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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions examined on each parcel were found to be suitable for standard septic systems. Satisfactory soil percolation rates of 16.7 min/in (Parcel 1) and 6.9 min/in (Parcel 2) were observed in the shallow soil zones at the test locations. The soil in the test areas was found to be clay and silty clay. The depth of ground water based on recent aquifer levels is estimated to be four to 10 feet below ground surface. The ground-water flow direction and rate could not be calculated because the vicinity of the Site was not mapped. Ground water depth and flow direction in the Delta islands is highly dependent on seasonal pumping and irrigation in the area. Because the percolation rates encountered fall between 5.0 and 30.0 min/in, the San Joaquin County Environmental Health Department will require an eight-foot separation from the bottom of any future dispersal system to ground water. No construction is planned. No wells are located on the Site. No water sample was collected as part of this investigation. The Mussis have no plans to develop the Site, and there are currently no structures on the Site. Based on the method and assumptions described, maintaining zero development on each parcel would result in a buildup of nitrates in 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 theoretical five-bedroom house and three-bedroom second unit dwelling for each parcel. These were considered so that, should the Mussis at some point in the future decide to build on the land, nitrate loading will have been addressed. Based on the method and assumptions described, the nitrate loading calculation indicates that the use of on-site septic tanks and drain field systems on the Site have the potential to cause a buildup of nitrate in the aquifer up to 0.5 mg/L-N for Parcel 1 and 0.6 mg/L-N for Parcel 2. Both results are well below the US EPA drinking water recommendation of 10 mg/L-N. No nitrate mitigation is recommended for any future primary and second unit dwellings on the Site totaling up to eight bedrooms per parcel. LOGE 20-08 Page 14