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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 2014 and spring of 2015 were the most recent available from this source (Plates 5 and 6). According to an analysis of these maps, the ground-water elevation is approximately 37 to 47 feet below mean sea level, depending on the time of year; the ground-water flow is to the southwest at a rate of approximately 3.7 to 4.5 feet per mile. Given that the ground elevation of the Site is 110 to 120 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to range between 147 to 167 feet, depending on the time of year. 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 and cattle ranches, 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. Live Oak reviewed the San Joaquin County Environmental Health Department's Water Well Data Table dated March 10, 2009 for nearby addresses that have been tested for nitrate and dibromochloropropane (DBCP). Four wells were identified at addresses within approximately two miles of the subject Site. All of the wells had been tested for DBCP; it was not detected in any of the wells. All the wells had been tested for nitrate; it was detected in three of the wells at concentrations of 3.5 to 14.0 mg/L. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L (10 mg/L-N). The MCL for DBCP is 0.2 µg/L. On-Site Wells One irrigation well i'§ located on the Site. One well permit, a 1998 permit for a new irrigation—well, was identified for the Site address at the San Joaquin County Environmental Health Department. A copy of the permit has been included in Appendix 4 of this report. Water Sample Live Oak collected a water sample from t*dom stic II on September 14, 2016. The �{ sample was analyzed for nitrate and dibr6mochloro ropane (DBCP) per San Joaquin �4 • County Environmental Health Department policy. LOGE 1621 Page 3