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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 septic systems. A satisfactory soil percolation rate of 2.25 min/in was observed in the shallow soil zone at the test location. The soil in the test area was found to be clay. The percolation test is considered applicable to an area approximately 100 feet in radius. The depth of ground water based on recent aquifer levels is approximately 35 to 40 feet below ground surface. The ground-water flow beneath the Site is to the north at a rate of approximately 8 to 12 feet per mile. Because the percolation rate encountered falls between 1.0 and 5.0 min/in, the San Joaquin County Environmental Health Department will require a 20-foot separation from the bottom of the dispersal system to ground water. Based on the anticipated depth to water beneath the Site, this requirement should not present a problem for development of the Site. A water sample was collected from the domestic well on the Site as part of this investigation. Results of the water sampling are not yet available from the laboratory. As soon as the analysis is complete, Live Oak will provide copies of the test results. The domestic well was also tested for coliform and general minerals by the San Joaquin County Environmental Health Department on May 23, 2019. Aaron Gooderham, Registered Environmental Health Specialist at the San Joaquin County Environmental Health Department, indicated that coliform and E. coli were both detected in the well water. Live Oak has submitted a Public Record Request for results of this testing and will provide those results as well as soon as they become available. Based on a review of San Joaquin County Environmental Health Department maps, it does not appear that nitrate or DBCP have been detected above their MCLs in wells within one mile of the Site. 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 has the potential to cause a buildup of nitrate in the aquifer up to 14.1 mg/L-N for two three- bedroom houses or 14.7 mg/L-N for a three-bedroom house and a four-bedroom house. Both results exceed the US EPA drinking water recommendation of 10 mg/L-N. Due to the conservative nature of the calculation, clayey soil present, and lack of existing nitrate exceedances in the area, the actual nitrate loading experienced on the Site over time may be less than predicted. LOGE 2106 Page 14