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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 fall of 2017 and the spring of 2018 were the most recent available from this source. According to an analysis of these maps (Plates 5 and 6), ground water elevation is approximately 33 to 40 feet above mean sea level; the Site is slightly beyond the mapped area for 2018. Ground water appears to flow to the northwest at a rate of approximately 5 feet per mile in the fall of 2017. Given that the ground elevation of the Site is approximately 83 to 84 feet above mean sea level, the depth to water below the Site is estimated to be approximately 43 to 51 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. The Site is located adjacent to the east of a former poultry farm. A cattle facility is less than one-half mile to the west. The vicinity of the site is primarily orchards. 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, four wells within a one-mile radius of the subject Site have been tested for nitrate. Two of these wells were found to contain nitrate at a concentration between 0.1 and 5.0 mg/L; and two were found to contain nitrate at a concentration between 5.1 and 10.0 mg/L-N. According to the DBCP map, two wells within a one-mile radius of the Site have been tested for DBCP. No DBCP was detected in one of the wells; it was detected over 0.2 ug/L in the other well. The Maximum Contaminant Level (MCL) for nitrate is 10 mg/L-N; the MCL for DBCP is 0.2 ug/L. LOGE 2111 Page 3