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NITRATE LOADING POTENTIAL FOR PARCEL 2 <br />IN,,,(1 -d)+RNb <br />Nr= (I+R) <br />Where: <br />Nr = Resultant average concentration of nitrate -nitrogen in effluent recharge water - (ppm NO, -N). <br />I = Volume rate of wastewater entering the soil averaged over the gross developed area in in/yr. <br />Nw = Total nitrogen concentration of wastewater assumed to be 45 mg N/L <br />d = Fraction (%) of nitrate -nitrogen combined loss in the soil due to denitrification. <br />R = Net Rainfall Recharge determined by the document found in Appendix B. <br />Nb = Background nitrate -nitrogen concentration of rainfall recharge, exclusive of wastewater influences <br />INW(1 -d)+RNb <br />Nr = (I + R) <br />Values and Assumptions: <br />For nitrate loading calculations, the EHD has specified wastewater flow projections from single family residential <br />(SFR) structures to be calculated as follows: 100 gallons per day (gpd) for the first bedroom and 50 gpd for all <br />subsequent bedrooms within the structure. <br />I = 12 Bedrooms = 650 gals/d x 365 = 237.250gals/yr = 31,718 cu ft = 3.92 in/yr <br />2.23 Ac x 43,560 sq ft/Ac x (1 ft/12 in) <br />Nw = 45 mg N/L <br />d = 45% denitrification factor based on the nitrate -nitrogen concentrations observed in the soil chemistry test results. <br />R = 8.82 in/yr <br />Nb = Assumed to be 0.1 ppm NO3-N <br />(3.92 in/yr) (45 mom) (1 - 0.45) + (8.82 x 0. I in <br />Nr = (3.92 in/yr + 8.82 in/yr) <br />Nr = 7.7 ppm as nitrate -nitrogen (NO3-N); 34.3 ppm as nitrate (NO3). <br />Parcel l can support 12 bedrooms. <br />10 <br />Chesney Consulting <br />