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4.0 RESULTS <br /> • 4 1 Depth to Groundwater and Hydraulic Gradient <br /> t <br /> The depth to groundwater on June 16 was between 36 and 37 feet, which is a nearly identical to <br /> the depth in October 2003 and January 2004 (Table 1) The calculated elevation of the water <br /> table is approximately 21 feet below sea level <br /> Figure 3 illustrates the hydraulic gradient and general direction of groundwater flow As in <br /> previous quarters, the contours form an arcuate pattern and indicate that the piezometric surface <br /> slopes eastward <br /> 4 2 Analytical Results <br /> Hydrocarbon concentrations in June were quite similar to those measured in January in most <br /> wells, although there were slight upward or downward changes The concentration of most <br /> analytes increased by 10%or more in VM-2, which is the only well that showed sizable changes <br /> Concentrations in this well have been consistently much higher than in any other wells, implying <br /> that the plume of contaminated groundwater rather tightly encircles this well There has been no <br /> obvious outward spread of hydrocarbons in several quarters <br /> The laboratory noted that the TPH-g chromatogram for VM-3 does not match the standard <br /> gasoline chromatogram This is further implied by the absence of any of the BTEX compounds in <br /> this sample These results suggest that the TPH-g detected in this sample is not gasoline, but <br /> rather some non-petroleum hydrocarbon, such as the chlorinated hydrocarbons that we previously <br /> . reported in 1996 and 1997 <br /> 5.0 CONCLUSIONS <br /> Groundwater monitoring in the first and second quarters of 2004 supports the data collected in <br /> 2003 regarding the direction of groundwater flow and the extent of groundwater contamination <br /> Both the water depth and plume extent are stable at the present time, and concentrations have <br /> neither risen nor declined in most wells <br /> The soil vapor extraction system is on track to be operational by late summer The vapor unit is <br /> curtendy being refurbished foradditionaI use, and the electrical system is being installed at the <br /> site This work should be completed sometime in July, and testing of the equipment could begin <br /> in late July or August <br /> • 3 <br />