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Water Sample /A water sample was collected from the domestic well on the Site on June 25, 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_ The sample was placed on ice and transported under chain of custody to FGL Environmental, Stockton. The Chain of Custody document and analytical reports prepared by FGL Environmental have been included in Appendix 4 of this report. Nitrate was detected in the water sample at 7.1 mg/L-NO3, well below the maximum contaminant level (MCL) set by the US EPA of 45 mg/L-NO3. 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 was detected in the water sample ata concentration of 0.60 :uglL gnificcaantly above tFIMCL�,of 0:2 ugIL�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 (USGS, 1979). Two map units of the Modesto Formation upper member are depicted on the Site. The first map unit represents "arkosic alluvium forming Mokelumne River terraces and alluvial fan; chiefly sand with minor gravel and silt; probably glacial outwash.° The second map unit represents "arkosic sand forming low dunes on the Mokelumne River fan; probably eolian, although not well sorted" (Plate 7). The surface and near surface soils located at the Site are reported by the USDA Web Soil Survey to be composed of Tokay fine sandy loam, 0 to 2 percent slopes, and LOG E0911 Page 4