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Various scientific methods exist to estimate nitrate-nitrogen loading. This study uses the <br /> Hantzsche/Finnemore Formula to predict the average resultant concentration of nitrate-nitrogen in <br /> effluent recharge water. As referenced above and calculated below,the proposed project has been <br /> assessed from the standpoint of nitrate loading on an areal loading basis correlated with the total <br /> number of anticipated people (employees and customers)per workday. These two factors <br /> primarily dictate the average resultant concentration of nitrate-nitrogen in the recharge water, <br /> which should not exceed 10 ppm nitrate-nitrogen(45 ppm as nitrate). The following calculations <br /> demonstrate that the anticipated effluent recharge water from the proposed project will not exceed <br /> 10 ppm NO3-N. <br /> CALCULATED NITRATE LOADING FROM THE ANTICIPATED NUMBER OF <br /> PEOPLE (EMPLOYEES AND CUSTOMERS) THAT MAY POTENTIALLY USE THE <br /> ON-SITE RESTROOM FACILITIES DAILY, USING 15 GALLONS/PERSON/DAY= <br /> HANTZSCHEIFINNEMORE EQUATION <br /> IN 0 - d) + 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 <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 <br /> Nb= Background nitrate-nitrogen concentration of rainfall recharge, exclusive of wastewater <br /> influences (ppm NO3-N) <br /> Values and Assumptions <br /> 12 Employees (Daily Average) + 25 Customers (Daily Average) = 37 People <br /> 1=37 people x-l5 gals/person/d x 260 work dlyr= 144,300 pais=total WW/yr= 19,291 cu ft= 1.48 in/yr <br /> 3.6 Ac x 43,560 sq ft/Ac x (1 ft/12 in) <br /> Nw= 103 mg NIL <br /> d = Assume 20% due to a fine-grained soil <br /> R = 17 in/yr. <br /> Nb= Assumed to be 0.1 ppm NO3-N <br /> 1.48 in/yr 103 m N/L 1 - 0.20 + 17 in/yr x 0.1 mg/L) <br /> Nr = (1.48 in/yr+ 17 in/yr) <br /> Nr = 6.7 ppm as nitrate-nitrogen(NO3-N) or 29.8 ppm as nitrate (NO3) <br /> 9 <br /> Chesney Consufting <br />