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Nitrate Mass Balance Calculation <br /> (2-bdrm Res + 3-bdrm SDU, 4.91 acres) <br /> Data Input: <br /> Occupancy: 7 people Waste Loading(W): 1.34 in/yr <br /> Gallons Per Person Per Day: 70 gpd/person Site Area(A): 4.91 Acre <br /> Effluent Quantity(Q): 490 Gals -- Concentration Rain(Nb): 0.17 mg/L-N <br /> Effluent Stream(Nw): 45.00 mgt-N Denitrification <br /> Deep Perc.of Rain(R):'V-29inches <br /> Result: <br /> Mass Balance(Nc): 7.33 mg/L-N <br /> MCL Drinking Water Nitrate as N: 10.00 mg/L-N <br /> Percent of MCL Nitrate as N 73% <br /> Equations: <br /> 7 people x 70 gals/day/person =490 gals/day Find Effluent Quantity(Q) <br /> (W) in = (Q) gal x 1 ft3 x 365 day x 1 acre x 12 in x 1 Find <br /> yr day 7.48 gal 1 year 43,560 ftz 1 It (A) <br /> 1.34 in/yr(site)=490 gal/day x(1 cu-ft/7.48 gals)x(365 days/1 year)x(1 acre 143,560 sq-ft)x(12 in/1 ft)x(1 site 14.91 acres) <br /> N,= WN-0-d)+RN Hantzsche-Fennemore Equation(Nc) <br /> W+R <br /> 7.33 mgt-N=((1.34 in/yr x 45 mg/L-N x(1-0.1))+(6.21 intyr x 0.17mg/L-N))/(1.34 intyr+6.21 in/yr) <br /> Variables: <br /> Nc=Average nitrate-N concentration(mg/I)of combined effluent and rainfall percolate(7.33 mg/L-N). <br /> W=Uniform waste water loading for study area(in/yr)(1.34 inches/year). <br /> Nw=Total nitrate-N concentration of waste water percolate(45 mg/L-N). <br /> d=Fraction of nitrate-N loss due to denitrification in the soil(10%). <br /> R=Uniform deep percolation of rainfall(6.21 in/yr). <br /> Nb=Background nitrate-N concentration of rainfall(0.17 mg/L-N). <br /> Assumptions: <br /> 1. Nitrate-N concentration of waste stream based on estimate of 45 mg/L-N. <br /> Assumption based on work from Hantzsche and Finnemore,1992. <br /> 2. Fraction of nitrate-N loss due to denitrification in the soil is assumed to be 10%. <br /> Assumption based on work from Hantzsche and Finnemore, 1992. <br /> 3. Estimated deep percolation of rainfall is 6.21 in/yr,see deep percolation of rain worksheet. <br /> 4. Assume background nitrate-N concentration of rainfall is 0.17 mg/L-N based on range by <br /> Hantzsche and Fennemore,1992. <br /> 99 itso <br /> NEIL O.ANDERSON&ASSOC.,INC. <br /> MOEOINCAL 80'AC✓:9•BOINMNO LADORATOWW Z "' <br /> Zl N9u91911Ln Lodi,CA 99140 O �` <br /> (10)NT-90I 1 <br /> ltO'N <br /> PLATE 9 <br />