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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 the spring and fall of 2021 were the most recent available from this source. According to an analysis of these maps (Plates 5 and 6), ground water elevation is approximately 30 to 40 feet below mean sea level. Ground water appears to flow to the northeast in the general area, at a rate of approximately 3 to 4 feet per mile; the fall map indicates that the flow direction has been impacted by a nearby well. Given that the ground elevation of the Site is approximately 55 feet above mean sea level, the depth to water below the Site is estimated to be approximately 85 to 95 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 nitrate map, 19 wells within a one-mile radius of the subject Site have been tested for nitrate. Nitrate was detected at concentrations between 0.1 and 5.0 mg/L-N in 13 of the wells, at concentrations between 5.0 and 10.0 mg/L-N in 4 of the wells, and at a concentration over 10.0 mg/L-N in one well; no DBCP was detected in the final well. According to the DBCP map, 11 wells within a one-mile radius of the Site have been tested for DBCP. No DBCP was detected in 10 of the wells; DBCP was detected at a concentration between 0.01 and 0.2 µg/l_ in the remaining well. On-Site Wells A domestic well is located on the Site (Plates 2 and 3). Live Oak reviewed the files of the San Joaquin County Environmental Health Department for the Site address; one well permit was identified. The permit, dated June 2021, was for a new domestic well. Standing water was recorded as 95 feet, and the total depth was recorded as 245 feet; the grout seal was placed at a depth of 100 feet. LOGE 2245 Page 3