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' 11 February 2005 . AGE-NC Project No 02-0926 ' Page 2 of 4 well were transferred into three 40-milliliter(ml) volatile organic analysis(VOA)vials containing ' 0 5 ml 18% hydrochloric acid solution as a sample preservative, one 1-liter amber bottle without preservative, and one 16-ounce plastic bottle The samples were labeled with the monitoring well ' designation,date,time of sampling,and the sampler's initials and transported In a chilled container under chain of custody to Cal Tech Environmental Laboratories (CTEL), a Department of Health Services-certified analytical laboratory, for analysis The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline(TPH-g),diesel(TPH-d),and motor oil (TPH-mo) in accordance with EPA method 8015M, • Benzene,toluene,ethylbenzene,and total xylenes(BTEX)and fuel additives tertiary butanol (TBA), di-Isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), methyl tertiary-butyl ether (MTBE), 1,2-dibromoethane (EDB), and ' 1,2-dichloroethane(1,2-DCA) in accordance with EPA method 8260B, and • Total lead in accordance with EPA method 6010B ' . 3.0. FINDINGS Ground water elevation and flow direction were Inferred from field data, hydrocarbon-Impact to ' ground water was quantified by laboratory analysis of the ground water samples 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION The elevation of ground water in each of the monitoring wells was calculated by subtracting the ' depth to ground water from the surveyed relative casing elevations(Table 1) Depths to ground water averaged approximately 44 50 feet below surface grade (bsg) Ground water elevation at the site ranged from 25 05 feet (MW-3) to 26 28 feet (MW-2) below mean sea level (MSL) The ground ' water gradient was calculated to be approximately 0 02 foot/foot(ft/ft)toward the northeast During this monitoring event,the ground water elevations were within the screened Intervals of the wells Figure 3 illustrates the contoured ground water elevations as measured on 11 October 2004 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g, benzene, toluene, and xylenes were detected in the ground water sample collected from monitoring well MW-3 at concentrations of 110 micrograms per liter(µg/1), 6 9 µg/l, 3 2 µg/1,and 11 3 µg11, respectively 1,2-DCA was detected in the ground water samples collected from wells _• MW-1 and MW-3 at concentrations of 8 8 µg/1 and 86 µg/l, respectively A concentration map Advanced GeoEnvironmeatal,Inc