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I 30 May 2005 AGE-NC Project No 02-0964 Page 2 of 4 MW-1 were transferred into three 40-milliliter(ml)volatile organic analysis(VOA)vials containing 0 5 ml 18%hydrochloric acid solution as a sample preservative 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(DHS)-certified analytical laboratory for analysis The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015M, • Volatile aromatic compounds benzene,toluene,ethylbenzene,and total xylenes(BTEX)with fuel oxygenates tertiary butanol(TBA), di-isopropyl ether(DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether(TAME), methyl tertiary butyl ether (MTBE), and fuel lead scavengers ethylene dibromide(EDB)and 1,2-dichloroethane(1,2-DCA)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 quantified by laboratory analysis of the ground water sample 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 about 28 85 feet below surface grade(bsg) Ground water elevations at the site ranged from 16 95 feet(MW-3)to 17 95 feet(MW-1)below mean sea level (MSL) The ground water gradient was calculated to be approximately 0 008 foot/foot (ft/ft) toward the east-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 31 March 2005 I 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES Dunn this monitoring event a sample was only taken from well MW-1 TPH- was detected in the During g p Y g water sample from well MW-1 at a concentration of 12,000 micrograms per liter(µg/1),benzene was detected at a concentration of 490 pg/l, toluene was detected at a concentration of 28 pg/l, and ethylbenzene and total xylenes were detected at concentrations of 1,500 µg/I and 6,640 µg/1, Advanced GeoEnvironmental,Inc I