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1 ' 25 October 2005 AGE-NC Project No 95-0167 Page 3 of 4 line failure causing a ground water level mounding near the well location With the omission of the ' data from well MW-2,the general ground water flow direction is east-northeast Figure 3 illustrates the contoured ground water elevations as measured on 15 December 2004 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES During the December 2004 ground water monitoring event, TPH-g was detected in ground water samples collected from monitoring wells MW-1 and MW-7 at concentrations of 16,000 micrograms ' per liter (µg11) and 380 µg/l, respectively BTEX compounds were detected in the ground water samples collected from monitoring wells ' MW-1 and MW-7 at maximum concentrations in well MW-I of 2,800 µg/1 benzene, 3,100 µg/l toluene, 850 µg/1 ethylbenzene, and 3,600 µg/I total xylenes ' No additional petroleum hydrocarbon constituents were detected in any of the ground water samples analyzed Analytical results of ground water samples collected during the December 2004 monitoring event are summarized in Table 2 Figure 4 illustrates the estimated lateral distribution ' of dissolved TPH-g at the site The laboratory report(CTEL Project No CT214-0412119), quality assurance/quality control (QA/QC)report, and chain of custody forms are included in Appendix C Documents confirming the upload of laboratory electronic deliverable format(EDF)files and depth ' to water measurements to GeoTracker are included in Appendix D 4.0. SUMMARY AND CONCLUSIONS • On 15 December 2004, depths to ground water ranged from 16 40 feet to 17 20 feet below ' the tops of the well casings Ground water elevations at the site averaged approximately 5 35 feet below MSL, indicating an average elevation decrease of 0 20 feet since the last ' monitoring event in September 2004 • The shape of the water table at the time of the December 2004 monitoring event was in the form of a mound centered over monitoring well MW-2,with a trough on the west end of the ' site Ground water at the site was determined to be flowing radially outward from the mound under an average hydraulic gradient of approximately 0 0035 ft/ft � TPH-g was detected in ground water samples collected from monitoring wells MW-1 and _ 3 MW-7 at concentrations of 16,000µg/1 and 380 µg/1, respectively BTEX compounds were detected in the ground water samples collected from monitoring wells MW-1 and MW-7 at ' maximum concentrations in well MW-1 of 2,800µg/1 benzene,3,100 4g/1 toluene,850µg/1 . ethylbenzene, and 3,600 µg11 total xylenes ' Advanced GeoEnvironmental,Inc