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FFFrom loyees and customers who may potentially use the toilet/sink, etc. on a workday basis. umed there will be no cooking within kitchen/office areas in any of the existing or future gs, and consequently no need for garbage disposals. Therefore, there should be no highly trated organic loading. The characteristics of the wastewater flow will be predominately ater from toilets, with a comparatively small volume of graywater from sinks, or other s of graywater. Additional wastewater constituents may consist of coffee,juices or other type liquids to the system. No industrial or commercial chemicals, solvents, etc, should oduced into any of the septic systems. he 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 graywater from showers, laundry, etc. would provide. The scientific literature cites nitrogen concentrations in residential septic effluent typically ranging from 17 mg NIL for basins, sinks, etc. to 140 mg NIL for toilet wastes. Therefore, considering a 70130 percent usage for toilet water volume and sink water volume, respectively, a value of 103 mg NIL of septic effluent will' .be used to calculate nitrate-nitrogen loading for this project. B. PREDICTED NITRATE-NITROGEN LOADING The calculated or estimated nitrate-nitrogen impact to the soil and ultimately to the groundwater is difficult to determine due to the number of variables involved. These variables include 1.) past installation methods of the on-site septic systems, 2.) future replacement methods for failed systems, 3.) impact from upgradient nitrate sources, 4.) variability in wastewater flows, nitrogen concentrations and dilution effects, 5.) changes in groundwater directional flow and elevation, and b.) denitrification potential and landscape uptake of nitrogen. Various scientific methods exist to estimate nitrate-nitrogen loading. This study uses the " Hantzsche/Finnemore Formula to predict the average resultant concentration of nitrate-nitrogen in effluent recharge water. As calculated below, each parcel has been assessed individually on an areal loading basis and the total number ofpeople per workday. These two factors dictate that the j average resultant concentration of nitrate-nitrogen in the recharge water cannot exceed 10 ppm k nitrate-nitrogen. However, as referenced above in Section lI D,the current water table nitrate concentration is 13% over the MCL for nitrate (52 ppm vs. 45 ppm). Therefore,the calculated maximum number of people each Parcel can theoretically support has been reduced by 13%to balance wastewater recharge with the existing water table nitrate concentration. PREDICTED NITRATE-NITROGEN LOADING FROM A COMPLETELY BUILT- OUT PROJECT USING CONVENTIONAL SEPTIC SYSTEMS WITH THE MAXIMUM NUMBER OF PEOPLE ON PARCEL 1: 6 7laffey AB research