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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 4 and 5), ground water elevation is approximately 5 to 25 feet above mean sea level, depending on the season; the ground-water flow beneath the Site is to the north or northwest at a rate of approximately 16 to 20 feet per mile. Given that the ground elevation of the Site is approximately 130 to 138 feet above mean sea level, the depth to water below the Site is estimated to be approximately 105 to 133 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. Triple E Produce, formerly located on the Site, was investigated for pollution of the ground water with trihalomethanes (especially chloroform) from 1990 through 2005 under the oversight of the California Regional Water Quality Control Board (GeoTracker, 2020). Several monitoring wells were installed on the Site, thorough which water quality was monitored. In 2005, the California Regional Water Quality Control Board issued a No Further Action letter based on the low and stable concentrations of chloroform detected. A second case, in which Triple E is listed as a land disposal site, remains open; no information was available from GeoTracker for this case. 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. According to the nitrate map (Plate 6), four wells within a half-mile radius of the subject Site have been tested for nitrate, it was detected in three at concentrations greater than 10.0 mg/L-N, and in the remaining well at a concentration between 5.1 and 10.0 mg/L-N. According to the DBCP map (Plate 7), two wells within one-half mile of the Site were tested for DBCP; no DBCP was detected in LOGE 20-60 Page 4