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I <br /> Evaluation of Hydrocarbons May 17, 1990 <br /> Waterfront Redevelopment, Stockton, California AGS 39048-2W <br /> beneath the City's Waterfront Redevelopment Property (Applied GeoSystems Work Plan <br /> No. 39048-1W, dated June 21, 1989). <br /> After approval of this work plan, an Applied GeoSystems geologist was onsite between <br /> August 29 and September 18, 1989, to perform a soil-vapor survey, observe the drilling of <br /> three soil borings and construction of three ground-water monitoring wells, develop the <br /> wells, and sample the ground water in the wells. In addition, Moldenhauer Engineering <br /> Company of Davis, California, surveyed the tops of the casings of the monitoring wells to <br /> provide data to evaluate the ground-water flow direction and gradient beneath the site. <br /> The soil-vapor survey results indicated that benzene was present in the soil vapor beneath <br /> the former Unocal property at 1.0 part per million [ppm]), and toluene was present in soil <br /> vapor beneath each of the other parcels at 1.0 to 6.0 ppm. We detected total xylene <br /> isomers at 1.0 ppm beneath the former Morton Paint property. These results were <br /> interpreted and used to decide the locations of the monitoring wells. <br /> Results of analyses of soil and ground-water samples indicate that soil beneath the former <br /> Unocal parcel contains gasoline constituents at concentrations generally not acceptable to <br /> local and State agencies. Additionally, the ground water beneath the Unocal property <br /> contains gasoline and diesel fuel. Benzene was detected at 0.071 ppm in the ground-water <br /> sample collected from monitoring well MW-1. The Maximum Contaminant Level <br /> 4 <br /> App/ied GeoSystems <br />