ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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implementation of this alternative,no significant water quality impacts were identified for the project;therefore, this alternative would not avoid or lessen any significant impacts.Nonetheless,because effluent constituent concentrations would be reduced compared to the project, overall impacts of this alternative on surface water quality would be less than the proposed project.[Less] Fishery Resources The existing WQCF does not comply with one objective of the 1972 "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of California,"also referred to as the Thermal Plan. While this alternative would increase the effluent discharge rate to 27 mgd,which would result in the exceedance of all three thermal plan objectives (see Section 4.13, "Fisheries and Aquatic Resources"),recommended mitigation would require the construction of cooling towers at the WQCF. The cooling towers would bring the WQCF's effluent into compliance with all three objectives of the Thermal Plan and would eliminate the WQCF's existing exceedance of one Thermal Plan objective. As such,thermal impacts to fisheries under this alternative would be similar to the project. While no significant water quality impacts were identified for the project,this alternative would result in an effluent with lower concentrations of specific constituents including TDS,metals (including aluminum), ammonia, and organic compounds, and electrical conductivity. Therefore, existing constituent-based impacts to fishery resources (although less than significant)would be reduced compared to what would occur under the project. Further,this alternative would reduce the project's cumulative contribution to constituent based impacts in the San Joaquin River and Delta. Overall, fishery impacts would be less than significant, similar to the project, but would be less than the project because of reduced constituent concentrations that would be present in the WQCF effluent.[Less] 7.3.4 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 Manteca WQCF and Collection System Master Plans EIR EDAW City of Manteca 7-11 Alternatives to the Proposed Project