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F <br /> antzsche/Finnemore Equation is used to estimate the resultant average nitrate-nitrogen <br /> ntration in the effluent recharge water at a maximum volume of 2,500 gpd: <br /> TZSCHEIFINNEMORE EQUATION <br /> INw(1 - dl +R Nb <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 <br /> inches per yr. Total area of subject property =6.2 ac. <br /> Nw= Total nitrogen concentration of wastewater in N mg/L (87 mg N/L/day) <br /> d = Fraction (%) of nitrate-nitrogen loss due to denitrification in the soil <br /> R = Average recharge rate of rainfall - inches per yr(11 in.) <br /> Nb= Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater <br /> influences (ppm NO3-N) <br /> Values and Assumptions: <br /> 2.500 gals/day x 255 workdav/vr=637.500 eals/vr= 85.227 cu ft W W/Y = 3.8 in/yr <br /> 1 = 43,560 cu ft/Ac ft x 6.2 Ac x (111/12 in) <br /> Nw= 87 mg N/L - with no nitrogen reduction in a septic tank= 87 mg N/L <br /> d = 10% from biomat formation and 5%from low clay content percentage soil under leachlines. <br /> Nb = Assumed to be 0.1 ppm NO3-N <br /> 3.8 in/yr (87 mg N/L) 0 - 0.15) + 01 in/yr x 0.1 mg/L) <br /> Nr = (3.8 in/yr+ 11 in/yr) <br /> Nr = 19.1 ppm as NO3 N or 85 ppm as NO3 <br /> The nitrate concentration observed in the groundwater under the property (62 ppm NO3) is 27% <br /> lower than the nitrate loading calculated for untreated wastewater effluent recharge from the Aqua <br /> Pools facility (85 ppm as NO3). Both concentrations exceed the Maximum Contaminant Level <br /> (MCL) for nitrate in drinking water, which is 45 ppm. <br /> B. Wastewater Disposal System Design Specifications <br /> Anticipated Wastewater Flow Volumes <br /> EHD uses a number of criteria to project wastewater flow volumes, typically based upon Published <br /> Sewage Standards Data: 1.) 15 gals per industrial employee and customers per day, 2.) The number <br /> of bathroom fixtures, or bedrooms (e.g., 150 gal/toilet fixture for store employee/public use), 3.) <br /> The number of parking stalls, and/or 4.) Historical wastewater flow data for a specific facility that <br /> can be compared with a new facility. The following Chart illustrates wastewater flow using each of <br /> these applicable parameters: <br /> Page-7- <br /> Chesney Consulting <br />