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Wastewater Flow Characteristics It is assumed there will be no cooking, or food production in the future Office Building. Therefore, there should be no concentrated organic loading. The characteristics of the wastewater flow will be predominately blackwater from toilets, with a comparatively small volume of graywater from sinks, or other sources of graywater. Additional wastewater constituents may consist of coffee,juices or other similar type liquids to the system. No industrial or commercial chemicals, solvents, etc. are to be introduced into the septic system. From the anticipated wastewater characteristics described above, the nitrogen emanating from the project may be at a higher concentration than what would normally be found in a typical domestic or household system. This can be attributed to the lack of a dilution effect that household graywater from showers, laundry, and dishwashing. The scientific literature cites nitrogen concentrations in residential septic effluent typically ranging from 17 mg N/L for basins, sinks, etc. to 140 mg N/L for toilet wastes. Therefore, considering a 70/30 percent usage for toilet water volume and sink water volume, respectively, as described in the USEPA Design Manual, a value of 103 mg N/L of septic effluent will be used to calculate nitrate-nitrogen loading for this project. A value of 66 mg N/L is typically used for residential calculations, as indicated in the scientific literature. B. CALCULATED NITRATE-NITROGEN LOADING The calculated nitrate-nitrogen impact to the soil and ultimately to the groundwater is difficult to determine due to the large number of variables involved, and variables unknown at this time. These include: 1.) Impact from upgradient nitrate sources, 2.) Variability in wastewater flows, nitrogen concentrations and dilution effects from effluent and stormwater recharge, 3.) Changes in groundwater directional flow and elevation, 4.) Denitrification potential within the soil environment and within the confined and unconfined aquifers and 5.)Potential landscape uptake of nitrogen. The Hantzsche/Finnemore Formula is used below to predict the average resultant concentration of nitrate-nitrogen in the effluent recharge water. As calculated below,the property has been assessed on a total areal loading basis of 4.08 acres for the existing and proposed expansion land area of the Blue Rhino facility exclusively, correlated with 360 gallons Average Daily Flow (ADF). These two factors primarily dictate the average resultant concentration of nitrate-nitrogen in the recharge water, which cannot exceed 10 ppm nitrate-nitrogen(45 ppm as nitrate). NLS§3.4,3.5,3.6 PREDICTED NITRATE-NITROGEN LOADING FROM THE PROPOSED BLUE RHINO PROJECT USING THE MAXIMUM AVERAGE DAILY FLOW(ADF)OF 360 GALLONS PER DAY,SIX DAYS PER WEEK,51 WEEKS PER YEAR,AND TAKING THE PROJECT AREA OF 4.08 ACRES INTO CONSIDERATION: HANTZSCHEIFINNEMORE EQUATION INw(1 - d) +R Nb Nr= (I+R) 6 Chesney Consulting