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30 July 2019 AdvancedGeo AGE Project No. 19-4772 f- i�vironmentaI Page 12 of 14 RESIDENTIAL: The Hantzsche / Finnemore (Nr) equation for residential home application: Nr = IxNw (1-d) + RxNb = (I+R) Definitions.- Nr efinitions:Nr = The average concentration of nitrate-nitrogen in the recharged waste water parts per million of nitrate-nitrogen. I = Volume rate of wastewater entering the soil averaged over the gross developed area (acres) in inches per year. The total wastewater volume for proposed project will be 450 gpd (existing system) + 300 gpd (proposed system) x 365 days of proposed operation _ (450 + 300) x 365 days _ 7.48 gallons per cubic foot = 36,598 cubic feet of wastewater. Does not account for evapotranspiration likely to occur. NW = Total nitrogen concentration of wastewater at 45 mg/L-N based on the average discharge. Accounting for the loss of mg/L-N in the septic tank at 15% = 45-15%= 38.25 and the loss from the biomat at 10% 38.25 - 10% = 34.425 mg/L-N d = Fraction of nitrogen concentration removed from the wastewater due to denitrification within the soil (30 percent for clay type soils), \ R = Average rainfall rate per year'13 113 inches. Y'\ Nb = Background nitrate-nitrogen concentration of rainfall recharge, from wastewater influences. EXISTING HOME AND PROPOSED MOBILE HOME CALCULATIONS (COMBINED): Nr = IxNw (1-d)+ RxNb = (I+R) Assumptions: = 273,750 gallons = 36,598 cubic feet wastewater - [(1.16 acres x 43,560 feet') _ 12 inches] = 8.69 inches/year NW = 34.425 mg/L-N d = 30 percent denitrification . R = 13.13 inches/year Nb = 0.1 milligram per liter Nr = [8.69 inches/year x 34.425 mg/L-N (1-0.30)] + (13.13 inches/year x 0.1 milligram per liter) - (8.69 inches/year + 13.13 inches/year) Nr = 210.72 = 21.82 = 9.65 Nr = 9.66 ppm nitrogen (NO3_N)