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10 June 2014 AGE Project No. 14-3035 Page 13 of 16 DENITRIFICATIONS CAUSED BY SOILS The process of denitrification is important when utilizing subsurface septic lines and regularly occurs in the soil within the leachfields where bacteria utilize oxygen in the nitrate to release nitrogen gas out to the atmosphere. The denitrification process is controlled by waste concentrations, soil type, annual rainfall, pH of the soils, organic concentration of the soil (TOC) and exposure time to nitrogen. The soils with a high or moderate clay content, higher organic content, high pH and adequate soil moisture denitrify the concentrations by 30 percent and less desirable soils with more sands and faster percolation rates (less moisture and clay content) denitrify only about 10 percent. 9.5. MASS BALANCE OF NITROGEN LOADING The EHD requires the user to considering all potential sources identified for wastewater generation. Further the EHD supports the use of Hantzsche / Finnemore, or other appropriate formula/model to calculated a mass of nitrogen loading. COMMERICAL The Hantzsche / Finnemore (Nr) equation for commercial application: Nr = IxNw (1-d)+ RxNb = (I+R) 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 300 gpd x 156 of 365 days of proposed operation (0.427 [42%] operation over 365 days a year) = 365 days X 300 gallons = 109,500 gallons X 0.427 = 45,900 gallons. Volume of wastewater is expressed as 45,900 gallons _ 7.48 gallons per cubic foot = 6,148.4 cubic feet of wastewater. Does not account for evapotranspiration likely to occur. NW = Total nitrogen concentration of wastewater at 85 mg/L-N based on the average discharge. Accounting for the loss of mg/L-N in the septic tank at 15% 85-15%= 72.25 and the loss from the biomat at 10% 55.25 - 10% = 65 mg/L-N d = Fraction of nitrogen concentration removed from the wastewater due to denitrification within the soil (20 percent for clay type soils). R = Average rainfall rate per year: 12 inches. Nb = Background nitrate-nitrogen concentration of rainfall recharge, from wastewater influences. Advanced GeoEnvironmental,Inc.