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I. EXECUTIVE SUMMARY The following document describes the history, extent of impact, and prescribed remedial actions for hydrocarbon concentrations at the Former Canteen Facility located just east of Highway 99, between Waterloo Road (Highway 88) and Fremont Street (Highway 26) The one-acre property is zoned for manufacturing and light industrial use, there are no residences in the immediate area It is located in Section 31, T 2N , R 7E , M B B &M , on a portion of Section 54 Weber Grant, San Joaquin County, California (Figures 1 and 2) This Remedial Action Plan (RAP) includes an assessment of the impacts from the UST release, proposed cleanup levels for groundwater and soils, the results of feasibility testing conducted at the site, and proposed monitoring and reporting requirements for the recommended remediation technology The RAP is intended to provide further details and in-depth design of the conceptual remediation system presented in the Corrective Action Plan (CAP) dated June 11, 2002 Ina letter dated July 31, 2002, the San Joaquin County Environmental Health Department concurred with the preliminary design as presented in the CAP and gave approval to finalize the design and submit a RAP for the site Results of the soil and groundwater sampling conducted during the assessment portion of the project indicate that the horizontal and vertical extent of the hydrocarbon impact from the underground storage tank(UST) release has been delineated Concentrations of sorbed-phase (soil)hydrocarbon concentrations were compared to the Environmental Protection Agency (EPA)Region 9 Preliminary Remediation Goals (PRGs) The soil samples collected from the south and southeast walls of the UST excavation at depths between 14 and 19 feet below ground surface (bgs) exceeded the Industrial PRGs for benzene, toluene, and xylenes The benzene PRG was also exceeded in borings SB-2 and SB-13D at approximately 46 5 feet bgs A maximum TPH-G concentration of 17,600 mg/kg was detected in the soil samples (southeast wall of UST excavation @ 19 feet bgs) Concentrations of dissolved-phase hydrocarbons in the groundwater exceeded the California Department of Health Services Drinking Water Standard Maximum Contaminant Levels (CAMCLs) for benzene, toluene, ethylbenzene, xylenes, methyl-tertiary-butyl ether (MTBE), and 1,2-dichloroethane (1,2-DCA) A maximum TPH-G concentration of 220,000 µg/L (MW-13) was detected in the groundwater samples The majority of the groundwater impacts are centered on the MW-3 and MW-13 series of wells The 1,2-DCA concentrations have only been detected in off-site monitoring well MW-11 and may not be related to the UST release Based on the site assessment results, remediation of both soil and groundwater is required Three of fourteen remedial technologies screened were deemed feasible for remediation of both the I-i