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• Water Sample Live Oak collected a water sample from the domestic well on the Site on November 15, 2016. 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. Nitrate was detected at a concentration of 14.8 mg/L-N in the water sample. DBCP was detected at a concentration of 0.05 �tg/L in the sample. 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 3.0 mg/L-N. Nitrate may be increasing in areas with concentrations of 5.5 mg/L-N or more (Hull, 1984). The US EPA has set the Maximum Contaminant Level (MCL) for nitrate as N at 10 mg/L. • 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, equivalent to µg/L) 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. The laboratory analytical results are attached as Appendix 5 of this report. Soil Profile and Geologic Information The Site is depicted on the Preliminary geologic map of Cenozoic deposits of the Bellota Quadrangle, California (Marchand and Bartow, 1979). The Site is depicted within a map unit of the Modesto Formation upper member, described as "foothill- derived alluvial silt, clay and minor sand forming terraces, upper fans, and following distributaries across lower fans; abundant volcanic detritus" (Plate 7). The surface and near surface soils located at the Site are reported by the USDA Web Soil Survey to be composed of Archerdale clay loam (Plate 8) (USDA, 2016). The table below presents some selected properties of this soil: • LOGE 1628 Page 4