Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

REGIONAL GROUNDWATER FACILITIES PROJECT FEASIBILITY STUDY 24 Zone 7 Water Agency December, 2025 8. Operations & Maintenance Cost O&M cost compares the relative effort and expense required to operate and maintain the facilities, referencing estimates presented in Section 3. Costs include power, staffing, treatment requirements, routine maintenance, and eventual well rehabilitation. Alternatives with limited treatment needs, fewer facilities, and reduced community interface generally score higher, while those with multiple wells, greater treatment potential, or higher community-facing obligations (e.g., landscaping, noise control) score lower. 4.1.2. Weighting Criteria The six weighted evaluation criteria were assigned percentage values agreed upon by Zone 7 and the City to reflect their relative importance in selecting a preferred project. The final weighting framework is summarized in Table 6 below along with a concise description of the evaluation criteria. Table 6. Project Alternative Weighting Criteria Project Alternative Evaluation Criteria (Scoring Weight) Evaluation Criteria Summary Weighting Water Production Capacity Ability to satisfy Zone 7’s drought-year target of 7,000 AFY, which includes the City’s GPQ of 3,500 AFY. Zone 7 applies a 75% reliability factor (limiting average annual runtime to 18 hr/day; up to 24 hr/day during summer months). Pass/Fail Groundwater Basin Sustainability Conformance to Zone 7’s Livermore Valley Alternative Groundwater Sustainability Plan. Alternatives must not cause undesirable results such as chronic lowering of groundwater levels or degradation of water quality. Pass/Fail Community & Environmental Impacts Proximity to residential areas and sensitive receptors, and the anticipated level of public concern or required outreach. Alternatives with fewer short-term and long- term community/environmental effects are more favorable. 10% Capital Cost Relative initial investment required, including wells, pipelines, treatment, electrical, and sitework. Alternatives are compared qualitatively; lower-cost options are more favorable. 25% Water Quality / Treatment Impacts Alternatives located nearer to the PFAS footprint carry higher long-term treatment risk; those farther away are more favorable. 10% Implementation Schedule Expected timeframe from project approval to water delivery, including planning, permitting, construction, and startup. Shorter-duration or more easily phased alternatives are more favorable. 15%