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14 July 2006 <br /> • AGE-NC Project No 95-0137 <br /> Page 2 of 4 <br /> vials and into two 1-liter amber bottles Samples were properly labeled,stored in a chilled container, <br /> and transported under chain of custody to Cal Tech Environmental Laboratories(CTEL),a California <br /> Department of Health Services(DHS)-certified laboratory,for analysis Each sample was analyzed <br /> for <br /> • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br /> respectively) in accordance with EPA Method 8015 Modified, and <br /> • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and fuel oxygenates methyl <br /> tertiary-butyl ether(MTBE), tertiary-butyl alcohol (TBA), dl-isopropyl ether(DIPE), ethyl <br /> ' tertiary-butyl ether(ETBE),tertiary-amyl methyl ether(TAME), 1,2-dibromoethane(EDB), <br /> and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B <br /> y. <br /> 3.0. FINDINGS <br /> ' Ground water elevation, flow direction, and gradient were determined from field data collected on <br /> 15 May 2006, the contaminant impact to ground water was quantified from laboratory data <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> ' <br /> Depths to ground water during the May 2006 monitoring event ranged from 20 60 feet (MW-3) to <br /> 23 49 feet(MW-9)below the tops of the well casings,the average depth to ground water decreased <br /> ' approximately 0 8 feet since the February 2006 quarterly monitoring event The calculated ground <br /> water elevations ranged from 36 17 feet (MW-8)to 39 27 feet (MW-5) <br /> ' The ground water flow direction was northwest across the former UST area at the site,at a hydraulic <br /> gradient of approximately 0 0001 fool/foot(ft/ft)(Figure 3) Upgradient of the former UST area,the <br /> ' ground water flow direction was northwest with a gradient of approximately 0 04 ft/ft, away from <br /> well MW-5 N�n�� F����,, a1 4L <br /> A <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> ' TPH-d was detected in the off-site well MW-6 (Jimco Truck Plaza) at a concentration of 33,000 <br /> micrograms per liter (gg/l) TPH-g was detected in wells MW-6 and MW-8 at concentrations of <br /> 28,000 �Lgll and 160 µg/l,respectively, however,the detection of TPH-g in MW-6 was noted by the <br /> ' laboratory to be mostly in diesel range organic <br /> 1 <br /> • <br /> ' Advanced GeoEnvironmental,Inc <br /> 1 <br />