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CONCLUSIONS AND RECOMMENDATIONS In summary, the soil conditions examined at the Site were found to be suitable for standard septic systems utilizing leach lines with seepage pits. No new construction is planned at this time. Satisfactory soil percolation rates of 27.8 min/in (Parcel 1), 5.8 min/in (Parcel 2), 5.6 min/in (Parcel 3), and 9.3 min/in (Parcel 4) were observed at the test locations. The soils in the test locations were found to be mixtures of clay, silt and sand. The depth of ground water based on recent aquifer levels is approximately 110 to 123 feet below ground surface. The ground -water flow is to the north or east at a rate of approximately 2 to 4 feet per mile in the vicinity of the Site. A water sample was collected from the domestic well on the Site as part of this investigation. Nitrate was detected in the sample at a concentration of 5.0 mg/L-N, well below the MCL of 10 mg/L-N. DBCP was detected in the sample at a concentration of 0.015 ug/L, below the MCL of 0.2 ag/L but above the MCLG of zero. Based on the methods and assumptions described, the nitrate loading calculation indicates that the use of existing septic tanks and drain field systems on Parcel 3 of the Site has the potential to cause a buildup of nitrate in the aquifer up to 2.9 mg/L-N, well below the maximum drinking water standard of 10 mg/L-N. Were two houses to be placed in the future on each currently vacant parcel, the maximum buildup of nitrates in the aquifer from the use of septic systems is predicted to be 3.1 mg/L-N for Parcel 1 and 3.2 mg/L-N for Parcels 2 and 4. For any parcel remaining undeveloped, the predicted nitrate loading will be equivalent to the nitrate concentration of rainwater, 0.15 mg/L-N. Because of the favorable result of the nitrate loading calculations, no nitrate mitigation is recommended at this time. LOGE 2153 Page 15