Laserfiche WebLink
EVALUATION OF GROUNDWATER SUPPLY ALTERNATIVES WITHIN BERNAL SUBBASIN <br />APRIL 2026 / FINAL / CAROLLO <br />CITY OF PLEASANTON 22 <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 3 - <br />City Only Project 5 Can deliver <br />greater than <br />3500 AFY and <br />max day supply <br />of 4,400 gpm if <br />required based <br />on operation of <br />both wells. <br />4 Greatly <br />improves <br />reliable supply <br />during drought, <br />two well <br />facilities <br />provides <br />redundancy for <br />short-term <br />outages, <br />separate <br />source from <br />Zone 7 <br />provides some <br />redundancy for <br />regional <br />outages <br />(although <br />limited), and <br />less demand <br />placed on Zone <br />7 system <br />reduces the risk <br />of 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 />5 Provides City <br />maximum control <br />of source water <br />blending as City <br />owns and <br />operates <br />groundwater <br />wells directly into <br />distribution <br />system. <br />2 Treatment <br />expansion under <br />this alternative <br />may occur at the <br />park locations <br />but there is a risk <br />that off-site <br />location would <br />be required due <br />to impacts to <br />park being too <br />great. <br />2 City park sites <br />do have space <br />for expansion <br />but availability <br />to use is at a <br />high risk do to <br />significant <br />impacts to park <br />use. Park use <br />or off-site use <br />poses a higher <br />risk on ease to <br />permit and cost. <br />Ability to <br />operate poses <br />a moderate risk <br />as treatment <br />technologies for <br />future <br />regulations may <br />require change <br />to City’s <br />operational <br />certifications. <br />2 Project requires <br />construction of <br />groundwater <br />supply <br />improvements at <br />parks that will <br />have moderate <br />to 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 />2 Project requires <br />new permanent <br />facilities only in <br />parks (but with <br />chemical <br />storage) <br />representing <br />moderate to <br />significant <br />impacts. <br />1 Implementation <br />schedule for City <br />groundwater <br />supply <br />improvements <br />and distribution <br />improvements is <br />approximately <br />3.5 to 4 years <br />(accounts for <br />longer predesign <br />and permitting <br />time needed). <br />2 City <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 />However, City is <br />lead agency and <br />therefore can <br />directly manage <br />schedule risk. <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 />66.0 <br />