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November 30,2007 <br /> NOA Project Number: E07192A <br /> and Finnemore mention that"...the equation ignores dispersion,lateral flow, and mixing with <br /> ground water flow from up-gradient areas. These processes would generally contribute to additional <br /> reduction of nitrate-nitrogen concentrations in ground water to the extent that the nitrate-nitrogen <br /> concentration of ground-water flow from up-gradient areas is lower." <br /> The Hantzsche and Fennemore approach is "...a conservative (worst case) first approximation of <br /> ground-water nitrate-nitrogen concentration resulting from the combined effect of on-site sewage <br /> disposal systems and precipitation. This (the equation and approach) is for estimation of long-term <br /> effect(i.e., over years) on ground-water quality, and is not intended for prediction of seasonal <br /> changes" (Hantzsche and Finnemore, 1992). <br /> The method takes into account the development area, soil denitrification factor,rainfall volume, <br /> rainfall nitrate concentration,waste effluent quantity, and waste effluent nitrate concentration. The <br /> formula, assumptions and calculations used for the analysis are shown on Plates 9 and 10. The units <br /> of nitrate used in the mass balance equation are nitrate-N,whose maximum drinking water <br /> contaminant level is 10 mg/L. <br /> 1.0 CHEMICAL AND PHYSICAL PROPERTIES OF SOIL <br /> 1.1 Chemical and Physical Soil Properties <br /> For a discussion of on-site soil properties,refer t Section 5 0 SSS. <br /> 1.2 Mass Transport Soil Properties <br /> The pe�Folation rts have revealed that the soils e fairl permeable. These soils will allow <br /> moderate to rapid infiltration of water through the a soils.The longer the effluent remains <br /> near the surface,the more treatment is enhanced due to natural processes within the soil. If the / <br /> permeable soils exist to the depth of the ground water table,it is possible that surface contaminates <br /> may be transported fairly rapidly. <br /> 2.0 GROUND WATER ANALYSIS <br /> 2.1 Regional Ground Water <br /> A discussion of regional ground water,incl ground water and directional ground / <br /> water gradient,is included in Section .1 o e SSS. ' o <br /> 4ignificant seasonal trends were evident <br /> from the maps consulted. <br /> 4 <br />