8653 Calaveras Road

8653 Calaveras Road

Project Title: Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir (Sunol Valley Water Treatment Plant Ozonation Facility and Other Site Improvements Project) On December 3, 2009, the San Francisco Planning Commission (SFPUC) certified the Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir Final Environmental Impact Report (EIR), and the SFPUC subsequently approved the project (San Francisco Planning Department file number 2006.0137E). The approved project analyzed in the EIR includes the construction and operation of a new treated water reservoir, a new chlorine contact tank and associated water treatment facilities, an additional flocculation and sedimentation basin, new effluent pipelines, and a new 78 inch pipeline connecting the treated water reservoir to the existing 78 inch plant discharge pipeline, which transports water from the Sunol Valley Water Treatment Plant (the plant) to the existing Alameda Siphons (where treated water enters the water transmission system). The plant occupies 28 acres in unincorporated Alameda County, approximately 3 miles south of the intersection of Calaveras Road and Interstate 680. Following implementation of the approved project, the plant is currently developed with approximately 30 buildings and structures, including an operations building and various water treatment facilities such as water and chemical storage tanks, flocculation and sedimentation basins, and filter bays. The SFPUC proposes to modify the approved Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir project to construct a new ozonation facility and a new polymer feed facility at the plant, and to conduct repairs and improvements to existing treatment facilities at the plant. SFPUC also proposes electrical equipment upgrades at facilities that deliver power to the treatment plant to ensure that operation of the ozonation facility does not cause overloads on the Calaveras Substation main transformer, approximately 2 miles north of the plant. The proposed new ozonation facility, new polymer feed facility, upgrades to existing plant treatment facilities, and electrical upgrades constitute the modified project. The purpose of the modified project is to ensure reliable operation of the treatment plant and to meet customer expectations regarding water quality. The proposed ozonation facility is designed to reduce the concentration of taste-and-odor-causing compounds in the plant’s raw water. The proposed polymer (flocculation aid) feed facility is designed to address turbidity issues during high flow rates at each of the five existing sedimentation basins at the plant. Other proposed repairs and improvements to existing treatment facilities at the plant include repairing the lining of the flocculation and sedimentation basins, replacing the cationic polymer (coagulant aid) system, and replacing the filter inlet and waste valves. Electrical upgrades are proposed at the plant and at a former tree nursery site and the San Antonio Pump Station, approximately 0.2 mile and 1.5 miles north of the plant, respectively. SFPUC also proposes to use the former tree nursery site for construction staging. The plant, former tree nursery site, and San Antonio Pump Station compose the modified project site.

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Alameda, San Francisco