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0 <br /> 1,800 and 8,100 mg/kg respectively. Significant concentrations of TPHg were detected above <br /> and near the groundwater table, but not below it. For example, the samples from boring 16B-6b <br /> at 16.5, 18.5 (the approximate groundwater elevation), and 24.5 feet bgs, contained TPHg <br /> concentrations of 16,000, 6,000 and below detection limits. <br /> MTBE was not detected in any samples at method detection limits. Benzene was below <br /> detection limits in all soil samples except for the samples from B16-7b at 17 feet bgs and 16B-11 <br /> at 25 feet bgs, which contained 100 mg/kg and 0.17 mg/kg respectively. Benzene may have <br /> been present in other samples with high TPHg concentrations, but the high TPHg concentrations <br /> resulted in elevated benzene detection limits. Various amounts of toluene, ethylbenzene, total <br /> xylenes compounds were detected in samples that contained TPHg, as shown in Table 1. <br /> The analytical laboratory qualified several of the TPHg detections as not matching the standard <br /> pattern,but stated that the product could be older degraded gasoline. <br /> 4.3.2 Groundwater Results <br /> Prior to sampling, a new bailer was lowered into all of the wells in the investigation area(VW-1, <br /> VW-2,VW-3, VW-5,EW-3,EW-4 and MW-3)and each boring to look for free product. Free <br /> product was not identified in the vapor wells VWl through VW5, extraction wells (EW3 and <br /> EW4) or monitoring well MW-3. A hydrocarbon sheen and strong hydrocarbon odor were noted <br /> in all of the borings except for 16B•11. Strong hydrocarbon odors were noted in all wells except <br /> for VW-1 and VW-2. <br /> Groundwater samples were obtained from groundwater extraction well EW-4, and from borings <br /> 16B-6b and 16B-8 through 16B-11. Boring 16B-7b was advanced with a small drill rig that met <br /> refusal at 18 feet bgs,before groundwater was encountered. EW-4 was not purged prior to <br /> sampling. <br /> 6 <br /> 25971014-DGD 7 April 2004 <br />