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. Total Petroleum Hydrocarbon and total BTEX concentrations in VM-2 are graphed against time <br /> in Figure 4 The graph clearly illustrates the trend of increasing concentrations In other wells, <br /> concentrations have fluctuated over time and shown few, if any, consistent trends In VM-1, for <br /> example, concentrations remained relatively constant from 1995 through 1998, but then the TPH- <br /> g concentration spiked to its highest level in early 1999 (Figure 5) BTEX concentrations did not <br /> follow suit, and actually declined in early 1999 and remained low until early 2000 After peaking <br /> in early 1999, the TPH-g concentration began a long decline, and at present the concentration has <br /> returned to the level in 1995 However, BTEX began rising in 2000 as TPH-g was declining, but <br /> declined again in late 2000 and by the end of the year, both TPH-g and BTEX concentrations <br /> were very low Since then they have risen and fallen in phase <br /> The sample from VM-4 was also analyzed for gasoline oxygenates, using EPA method 8260, <br /> because MTBE has been reported in four previous samples from this well (Table 3) <br /> Concentrations have always been low, so it is not surprising that the concentration in the March <br /> 2002 sample was below the detection limit As Table 3 shows, oxygenates have never been <br /> detected in VM-2 or VM-3, and only once in VM-1 Hence, it is clear that they are not a <br /> significant component of the contaminant plume <br /> 5.0 CONCLUSIONS <br /> Groundwater continued to flow to the northeast during the quarter This has been the <br /> predominant flow direction throughout the investigation of the site <br /> Contaminant concentrations continue to rise in VM-2 and fluctuate periodically in others This is <br /> somewhat surprising, because such fluctuations are most often due to fluctuations in the depth to <br /> groundwater or in the direction of groundwater flow Neither of these phenomena is particularly <br /> evident at this site, the flow direction is almost always to the northeast, and the depth to <br /> groundwater has not changed by more than a fraction of an inch since the early part of December <br /> 2001 Hence, we are unable to account for the increased concentrations this quarter <br /> 4 <br />