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16 Febuary 2022 <br />Project No. 22-6747 <br />Page 11 of 13 <br />AdvancedGeo <br />An Employee -Owned Company <br />(acres) in inches per year. The total wastewater volume for proposed project will be 200 <br />gpd (proposed system) x 365 days of proposed operation = 200 x 365 days - 7.48 gallons <br />per cubic foot = 9,759 cubic feet of wastewater. Does not account for evapotranspiration <br />likely to occur. <br />NW = Total nitrogen concentration of wastewater at 45 mg/L-N based on the average <br />discharge. Accounting for the loss of mg/L-N in the septic tank at 15% = 45-15%= 38.25 <br />and the loss from the biomat at 10% 38.25 - 10% = 34.425 mg/L-N. <br />d = Fraction of nitrogen concentration removed from the wastewater due to denitrification <br />within the soil (30 percent for clay and loamy soils). <br />R = Estimated Deep percolation / average rainfall recharge rate per year: 2.99 inches. <br />Nb = Background nitrate -nitrogen concentration of rainfall recharge: 1.0 mg/I. The Nb is <br />an average value determined for San Joaquin County by the EHD. <br />PROPOSED HOME CALCULATIONS: <br />Nr = I x Nw (1-d) + R x Nb=(I+R) <br />Assumptions: <br />= 73,000 gallons = 9,759 cubic feet wastewater - [(0.460 acres x 43,560 feet') _ 12 <br />inches] = 9,759 - 1,670 = 5.84 inches/year <br />NW = 34.425 mg/L-N <br />d = 30 percent denitrification <br />R = 2.99 inches/year <br />Nb = 1.0 milligram per liter <br />Nr = [5.84 inches/year x 34.425 mg/L-N (1-0.30)] + (2.99 inches/year x 1.0 milligram per <br />liter) _ (5.84 inches/year + 2.99 inches/year) <br />Nr = 143.72 - 8.83 = 16.28 <br />Nr = 16.28 ppm nitrogen (NO3_N) <br />9.7. IMPACT OF NITROGEN LOADING FROM SITE PROJECT TO <br />DOWNGRADIENT WATER SOURCES <br />The recharging of groundwater is the most likely potential feature that could impact future <br />nitrogen loading. Since the subject property is flat, AGI does not anticipate percolating <br />effluent will affect any nearby water sources. Based on the volume of wastewater to be <br />generated and the depth to groundwater (110 feet bsg), the potential vertical migration <br />