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10 June 2014 AGE Project No. 14-3035 Page 15 of 16 Assumptions: I = 131,400 gallons = 17,566 cubic feet wastewater _ [(18 acres x 43,560 feet2) = 12 inches] = 0.268 inches/year NW = 49.73 mg/L-N d = 20 percent denitrification R = 12 inches/year Nb = 0.1 milligram per liter Nr = [0.268 inches/year x 34.425 mg/L-N (1-0.20)] + (12 inches/year x 0.1 milligram per liter) _ (0.268 inches/year + 12 inches/year) Nr = 8.58 _ 12.268 = 0.699 Nr = 0.699 ppm nitrogen (NO3_N) 9.6. IMPACT OF NITROGEN LOADING FROM SITE PROJECT The deep, recharging of groundwater is the most likely potential feature that could be impacted by nitrogen loading. However, the potential vertical migration of the wastewater would be lesser with the current septic design. Based on the low volume of wastewater to be generated and the significant depth to ground water, the potential vertical migration would not likely degrade the local ground water. A total of 0.496 new load of NO3 and 0.699 ppm existing load of NO3 or total of 1.165 ppm of nitrogen will be added to the subject site through waste water recharge. 10.0. TOTAL NITRATE IMPACT FROM PROPOSED PROJECT Based on the assumptions of the report, proposed NO3_N mass of wastewater and the calculations of the NO3_N loading predicted, the proposed development should not negatively impact NO3_N loading rates within the aquifer. The soil at the site appear to be adequate for nitrate degradation and proper leaching of wastewater. 11.0. MITIGATION METHODS PROPOSED To mitigate any known or potential future impacts to soil and ground water from nitrate from proposed new development and increased septic usage, the following mitigations could be implementated: • Maximize wastewater hold time where practical; • Avoid use of bioattenuation chemicals (bleach etc.); • Properly and regularly maintain property septic systems; Advanced GeoEnvironmental,Inc.