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September 20,2002 <br /> Job Number: LG02-261 <br /> Page 7 <br /> Table 4. <br /> Summary of Percolation Test. <br /> Percolation Test No. Test Period Test Depth Percolation Rate Comment <br /> (Hrs) (ft) (minutes/inch) <br /> Parcel 1,(2.0-acres) 1 3 3.09 Passed Test <br /> Parcel 2,(2.0-acres) 1 3 4.17 Passed Test <br /> Parcel 3,(2.0-acres) 1 3 1.67 Passed Test <br /> Parcel 4,(2.0-acres) I 3 2.87 Passed Test <br /> Parcel 5,(45.6-acres) 1 3 4.17 Passed Test <br /> A satisfactory percolation rate is less than or equal to 60 minutes per inch (drop) per <br /> County requirements. The percolation rate of the soil on each of the five (5) parcels was found <br /> to be satisfactory. <br /> VII. NITRATE LOADING STUDY <br /> A build up of nitrates in ground water can cause a temporary blood disorder in infants <br /> called methemoglobinemia(blue baby syndrome). Serious and occasionally fatal poisonings of <br /> infants have occurred following the ingestion of water containing nitrate concentrations greater <br /> than 10 mg/L nitrate as N or 45 mg/L nitrate as NO3. <br /> Because of the concern of nitrate leaching into ground water, a nitrate loading analysis <br /> was required by the County to estimate the average nitrate concentration of percolating water for <br /> the subject parcel. If a site is contributing excess nitrogen to ground water, ground water quality <br /> can be impacted. The nitrate sources considered for this project are percolating septic effluent <br /> from proposed facility, and deep percolation of rain water containing nitrate. <br /> The method utilized in this analysis is based on a simple mass balance formula discussed <br /> in a published article by Hantzsche and Finnemore'that provides a convenient and simplified <br /> method to estimate long-term ground-water nitrate impacts on an area-wide basis. Hantzsche and <br /> Finnemore found that over a long period of time, water quality in the upper saturated ground- <br /> water zone closely approximates the quality of percolating recharge waters. They believe that <br /> 7 Hantzshe N.N.,Finnemore,E.J. 1991,Predicating Ground-Water Nitrate-Nitrogen Impacts. Ground <br /> Water,Vol. 30,No.4. <br /> dOER50 <br /> � 1 <br /> Z W <br /> i Q ~ <br /> r <br />