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B. CALCULATED NITRATE -NITROGEN LOADING NLS§ 3.4, 3.5, 3.6. The calculated nitrate -nitrogen impact to the soil and potentially to the groundwater is difficult to determine due to the large number of variables involved and variables unknown at this time. These include: 1.) Impact from agricultural upgradient nitrate sources, 2.) Variability in wastewater flows, effluent nitrogen concentrations and dilution effects, 3.) Changes in groundwater directional flow and elevation, 4.) And of significant importance is not only the denitrification potential of the indigenous clay loam soils, but equally important is the diminished nitrification potential within this soil environment at the soil effluent interface. The small pore space within this soil significantly reduces oxygen content, thus impeding nitrification. The Hantzsche/Finnemore Formula is used below to predict the average concentration of nitrate - nitrogen in effluent recharge water from the proposed wastewater management system. The calculations are based on a total areal loading basis of 36 acres, correlated with the annually projected wastewater flows of 17,555 gpy. HANTZSCHEIFINNEMORE EQUATION INW(1- d)+RNb Nr = (I + R) Where: Nr = Resultant average concentration of nitrate -nitrogen in recharge water - (ppm NO3-N) I = Volume rate of wastewater entering the soil averaged over the gross developed area in inches per yr Nw = Total nitrogen concentration of wastewater in mg N/L d = Fraction (%) of nitrate -nitrogen combined loss in the high clay content soil due to: 1.) Prevention of nitrification and 2.) The denitrification of nitrate molecules that may form. R = Average recharge rate of rainfall - inches per yr NLS§ 3.2 Nb = Background nitrate -nitrogen concentration of rainfall recharge, exclusive of wastewater influences (ppm NO3-N)- Values and Assumptions: I = 17,555 gals = total WW/vr = 2,347 cu ft = 0.0177 in/yr 36.46 Ac x 43,560 sq ft/Ac x (1 ft/12 in) Nw = 62 mg N/L d = Assume 25% due to the high percentage of clay loam soil at the soil -effluent interface. R = 10 in/yr. Nb = Assumed to be 0.1 ppm NO3-N 0.0177 in/yr (62 m N/L) (1 - 0.25) + (10 in/yr x 0.1 mom) Nr = (0.0177 in/yr + 10 in/yr) Nr = 0.182 ppm as nitrate -nitrogen (NO3-N), 0.82 as nitrate (NO3) Chesney Consulting