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1 � r <br /> IL <br /> 02 Apnl ,2002 <br /> AGE-NC Project No 97-0312 <br />' Page 4of5, ' - _ 4 <br /> the first quarter 2002 are summarized on Tables 2 and 3 The analytical results of all water samples <br /> are summarized on Tables 4 and 5 Figures 4, 5 and 6 illustrate the areal extent of TPH-g-,benzene- <br /> and 1,2-DCA-impacted ground water <br /> ' 4.0. DISCUSSION AND CONCLUSIONS <br /> rBased upon data collected from the site, AGE concludes <br />' Ground water elevation increased approximately 167 feet at the site between the December <br /> 1 2001 and the February 2002 monitoring events The inferred ground water flow direction is <br /> toward the northeast The average ground water gradient was 0 0007 ft/ft across the site <br /> fDuring the February 2002 monitoring event TPH-g,TPH-d,and various BTEX constituents <br /> were detected in the water samples collected from monitoring wells UST-1 and UST-5 <br /> 1,2-DCA was detected in the water samples collected from UST-5 and UST-6 PCE was <br />' detected in the sample from UST-1 , <br /> • 1,1-DCA, 1,2-DCE and PCE were detected in the sample collected from the small domestic <br />' well at concentrations of 0 71 µg/l, 0 83 µg/l and 11 µg/1,respectively The concentration of <br /> PCE detected in the small domestic well sample was over the DHS Maximum Contaminant <br /> Level (MCL) of 5 µg/l, the detected concentrations of IJ-DCA and 1,2-DCE were below <br />' the MCL of 5 µg11 - <br /> • With exception of the HVOCs detected in the small domestic well sample, the detected <br /> 1 concentrations and extent of analytes of concern have remained relatively stable during the <br /> past two years of monitoring <br /> 5.0. ' RECOMMENDATIONS - <br /> 1 Based on the results of the quarterly ground water monitoring event, AGE recommeds <br />' • = Continued monitoring of the on-site monitoring and domestic wells The next monitoring <br /> event should be scheduled for May 2002 ' <br /> Pending pre-approval of costs, completion of the scope of work proposed in the AGE- <br /> prepared Monitoring Well Installation and Remediation Feasibility Testing WorkPlan,dated <br /> ,12 February 2002 Work to be completed includes abandonment,of UST-1, installation of <br />' a cluster-type monitoring well to replace UST-i and performance of remediation feasibility <br /> tests <br />' S Advanced GeoEnvironmental,Inc <br />