Laserfiche WebLink
7B. CALCULATED NITRATE-NITROGEN LOADING <br /> NLS§3.4,3.5,3.6. The calculated nitrate-nitrogen impact to the soil and potentially to the <br /> groundwater is difficult to determine due to the large number of variables involved and variables <br /> unknown at this time. These include: 1.) Impact from upgradient agricultural sources, 2.) <br /> Variability in wastewater flows, effluent nitrogen concentrations and dilution effects, 3.) Changes in <br /> groundwater directional flow and elevation, 4.)The denitrification potential of the indigenous soils. <br /> HANTZSCHEIFINNEMORE EQUATION <br /> INH,(1 -_dl+RNb <br /> Nr= (I+R) <br /> Where: <br /> Nr = Resultant average concentration of nitrate-nitrogen in effluent recharge water-(ppm NO3-N) <br /> I = Volume rate of wastewater entering the soil averaged over the gross developed area in ac-ft <br /> Nw = Total nitrogen concentration of wastewater in TKN mg/L <br /> d = Fraction(%)of nitrate-nitrogen combined loss in the soil due to denitrification. <br /> R = Estimated Annual Rainfall Recharge in ac-ft as determined on Page 6. <br /> Nb = Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater influences <br /> (ppm NO3-N)- <br /> Values and Assumptions: <br /> I= 4,440 gpd x 6 days/wk x 50 work wks/yr= 1,332,000 gals/yr=4.09 ac-ft <br /> Nw= 176 TKN mg/L <br /> d = The 31%based on the nitrate-nitrogen concentration reduction observed in the backhoe test pit soil analysis. <br /> R = 183.65 ac-ft <br /> Nb= Assumed to be 0.1 ppm NO3-N <br /> 4.09 ac-ft(176 mg`) 0 -0.31)+183.65 ac-ft x 0.1 mg/L) <br /> Nr = (4.09 ac-ft+ 183.65 ac-ft) <br /> Nr = 2.74 ppm as nitrate-nitrogen(NO3-N); 12.3 ppm as nitrate. <br /> i <br /> Page -8- <br /> Chesney Consulting <br />