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13 August 2019 AdvancedGeo <br /> AGE Project No. 19-4782 L n v i ro n m e n t a l <br /> Page 13 of 14 <br /> Assumptions: <br /> = 164,250 gallons = 21,959 cubic feet wastewater _ [(2.11 acres x 43,560 feet2) _ 12 <br /> inches] = 2.87 inches/year <br /> NW = 34.425 mg/L-N <br /> d = 15 percent denitrification <br /> R = 11.50 inches/year <br /> Nb = 0.1 milligram per liter <br /> Nr = [2.87 inches/year x 34.425 mg/L-N (1-0.15)] + (11.50 inches/year x 0.1 milligram per <br /> liter) _ (2.87 inches/year + 11.50 inches/year) <br /> Nr = 85.13 = 14.37 = 5.92 <br /> Nr = 5.92 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, AGE does not anticipate percolating <br /> effluent will affect any nearby water sources. Based on the volume of wastewater to be <br /> generated, the potential vertical migration would not likely degrade the local groundwater. <br /> A total of'5.92 ppm of additional nitrogen is estimated to be added to the site over the <br /> long term through waste water recharge from the proposed septic system. Added to the <br /> 2.7 ppm of Nitrate as N detected in the water well sample equals a total of 8.62 ppm of <br /> nitrates, still below the desired value of 10 ppm. <br /> 10.0. TOTAL NITRATE IMPACT FROM PROPOSED PROJECT <br /> Based on the method and assumptions described, proposed NO3_N mass of wastewater <br /> and the calculations of the NO3_N loading predicted, the proposed development should <br /> not negatively impact NO3_N loading rates within the aquifer. The soil at the site appear <br /> to be adequate for nitrate degradation and proper leaching of wastewater. A total of 5.92 <br /> ppm of additional nitrogen is estimated to be added to the site over the long term through <br /> waste water recharge from the proposed septic system. <br /> 11.0. MITIGATION METHODS PROPOSED <br /> To mitigate any known or potential future impacts to soil and groundwater of nitrate from <br /> the proposed septic system, the following mitigations could be implemented: <br />