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Nitrate Mass Balance Calculation <br /> (4-bdrm, 2.17 acres) <br /> Data Input: <br /> Occupancy: 5 people Waste Loading(W): 2.17 in/yr <br /> Gallons Per Person Per Day: 70 gpd/person Site Area(A): 2.17 Acre <br /> Effluent Quantity(Q): 350 Gals Concentration Rain(Nb): 0.17 mg/L-N <br /> Effluent Stream(Nw): 35.00 mg/L-N Denitrification(d): 10% <br /> Deep Perc.of Rain(R): 6.21 inches <br /> Result: <br /> Mass Balance(Nc): 8.28 mg/L-N <br /> MCL Drinking Water Nitrate as N: 10.00 mg/L-N <br /> Percent of MCL Nitrate as N 83% <br /> Equations: <br /> 5 people x 70 gals/day/person =350 gals/day Find Effluent Quantity(Q) <br /> (W) in = (Q) gal x 1 W x 365 day x 1 acre x 12 in x 1 Find <br /> yr day 7.48 gal 1 year 43,560 ft2 1 ft (A) <br /> 2.17 in/yr(site)=350 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 12.17 acres) <br /> N,= WN-0-d)+RN Hantzsche-Fennemore Equation(Nc) <br /> W+R <br /> 8.28 mg/L-N=((2.17 in/yr x 35 mg/L-N x(1-0.1))+(6.21 in/yr x 0.17mg/L-N))/(2.17 in/yr+6.21 in/yr) <br /> Variables: <br /> Nc=Average nitrate-N concentration(mg/1)of combined effluent and rainfall percolate(8.28 mg/L-N). <br /> W=Uniform waste water loading for study area(in/yr)(2.17 inches/year). <br /> Nw=Total nitrate-N concentration of waste water percolate(35 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 35 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 /> r 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 /> pt Rspy <br /> NEIL O.ANDERSON&ASSOC.,INC. <br /> �orewNc�m+N�swmnmiwc Lasonn*owes s <br /> 121buslon Ln.Lod.CA 94D O <br /> (2W)z7.Pm ISS Ir" <br /> PLATE 9 <br />