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' 09 January 2006 AGE-NC Project No. 95-0137 Page 2 of 4 vials and into one 1-liter amber bottle: Samples were properly labeled, stored in a chilled container, ' and transported under chain of custody to Cal Tech Environmental Laboratories(CTEL),a Calif6rnia Department of Health Services(DHS)-certified laboratory, for analysis. Each sample was analyzed for: • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d,- respectively) in accordance with EPA Method 8015 Modified; and ' Benzene; toluene, ethylbenzene, and total xylenes (BTEX) and.fuel oxygenates 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-dibromoethane(EDB), ' and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B. glaa ` ([�ZCe(j nt f ra fe. 94j � � J 1 7 i 3.0. FINDINGS Ground water elevation,flow direction, and gradient were determined from field data collected on '21 November 2005; the contaminant impact to ground water was quantified from laboratory data. 3.1. GROUND WATER GRADIENT AND FLOW DIRECTION Depths to groan •wat r during t November 2005 monitoring event ranged from 23-6$-feet{MW-4 mid AAWz to eet (MWp below the tops of the well casings; the average depth to ground Water increased approximately 0.5 feet since the August 2005 quarterly monitoring event. The calculated ground water elevations ranged from 33.92 feet (MW-4) to 37.36 feet (MW-5).The ground water flow direction was west to south west across the site, at a hydraulic gradient of ,. approximately 0.007 foot/foot(ft/ft), at the former UST release area(Figure 3). ' 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-d was detected in the off-site Jimco well MW-6 at a concentration of 26,000 micrograms per ' liter (µg/1). TPH-g was detected in wells MW-6 and MW-8 at concentrations of 25,000 4g11 and '300µg/l,respectively;however,the detection of TPH-g in MW-6 was noted by the laboratory to be mostly in diesel range organic. The fuel additive MTBE was detected in monitoring well MW-8 (off-site) at a concentration of 250 µg/l. The lead scavenger 1,2-DCA was thtdetected in the samples from wells MW-4, MW-9, ' and MW-10 at concentrations of 5.3 µg/l, 20 µg/l, and 48 µg11, respectively. TAME was detected • in well MW-8 at a concentration of 6.0 µg11. Advanced GeoEnvironmental,Inc.