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24 October 2003 AGE-NC Project No. 98-0497 Page 2 of 4 2.2. GROUND WATER SAMPLE COLLECTION Prior to the collection of ground water samples, the depth to ground water was re-measured in each well to ensure that a minimum of 80% of the initial water volume had recharged. Water,samples were then collected from each well using a clean,disposable plastic bailer.The waterwas transferred into one i-liter amber bottle and three chilled 40-m1 volatile organic analysis(VOA)vials containing 0.5 ml hydrochloric acid(18%)as a sample preservative. After collection,the samples were labeled and placed in a chilled container for transportation under chain-of-custody to McCampbell Analytical Laboratories(MAI),a Department of Health Services-certified analytical laboratory. Each sample was analyzed for: • Total petroleum hydrocarbons as gasoline and diesel(TPH-g and TPH-d)in accordance with EPA Method 8015 Modified; and • Benzene, toluene, ethylbenzene and xylenes (BTEX) in accordance with EPA Method 8021B. • Fuel additives including di-isopropyl ether(DIPE),ethyl tertiary-butyl ether(ETBE), methyl tertiary-butyl ether (MTBE), tertiary-amyl methyl ether (TAME), tertiary-butyl alcohol (TBA), 1,2-dibromoethane(EDB), 1,2-dichloroethane(1,2-DCA), ethanol and methanol in accordance with EPA Method 8260B. 3.0. FINDINGS Ground water elevation and flow direction were inferred from field data. Hydrocarbon-impact to ground water was assessed by laboratory analysis of the ground water samples. 3.1. GROUND WATER ELEVATION AND GRADIENT Ground water elevations were determined by subtracting the measured depths-to-water from the surveyed casing elevations. The average ground water elevation on 16 June 2003 was 39.0 feet below mean sea level (MSL), with the average depth to water at 63.9 feet below casing tops. The average ground water elevation in the wells was unchanged between the March and June 2003 monitoring events. Ground water was within the screened interval of each monitoring well. The water table flow direction at the former UST location was east-northeast under an average ;radient of 0.002 ft/ft. Figure 3 illustrates the contoured ground water elevations as measured on 16 June 2003. Advanced GeoEnvironmental,Inc.