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�.. 3o <br /> August 26,2002 <br /> Job Number:LG02-286 <br /> Page 7 <br /> tests were conducted. Essentially, a homogeneous brown fine to medium sand was encountered <br /> in the boring to a total depth of 3 feet. The 3 foot percolation test boring was converted into a <br /> shallow percolation test. <br /> The percolation test casing used for the test was 2-inch diameter PVC pipe with an open <br /> end on the top and bottom. Perforations were made on approximately the last 12-inches of the <br /> casing. Two (2) inches of"pea gravel'were placed in the bottom of the hole, the casing was <br /> installed, and 0.5 feet of"pea gravel'was backfilled within the annular space. The percolation <br /> test boring was pre-soaked 24-hours prior to the test. <br /> A one(1)hour percolation test was conducted for the percolation test. The test was <br /> conducted on August 2, 2002,in accordance with the requirements of San Joaquin County <br /> Environmental Health Division. Each percolation test was observed by Mr. Johnny Yoakum <br /> Environmental Health Specialist of the San Joaquin County Environmental Health Division. <br /> A satisfactory percolation rate of 1.4 min/inch was achieved. A satisfactory percolation <br /> rate is less than or equal to 60 minutes per inch(drop) for a shallow test. In addition to the soil <br /> suitability study, a nitrate loading study was required for project approval by the County. <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/1 nitrate as N or 45 mg/1 nitrate as NO;. <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 /> 7 Hantzshe N.N.,Finnemore,E.J. 1991,Predicating Ground-Water Nitrate-Nitrogen Impacts. Ground <br /> Water,Vol. 30,No.4. <br /> V :DEJ fO <br /> '4 <br /> Z <br /> O <br /> �JSOC\ <br />