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Water Sample Live Oak collected a water sample from the domestic well on the Site on January 30, 2019. The sample was 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 in the sample at a concentration of 36.8 mg/L-N. DBCP was not detected in the sample. For health reasons, we recommend that the well water not be consumed_until_nitrate levels can be reduced to below the MCL. Utilizing bottled water for drinking water maybe a good alternative to consider. 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 equivalent to 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-N. 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 pg/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 4 of this report. Soil Profile and Geologic Information The Site is mapped on the Preliminary geologic map showing Quaternary deposits of the Lodi quadrangle, California (Marchand and Atwater, 1979). It is depicted within a map unit of the Modesto formation lower member and two map units of the Modesto formation upper member. The units of the Modesto formation upper member are described as (Qm2) "arkosic alluvium forming Mokelumne River alluvial fan- chiefly sand, becoming finer-grained toward fan toe; probably glacial outwash" and (Qm2e) 11arkosic alluvium forming low dunes on the Mokelumne River fan and in the Delta-, probably eolian, although not well sorted." The Modesto formation lower member LOGE 20-02 Page 5