maintaining efficient pipeline routing to the HCF. Paired with the Tennis Park well, this alternative provides the two highest-yielding wells and maximizes production potential from the evaluated sites. Alternative 2 consists of one well at Tennis Park and one well at Hansen Park, each with an estimated well pump motor size requirement of approximately 700 horsepower. Raw water from the Hansen Park well would be conveyed via approximately 2,500 lineal feet of 16-inch diameter pipeline along Hansen Drive and Hopyard Road to the Tennis Park site, where flows would be combined. From there, approximately 1,500 lineal feet of 24-inch-diameter pipeline along Hopyard Road would convey combined flows from both well sites to the HCF for chloramination. The conceptual well pump station locations and associated pipeline alignments are shown in Figure 5. 3.2.3. Alternative 3 – Tennis and Del Prado Park Wells Alternative 3 consists of one well at Tennis Park and one at Del Prado Park (also located along Hansen Drive). The Hansen Drive frontage is the preferred location for production well placement, as it offers straightforward pipeline routing to the HCF and flexibility in siting the permanent well. When paired with Tennis Park, Del Prado Park represents the two wells furthest west of the known PFAS footprint, thereby minimizing potential for future PFAS treatment needs, although Del Prado (with an estimated 250 hp well pump motor size requirement) has lower yields than Hansen. The proposed well pump station locations and associated pipeline alignment (approximately 6,100 LF of up to 24-inch diameter pipe) are shown in Figure 6. 3.2.4. Alternative 4 – Tennis, Hansen, and Del Prado Park Wells This configuration includes wells at all three candidate sites: Tennis Park, Hansen Park, and Del Prado Park. It provides the maximum total pumping capacity along with enhanced operational flexibility, redundancy, and long-term resilience. Alternative 4 has the highest capital cost and the largest community footprint but offers the broadest set of benefits from a supply and operations standpoint. The proposed well pump station locations and associated pipeline alignments (approximately 7,500 LF up to 30-inch diameter pipe) are shown in Figure 7.