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' 13 January 2006 <br /> . AGE-NC Project No 98-0497 <br /> Page 2 of 4 <br />' 22 GROUND WATER SAMPLE COLLECTION <br /> Prior to the collection of ground water samples,the depth to ground water was re-measured in each <br />' monitoring well to ensure that a minimum 80% of the initial water volume had recharged Water <br /> samples were collected from each well using the inertia pump and dedicated tubing and a disposable <br /> bailer at well MW-5 The water was transferred into one I-liter amber bottle and three 40-milliliter <br />' (ml) volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid solution as a <br /> sample preservative After collection,the samples were labeled and placed in a chilled container for <br /> transport under chain of custody to Cal Tech Environmental Laboratories (CTEL), a California <br /> Department of Health Services(DHS)-certified analytical laboratory in Paramount,California The <br /> samples were analyzed for <br />' Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br /> respectively) in accordance with EPA Method 8015M, and <br /> • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and the fuel additive methyl <br /> tertiary-butyl ether(MTBE) by EPA Method 8260B <br />' • 3.0. FINDINGS <br />' Ground water elevation and flow direction were inferred from field data Hydrocarbon-impact to <br /> ground water was assessed by laboratory analysis of the ground water samples <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br />' At the time of the December 2005 sampling event, depths to ground water at the site ranged from <br /> 68 18 feet(MW-5)to 69 41 feet(MW-4)below the tops of the well casings Ground water elevation <br />' at the site averaged approximately 43 93 feet below mean sea level (MSL), indicating an average <br /> decrease in ground water elevations of 0 65 feet since the last monitoring event in September 2005 <br /> Ground water elevation data is included in Table 1 <br />' Ground water flow direction was calculated from the ground water elevation data The ground water <br /> was inferred to be flowing north-northeast at an approximate hydraulic gradient of 0 0008 ft/ft <br />' 3 Figure 3 illustrates the contoured ground water elevations as measured on 07 December 2005 _ <br /> • <br />' Advanced GeoEnvironmentai,Inc <br /> 1 <br />