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(- 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 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 from the proposed on-site septic system serving the restroom facilities. As calculated below, the property has been assessed on a gross developed area and not 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 cannot exceed 10 ppm nitrate-nitrogen (45 ppm as nitrate). Calculated nitrate-nitrogen loading from the developed area of the property: IN, (1 - d) + R N b NT = (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 area in inches per yr. The subject property is 15.71 acres, but the developed area is 4.48 acres. Nw = Total nitrogen concentration of wastewater in mg N/L d = Fraction (%) of nitrate-nitrogen loss due to denitrification in the high clay content soil. R = Average recharge rate of rainfall - inches per yr. From S.J. County Isohyetal Map. NLS§ 3.2 Nb = Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater influences (ppm NO3-N). Values and Assumptions: I= 64,500 gals = total WW/yr = 8,623 cu ft 0.531 in/yr 4.48 Ac x 43,560 sq 11/Ac x (1 ft/12 in) Nw = 62 mg N/L d = Assume 30% due to high percentage of clay soil and high CEC in upper soil profile. R = 13 in/yr. From S.J. County Isohyetal Map. NLS§ 3.2 Nb = Assumed to be 0.1 ppm NO3-N 0.531 in/yr (62 mg N/L) (1 - 0.30) + (13 in/yr x 0.1 mg/L) Nr = (0.531 in/yr + 13 in/yr) Nr = 1.8 ppm as nitrate-nitrogen (NO3-N) or 8.1 ppm as nitrate (NO3) 6 Chesney Consulting