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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions examined on each proposed parcel of the Site were found to be suitable for shallow septic systems utilizing leach lines or filter beds. No new construction is anticipated. Satisfactory soil percolation rates of 15.6 min/in (Parcel A) and 3.6 min/in (Parcel B) were observed at the test locations. The soils in the test locations were found to be sandy clay (Parcel A) and silty clay (Parcel B). The percolation tests are considered representative of soils within a 100-foot radius of each test location. Because of the percolation rate between 5.0 and 30.0 min/in encountered on Parcel A, 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. Because of the percolation rate between 1.0 and 5.0 min/in encountered on Parcel B, the San Joaquin County Environmental Health Department will require a 20-foot separation from the bottom of the dispersal system to ground water, unless mitigated by system design or enhancement. The depth of ground water based on recent aquifer levels is estimated to be less than 10 feet below ground surface for the majority of the Site. On March 26, 2021, Live Oak encountered first water at 5.97 feet below ground surface on Parcel B. It is anticipated that water levels beneath the Site will fluctuate, especially on a seasonal basis, depending on pumping practices in the area. The ground-water flow direction could not be determined in the immediate vicinity of the Site, though in general ground water appears to flow toward the north. A water sample was collected from the domestic well on the Site as part of this investigation. Neither nitrate nor DBCP was detected in the water sample. Based on the methods and assumptions described, the nitrate loading calculation indicates that the use of on-site septic tanks and drain field systems on the Site has the potential to cause a buildup of nitrate in the aquifer up to 4.5 mg/L-N for the existing home on Parcel A, 8.6 mg/L-N for two homes on Parcel A, 0.2 mg/L-N for no development on Parcel B, and 1.7 mg/L-N for two homes on Parcel B. The results of the nitrate loading estimates for each parcel are well below than the maximum drinking water standard of 10 mg/L-N. Because of the favorable results of the nitrate loading calculations, no nitrate mitigation is recommended at this time. LOGE 2121 Page 15