ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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generation;recreation; aesthetic enjoyment;navigation; and preservation and enhancement of fish,wildlife, and other aquatic resources or preserves"(Water Code Section 13050[f]). Additional protected beneficial uses of the San Joaquin River include groundwater recharge and freshwater replenishment. The Basin Plan contains specific narrative and numeric water quality objectives for a number of physical properties(e.g.,temperature,turbidity, and suspended solids),biological constituents (e.g., coliform bacteria), and chemical constituents of concern, including inorganic parameters,trace metals, and organic compounds.Water quality objectives for toxic priority pollutants(i.e., select trace metals and synthetic organic compounds)are included in the Basin Plan and the California Toxics Rule(CTR)that was adopted in May 2000. 1995 Bay-Delta Water Quality Control Plan The proposed project is within the legal boundary of the San Francisco Bay/Sacramento—San Joaquin Delta (Delta). The Central Valley Project(CVP) and State Water Project(SWP)are currently responsible for maintaining water quality in the Delta to standards established by the SWRCB as stipulated in the 1995 Bay-Delta Water Quality Control Plan(Bay-Delta Plan) (SWRCB 1995). This plan supersedes both the Water Quality Control Plan for the Delta and Suisun Marsh, adopted August 1978 and the Water Quality Control Plan for Salinity for the San Francisco Bay/Sacramento—San Joaquin Delta, adopted May 1991. As with other State water quality control plans,the Bay-Delta Water Quality Control Plan identifies the beneficial uses to be protected,the water quality objectives for reasonable protection of the beneficial uses, and a program of implementation for achieving the water quality objectives. Among the various criteria described in the Bay-Delta Plan are specific numeric standards for Delta inflow and outflow chloride, and electrical conductivity(EC) at various locations in the Delta(Table 4.9-8),numeric objectives for other water quality constituents,numeric operational constraints for the CVP and SWP, a narrative objective to protect salmon, and a narrative objective to protect brackish tidal marshes in Suisun Marsh. EC standards in the Delta exist for agricultural, fish, and wildlife beneficial uses. EC is a measure of water's ability to conduct an electric current, and is an indirect measure of the concentration of dissolved salts in water. The Bay-Delta Plan is the substantive regulatory authority over Delta hydrologic conditions. Compliance with the standards is maintained, in part,by regulating the releases from CVP and SWP reservoirs upstream of the Delta. During certain months of certain years, a major portion of inflow to the Delta is affected by CVP and SWP regulation. Table 4.9-8 Sacramento San Joaquin Delta Water Quality Control Plan Standards for Delta Inflow and Outflow, Chloride, and Electrical Conductivity. Location Parameter Standard Description Contra Costa Canal at Pumping Planta Maximum mean daily< 150 mg/1 Cl-for at #1 Chloride(Cl-) 240 days least the number of days shown during the calendar year Contra Costa Canal at Pumping Plant Chloride(Cl-) 250 mg/l Maximum mean daily(mg/1) #1 Sacramento River at Emmaton Electrical 0.45 EC b Maximum 14-day running average of mean Conductivity(EC) daily EC(mmhos/cm)Apr 1 through Aug 15 West Canal at mouth of Clifton Court Electrical Maximum monthly average of mean daily Forebay and Delta Mendota Canal at Conductivity(EC) 1.00 EC EC(mmhos/cm) Tracy Pumping Plant Sacramento River at Collinsville Electrical 8.00 EC c Maximum monthly average of both daily Conductivity(EC) high tide EC values(mmhos/cm) EDAW DER Hydrology and Water Quality 4.9-18 City of Manteca