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Ground Water Information Depth and Gradient Live Oak reviewed ground-water elevation information available from the San Joaquin County Flood Control and Water Conservation District to determine the ground-water levels near the Site. Data from spring and fall of 2016 were the most recent available from this source. According to an analysis of these maps (Plates 5 and 6), ground- water elevation is approximately one to eight feet below mean sea level. Ground water appears to flow to the north at a rate of approximately 3 to 4 feet per mile. Given that the ground elevation of the Site is approximately 16 feet above mean sea level, the depth to water below the Site is estimated to be approximately 17 to 24 feet. 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 maps, five wells within a half-mile radius of the subject Site have been tested for nitrate; nitrate was detected in three of these wells at concentrations between 0.1 and 5.0 mg/L-N, in one well at a concentration between 5.0 and 10.0 mg/L-N, and in one well at a concentration over 10 mg/L-N. According to the DBCP map, four wells within a half-mile radius of the Site have been tested for DBCP; no DBCP was detected in any of the wells. On-Site Wells A domestic well is 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 June 22, 2020. The sample was analyzed for nitrate and dibromochloropropane (DBCP) per San Joaquin County Environmental Health Department policy. LOGE 20-26 Page 3