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Section 2: Water Supply Options and Alternatives Water Supply Alternatives Study 2-7 DRAFT for review purposes only. Use of contents on this sheet is subject to the limitations specified at the end of this document. Water Supply Alternatives Study-Draft Report.docx Alternative 4 involves purchasing 100 percent of the City’s supply from Zone 7, regardless of the supply source (i.e., assumed to include some combination of supply from the State Water Project, groundwater, and future additions to Zone 7’s supply portfolio). This alternative would require confirmation from Zone 7 regarding agreement terms for Pleasanton’s purchase of an additional 3,500 AFY of supply, including: •Delivery confirmation: either year to year, which is the current interim solution, or longer term, which would require an agreement between the City and Zone 7 similar to the “June 2000 Agreement to Construct and Operate a Municipal Well on the Camp Parks Well Site between DSRSD and Zone 7” and would need to replace the supply from the City’s wells while committing to meet peak month and peak day demands (Figure 2-4) •Cost basis: anticipated to be a variable wholesale rate with an increase to the City’s fixed cost, based on a rolling average of the City’s water deliveries from Zone 7 over the previous 2 years •Potential concession for the City not using its GPQ Zone 7 staff have stated that they do not have redundant capacity within their system to pump the City’s GPQ over the long term, which may require capital improvements to secure the 3,500 AF in the same manner as is being considered in the other alternatives. This could increase the cost of Alternative 4, as these costs would likely be passed on directly to the City to avoid redirected impacts on other Zone 7 retailers. However, for this analysis, any City-specific capital improvements by Zone 7 have been excluded since they are not yet well-defined. Further, of the four shortlisted alternatives, Alternative 4 requires the most extensive infrastructure improvements, including more improvements to treated water distribution piping, a larger booster pump station at Zone 7’s Turnout 4 designed at 7,000 gpm capacity, and a new turnout from Zone 7 (Appendix E). As noted in the City’s 2020 Urban Water Management Plan (West Yost, 2021): “The City’s water supplies consist of purchases from Zone 7 (approximately 80 percent of supply in 2020) and groundwater pumped by the City (approximately 20 percent of supply in 2020). Of Zone 7’s supplies, imported water from the State Water Project makes up approximately 80 percent, with the remainder coming from groundwater and local surface water. The future reliability of Zone 7’s imported water is a concern. Drought, sea level rise, and natural disasters threaten the Sacramento-San Joaquin Delta (Delta), a critical component of the delivery system bringing water to Zone 7. As a result, Zone 7 is participating in various projects that would provide alternate water supplies or protect the existing delivery system against threats. These projects include installing a pipeline system beneath the Delta, desalinating brackish water (water with high salt content), reusing highly treated wastewater, and participating in the construction of a new reservoir to store surplus water in wet years.”