SU0010873 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 the fall of 2014 and spring of 2015 were the most recent available from this source (Plates 5 and 6). In the 2015 map, the vicinity of the Site has not been mapped. According to an analysis of the 2014 map, the ground-water elevation is approximately 35 feet above mean sea level; the ground-water flow is to the northwest at a rate of approximately 10 feet per mile. Given that the ground elevation of the Site is 75 to 80 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to range between 40 to 45 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 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). Six wells were identified at addresses within approximately 1.25 miles of the subject Site. All the wells had been tested for DBCP; it was detected in four of the wells, at concentrations of 0.26 to 2.96 ug/L. All the wells had been tested for nitrate; it was detected at concentrations of 3.3 to 135 mg/L. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L (equivalent to 10 mg/L-N). The MCL for DBCP is 0.2 ug/L. On-Site Wells One domestic well is located on the Site. Two well permits were identified for the Site at the San Joaquin County Environmental Health Department: • June 2007 permit for new domestic well. The permit indicates that the old well was to be destroyed at a later date. A septic system is depicted to the south of the house. • January 2008 permit for destruction of the old well. Copies of the permits have been included in Appendix 4 of this report. LOGE 1618 Page 3