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"` • �•�N rter l Rnderson (2091 333-83(]3 <br /> P. 2 <br /> Bencto Tank Lines, <br /> Nitrate Loading Study <br /> Page 2 <br /> SOIL PROFILE <br /> A test hole was excavated to determine the soil profile in the general area. The test hole <br /> was excavated with a 4.5 inch diameter land auger. For approximate location of the test hole see <br /> the attached Parcel Map. The test hole was logged by an engineer and a description of the soils <br /> encountered is presented on the attached Log of Boring Sheet. The soils encountered in the test <br /> boring consisted entirely of silty fine to medium sand continuing to the maximum depth explored <br /> of 10 feet. <br /> EXISTING GROUND WATER <br /> Water samples of the deep ground water were obtained from existing water wells <br /> servicing Building-1 and the Kenworth Building. Samples were tested for nitrates. Test results <br /> indicated that the well servicing Building-] has a current water nitrate concentration of 58mg/I <br /> and the well servicing the Kenworth building has a current water nitrate concentration of 29 <br /> mg/l. A copy of the laboratory test results is attached. <br /> NITRATE LOADING STUDY <br /> The nitrate loading study was performed by using a mass balance equation to obtain a <br /> simplified prediction of groundwater nitrate buildup from the proposed installation of a septic <br /> system. A summary of assumptions that were made and the calculations is attached. Although <br /> 80%of the future development will be covered with pavement,all site drainage will be collected <br /> in a storm retention pond. Since subsurface soils consisted entirely of sand, it was assumed that <br /> at least 80°le of the yearly rainfall will deep percoalte. A background nitrate level of 0.5 mg/I <br /> was assumed for rainfall. <br /> For the proposed development,with a 5.7 acre lot density,a resultant average nitrate level <br /> of percolate of 23A mgll was obtained. This level is below the MCL of 45mg1l and also below <br /> the existing ground water nitrate levels. <br /> LIMITATIONS <br /> 'Phe conclusions of this report are based on the information provided by Roger Liston of <br /> Beneto Tank Lines,Inc. regarding the proposed development,the nse of the subject property,and <br /> the site conditions as they existed at the Lime we excavated our test hole and performed the study. <br /> It was assaned that the test hole is representative of the subsurface conditions in the general area. <br /> veRaQ� <br /> aq�A <br /> SOS <br />