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Expected On-Site Maximum Septic Tank Usage Maximum expected septic usage on the Site would be from the existing system and a potential future system to service a secondary residence on the proposed homesite parcel. No residential construction is planned. 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 2013 and spring of 2014 were the most recent available from this source. According to an analysis of these maps (Plates 5 and 6), the ground water elevation is five to ten feet below mean sea level; the ground-water flow is to the north-northeast at a rate of approximately eight feet per mile. Given that the ground elevation of the Site is 50 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to range between 55 to 60 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). Four wells were identified at addresses within approximately one mile of the subject Site. All of the wells had been tested for nitrate; it was detected in all of the wells at concentrations ranging from 11.0 to 32.0 mg/L-NO3. Three of the wells had been tested for DBCP; it was not detected in any of the three. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L (10 mg/L nitrate as nitrogen). The MCL for DBCP is 0.2 µg/L. LOGE 1515 Page 3