Laserfiche WebLink
IWO <br /> `./ <br /> bw July 28,2006 <br /> NOA Project Number: E06068A <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 /> bw 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 /> sm effect (i.e., over years) on ground-water quality, and is not intended for prediction of seasonal <br /> changes" (Hantzsche and Finnemore, 1992). <br /> 60 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 through 16. The <br /> is- units of nitrate used in the mass balance equation are nitrate-N,whose maximum drinking water <br /> contaminant level is 10 mg/L. <br /> ,/2.0 CHEMICAL AND PHYSICAL PROPERTIES OF SOIL <br /> 2.1 Chemical and Physical Soil Properties <br /> For a discussion of on-site soil properties,refer to Section 5 of the SSS. <br /> L <br /> 2.2 Mass Transport Soil Properties <br /> �• Layered soils and consistency of silty sediments will typically provide an added degree of protection <br /> between percolating effluent at the surface and shallow ground water aquifers. Soils of this type do <br /> not typically present a high risk of excessive mass transport of nitrate or other constituents of <br /> concern. <br /> •• ✓3.0 GROUND WATER ANALYSIS <br /> 3.1 Regional Ground Water <br /> boo <br /> A discussion of regional ground water,including depth to ground water and directional ground <br /> water gradient,is included in Section 4.1 of the SSS. No significant seasonal trends were evident <br /> from the maps consulted. <br /> /3.2 Potential Ground Water Contamination Issues <br /> A discussion of issues related to potential ground water contamination is included in Section 4.2 of <br /> the SSS. <br /> bn <br /> 2 <br /> 60 <br />