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percent, and soils with high sand content tend to denitrify at a lower rate of about 10 <br />percent. <br />A standard denitrification factor of 25 percent (Crites and Tchobanoglous, 1998) was <br />selected for the Site because of the silty soil present at the percolation test location. <br />Nitrate Loading Estimate <br />A nitrate loading scenario was employed to determine the impact from the proposed <br />project to ground water. The scenario utilizes the variables discussed previously, which <br />represent the estimated conditions and uses associated with this project. The following <br />table presents a summary of the assumptions for the nitrate loading calculation for the <br />Site, as presented in Plate 15. <br />Table 3. Assumptions for Nitrate Loading Calculation <br />Variable Value Units Description <br />840 gpd Effluent flow rate <br />Nw 35 mg/L-N Effluent stream concentration <br />A 2.58 acres Site area <br />Nb 0.3 mg/L-N Concentration of rain <br />0.25 constant Denitrification factor <br />12.60 inches per year Recharge rate of rainfall <br />4.4 inches per year Uniform waste water loading (calculated) <br />The details of the nitrate loading calculation are included in Plate 15. The results of the <br />calculation are presented in the following table. <br />Table 4. Result of Nitrate Loading Calculation <br />Variable Value Units Description <br />Nc 7.0 mg/L-N Long-term average concentration of percolating effluent <br />LOGE 1934 Page 11