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FINAL DRAFT PRELIMINARY REPORT (Connections to EOCF #2) For the purpose of this study, we have assumed that the operable wells will have a typical production rate of 70% during the winter months (November through April) and 90% during the summer months (May through October). The following Table 2.2 summarizes the City of Orange demands and potential available excess groundwater. Table 2.2 City of Orange Summary of Demands and Potential Available Excess Groundwater Winter Months (Average) Summer Months (Average) Total Annual Demands (3-year Historical Average) City System Demands 678 MG 905 MG 9,496 MG Import Water 130 MG 232 MG 2,175 MG Groundwater Production 548 MG 673 MG 7,321 MG Basin Production Percentage 81% 74% 77% Typical Wells Operating (Potential Wells Available for Excess Groundwater) Historical Operation 8 wells operating (3 wells available) 7 wells operating (4 wells available) 8 wells operating (3 wells available) Assuming No Import Water 10 wells operating (1 well available) 10 wells operating (1 well available) 10 wells operating (1 well available) Note: Above table does not include the future wells (Well No. 28 and Well No. 29) In summary, the City of Orange may have one well or at most two wells capacity (if all of their wells are operable and in service and import water is available at their OC-67 and OC-69 MWD connections) that could be available to convey groundwater per the Emergency Services Program. The quantity of water will depend on the City's distribution system and corresponding facilities at the specific location of the proposed source connection. The potential available groundwater water will be summarized in Section 4. 2.4 City of Tustin The City of Tustin owns 11 groundwater wells but only have a total of eight (8) groundwater wells that are currently active and three (3) import water connections from East Orange County Water District (EOCWD). Two (2) of the City's wells currently are not active since their treatment system (RO) is not operable. The City is concerned that five (5) additional wells may be impacted in the near term by PFAS and will either need PFAS treatment facilities or blending facilities before they could be brought back online. If these five (5) wells are shut down, the City will lose approximately 50 percent of its total groundwater well capacity. The City of Tustin purchases it's imported water from the EOCWD. OC-43 and OC-48 are connected to the East Orange County Feeder No. 2. OC-60 is connected to the Allen-McColloch Pipeline. Table A-3 (within Appendix A), summarizes the eight (8) wells that had operated during the three-year historical period. During the three-year historical period, the City has pumped on an average 77% of its water demand from the groundwater basin. The City is currently planning (in two to three years) a new well to replace the existing Beneta Well. For the purpose of this study, we have assumed that the operable wells will have a typical production rate of 70% during the winter months (November through April) and 90% during the summer months (May through October). Orange 9t9%9 1District/Moulton Niguel Water District 30 — 17 5/17/2 A TECH Evaluation of Groundwater Conveyance Options