Laserfiche WebLink
N"O' I%W <br /> FFCBioma't <br /> g reductions in the pounds per acre nitrate-nitrogen loading from above are <br /> according to the scientific literature: <br /> removes 20%x 37 lbs=29.6 lbs <br /> ation removes 10%x 29.6 lbs=26.6 lbs <br /> Denitrification in silt soil strata removes 15%x 26.6 lbs=22.6 lbs <br /> Net total theoretical areal contribution=22.6 lbs N/Ac/yr. <br /> The calculated (or estimated)nitrate impact to the soil with the potential ultimately to impact the <br /> groundwater is extremely difficult to determine due to the number of variables involved. The <br /> following calculations are based upon using a conventional or traditional type of septic system <br /> consisting of a septic tank and a leachfield designed as a filter bed,per San Joaquin County <br /> Sewase Standards. �— <br /> HANTZSCHEIFINNEMORE EQUATION <br /> Mw(1 - d)+RNb <br /> Nr= (I +R) <br /> Where: <br /> Nr= Resultant average concentration of nitrate-nitrogen in recharge water- (ppm NO3-N) <br /> I = Volume rate of wastewater entering the soil averaged over the gross developed area in <br /> inches per yr <br /> Nw= Total nitrogen concentration of wastewater in N mg/L (90 mg N/L) <br /> d = Fraction(%) of nitrate-nitrogen loss due to denitrification in the soil <br /> R = Average recharge rate of rainfall - inches per yr(13) <br /> Nb= Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater <br /> influences (ppm NO3-N) <br /> Values and Assumptions <br /> 126 aWdav/0.92 Ac 365 d/vr = 1.84 in/yr. <br /> I= 43,560 cu ft/Ac ft x 7.48 gal cu ft x (1 ft/l2 in) <br /> Nw=90 mg N/L - 20% reduction from typ. septic tank =72 mg/L N <br /> d = 10% from biomat and 15% from saturated soil conditions within the filter bed area. <br /> Nb= Assumed to be 0.1 ppm NO3-N <br /> 1.84 in/yr(72 me.N/L) 0 - 0.25) +(13 in/yr x 0.1 mg/L) <br /> Nr = (1.84 in/yr+ 13 in/yr) <br /> Nr = 6.8 ppm as NO3-N or 30.2 ppm as NO3 <br /> Page -5- <br /> 4/at(ey Ag Researek <br />