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Table 3. Assumptions for Nitrate Loading Calculation <br /> Variable Value Units Description <br /> Q 280 gpd Effluent flow rate, 2-bedroom <br /> 420 gpd Effluent flow rate, 3-bedroom <br /> 560 gpd Effluent flow rate, 4-bedroom <br /> Nw 35 mg/L-N Effluent stream concentration <br /> A 0.98 acres Site area <br /> Nb 0.3 mg/L-N Concentration of rain <br /> d 0.35 constant Denitrification factor <br /> R 4.64 inches per year Recharge rate of rainfall <br /> W 3.8 inches per year Uniform waste water loading (calculated), 2-bedroom <br /> 5.8 Uniform waste water loading (calculated), 3-bedroom <br /> 7.7 Uniform waste water loading (calculated), 4-bedroom <br /> The details of the nitrate loading calculations are included in Plates 14 through 16. The <br /> results of the calculations are presented in the following table. <br /> Table 4. Results of Nitrate Loading Calculations <br /> Variable Value Units Description <br /> Nc, 10Long-term average concentration of percolating <br /> 2 bedrooms .5 mg/L-N effluent, 2-bedroom house <br /> Nc, 12Long-term average concentration of percolating <br /> 3 bedrooms .7 mg/L-N effluent, 3-bedroom house <br /> Nc, 14Long-term average concentration of percolating <br /> 4 bedrooms .3 mg/L-N effluent, 4-bedroom house <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 10.5 mg/L-N for a two-bedroom house, 12.7 <br /> mg/L-N for a three-bedroom house, and 14.3 mg/L-N for a four-bedroom house. <br /> The result of the nitrate loading estimate exceeds the maximum drinking water standard <br /> for a two-, three-, or four-bedroom house. <br /> LOGE 1910 Page 11 <br />