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As required by the laboratory, the sample was collected in a plastic container and two glass vials for nitrate and DBCP analysis, respectively. A tri Yblank was P also utilized. The sample was placed on ice and transported under chain of custody to FGL C� 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 Geolo is Information The Site is depicted on the Preliminary Geologic map of Cenozoic Deposits of the Bellota Quadrangle, California (Marchand and Atwater, 1979). The Site is depicted within the Riverbank Formation middle unit, described as "arkosic alluvium forming Mokelumne River terraces and alluvial fan; 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 and San Joaquin loam (Plate 8) (USDA, 2009). The table below presents some selected properties of these soils Table 1. Selected Properties of On-Site Soils (USDA, 1992) Soil Name Depth Unified Soil Salinity Soil Perme- Septic tank and Map Reaction ability absorption Symbol (in) Classification mrnhoslcm H P (in/hr) fields Bruella 0-18: Sandy loam; SC-SM, <2 6.1 -7.3 2.0-6.0 Severe: sandy loam, SM peres slowly 0-2% 18-31: Sandy clay loam, sandy <2 6.1 -7.3 0.2-0.6 slopes, 111 loam; SC 31-67: Sandy clay loam, clay <2 6.1 - 7.3 0.2-0.6 loam; SC, CL LOGE1017 Page 4