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reduction between 10 percent to 35 percent. Soils with higher clay content, moist soil conditions, high <br /> pH, and organic material denitrify by about 35 percent, and soils with high sand content and fast <br /> percolation rates tend to denitrify at a lower rate of about 10 percent. For purposes of this study, a <br /> denitrification factor of 15 percent was used, as soils in the area are sandy/sandy loam. <br /> Nitrate Loading Estimate <br /> A nitrate loading analysis was performed to determine the impact of on-site sewage disposal from the <br /> project on local ground water.The analysis uses assumptions as discussed.Table 1 provides a summary <br /> of assumptions used for the nitrate loading calculations. A more detailed review of assumptions and <br /> calculations is provided in Figure 3. <br /> Table 3.1 -Assumptions for Nitrate Loading Calculation <br /> Variable Value Units Description <br /> Q 33,326 gpd Sewage effluent flow rate <br /> Nw 75 mg/L-N Effluent nitrogen concentration <br /> A 199.32 acres Watershed area <br /> Nb 1.0 mg/L-N Concentration of rain <br /> d 15% unitless Denitrification factor <br /> R 10.07 inches per year Deep percolation of rain water <br /> W 2.25 inches per year Uniform waste water loading for calculation <br /> The results of the nitrate loading, or long term average concentration of percolating effluent, Nc, as <br /> calculated using the Hantzsche and Finnemore equation, are presented in Table 2. <br /> Table 3.2 - Result of Nitrate Loading Calculation <br /> Variable Value Units Description <br /> Nc 12.50 mg/L-N Long-term average concentration of percolating <br /> 61 Page <br />