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0� 7)Wastewater Flow Characteristics <br /> There will be no cooking, or food production in any of the referenced buildings. Therefore,there <br /> should be no concentrated organic loading. The characteristics of the wastewater flow will be <br /> predominately blackwater from toilets,with a comparatively small volume of graywater from sinks, <br /> or other sources of graywater. Additional wastewater constituents may consist of coffee,juices or <br /> other similar type liquids to the system. No industrial or commercial chemicals, solvents,etc. are to <br /> be introduced into the OWTS. <br /> The scientific literature cites nitrogen concentrations in domestic septic effluent typically ranging <br /> from 17 mg N/L for graywater to 140 mg N/L for blackwater toilet wastes. Therefore, based upon <br /> the findings by researcher Bauman, et al, a value of 62 mg N/L in the septic effluent will be used to <br /> calculate nitrate-nitrogen loading for this project(See Also Kaplan-Septic Systems Handbook,Pg. 147). <br /> B. CALCULATED NITRATE-NITROGEN LOADING <br /> The calculated nitrate-nitrogen impact to the soil and potentially to the groundwater is difficult to <br /> determine due to the large number of variables involved. These include: 1.) Impact from upgradient <br /> nitrate sources, 2.) Variability in wastewater flows, nitrogen concentrations and dilution effects <br /> from effluent and stormwater recharge, 3.) Changes in groundwater directional flow and elevation, <br /> 4.) Denitrification potential within the soil environment and within the confined and unconfined <br /> aquifers. <br /> The Hantzsche/Finnemore Equation is used below to predict the average resultant concentration of <br /> nitrate-nitrogen in effluent recharge water. As referenced,the property has been assessed on a total <br /> areal loading basis of 27.9 acres representing the APN, correlated with the 900 gallons per day from <br /> all six Unisex Restrooms, as calculated above. <br /> NLS§3.4,3.5,3.6 PREDICTED NITRATE-NITROGEN LOADING FROM THE PROPOSED COMPLETE <br /> BUILD-OUT OF THE RIVER OAK ORCHARD WALNUT FACILITIES: <br /> HANTZSCHEIFINNEMORE EQUATION <br /> INW(l - dib <br /> Nr= (I + R) <br /> Where: <br /> Nr= Resultant average concentration of nitrate-nitrogen in recharge water-(ppm NO3-N) <br /> I = Volume rate of wastewater entering the soil averaged over the gross developed area in inches per yr <br /> Nw= Total nitrogen concentration of wastewater in mg N/L <br /> d = Fraction(%)of nitrate-nitrogen loss due to denitrification in the soil <br /> R = Average recharge rate of rainfall- inches per yr NLS§3.2 <br /> Nb= Background nitrate-nitrogen concentration of rainfall recharge,exclusive of wastewater influences <br /> (ppm NO3-N) <br /> 6 <br /> Chesney Consulting <br />