Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

REGIONAL GROUNDWATER FACILITIES PROJECT FEASIBILITY STUDY 30 Zone 7 Water Agency December, 2025 5. RECOMMENDED PROJECT AND NEXT STEPS Based on the evaluation of project alternatives, Alternative 2 (Tennis and Hansen Wells) is identified as the recommended project. Of the alternatives that passed the pass/fail criteria for minimum drought year water production capacity, this alternative ranked highest following the scoring process. LSCE understands that this regional groundwater project is being considered as a joint effort between the City and Zone 7, reflecting the regional nature of groundwater planning and operations. It is important to note that well production capacity and annual project yield presented herein are preliminary estimates based on test well data and will need to be refined and confirmed upon installation and testing of the full- scale production wells. Design-bid-build (DBB) is assumed to be the primary project delivery method given both agencies’ familiarity and experience with this approach. However, design-build (DB) may also be considered if the agencies determine that early cost certainty or schedule acceleration is desirable. LSCE assumes the City and Zone 7 will coordinate the preferred delivery method prior to initiation of the detailed design effort. Implementation of Alternative 2 is anticipated to require approximately three to four years from completion of the 10 percent design phase through construction and startup. Figure 12 illustrates the anticipated project schedule, assuming a DBB delivery approach with drilling and civil improvement work implemented as separate, phased efforts. Key components of Phase II include:  Advancing the conceptual design from the 10% design level by further gathering additional City and Zone 7 input to define specific well station layouts, pipeline alignments, and integration with existing Zone 7 facilities.  Progressing through phased design (e.g., 30%, 60%, 90%, Final) for the production wells, pipelines, well station facilities, and related HCF upgrades.  Securing necessary permits and approvals, including but not limited to California Environmental Quality Act (CEQA) compliance, well drilling permits, utility service applications, and stormwater and air quality permits. To prevent schedule delays, particularly those affecting the start of well drilling, it is assumed that Zone 7 will lead CEQA compliance efforts and initiate related work early, potentially prior to formal selection of the design consultant, as this activity is on the project’s critical path.  Procuring drilling and general civil contractors through a competitive bid process under the selected project delivery method (e.g., design-build or design-bid-build). Construction of the wells is expected to proceed separately and in advance of DWSRF funding approval, which would be secured for the well pump station, pipeline, and HCF improvements.  Constructing, equipping, and commissioning the Tennis and Hansen production wells, associated station facilities, HCF upgrades, and transmission pipelines connecting the new wells with the HCF.  Off-site distribution system improvements downstream of the HCF that may be triggered by the increased capacity resulting from this Project are not included with Phase II but are being