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i r r l E 20 April 2005 AGE-NC Project No 96-0235 Page 3 of 5 elevation at the site was approximately 12 21 feet below MSL The average ground water elevation L t in the wells increased by approximately 2 11 feet since the November 2004 ground water monitoring ; event Figure 3 and Figure 4 illustrate the ground water potentiometnc surface based on the shallow- and intermediate-screened data sets Near the former UST cluster, ground water flow direction at the t shallow-screened data was inferred to be towards the west to northwest at a gradient of 0 003 ft/ft, ` the intermediate-screened data delineated a ground water flow direction toward the south to southeast at a gradient of 0 005 ft/ft Near the former UST No 3 excavation ground water flow ' direction at the shallow-screened data was inferred to be towards the east-southeast at a gradient of 0 003 ft/ft,ground water flow direction at the intermediate-screened level was inferred to be toward the south-southwest at a gradient of 0 008 ft/ft 3 2 ANALYTICAL RESULTS OF WATER SAMPLES 1r TPH-g was detected in the ground water samples collected from wells MW-1 and MW-2 at concentrations of 13,000 micrograms per liter(gg/1)and 15,000 µg/l,respectively TPH-d also was detected in samples MW-1 and MW-2 at concentrations of 1,500 µg/l and 5,400 µg/1,respectively , r r Various BTEX compounds were detected in samples MW-land MW-2 at maximum concentrations ' of 790 µg/1 benzene (MW-1), 280 µg/1 toluene (MW-2), 910 µg/1 ethylbenzene (MW-2) and 1,567gg/l xylenes (MW-2) - MTBE was detected in the water samples collected from MW-9, MW-10, MW-1 IB, MW-12B, MW-13B and MW-14B at concentrations ranging from 5 4 µg/1 (MW-13B) to 49 µg/l (MW-9) ' Water samples analyzed from MW-1, MW-2 and MW-I4B contained detectable concentrations of 1,2-DCA ranging from 3 4 µg/l (MW-2)to 9 9 µg/I (MW-14B) DIPE, ETBE, TAME, TBA, EDB were not detected above laboratory reporting limits in any of the water samples collected during the ' March 2004 monitoring event Analytical results of water samples collected during the first-quarter of 2005 are summarized In ' Tables 2 and 3,analytical results from previous monitornig events are summarized in Tables 4 and 5 Figures 5 and 6 illustrate the ground water contamination plumes in upper and lower groundwater intervals,respectively The laboratory report(CTEL Project No CT214-050353), chain of custody ' forms and the laboratory quality assurance/quality control (QA/QC) reports are included in Appendix C GeoTracker confirmation pages of the submitted`laboratory electronic deliverable h 1 format (EDF) files are included in Appendix D 1 Advanced GeoEnvironmental,Inc r