SR0082577_SSNL - Laserfiche WebLink

Home Browse Search

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), the ground- water elevation in the area ranges from 30 to 37 feet below mean sea level, depending on the season; the ground-water flow is to the northeast at a rate of approximately eight feet per mile. Given that the ground elevation of the Site is approximately 55 to 58 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to range from 85 to 95 feet below ground surface. 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 6 and 7). According to the nitrate map, four wells within a half-mile radius of the subject Site have been tested for nitrate; nitrate was detected in three of these wells at concentrations between 0.1 and 5.0 mg/L-N, and in one well at a concentration between 5.0 and 10.0 mg/L-N. According to the DBCP map, eight wells within a one-mile radius of the Site have been tested for DBCP; no DBCP was detected in seven of the wells, and it was detected in the eighth well at a concentration between 0.01 and 0.2 ug/L. The Site is located approximately 240 feet from the Asghar Texaco, a closed leaking underground storage tank case, and approximately 480 feet from the Lodi Airport, a leaking underground storage tank case that is eligible for closure, according to the State Water Resources Control Board's GeoTracker website. On-Site Wells A domestic well is currently located on the Site. LOGE 20-38 Page 3