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EXECUTIVE SUMMARY <br /> Upgradient Environmental Consultants visited the Valley Motors dealership on March 31 to <br /> measure water depths and collect groundwater samples from the six on-site wells The depth to <br /> groundwater is a few inches less than it was in October 1999,when the site was last monitored <br /> Depth measurements indicate that groundwater continues to flow to the east <br /> After measuring the depth to groundwater,the wells were purged with a submersible groundwater <br /> pump and water samples were collected with disposable Teflon bailers, poured into 40-m1 vials and <br /> preserved for laboratory analysis All samples were analyzed for TPH-gasoline using EPA method <br /> 602 and for BTEX using EPA method 8020 The samples from the two newest wells (VT-1 and <br /> SW-1)were also analyzed for five oxygenates using EPA method 8260,because these wells have <br /> not been sampled before <br /> Gasoline concentrations decreased in one well (VM-1,2400 ppb) since samples were collected in <br /> October,but increased in two others (VM-2 [33,000 ppb] and VM-3 [150 ppb]) BTEX <br /> concentrations exhibited the opposite trend, increasing in VM-1 and decreasing in the other two <br /> wells,but remain low overall BTEX concentrations also increased in VM-4 Higher concentrations <br /> were found in the air sparging well (SW-1) gasoline was detected at a concentration of 110,000 <br /> ppb and benzene was detected at 2,100 ppb No hydrocarbons were detected in the sample from the <br /> vapor extraction well (VT-1), but it appears that this sample came from residual groundwater that <br /> was trapped in the well cap below the bottom of the screened interval, and is not representative of <br /> true groundwater concentrations <br /> f <br /> 1 <br />