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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 zero to two feet above mean sea level. Ground water appears to flow to the north or northwest at a rate of approximately two to three feet per mile. Given that the ground elevation of the Site is approximately 12 to 15 feet above mean sea level, the depth to water beneath the Site is estimated to be approximately 10 to 15 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. 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, six wells within a one -mile radius of the subject Site have been tested for nitrate. Three of these wells were found to contain nitrate at concentrations between 0.1 and 5.0 mg/L, one was found to contain nitrate at a concentration between 5.1 and 10.0 mg/L, and nitrate was detected in the final two wells at concentrations over 10 mg/L-N. According to the DBCP map, four wells within a one -mile radius of the Site have been tested for DBCP. DBCP was not detected in any of these wells. The US EPA has set the Maximum Contaminant Level (MCL) for nitrate at 10 mg/L-N. The US EPA set the MCL for DBCP at 0.2 parts per billion (ppb, equivalent to ug/L) because it believes that given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water. The Maximum Contaminant Level Goal (MCLG) for DBCP is zero. LOGE 2142 Page 4