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i <br /> 13 December 2004 <br /> AGE-NC Project No 99-0645 <br />' Page 6 of 7 <br />' 3 3 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> Depth to ground water at the site on 20 October 2004 ranged from 97 37 feet to 97 67 feet below the <br />' monitoring well casing tops The ground water elevation in each well was calculated from this data <br /> The ground water elevations ranged between 52 11 feet(MW-1)and 52 15 feet(MW-2)below mean <br /> sea level(MSL) Ground water decreased an average of 4 feet since the June 2004 monitoring event <br />' (Table 1) <br /> At the time of the October 2004 monitoring event, the ground water flow direction was inferred to <br />' be south-southwest at a gradient of approximately 0 001 ft/ft Figure 3 illustrates the contoured <br /> ground water elevations <br />' 3 4 ANALYTICAL RESULTS OF WATER SAMPLES <br />' COCs were not detected in ground water samples MW-1 and MW-2, however, TPH-g and BTEX <br /> compounds were detected for the first time in sample MW-3 at concentrations of 600 µg/1 TPH-g, <br /> • 5 3 µg/l benzene, 17 gg/l toluene, 9 7 µg11 ethylbenzene and 67 µg/1 xylenes Because of the <br />' anomalous presence of petroleum hydrocarbons at relatively high concentrations, well MW-3 was <br /> re-sampled on 29 October 2004,COCs were not detected in the 29 October sample from well MW-3 <br />' Analytical results from the ground water samples are summarized in Tables 2 and 3 The laboratory <br /> report (CTEL Project No CT214-04010116 and 0411002), QA/QC and chain of custody are <br />' included in Appendix E GeoTracker confirmation pages of the submitted laboratory electronic <br /> deliverable format (EDF) files are included in Appendix E <br />' 4.0. SUMMARY AND CONCLUSIONS <br />' Based on the data collected from the site, AGE concludes <br /> • Approximately 360 kg (794 pounds) or 127 gallons of hydrocarbons were extracted and <br />' adsorbed by the SVE system between 05 October and 17 November 2004 Soil vapor <br /> extraction samples were adequate for continued remediation <br />' • Ground water flow direction is estimated to be towards the south-southwest at a gradient of <br /> approximately 0 001 ft/ft during the October sampling and monitoring event The ground <br /> water flow direction at the site had been westerly since installation of well MW-Ir in 2003 <br /> I <br />' Advanced GeoEnvironmental,Inc <br /> I <br />