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CALCULATED NITRATE-NITROGEN LOADING NLS§3.3,3.4,3.5,3.6. 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 upgradient agricultural sources, 2.) Variability in wastewater flows, nitrogen concentrations and dilution effects from stormwater recharge, 3.) Changes in groundwater directional flow and elevation, 4.)Denitrification potential within the clay soil environment and within the confined and/or unconfined aquifers. The Hantzsche/Finnemore Formula is used in this report to predict the average resultant concentration of nitrate-nitrogen in effluent recharge water. As calculated below, the property has been assessed on a total areal loading basis correlated with the total projected yearly wastewater flow volumes calculated above. These two factors primarily estimate the average resultant concentration of nitrate-nitrogen in the recharge water. This concentration shall not exceed 10 ppm nitrate-nitrogen(45 ppm as nitrate). If the concentration exceeds this standard, mitigation measures must be implemented according to EHD. Calculated nitrate-nitrogen loading from the entire subject property: I&(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 loss due to denitrification in the soil 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=840 x 365 d/vr=306,600 gals=total WW/yr—40,990 cu ft =7.3 in/yr 1.54 Ac x 43,560 sq ft/Ac x (1 ft/12 in) Nw=62 mg N/L d = Assume 35%due to very high percentage of fine-grained clay soil. R = 9 in/yr. Nb= Assumed to be 0.1 ppm NO3 N 7.3 in/vr(62 mg N/Ll (1 -0.35)+(9 in/yr x 0.1 mg/L) Nr = (7.3 in/yr+9 in/yr) Nr = 18.1 ppm as nitrate-nitrogen(NO3-N)or 80.6 ppm as nitrate(NO3) Page 5 of 13