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• table presents a summary of the assumptions for the nitrate loading calculation for the <br /> Site, as presented in Plate 11. <br /> Table 4. Assumptions for Nitrate Loading Calculation <br /> Variable Value Units Description <br /> Q 152.5 gpd Effluent flow rate <br /> Nw 85.0 mg/L-N Effluent stream concentration <br /> A 0.94 acres Site area <br /> Nb 1.00 mg/L-N Concentration of rain <br /> d 0.35 constant Denitrification factor <br /> R 11.5 inches per year Deep percolation of rain water <br /> W 2.18 inches per year Uniform waste water loading for calculation <br /> The details of the nitrate loading calculation are included in Plate 11. The results of the <br /> calculation are presented in the following table. <br /> • Table 5. Result of Nitrate Loading Calculation <br /> Variable Value Units Description <br /> Nc 9.65 mg/L-N Long-term average concentration of percolating effluent <br /> The US EPA recommended MCL for nitrate in drinking water is 10 mg/L-N. In a worst- <br /> case situation, the maximum buildup of nitrates in the aquifer from the use of septic <br /> systems on the Site is predicted to be 9.65 mg/L-N. The result of the nitrate loading <br /> estimate is below the maximum drinking water standard. <br /> Discussion of Nitrate Loading Results <br /> Total Nitrate Impact <br /> Based on the method and assumptions described, the result of the nitrate loading <br /> estimate indicates that the proposed uses of the Site should not cause a buildup of <br /> nitrates in the aquifer above 10 mg/L-N. Because of the satisfactory result, no <br /> mitigation measures are recommended at this time. <br /> • LOGE 1806 Page 10 <br />