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Expected On-Site Maximum Septic Tank Usage Maximum expected septic usage on the Site would be from the existing systems and any future residential uses.' No construction is planned at this time. However, County regulations would allow the placement of a primary and secondary residence on Parcel 1 at some point in the future. Septic system design should be based on the On-Site Wastewater Disposal Standards (2003) 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 the fall of 2013 and spring of 2014 were the most recent available from this source. According to an analysis of these maps (Plates 6 and 7), ground water elevation ranges from approximately five feet below to five feet above mean sea level; ground water flows down to the northwest in the vicinity of the Site at a rate of 8 to 10 feet per mile. Given that the ground elevation of the Site is approximately 100 to 107 feet, based on the County ground water maps the depth to ground water below the Site is estimated to range between 95 to 112 feet, depending on the season and location on the Site. 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 EHD's Water Well Data Table dated March 10, 2009 for nearby addresses that have been tested for nitrate and dibromochloropropane (DBCP). Nine wells were tested in 1999 at an address approximately one mile from the subject Site. Nitrate was detected in the wells at concentrations ranging from 9.0 to 13.0 mg/L. Three additional wells were identified at addresses located within approximately three miles of the Site. DBCP was not detected in the wells. Nitrate as NO3 was detected in the wells at concentrations of 9.6 to 64.0 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 pg/L. LOGE 1415 Page 3