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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions examined near the proposed septic system drain field were found to be suitable for a septic system. A satisfactory soil percolation rate of 5.68 min/in was observed in the shallow soil zone at the test location. The soil to a depth of two feet below ground surface was sandy silt with considerable amounts of gravel and construction debris mixed throughout. Live Oak excavated numerous borings to varying depths between six inches and 3.35 feet across the proposed leach field area, and encountered this mixed debris in all locations. Beneath this layer, clay was encountered to the full depth of the percolation test hole (3.35 feet). Based on the draft Geotechnical Investigation prepared by Quantum Geotechnical, the depth to ground water beneath the Site is approximately 15 to 16 feet. According to maps reviewed, ground water flows to the northwest or southwest in the area at a rate of approximately 2.5 to 5 feet per mile. Because of the percolation rate between 5.0 and 30.0 min/in encountered in the test hole, the San Joaquin County Environmental Health Department will require an 8-foot separation from the bottom of the dispersal system to ground water, unless mitigated by system design or enhancement. Given the depth to water measured by Quantum Geotechnical, no modification to a standard, shallow system should be necessary to fulfill this requirement. A water sample was collected from the public well southeast of the restaurant on the Site as part of this investigation. Neither nitrate nor DBCP was detected in the sample. A previous sample collected in June and provided by Mr. Rizkallah indicated a detection of nitrate at 0.48 mg/L-N, well below the MCL of 10 mg/L-N. Based on nearby well testing results, however, elevated nitrate levels appear to be common in the area. In the June sample, the laboratory also reported a detection of manganese at 289 ug/L, above the MCL of 50 ug/L. An out-of-service well is also located in the vicinity of the shop on the Site. The Site is the location of a closed leaking underground fuel tank investigation. GeoTracker lists several "post closure management requirements" that could affect new construction. In addition, it appears that Advanced GeoEnvironmental recently conducted some sampling at the Site, detected residual levels of petroleum hydrocarbons and volatile organic compounds, and recommended that a soil vapor barrier be installed beneath any new structures where people will work. An environmental review of the Site is beyond the scope of the Soil Suitability/Nitrate Loading Study, as is consideration of the impact of the proposed septic system on any existing contamination at or beneath the Site. LOGE 2240 Page 16