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Expected On-Site Maximum Septic Tank Usage Maximum expected usage on the Site is from the existing three-bedroom house on Parcel 2. A second unit dwelling could be allowed in the future on Parcel 2, as well as primary and second unit dwellings on Parcel 1; no new construction is anticipated. Any future 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 30 to 40 feet above mean sea level; ground water flows predominantly toward the northwest at a rate of approximately nine to 11 feet per mile in the vicinity of the Site. Given that the ground elevation of the Site is approximately 105 feet above mean sea level, the depth to water below the Site is estimated to be to 65 to 75 feet, depending on the season. 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. 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). A domestic well at the Site address of 19401 Dahlin had been tested in 1995; DBCP was detected in the sample at a concentration of 1.9 ug/L, and nitrate was detected at a concentration of 74 mg/L-NO3. No other wells that had been tested were identified within one-quarter mile. The Maximum Contaminant Level (MCL) set by the US EPA for nitrate as NO3 is 45 mg/L. The MCL for DBCP is 0.2 ug/L. LOGE 1907 Page 3