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Expected On-Site Maximum Septic Tank Usage Maximum expected septic usage on the Site would be from the existing house and a potential second dwelling unit on Parcel 4, as well as potential future primary and secondary residences on Parcels 1 through 3. No new residential construction is planned at this time. 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. According to an analysis of these maps (Plates 5 and 6), the ground water elevation in the vicinity of the Site is approximately 43 to 44 feet below mean sea level; the ground-water flow direction is to the west or west-southwest at a rate of approximately four to eight feet per mile. Given that the ground elevation of the Site is 90 to 95 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to range between 133 to 139 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). Ten nearby wells were identified within approximately 1.5 miles of the Site. All of the wells were tested for DBCP; it was not detected. All of the wells were tested for nitrate as NO3; it was detected in eight at concentrations of 4.5 to 7.7 parts per million (ppm). The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 ppm; the MCL for DBCP is 0.2 parts per billion (ppb, equivalent to µg/L). On-Site Wells One domestic well exists on the Site. No well permits were identified for the Site at the San Joaquin County Environmental Health Department. LOGE 1602 Page 3