SITE INFORMATION AND CORRESPONDENCE

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• • CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD CENTRAL VALLEY REGION MONITORING AND REPORTING PROGRAM NO. R5-2004-0804 CALIFORNIA WATER CODE SECTION 13267 FOR WESTERN FARM SERVICE, INC. FORMER PUREGRO AGRICULTURAL CHEMICAL FACILITY STOCKTON, SAN JOAQUIN COUNTY The agricultural chemical facility at 1905 North Broadway Avenue in Stockton(site) was owned by Unocal until February 1993. At that time it was purchased by Crop Production Services (CPS), which was owned by Agrium. The site operated as CPS until Agrium purchased Western Farm Service, Inc. (Discharger) in 1995. The soil and groundwater are polluted with nitrate compounds, volatile organic compounds, chlorinated herbicides, and fumigants from discharges to former ponds and operations at the site. There are three water bearing zones. The first aquifer is about 45 to 88 feet below ground surface (bgs), the second aquifer is about 95 to 110 feet bgs, and the third aquifer is about 150 to 180 feet bgs. This pollution impaired the beneficial use of this water resource. A cap/liner was constructed over the two former evaporation ponds to prevent continued release of contaminants from the soil into the groundwater and is monitored annually. This Monitoring and Reporting Program (MRP) is issued pursuant to Section 13267 of the California Water Code and is necessary to delineate groundwater pollutant plumes and determine whether remediation efforts are effective. Existing data and information about the site show the presence of various chemicals, including nitrogen compounds, chloroform, methylene chloride, tetrachloroethene, bromodichloromethane, 1,2,3-trichloropropane, 1,2-dichloropropane, dibromochloromethane, dinoseb, 2,4-dichlorophenoxyacetic acid, 1,2-dibromoethane, and 1,2-dibromo 3-chloropropane emanating from the property under the control of the Discharger. The Discharger shall not implement any changes to this MRP unless and until a revised MRP is issued by the Executive Officer. This MRP replaces the requirements listed in MRP No. R5-2002-0826, which was issued on 8 August 2002. Prior to construction of any new groundwater monitoring or extraction wells, and prior to destruction of any groundwater monitoring or extraction wells, the Discharger shall submit plans and specifications to the Board for review and approval. Once installed, all new wells shall be added to the monitoring program and shall be sampled and analyzed according to the schedule below. GROUNDWATER MONITORING As shown on Figure 1, there are 27 monitoring wells and two extraction wells. The groundwater monitoring program for 26 monitoring wells, one extraction well, and any wells installed subsequent to the issuance of this MRP, shall follow the schedule below. Monitoring well MW-8 and extraction well E-2 are near wells screened in the same or comparable intervals and therefore are not sampled. These wells are not scheduled for destruction because they might be used for remedial purposes. Sample collection and analysis shall follow standard EPA protocol.