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Ground Water Information t 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 fall of 2014 and spring of 2015 were the most recent available from this source (Plates 5 and 6). Ground-water levels were not mapped for the vicinity of the Site in either map; based on the nearest contours available, it appears that ground water may be present at 10 to 20 feet below sea level in the area. Given that the ground elevation of the Site is 10 to 15 feet below sea level, the depth to water below the Site is estimated to be from zero to ten feet. Ground-water flow in the Delta is known to be significantly influenced by agricultural pumping and irrigation activities. No attempt was made to determine the ground-water gradient on the Site. On February 28, 2017, Live Oak advanced a soil boring to a depth of eight feet below ground surface for the purpose of soil logging and determining depth to ground water. Ground water was encountered at a depth of 3.6 feet below ground surface. Because of recent heavy rains, it is unclear whether the water encountered is true ground water or may represent downward-percolating rainwater. 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. 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), common ground-water contaminants in San Joaquin County. Two wells were identified within approximately one-third of a mile of the Site. Nitrate as NO3 was not detected in either well; the wells had not been tested for DBCP. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L (equivalent to 10 mg/L nitrate as N); the MCL for DBCP is 0.2 µg/L. On-Site Wells According to the site plan, one domestic well exists on the Site. One well permit for the Site was identified from San Joaquin County Environmental Health Department records. • LOGE 1708 Page 3