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PERCOLATION TESTING <br /> The percolation testing was conducted on the same date as perc testing for the Carmelo's <br /> Industrial Park project, directly to the north. The test boring for the subject property was <br /> prepared to a depth of 18 inches in the location referenced on the Site Plan. Test results are <br /> found on the attached FIELD PERCOLATION TESTINO REPORT under TEST HOLE#S.L.F. for South <br /> Leachfield. The test results reveal a comparatively rapid perc rate of 17 minutes per inch, <br /> considering the clay content and tightness of the soil. This permeability can be attributed to the <br /> high gravel content which allows the formation of conduits to facilitate the downward movement <br /> of water. Although the test boring was pre-saturated, the rate did not appear to slow significantly <br /> over the test duration. Over time, and given the indigenous subsurface clay soils, perc rates <br /> i would have probably reached equilibrium at a much slower rate than what was observed by the <br /> test results. <br /> NITRATE LOADING CALCULATIONS <br /> Using the Hantzsche/Finnemore Equation to predict nitrate-nitrogen loading based on the <br /> proposed occupancy numbers and the use of a conventional septic system: <br /> HA NTZS CHEIFINNEMORE E QUATION <br /> Mi,,,(I - 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 NIL <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 /> I= 375 szals/d x 260 work d/yr=97,500 gals =total WW/yr= 13,035 cu ft = 5.0 in. /� <br /> 31,631 sq ft <br /> Nw= 103 mg NIL: 20%reduction from septic tank+ 10% removal from biomat= 74 mg NIL <br /> d = Assume 30% <br /> R = 10 in/yr. However, 75% of total area covered w/roofs and asphalt .•. 2.5 in/yr. <br /> Nb= Assumed to be 0.1 ppm NO3-N <br /> 5.0 in/yr 74 mg NIL (I - 0.30) + (2.5 in/yr x 0.1 mg/L) <br /> Nr = (5.0 in/yr+ 2.5 in/yr) <br /> Nr = 34.6 ppm as nitrate-nitrogen(NO3-N) or 155.6 ppm as nitrate (NO3) <br /> -2- <br /> Naffey Ag research <br />