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18 September 2020 AdvancedGeo Project No. 20-6116 An Employee-Owned Company Page 13 of 15 The Hantzsche / Finnemore (Nr) equation for residential home application: Nr = IxNw (1-d) + RxNb = (I+R) Definitions: Nr = The average concentration of nitrate-nitrogen in the recharged wastewater parts per million of nitrate-nitrogen. RESIDENTIAL: I = Volume rate of wastewater entering the soil averaged over the gross developed area (acres) in inches per year. The total wastewater volume is 150 gpd (future residential system) x 365 days of proposed operation = 150 x 365 days _ 7.48 gallons per cubic foot = 7,320 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 (25 percent for loamy sandy soils). R = Estimated Deep percolation / average rainfall recharge rate per year: 3.00 inches. Nb = Background nitrate-nitrogen concentration of rainfall recharge: 1.0 mg/I. The Nb is an average value determined for San Joaquin County by the EHD. FUTURE RESIDENTIAL CALCULATIONS: Nr = IxNw (1-d)+ RxNb _ (I+R) Assumptions: = 54,750 gallons = 7,320 cubic feet wastewater- [(40 acres x 43,560 feet2) _ 12 inches] = 7,320 = 145,200 = 0.05 inches/year NW = 34.425 mg/L-N d = 25 percent denitrification R = 3.00 inches/year Nb = 1.0 milligram per liter Nr = [0.05 inches/year x 34.425 mg/L-N (1-0.25)] + (3.00 inches/year x 1.0 milligram per liter) _ (0.05 inches/year + 3.00 inches/year) Nr = 4.29 = 3.05 = 1.41 Nr = 1.41 ppm nitrogen (NO3_N)