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I04 March 2005 f� AGE-NC Protect No 01-0877 ' Page 2 of 4 analysis(VOA)vials containing 0 5 ml 18%hydrochloric acid solution as a sample preservative,and ' one 1-liter amber bottle without preservative After collection, the samples were properly labeled, placed in a chilled container, and transported under chain of custody to Cal Tech Environmental ' Laboratories (CTEL), a State of California Department of Health Services (DHS)-Environmental Laboratory Accreditation Program certified(#2424)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 8015 Modified, and ' Benzene,toluene, ethylbenzene, and total xylenes(BTEX)and volatile organic compounds methyl-tertiary-butyl ether(MTBE),tertiary butyl alcohol(TBA),di-Isopropyl ether(DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), 1,2-dichloroethane ' (1,2-DCA) and 1,2-dibromoethane (EDB) In accordance with EPA Method 8260 ' 3.0. FINDINGS ' .' Ground water flow direction, elevation, and gradient were determined from data collected in the field The hydrocarbon Impact to ground water was quantified by the laboratory data obtained from the ground water samples ' 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION At the time of the October 2004 sampling event, depths to ground water ranged from 28 07 to 28 71 ' feet below the tops of the well casings(Table 1) The average ground water elevation at the site was approximately 18 36 feet below mean sea level (MSL), which Indicates a decrease in the static ground water elevation of approximately 107 feet since the last monitoring event The ground water ' table forms a shallow northeast trending plunging-ridge, with a net ground water flow toward the northeast under a gradient of approximately 0 004 foot/foot (Figure 3) During the October 2004 monitoring event,ground water levels were within the screened interval of each well,Indicating that ' the wells were screened properly to yield representative ground water samples ' 32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in all ground water samples at concentrations ranging from 76,000 micrograms ' per liter(µg/1)in sample MW-4 to 250,000 µg/1 In sample MW-3 BTEX compounds were detected in water samples collected from all wells, the maximum concentrations were 63,000 µg/l benzene ' Advanced GeoEnvironmental,Inc