Laserfiche WebLink
HANTZSCHEIFINNEMORE EQUATION: <br /> 1&(I - d)+RNh <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 /> Values and Assumptions: <br /> I=33 Employees/Customers x 15 rals/petson/d x 255 Work d/vr— 126,225 Gals=total WW/yr= 16,875 cu ft=0.55 in/yr <br /> 8.42 Ac x 43,560 sq fl/Ac x (1 ft/12 in) <br /> Nw= 103 mg N/L: 20%reduction from the septic tank =(1-0.2)103 = 82 mg N/L <br /> d = Assume 15%due to fine-grained silty sand soil located at the 8-ft depth with decrease in NO3-N concentration. <br /> R = 1 l.5 in/yr. <br /> Nb= Assumed to be 0.1 ppm NO3-N <br /> 0.55 in/yr(82 mg N/L) (1 -0.15)+(11.5 in/yr x 0.1 mg/L) <br /> Nr in/yr+ 11.5 in/yr) <br /> Nr:'_' 3.3 ppm as nitrate-Nitrogen (NO3-N)or 14.8 ppm as nitrate(NO3) <br /> IV. WASTEWXTER MANAGEMENT SYSTEM - OPERATIONAL CRITERIA <br /> SSS§3.7. Disqussions on the efficient operation of the effluent disposal method, disposal field <br /> longevity, and-environmental protection are based upon the environmental parameters discussed <br /> within this report. The wastewater management system to be constructed is described as follows, <br /> and is based upon discussions with EHD personnel and the EHD Sewage Standards. <br /> A. SEPTIC TANK <br /> Septic tanks store the accumulated sludge, scum and effluent(clear zone)volumes, which in turn <br /> affect treatment of Total Nitrogen(TN)within the tank. Total Nitrogen is the summation of <br /> ammonia-nitrogen(NH,) and organic nitrogen(proteins, amino acids, enzymes, etc.). Since the <br /> septic tank is predominately anaerobic,nitrogen cannot exist in its oxidized state as nitrate within <br /> the septic effluent for any length of time. Nitrate is quickly reduced to NO or NO,. If nitrate <br /> existed in the tank effluent, this would also be added to ammonium and organic nitrogen to arrive <br /> at Total Nitrogen. <br /> 9 <br />