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lie 10 Fe ' bruary 2003 AGE-NC Project No 95-0167 Page 2 of 4 sample was transferred into 40-m1 VOA vials containing 0 5 ml 18%hydrochloric acid as a sample preservative After collection,the samples were properly labeled,placed in a chilled container and ' transported under chain-of custody to McCampb ell Analytical,Inc (MAI),a California Department of Health ServicesDHS -certified laboratory,( } and were analyzed for ' Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified, • Benzene, toluene, ethylben7ene and total xylenes (BTEX) and methyl-tertiary butyl ether (MTBE) in accordance with EPA Method 8021B, and • The fuel additives di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETRE), MTBE, tertiary-amyl methyl ether (TAME), tertiary butanol (TBA), methanol, ethanol, 1,2- dibromoethane(EDB) and 1,2-dichloroethane(1,2-DCA) in accordance with EPA Method 8260B 3.0. FINDINGS r 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 giound water samples 3 1 GROUND WATER ELEVATION AND GRADIENT For the December 2002 sampling event,depths to ground water ranged from 15 48 feet to 16 28 feet below the tops of the well casings Ground water elevations at the site ranged from 5 87 feet(MW-5) to 7 19 feet(MW-2) below mean sea level (MSL) Ground water was within the screened interval ' ofMW-1 through MW-6 The ground water flow direction was determined by plotting and contouring the ground water elevation data The shape of the water table at the time of the December 2002 monitoring event was in the form of a northwest-plunging trough, net flow of ground water at the site was determined to be to the northwest under an average gradient of 0 03 ft/ft Figure 3 illustrates the contoured ground Iwater elevations as measured-on 1 I December 2002 ' 32 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the water samples collected from monitoring wells MW-1 and MW-2 at concentrations of 33,000 micrograms per liter(µg11) and 540 µg/l, respectively ' Advanced GeoEnvironmental,Inc L