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4 P - 22 April 2009 AGE-NC-09-1683 Page 15 of 19 The maximum usage of wastewater in the new multi-purpose room with one unisex bathroom by 250 visitors (the maximum) is 3 gallons per day (gpd) per person, and 4 employees is 6 gpd per person. Additionally, the maximum usage of wastewater in the one unisex bathroom warehouse facility by 3 employees is 6 gpd per person. Other waste should not contain appreciable concentrations of nitrogen (workers washing hands and glassware). A total of 792 gpd is the projected maximum total daily waste quantity (nitrogen loading includes 250 visitor bathroom trips/day x 3 gpd= 750 gallons and 7 worker with two bathroom trips/day x 3 gpd=42 gallons). The total nitrate-nitrogen(NO3_N)average concentrations in domestic waste ranges between 20 to 85 milligram total nitrogen liter(mg/1-N)with an average of 45 mg/1-N when washing and sanitation is considered. It is estimated the proposed commercial nitrogen waste concentration will be worst case potential of 85mg/1-N and a weighted average will be used to calculate the total mg/1-N loading over a long term for site property.The weighted average calculation for total nitrogen concentrations for on-site commercial flow is proposed as the following: Commercial volume 792 gpd (750 gpd at the multi-purpose room and 42 gpd at the warehouse),- Commercial arehouse);Commercial concentration 85 mg/1-N; and The flow concentration of 51,480 mg/1-N gallon. 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. Advanced GeoEnvlronmental,Inc.