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Potential Ground Water Contamination Issues The Soil Suitability Study is not intended to be an investigation into ground-water contamination sources, and no such investigation was conducted. Many sources can contribute to ground water contamination, including leaking underground storage tanks, agricultural activities, dairies, septic systems, and storm water infiltration. Agricultural activities and the use of septic systems in the area are known ground water contamination sources with the potential to impact the Site. Two common ground-water contaminants in San Joaquin County are nitrate and dibromochloropropane (DBCP). Live Oak reviewed the San Joaquin County Environmental Health Department's maps of Nitrate — Land Use Data and DBCP— Land Use Data dated February 20, 2019. According to the nitrate map (Plate 9), five wells within a half-mile radius of the subject Site have been tested for nitrate. Nitrate was detected in all five wells at concentrations between 0.1 and 5.0 mg/L-N. According to the DBCP map (Plate 10), two wells within a half-mile radius of the Site have been tested for DBCP; it was detected in one well at a concentration over 0.2 [g/L but was not detected in the other well. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate is 10 mg/L-N; the MCL for DBCP is 0.2 ug/L. On-Site Wells A domestic well is currently located on the Site. No well permits were identified for the Site from among the files of the San Joaquin County Environmental Health Department. Water Sample Live Oak collected a water sample from the domestic well on the Site on February 19, 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. Trip blanks were 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 2.4 mg/L-N. DBCP was not detected. The laboratory analytical results are attached as Appendix 5 of this report. 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 LOGE 1850 Page 4