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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 38 to 40 feet above mean sea level; ground water flows predominantly toward the north of a rate of approximately zero to eight feet per mile in the vicinity of the Site. Given that the ground elevation of the Site is approximately 70 feet, the depth to water below the Site is estimated to be 3q to 32 feet, depending on the season. San Joaquin County experienced its highest recent ground-water levels in 1983 and 1999. Maps of ground-water levels were reviewed for this study (San Joaquin County Flood Control and Water Conservation District, 1983 and 1999); however, the Tracy area was not mapped during these years. 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 sources of ground water contamination 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, two wells within a one-mile radius of the subject Site have been tested for nitrate. Both of these wells were found to contain nitrate at a concentration greater than 10 mg/L-N. According to the DBCP map, one well within a one-mile radius of the Site has been tested for DBCP; no DBCP was detected. On-Site Wells Two wells are currently located on the Site. The eastern of the two is a'rel_a_tively new, deep well, according to Alberto Vasquez, engineer for the project; the western well is old, uncapped, and appears to be shallow. No well permits were identified for the Site from among files at the San Joaquin County Environmental Health Department. LOGE 1947 Page 3