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CONCLUSIONS AND RECOMMENDATIONS <br /> In summary, the soil conditions examined near the proposed septic disposal field of the <br /> Site were found to be suitable for a standard septic system. <br /> A satisfactory soil percolation rate of 25.0 min/in was observed at the test location. The <br /> shallow soil in the test location was found to be silty clay with fine sand. <br /> The depth of ground water based on recent aquifer levels is approximately 85 to 95 feet <br /> below ground surface. The ground-water flow is to the northeast in the general area, at <br /> a rate of approximately 3 to 4 feet per mile. <br /> A water sample was collected from the domestic well on the Site as part of this <br /> investigation. Nitrate was detected in the sample at a concentration of 3.6 mg/L-N, well <br /> below the MCL of 10 mg/L-N. DBCP was not detected in the sample. <br /> Based on the methods and assumptions described, the nitrate loading calculation <br /> indicates that the use of existing and proposed septic tanks and drain field systems on <br /> the Site has the potential to cause a buildup of nitrate in the aquifer up to 5.3 mg/L-N, well <br /> below the maximum drinking water standard of 10 mg/L-N. <br /> Because of the favorable result of the nitrate loading calculation, no nitrate mitigation is <br /> recommended at this time. Septic system construction should follow the San Joaquin <br /> County On-Site Wastewater Treatment Systems Standards (2017) where applicable. In <br /> this area, most systems utilize leach lines with 25-foot deep seepage pits. <br /> LOGE 2312 Page 13 <br />