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Table 7. Assumptions for Nitrate Loading Calculation, Designated Remainder <br />Variable <br />Value <br />Units <br />Description <br />Q <br />300 <br />gpd <br />Effluent flow rate <br />Nw <br />35 <br />mg/L-N <br />Effluent stream concentration <br />A <br />52.81 <br />acres <br />Site area <br />Nb <br />0.136 <br />mg/L-N <br />Concentration of rain <br />d <br />0.25 <br />constant <br />Denitrification factor <br />R <br />2.94 <br />inches per year <br />Recharge rate of rainfall <br />W <br />0.1 <br />inches per year <br />Uniform waste water loading (calculated) <br />The details of the nitrate loading calculations are included in Plates 18 through 21. The <br />results of the calculations are presented in the following table. <br />Table 8. Results of Nitrate Loading Calculations <br />Variable Value Units Description <br />Nc, Parcel 1 4.2 mg/L-N Long-term average concentration of percolating effluent, <br />existing 3 -bedroom house <br />Nc, Parcel 2 3.3 mg/L-N Long-term average concentration of percolating effluent, <br />potential future 5 -bedroom house <br />Nc, Parcel 3 9.2 mg/L-N Long-term average concentration of percolating effluent, <br />potential future 4 -bedroom house <br />Nc, Designated 08 m/L-N Long-term average concentration of percolating effluent, <br />Remainder .g existing 2 -bedroom house and 2 -bedroom mobile home <br />Based on the methods and assumptions described, the use of existing and potential <br />future septic tanks and drain field systems on the Site yields a calculated buildup of <br />nitrates in the aquifer up to 4.2 mg/L-N for Parcel 1, 3.3 mg/L-N for Parcel 2, 9.2 mg/L-N <br />for Parcel 3, and 0.8 mg/L-N for the Designated Remainder. <br />The US EPA recommended MCL for nitrate in drinking water is 10 mg/L-N. The results <br />of the nitrate loading calculations for all four parcels are below the maximum drinking <br />water standard. <br />LOGE 2233 Page 16 <br />