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' 01 October 2004 <br /> AGE-NC Project No 02-0950 <br />' Page 2 of 4 <br />' a sample preservative and 16-oz plastic bottles containing 5 ml of nitric acid as a sample <br /> preservative After collection, the samples were properly labeled, placed in a chilled container and <br /> transported under chain-of-custody to Cal Tech Environmental Laboratories (CTEL), a California <br />' Department of Health Services-certified analytical laboratory, for analysis The samples were <br /> analyzed for <br /> • Total petroleum hydrocarbons as gasoline (TPH-g) and diesel (TPH-d) in accordance with <br />' EPA Method 8015 Modified, <br /> • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and the volatile organic <br /> I compounds methyl-tertiary-butyl ether(MTBE), tertiary butyl alcohol (TBA), di-isopropyl <br /> ether (DIPE), ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), <br /> 1,2-dichloroethane (1,2-DCA) and 1,2-dibromoethane (EDB) in accordance with EPA <br /> Method 8260, and <br /> • Total lead in accordance with EPA Method 6010B <br /> 3.0. FINDINGS <br /> Ground water elevation, flow direction, and gradient were determined from field data collected on <br /> 20 April 2004 The contaminant impact to soil and ground water was quantified from the laboratory <br /> analytical data <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> At the time of the April 2004 sampling event, depths to ground water ranged from 18 29 (MW-3) <br /> feet to 18 65 (MW-2) feet below the tops of the well casings Ground water elevation at the site <br /> averaged approximately 10 61 feet below mean sea level (MSL) which indicated an increase in <br /> groundwater elevation of approximately 0 86 feet between January 2004 and April 2004(Table 1) <br /> During this monitoring event, the ground water levels in the wells were at Ieast four feet below the <br /> tops of the well screens, indicating that the wells are screened properly to yield representative <br />' shallow ground water samples <br /> Ground water flow was inferred to be flowing towards the cast with an average hydraulic gradient <br /> of 0 002 foot/foot, the direction rotated more easterly since the last quarter while the gradient was <br /> much shallower than previous quarters Figure 3 illustrates the contoured ground water elevations <br /> as measured on 20 April 2004 Ground water directions and gradients can vary greatly as they are <br /> influenced by seasonal changes to the static water table <br /> Advanced GeoEnvironmental,Inc <br />