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. EXECUTIVE SUMMARY <br /> Upgradient Environmental Consultants visited the Valley Motors dealership on December l 1 to <br /> measure water depths and collect groundwater samples The depth to groundwater is about 2 feet <br /> greater than it was in September, and now averages about 33 feet below grade Depth <br /> measurements indicate that groundwater currently flows to the northeast Historically, the flow <br /> direction has varied from northeast to southeast <br /> After the depth to groundwater was measured,the four morutonng wells were sampled with <br /> disposable Teflon bailers and the samples were poured into 40-m1 vials The samples were <br /> transported to Excelchem Environmental Laboratory and analyzed for TPH-gasoline using EPA <br /> method 602 and for BTEX using EPA method 8020 <br /> Hydrocarbon concentrations declined slightly in VM-I and VM-3 and remained essentially <br /> unchanged in VM-4 A larger decline was observed in VM-2, but concentrations in this well remain <br /> elevated (TPH-g= 59,000 µg/l,total BTEX=2 1,100 µg11) <br /> Hydrocarbon concentrations in two wells were plotted against time In the well nearest the former <br /> dispenser island (VM-2), concentrations have fluctuated up and down from quarter to quarter but <br /> there has been an overall increase in both TPH-g and BTEX concentrations since 1998 The <br /> magnitude of the quarter-to-quarter fluctuations has increased during that period Concentrations in <br /> the well nearest the former underground storage tanks (VM-1)have not followed the pattern in <br /> VM-2 The TPH-g concentration remained relatively constant from September 1995 until <br /> September 1998, but then increased sharply at the end of 1998 In early 1999, the concentration <br /> began a general decline and has now returned to the 1995 level In contrast, BTEX concentrations <br /> decreased at the end of 1998 while the TPH-g concentration was increasing In early 2000, BTEX <br /> concentrations began rising while the TPH-g concentration was declining This out-of-phase pattern <br /> ended at the end of 2000, and during 2001 TPH-g and BTEX concentrations increased and <br /> decreased in concert <br /> • <br /> 1 r ', <br />