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mple Given that the ground elevation of the Site is approximately 50 feet above mean sea level, the depth to water below the Site is estimated to be approximately 35 to 40 feet. - San Joaquin County experienced its highest recent ground-water levels in 1983 and 1999 (Plates 7 and 8). Based on review of maps*—ground-water levels for spring of those years, depth to water was approximatlely 2O feet ç,San Joaquin County Flood Control and Water Conservation District, 1983 and-1.999y: 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), six wells within a half-mile radius of the subject Site have been tested. Nitrate was detected in two of the wells at concentrations between 5.1 and 10 mg/L-N, and in the remaining four at concentrations over 10 mg/L-N. Three wells within a half-mile radius of the Site were tested for DBCP; no DBCP was detected (Plate 10). The Maximum Contaminant Level (MCL) set by the US EPA for nitrate is 10 mg/L-N; the MCL for DBCP is 0.2 lig/L. The surrounding agricultural properties are mainly orchards; elevated nitrate levels in the area likely derive from fertilizer application on these properties. On-Site Wells A_domestic well is currently located on the Site. One well permit was identified for the Site from ape;_ng t files of the SarT3-66-quin County Environmental Health Department. The permit, dated .vember 2016, was for a new well 270 feet deep; the grout seal depth was 200 feet. his permit has been included in Appendix 4 of this report. Live Oak collected a water sample from the domestigmell on the Site on May 17, 2019. The sample was analyzed for nitrate and dibromochloropropane (DBCP) per San Joaquin County Environmental Health Department policy. LOGE 1924 Page 3