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1 <br />' 14 February 2003 <br /> AGE-NC Project No 98-0497 <br />' Page 2 of 4 <br />' 2 2 GROUND WATER SAMPLE COLLECTION <br /> Prior to the collection of ground water samples, the depth to ground water was re-measured in each <br />' well to ensure that a minimum of 80% of the initial water volume had recharged Water samples <br /> were then collected from each well using a clean,disposable plastic bailer The water was transferred <br />' into one 1-liter amber bottle and three chilled 40-m1 volatile organic analysis(VOA)vials containing <br /> 0 5 mI hydrochloric acid(18%)as a sample preservative After collection,the samples were labeled <br /> and placed to a chilled container for transportation under chain-of-custody to McCampbell <br />' Analytical Laboratories(MAI),a Department ofHealth Services-certified analytical laboratory Each <br /> sample was analyzed for <br /> • Total petroleum hydrocarbons as gasoline and diesel(TPH-g and TPH-d)In accordance with <br />' EPA Method 8015 Modified, and <br /> • Benzene,toluene,ethylbenzene and xylenes(BTEX)and methyl tert-butyl ether(MTBE) in <br />' accordance with EPA Method 8021B <br />'• <br /> 30. 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 />' Ground water elevations were determined by subtracting the measured depths-to-water firoin them <br /> surveyed casing elevations The average ground water elevation on 27 December 2002 was 40 feet <br /> below mean sea level (MSL), with the average depth to water at 65 4 feet below casing tops The <br />' average ground water elevation to the wells had decreased 0 1 feet since the last ground water <br /> monitoring event Ground water was within the screened interval of each monitoring well <br />' The shape of the water table at the time of the December 2002 monitoring event was in the form of <br /> a south-plunging trough,net flow of ground water near the former UST location was determined to <br /> be to the southeast under an average gradient of 0 001 ft/ft Figure 3 illustrates the contoured ground <br />' water elevations as measured on 27 December 2002 <br />' Advanced GeoEnvironmental,lue <br />