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. A S S O C I A T E S I N C <br /> an average decrease in the water table elevation of approximately 2 26 feet since March 2001 <br /> The water level data were used to develop the groundwater elevation contour map (Figure 3) <br /> Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer <br /> beneath the site generally flowed towards the south The average hydraulic gradient on June 12, <br /> 2001 was calculated to be 0 002 ft/ft or approximately 11 ft/mile A summary of groundwater <br /> monitoring data is presented in Table 1 <br /> ANALYTICAL RESULTS <br /> TPHd was detected above laboratory detection limits in the samples collected from wells MW3 <br /> and MW4 at concentrations of 120 parts per billion (ppb) and 450 ppb, respectively TPHg, <br /> BTEX, and MTBE were not detected in the sample collected from well MW3 BTEX and <br /> MTBE were not detected in the sample collected from well MW4 The samples collected from <br /> wells MW1, MW5, and MW6 contained no detectable concentrations of TPHg, TPHd, BTEX, or <br /> MTBE Well MW2 was not sampled due to the presence of free product A summary of <br /> analytical results is presented in Table 2 Laboratory data sheets and chain-of-custody <br /> documentation are contained in Attachment 2 <br /> CONCLUSIONS <br /> Concentrations from wells MW 1 and MW3 through MW6 remain generally consistent with the <br /> results from the previous sampling event Free product was still present in well MW2 during the <br /> sampling event The direction and magnitude of groundwater flow as generally consistent with <br /> the previous sampling event, and groundwater elevations have increased since March 2001 <br /> RECOMMENDATIONS <br /> Based on the results of the second quarter 2001 monitoring episode, we recommend the <br /> following <br /> + Conduct the Third Quarter 2001 groundwater monitoring and sampling of wells MW 1 <br /> through MW6 and analyze samples for TPHg, TPHd and BTEX <br /> ATC will summarize the Third Quarter 2001 groundwater monitoring activities in a <br /> Corrective Action Plan (CAP) The CAP will also include mass balance calculations and <br /> a cost effectiveness evaluation of different remediation technologies for the site <br /> w 162500\quartlyl2gr-2001 doe 3 <br /> c <br />