ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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Joaquin River. On-site land application would involve the disposal of approximately 0.73 mgd of wastewater on 190 acres of City-owned land.Urban landscape irrigation would involve the discharge of approximately 3.28 mgd of wastewater to 817 acres of irrigable City-owned urban land including parks, schools, cemeteries, and golf courses. All other treated effluent(22.99 mgd)would be pumped through the existing outfall pipe and a newly constructed outfall pipe to the San Joaquin River. Table 1 summarizes proposed treated effluent disposal methods for the WQCF at plant buildout: Table 1 Treated Effluent Disposal Methods at Buildout Disposal Option Average Discharge Rate, mgd Percentage of Total Discharge On-Site Land Application 0.73 3% San Joaquin River Discharge 22.99 85% Urban Landscape Irrigation 3.28 12% Total 27.00 100% Source: Nolte Associates,Inc.2005. 3.3 PROPOSED TRUNK SEWERS The proposed project would incrementally add new trunk sewer segments to meet the development goals adopted in the City of Manteca General Plan 2023. Building upon the existing collection system, a gravity trunk sewer collection system would convey wastewater to an influent pump station located at the WQCF. As shown on Exhibit 3,the proposed project would construct three large diameter trunk sewers to collect wastewater from the north, central, and south sections of the City. The north and south trunk sewers would collect flow from areas where future growth is expected,while the central trunk sewer would connect the existing collection system to the north trunk sewer. The proposed north trunk sewer would include thirty 10-to 60-inch diameter sewer segments measuring 44,219 feet(approximately 8.4 miles),while the south trunk sewer would include forty-six 15-to 60-inch diameter sewer segments measuring 63,561 feet(approximately 12 miles). Measuring 4,522 feet(approximately 0.9 mile),the central trunk sewer would include twelve 36-inch diameter sewer segments, and would eliminate the need for the existing Union Road pump station. 3.4 EXISTING COLLECTION SYSTEM IMPROVEMENTS The proposed project also includes several minor improvements to existing sewer lines. Hydraulic modeling and a review of historical records found no major deficiencies in the existing collection system;however, several minor problems were identified including pipeline obstructions and miscellaneous flow problems. To address these problems,the proposed project includes a total of 11 collection system improvement projects such as manhole rehabilitations and eliminating pipeline sags throughout the City. These improvements would generally be located within the existing collection system network. City of Manteca WQCF and Collection System Master Plan 2005 Update May 2006 7 Notice of Preparation