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i IIn n Water Sample A water sample was collected from the domestic well on the Site on October 21, 2009 by David Welch. The sample was to be analyzed for Nitrate and dibromochloropropane (DBCP) per San Joaquin County Environmental Health Department policy. As required by the laboratory, the sample was collected in a plastic container and two glass vials for nitrate and DBCP analysis, respectively. A trip blank was also utilized. The sample was placed on ice and transported under chain of custody to FGL Environmental, Stockton. Results of the tests are forthcoming. Nitrate is commonly detected in shallow ground water aquifers of the Central Valley. Application of fertilizers, livestock waste, and untreated septic tank waste can all contribute to nitrate in ground water. Nitrate is mobile and tends to accumulate in shallow ground water zones. Based on work in the Sacramento Valley from the early 1900s, it is estimated that under "natural" conditions, ground water contains nitrate at concentrations no more then about 13.5 mg/L-NO3 (3 mg/L-N). Nitrate may be increasing in areas with concentrations of 24.75 mg/L-NO3 (5.5 mg/L-N) or more (Hull, 1984). DBCP is a nematocide and soil fumigant for vegetables and grapes. It is known to cause male reproductive effects and is classified as a probable human carcinogen. Most domestic use of DBCP was discontinued in 1977 through 1979. The US EPA set the MCL at 0.2 parts per billion (ppb) because it believes that given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water. The Maximum Contaminant Level Goal (MCLG) for DBCP is zero. Soil Profile and Geologic Information The Site is depicted on the Preliminary Geologic map of Cenozoic Deposits of the Bellota Quadrangle, California (Marchand and Atwater, 1979). A map unit of the Riverbank Formation middle member is depicted on the Site. This map unit represents "arkosic alluvium forming Mokelumne River river terraces and alluvial fans; chiefly sand; probably glacial outwash" (Plate 7). The surface and near surface soils located at the Site are reported by the USDA Web Soil Survey to be composed of Bruella sandy loam, 0 to 2 percent slopes, Bruella sandy loam, hard substratum, 0 to 2 percent slopes, and San Joaquin loam, thick surface, 0 to 2 percent slopes (Plate 8) (USDA, 2009). The table below presents some selected properties of these soils: C7 LOGE0915 Page 4