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Fwhere: anoglous Formula F -nitrogen loading in lbs/ac-day LW = wastewater loading in gals/ac-day=2,475 gals/day=20 ac= 123.8 gals/ac-day CN = nitrogen concentration: average determined to be 87 mg N/L F= conversion factor: 8.34 lbs/[10'gal-(mg/L)] LN= 123.8 gals/ac-day x 87 mg N/L x (8.34)(10"6) =0.09 lbs N/ac•day x 365 days/yr= 32.8 lbs N/ac/yr. The disposal area will be approximately 0.83 acres, say 1.0 acres. Therefore,the Crites/Tchobanoglous Formula nitrate-nitrogen loading is approximately 32.8 lbs N/ac/yr x 1.0 acre =33 lbs N/yr. Comparing the Hantzsche/Finnemore Equation with the Crites/Tchobanoglous Formula by using the results from the Hantzsche/Finnemore Equation of 7.4 ppm N0;N(32.9 ppm NO3): 7.4 ppm nitrate-nitrogen x 2.72 (conversion factor)=20.1 lbs N in an acre-foot of water. 903,375 gallons wastewater/yr- 325,851 gals/ac-ft water=2.77 ac-ft of wastewater disposed/yr x 20.1 lbs N/ac-ft= 56 lbs N/yr according to the Hantzsche/Finnemore Equation. Therefore, the Crites/ Tchobanoglous Formula predicts approximately 1.7 times less nitrate-nitrogen loading (in terms of lbs N/yr) than predicted by the Hantzsche/Finnemore Equation(33 lbs N/yr vs. 56 lbs N/yr). Kaplan ParallelepiRed Method Assumptions: 1.) The entire concentration of Total Nitrogen(87 ppm) is completely nitrified and percolates to the water table, 2.) Water table depth of five feet(mixing layer) is used based on encountered geology in our deep boring, in which there was a significant clay stratum five feet below the water table, 3.) Porosity is 33%, 4.) The entire length(N-S) of the disposal area is used, 5.)No nitrogen input from on-site landscape fertilization, 6.) Water table Darcy velocity is unknown,but assumed to be 1.0 ft/day due to clayey gravel characteristics, 7.) Groundwater flow direction is due north. Volume of dilution: 350 ft length x 5 ft depth mixing layer x 1 foot/day x 365 days/yr x 1 m3/35.3 ft3 = 18,095 m /yr 18,095,000 = 18,095,000 kg water/yr x 33%porosity= 5,971,300 kg water/yr. Amount of Nitrate: Taking the average of the lbs N/yr as determined from the Hantzsche/Finnemore Equation= 56 lbs N/yr x 0.4536 (conversion factor) =25.4 kg N/yr Increase in Mixing Layer Concentration: 25.4 kg N- 5.971 million kg water=4.3 ppm NO3 N(19.0 ppm NO3). The increase in mixing layer nitrate concentration as predicted by the Kaplan Method is also 1.7 times less than the Hantzsche/Finnemore Equation determination(4.3 ppm NO3-N vs. 7.4 ppm NO3 N). Page-18- Chesney Consulting