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Ground Water Information <br /> Depth and Gradient <br /> Live Oak reviewed ground water elevation information available from the San Joaquin <br /> County Flood Control and Water Conservation District to determine the ground water <br /> levels near the Site. Data from spring and fall of 2016 were the most recent available <br /> from this source. According to an analysis of these maps (Plates 4 and 5), ground <br /> water elevation is approximately five to eight feet below mean sea level. Ground water <br /> flows down to the east or east-southeast at a rate of approximately eight to 11 feet per <br /> mile. <br /> Given that the ground elevation of the Site is approximately seven to ten feet above <br /> mean sea level, the depth to water below the Site is estimated to be approximately 12 to <br /> 18 feet. <br /> San Joaquin County experienced its highest recent ground-water levels in 1983 and <br /> 1999. Maps of ground-water levels were reviewed for this study (San Joaquin County <br /> Flood Control and Water Conservation District, 1983 and 1999); however, the Tracy <br /> area was not mapped during these years. <br /> Potential Ground Water Contamination Issues <br /> The Soil Suitability Study is not intended to be an investigation into ground-water <br /> contamination sources, and no such investigation was conducted. Many sources can <br /> contribute to ground water contamination, including leaking underground storage tanks, <br /> agricultural activities, dairies, septic systems, and storm water infiltration. Agricultural <br /> activities and the use of septic systems in the area are known ground water <br /> contamination sources with the potential to impact the Site. <br /> Two common ground-water contaminants in San Joaquin County are nitrate and <br /> dibromochloropropane (DBCP). Live Oak reviewed the San Joaquin County <br /> Environmental Health Department's maps of Nitrate — Land Use Data and DBCP— Land <br /> Use Data dated February 20, 2019. According to the nitrate map (Plate 6), four wells <br /> within a half-mile radius of the subject Site have been tested for nitrate; nitrate was <br /> detected in all four wells at concentrations between 0.1 and 5.0 mg/L-N. According to <br /> the DBCP map (Plate 7), only one well within a half-mile radius was tested for DBCP; it <br /> was not detected. <br /> On-Site Wells <br /> One domestic well is currently located on the Site. Mr. Kumar indicated that the well is <br /> not currently operational. <br /> LOGE 1910 Page 3 <br />