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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 2 feet above to 18 feet below mean sea level, depending on the season; the ground-water flow beneath the Site is to the east or northeast at a rate of approximately 12 to 17 feet per mile. Given that the ground elevation of the Site is approximately 70 to 72 feet above mean sea level, the depth to water below the Site is estimated to be approximately 68 to 90 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. According to the nitrate map (Plate 7), three wells within a half-mile radius of the subject Site have been tested for nitrate; nitrate was detected in all three at concentrations between 5.1 and 10.0 mg/L-N. According to the DBCP map (Plate 8), two wells within a half-half mile radius of the Site were tested for DBCP; no DBCP was detected in either 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 No wells are 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 No water sample was collected as part of this investigation. LOGE 20-44 Page 3