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Expected On-Site Maximum Septic Tank Usage Maximum expected usage on the Site would be from the proposed employees and customers of the new winery. Septic system design should be based on the San Joaquin County On-Site Wastewater Treatment Systems Standards (2017) or other engineering recommendations. 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 5 and 6), ground water elevation is approximately 45 to 50 feet below mean sea level; ground water flows to the south or south-southeast in the area at a rate of approximately three feet per mile. Given that the ground elevation of the Site is approximately 95 to 100 feet above mean sea level, the depth to water below the Site is estimated to be approximately 140 to 150 feet. San Joaquin County experienced its highest recent ground-water levels in 1983 and 1999. Review of ground-water maps for these years (Plates 7 and 8) reveals that depth to water would have been approximately 120 to 125 feet in these years. 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. According to the nitrate map (Plate 9), no wells within a half-mile radius of the subject Site have been tested for nitrate. One well within a one-mile radius was tested; nitrate was detected at a concentration between 0.1 and 5.0 mg/L-N. According to the DBCP map (Plate 10), one wells within a one-mile radius of the Site has been tested for DBCP; it was not detected. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate is 10 mg/L-N; the MCL for DBCP is 0.2 ug/L. LOGE 1913 Page 3