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Live Oak inspected the on-site soil near the proposed new residential area on November 9, 2018. The surface and near-surface soils were found to be silty, fine sand. Mass Transport Soil Properties The soil type will allow moderate infiltration of water through the surface soils. The longer the effluent remains near the surface, the more biologic treatment may occur. In a situation where permeable soils exist to the depth of the aquifer, it is possible that any remaining surface contaminants may be transported to the first saturated zone of the aquifer. Groundwater Analysis 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 spring and fall of 2016 were the most recent available from this source (Plates 6 and 7). According to an analysis of these maps, the ground-water elevation in the area is approximately 16 to 23 feet above mean sea level. The ground-water flow direction is to the north-northwest at a rate of approximately 10 to 11 feet per mile. Given that the ground elevation of the Site is approximately 80 feet above sea level, based on the County ground water maps the depth to ground water below the Site is estimated to be 57 to 64 feet below ground surface. Potential Ground Water Contamination Issues The Nitrate Loading 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). Five wells were identified in a search of addresses within approximately one mile of the subject Site. Nitrate was detected in all five wells, at concentrations ranging from 19.6 to 135 mg/L-NO3 (4.4 to 30 mg/L-N). DBCP was detected in four of the samples, at concentrations ranging from 0.26 to 2.96 LOGE 1844 Page 3