SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

C ` f i CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD CENTRAL VALLEY REGION ORDER NO. 91-238 NPDES NO. CA0082821 WASTE DISCHARGE REQUIREMENTS FOR ARCO PRODUCTS COMPANY ARCO STATION 434 GROUND WATER TREATMENT: SYSTEM DISCHARGE SAN JOAQUIN COUNTY The. California Regional Water Quality Control Board, Central Valley Region, (heieafter Board) 'finds -that: 1. ARCO Products Company (hereafter Discharger) submitted a Report of Waste Discharge, dated 15 March 1991, and applied for authorization to dischar e waste under the National Pollutant Discharge Elimination System (NPOESI. Additional information regarding the proposed discharge was received 28 May 1991. 2. The Discharger proposes to discharge waste from a gasoline-spill ground water treatment system into a storm drain tributary to South Main Canal , a water of the United States, at a point in Section 11, T3N, R6E, MDB&M. Pumped ground water will be treated serially through two exchangeable activated carbon units, and then discharged to the storm drain. The activated carbon is regenerated or disposed of off-site. When breakthrough of the lead carbon unit is detected, the lead unit is removed, the trailing unit switched to the lead position, and a fresh unit is . installed in the trailing position. The treatment system is initially designed for a flow of 2 gpm (3000 gpd) of extracted ground water. Should continued investigation of the ground water plume determine that higher extraction rates are needed to capture - the contaminants, the treatment system may be expanded to treat up to 15 r .gpm ,(21,600,gpd}.., 3. The Report of Waste Discharge describes the initial proposed discharge as follows: Monthly Average Flow: 2200 gallons per day (gpd) Maximum Daily Flow: 2880 gpd Design Flow: 2880 gpd Constituent m9d Total Petroleum <1 mg/l . Hydrocarbons Benzene <0,7 ug/l Ethylbenzene <680 ug/l Toluene <100 ug/l Xylene <620 ug/l Lead 0.01 mg/l