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' 30 May 2005 u • AGE-NC Project No 02-0926, ' Page 2 of 4 1 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 1 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 1 J. 3.0. FINDINGS Ground water elevation and flow direction were inferred from field data, hydrocarbon-impact to ' groundwater 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 43 85 feet below surface grade (bsg) Ground water elevation at the site ranged from 24'43 feet (MW-3) to 25 66 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 19 January 2005 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g, benzene, toluene, ethyl-benzene and xylenes were detected in the ground water sample collected from monitoring well MW-3 at concentrations of 3 50 micrograms per liter(µg/l),3 1 µg11, ' 9 1 µg/1, 5 2 µg/1, and 50 µg11, respectively 1,2-DCA was detected in the ground water samples • collected from wells MW-1 and MW-3 at concentrations of 7 1 µg/1 and 32 µg/1, respectively ' Advanced GeoEnvironmental,Ine