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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 (Plates 7 and 8). According to the nitrate map, 11 wells within a one-mile radius of the subject Site have been tested for nitrate. Nine of these wells were found to contain nitrate at concentrations between 0.1 and 5.0 ring/L-N, and two wells were found to contain nitrate at concentrations between 5.1 and 10 mg/L- N. According to the DBCP map, 11 wells within a one-mile radius of the Site have been tested for DBCP. DBCP was detected at concentrations between 0.01 to 0.2 lig/L in four of the wells and at concentrations over 0.2 [A,g/L in two of the wells; no DBCP was detected in the remaining five wells. On-Site Wells A domestic well and two irrigation wells are located on the Site (Plate 3). Two well permits were identified for the Site from among the files of the San Joaquin County Environmental Health Department: April 2008 permit for replacement irrigation well. The well was 500 feet deep, with a grout seal at 50 feet (8450). September 2019 permit for new irrigation well. The well was 835 feet deep, with a grout seal at 202 feet (8458). The permits have been attached in Appendix 4 of this report. Water Sample Live Oak collected a water sample from the domestic well on the Site on April 5, 2021. 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. LOGE 2062 Page 4