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05 November 2014 AGE Project No. 14-3119 Page 13 of 17 waste concentration will be between 45 mg/1-N and 85 mg/1-N; depending on the site source of the water. To prepare a conservative estimate, the concentration will be 85 mg/1-N for the restroom loading (a heavy-weighted average) loading will be used to calculate the total mg/1-N loading over a long term for subject property. The weighted average calculation for total nitrogen concentrations for on-site commercial flow is proposed as the following: • Restroom volume 5 gpd per person (99) and 3 workers per day = 510 gpd concentration will be 85 mg/1-N • Commercial concentration based on industry and SJCO EHD standards 9.5. 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. 9.6. 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. Current - RESIDENTIAL The Hantzsche / Finnemore (Nr) equation for residential home 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 720 gpd x 365 days of proposed operation = 262,800 gallons + 7.48 gallons per cubic foot = 35,133 cubic feet of wastewater. Does not account for evapotranspiration likely to occur. Advanced GeoEnvironmental,Inc.