ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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MODIFIED PIPELINE ALIGNMENT ALTERNATIVE The proposed project would incrementally add new collection system sewer pipelines to meet the development goals adopted in the City of Manteca General Plan 2023. Building upon the existing wastewater collection system,new wastewater collection system pipelines would convey wastewater to an influent pump station at the WQCF. In addition, a new recycled water distribution system would be constructed in stages to supply recycled water citywide. Implementation of the proposed project would also result in construction of an approximately 14,000-foot 48-inch diameter outfall pipeline parallel to the existing outfall pipeline. Although proposed pipelines would mainly be constructed within developed roadways, some proposed pipeline segments would traverse sensitive biological habitats such as freshwater marsh and riparian forest habitats. This alternative would modify the pipeline alignments to avoid sensitive biological habitats wherever feasible. The proposed pipeline routes for the wastewater collection system, effluent outfall, and recycled-water distribution system cross or are located immediately adjacent to three canals that contain sensitive biological habitats (Exhibits 4.5-1,4.5-2a,4.5-2b, and 4.5-2c). The proposed wastewater collection system would cross a drainage canal north of Yosemite Avenue and west of Airport Way(Exhibit 4.5-2a). The crossing,referred to as Alignment A,is located 1,000 feet east of the confluence of the drainage canal with the French Camp Outfall Canal. Beginning at a point just west of Airport Way and north of the Southern Pacific Railroad tracks, another portion of the proposed wastewater collection system route (referred to as Alignment B)would be located within 5 feet of a drainage canal for approximately 2,000 feet(Exhibit 4.5-2b). This canal is also a tributary of the French Camp Outfall Canal and averages 20 feet wide. Water and dense freshwater marsh vegetation types are present within and along the banks of the channel. The proposed wastewater collection system also crosses the French Camp Outfall Canal south of the WQCF property and north of SR 120(Exhibit 4.5-2c). This area,referred to as Alignment C, contains water and freshwater marsh vegetation in the channel of the canal. The modified pipeline alignment alternative would alter the three pipeline alignments that cross or are located immediately adjacent to canals that contain sensitive biological habitats. At Alignment A,the alternative would realign the pipeline to the east and north of the French Camp Outfall Canal to avoid crossing the drainage canal. At Alignment B,the pipeline alignment would be realigned northeast and away from the drainage canal to avoid dense freshwater marsh habitat. Lastly,the alternative would realign Alignment C east of the drainage canal. At Alignment C,the City has determined that it is infeasible to modify the collection system alignment. The collection system pipeline alignment south of the WQCF was established considering the location and depth of the influent pump station constructed at the WQCF under the Phase III improvements project. Due to topography and long trunk sewer lengths,there is minimal flexibility in modifying the collection system pipeline route in the vicinity of freshwater marsh habitat north of SR 120 and east of McKinley Avenue without compromising the ability to convey wastewater to the influent pump station by gravity. Because of the congested core of the treatment plant site and the desire to limit construction impacts,the influent pump station was sited along the easterly boundary of the city property. Therefore, it would be infeasible to realign the collection system at Alignment C because it is essentially fixed to allow for connection to a previously constructed stub within the treatment plant core. ENVIRONMENTALLY SUPERIOR ALTERNATIVE The State CEQA Guidelines require identification of an environmentally superior alternative. If the No Project Alternative is environmentally superior,CEQA requires selection of the"environmentally superior alternative other than the no project alternative"from among the project and the alternatives evaluated. Table 2-1 identifies whether each of the three alternatives would have"greater,""less,"or"similar"impacts as the project for each of the 13 environmental issue areas evaluated in this Draft EIR. Based on the listing of lesser and greater impacts as identified in Table 2-1,the No Project Alternative would appear to be the environmentally superior alternative. The No Project Alternative would avoid the project's significant and unavoidable impacts EDAW Manteca WQCF and Collection System Master Plans EIR Executive Summary 2-4 City of Manteca