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B. CALCULATED NITRATE-NITROGEN LOADING <br /> NLS§3.4,3.5,3.6 The calculated nitrate-nitrogen impact to the soil and ultimately to the <br />(3 groundwater is difficult to determine due to the large number of variables involved and variables <br /> 3 4) unknown at this time. These include: 1.)Future installation methods and design of the on-site <br /> wastewater treatment system for any future project, 2.) Impact from upgradient nitrate sources, 3.) <br /> Variability in wastewater flows, nitrogen concentrations and dilution effects from effluent and <br /> stormwater recharge, 4.) Changes in groundwater directional flow and elevation, 5.) Denitrification <br /> potential within the soil environment and within the confined and/or unconfined aquifers and 6.) <br /> Potential landscape uptake of nitrogen. <br /> 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 from a conventional septic system. As calculated below, the property has been <br /> >) assessed on a total areal loading basis correlated with the total number of people on-site everyday of <br /> the year. These two factors primarily estimate the average resultant concentration of nitrate-nitrogen <br /> in the recharge water. As referenced,this concentration cannot exceed 10 ppm nitrate-nitrogen (45 <br /> ppm as nitrate). <br /> PREDICTED NITRATE-NITROGEN LOADING FROM A COMPLETELY BUILT- <br /> OUT PROJECT USING AN E.H.D. APPROVED SEPTIC SYSTEM. THE MAXIMUM <br /> NUMBER OF PEOPLE APN 059-140-37 (16.26 Acres) CAN SUPPORT WITHOUT <br /> EXCEEDING THE M.C.L. FOR NITRATE _ <br /> HANTZSCHEIFINNEMORE EQUATION <br /> INw(1 - d) + RN6 <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 NIL <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 /> Values <br /> 03 N).Values and Assumptions: <br /> I=150 people Maximum x 15 gals/person/d x 365 d/vr—821,250 gals=total WW/yr= 109.793 cu ft= 1.86 in/yr <br /> 16.26 Ac x 43,560 sq ft/Ac x (l ft/12 in) Gtcf.;R <br /> 9 <br /> Chesney Consulting <br />