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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions on each proposed parcel of the Site were found to be suitable for standard septic systems utilizing leach lines and seepage pits. No septic construction is proposed. Satisfactory soil percolation rates of 2.4 min/in (Parcel 1), 16.7 min/in (Parcel 2), 12.5 min/in (Parcel 3), 50.0 min/in (Parcel 4), 10.0 min/in (Parcel 5), 35.7 min/in (Parcel 6), 20.8 min/in (Parcel 7), and 50.0 min/in (Parcel 8) were observed at the test locations. The variability of the test results reflects the wide range of soil types encountered across the Site, including clays, sands, silts, gravel, and cobbles. The depth of ground water based on recent aquifer levels is approximately 205 to 334 feet below ground surface. Regional ground water appears to flow to the southwest; the rate could not be calculated because the Site is beyond the mapped area. 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. Because of the percolation rates between 5.0 and 30.0 min/in encountered on Parcel 2, 3, 5, and 7, an eight-foot separation from the bottom of the dispersal system to ground water will be required. Based on the anticipated depth to ground water, no modifications to standard septic systems should be necessary. Neither well on the Site is currently operational; no water sample was collected as part of this investigation. Based on a review of the San Joaquin County Environmental Health Department's maps of nitrate and DBCP detections in nearby wells, neither contaminant appears to be present above the MCL in the vicinity of the Site. There are no plans to develop the Site, and there are currently no structures on the Site. Based on the method and assumptions described, rnp ntaining zero development on each parcel would result in a buildup of nitrates 'n the aquifer up to 0.3 mg/L-N, equivalent to the measured rainwater concentration. For the purpose of this study, however, Live Oak assumed a hypothetical five-bedroom primary residence and three-bedroom second unit dwelling for each parcel. These were considered so that, should the owners at some point in the future decide to build on the land, nitrate loading will have been addressed. Utilizing 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 0.5 mg/L for Parcel 8, and 0.6 mg/L for Parcels 1, 2, 3, 4, 5, 6, and 7, well below the MCL of 10 mg/L-N. Because of the favorable result of the nitrate loading study, no nitrate mitigation is recommended. LOGE 20-29 Page 16