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EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN <br />APRIL 2026 / FINAL / CAROLLO <br />CITY OF PLEASANTON 21 <br />Alternative <br />Water Supply Reliability Water Quality Reliability Ease of Expansion for Treatment Community and Environmental Impacts Implementation Schedule <br />Total <br />Score <br />Ability to deliver the <br />City's annual GPQ <br />(3,500 AFY) and assist <br />in meeting max day <br />demands by providing <br />max day supply of 4,400 <br />gpm for both existing <br />and future conditions. <br />Provide reliable water <br />supply delivery during <br />drought conditions, <br />redundancy for short- <br />term facility outages <br />(planned and <br />unplanned), ability to <br />mitigate impacts of <br />emergency outages <br />occurring at the regional <br />supply level, and reduce <br />risk of low supply <br />pressures at turnouts <br />Ability to deliver water <br />quality at or below <br />current regulatory <br />requirements <br />Flexibility in source <br />blending and locational <br />delivery to aid in the <br />City's management of <br />water quality within the <br />distribution season <br />based on seasonal <br />changes. <br />Feasibility to expand new <br />groundwater facilities for <br />the purposes of <br />additional treatment if <br />required to meet future <br />groundwater regulations <br />Availability of space, <br />ease to permit, ability to <br />operate, and cost risk. <br />Short-term impacts from <br />construction activities. <br />Impact categories <br />include aesthetics, air <br />quality, hazard materials, <br />noise, traffic, and <br />recreational use. <br />Long-term impacts from <br />new facilities park users, <br />nearby residents, and <br />the environment. Impact <br />categories include <br />aesthetics, air quality, <br />hazard materials, noise, <br />traffic, and recreational <br />use. <br />The anticipated time <br />from project approval to <br />water production. This <br />includes pre-design, <br />design, construction and <br />corresponding permitting <br />where applicable to each <br />alternative. <br />Potential for delays in <br />implementation schedule <br />and impacts to City. <br />Criteria <br />Weighting <br />5 5 3 4 3 <br /> Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale Score Rationale <br />Alternative 2 - <br />Joint Project 4 Zone 7 would be <br />contractually <br />required to <br />deliver 3500 <br />AFY and max <br />day supply of <br />4,400 gpm. Zone <br />7 would likely <br />have the <br />capacity to <br />exceed both if <br />required but <br />would not be <br />contractually <br />required to do <br />so. <br />3 Greatly <br />improves <br />reliability of <br />supply during <br />drought and <br />project has <br />redundancy for <br />short-term <br />outages. <br />However, City <br />does not <br />improve its <br />supply <br />redundancy for <br />certain regional <br />outages (i.e. <br />Zone 7 <br />transmission <br />main breaks <br />impact multiple <br />turnouts) and <br />the more <br />demand placed <br />on Zone 7 <br />system the <br />higher risk of <br />low pressure <br />issues at <br />turnouts and <br />the need for <br />booster <br />stations. <br />5 Can meet <br />current water <br />quality <br />regulations. <br />3 Provides <br />moderate <br />contractual and <br />operational <br />control over <br />source blends <br />(i.e. Zone 7 will <br />endeavor to <br />operate Project <br />facilities to <br />improve <br />groundwater <br />blends when <br />requested by <br />City but cannot <br />provide <br />guarantees and <br />reserves right to <br />provide 100% <br />surface water if <br />needed for <br />regional <br />purposes). <br />3 Treatment <br />expansion under <br />this alternative <br />would likely <br />occur at Zone 7’s <br />Hopyard <br />Chloramination <br />Facility. <br />4 Moderate risk <br />to availability of <br />space since <br />Zone 7 <br />Hopyard <br />Chloramination <br />facility does <br />have space to <br />expand on site <br />and there is a <br />potential to <br />utilize adjacent <br />City owned <br />parcel. As a <br />result, this <br />alternative also <br />has moderate <br />risk on ease to <br />permit and <br />costs. There is <br />little risk of <br />Zone 7 ability to <br />operate as <br />Zone 7 <br />currently has <br />experience/certi <br />fications to <br />operate most <br />treatment <br />technologies <br />likely needed <br />for future <br />regulations. <br />2 Project requires <br />construction of <br />groundwater <br />supply <br />improvements at <br />parks and Zone <br />7 Hopyard facility <br />that will have <br />moderate to <br />significant <br />impacts requiring <br />mitigation <br />measures. <br />Project also <br />requires <br />construction of <br />City distribution <br />improvements <br />primarily in right <br />of way with <br />moderate <br />impacts requiring <br />mitigation <br />measures. <br />3 Project requires <br />new permanent <br />facilities in parks <br />(no chemical <br />storage) and <br />upgrade of Zone <br />7 hopyard facility <br />(expansion of <br />chemical <br />facilities) <br />representing <br />moderate <br />impacts. Project <br />also requires <br />City construction <br />of new turnout <br />facility building <br />(with chemical <br />storage) on City <br />owned parcel <br />with moderate <br />impacts. <br />2 Implementation <br />schedule for joint <br />groundwater <br />supply <br />improvements <br />and City <br />distribution <br />improvements is <br />approximately <br />3.5 years. <br />2 Joint <br />groundwater <br />improvements <br />represents <br />moderate to high <br />potential for <br />delays due to <br />unknowns <br />associated with <br />well drilling and <br />since significant <br />permitting is <br />required. <br />Additionally, <br />Zone 7 is lead <br />agency and <br />therefore City <br />cannot manage <br />delay risk as <br />effectively. <br />Impacts of <br />delays to City is <br />high as interim <br />supply of GPQ is <br />provided by <br />Zone 7 at <br />wholesale rate. <br /> <br />City distribution <br />improvements <br />represent <br />moderate <br />potential for <br />delay and <br />impacts are low. <br />64.0