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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 were observed at the test locations on each proposed parcel. For this study, Live Oak demonstrated a percolation rate of 5.21 min/in on Parcel 2; the other parcels previously achieved passing percolation rates as well. The percolation tests are considered representative of soils within a 100 -foot radius of each test location. The soils in the locations tested by Live Oak were found to be silty clay with sand and silt with fine sand; the Soil Survey lists soils across the Site as Capay clay and EI Solyo clay. The depth of ground water based on recent aquifer levels is estimated to be 50 to 75 feet. The ground -water flow direction is to the northeast the immediate vicinity of the Site, at a rate of approximately six to nine feet per mile. Because of the percolation rate between 5.0 and 30.0 min/in encountered on Parcel 2, 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 1, the San Joaquin County Environmental Health Department will require a 20 -foot separation from the bottom of the dispersal system to ground water for future development, unless mitigated by system design or enhancement. Based on the ground -water levels in the area, no modification to standard septic systems should be required. A water sample was collected from the domestic well on the Site as part of thiE investigation. Nitrate was detected in the water sample at a concentration of 5.4 mg/L- N, well below the MCL of 10 mg/L-N. DBCP was not detected. Based on the methods and assumptions described, the nitrate loading calculatior 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 7.0 mg/L-N for the existing home on Parcel 1, 8.3 mg/L-N for the existing home on Parcel 3, 0.15 mg/L-N for nc development on Parcel 2, and 1.9 mg/L-N for two homes on Parcel 2. The results of the nitrate loading estimates for each parcel are below 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 2141 Page 15