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' 24 May 2005 . AGE-NC Protect No 98-0448 ' Page 5 of 9 ' 4.0. FINDINGS AGE determined ground water flow direction and gradient from the field data collected on 24 March ' 2005, the contaminant impact to ground water was assessed from the laboratory data From field data collected at the SVE remediation system between 22 December 2004 and 08 March ' 2005, AGE determined the average TPH-g concentration and the average flow rate and calculated the'approximate mass and volume of hydrocarbons removed ' 4 1 GROUND WATER ELEVATION AND GRADIENT ' On 24 March 2005,the depths to ground water were measured at between 17 30 feet and 19 97 feet below the tops of the well casings (Table 2) The March 2005 ground water elevations,at the site were calculated to be between 8 85 feet (MW-4A) and 10 84 feet(MW-4B) below mean sea level ' (Table 2), ground water elevations are depicted on Figure 3 Generally, ground water elevation at the site increased an average of 2 75 foot between the December 2004 and the March 2005 ground ' water monitoring events The March 2005 ground water flow direction at the site was inferred to be southwest, at an ' approximate gradient of 0 015 ft/ft (Figure 3) The flow direction this quarter was consistent with historical flow directions ' -4 2 LABORATORY RESULTS OF GROUND WATER SAMPLES ' During the March 2005 monitoring events, TPH-g was only detected in the water sample collected from well MW-2 at a concentration of 6,400 micrograms per liter (µg/1) The inferred extent of dissolved TPH-g during the March 2005 ground water monitoring event is depicted in plan view in ' Figure 4 - µ Toluene, ethylbenzene and total xylenes were detected at concentrations of 4 8 µg/1 toluene, 140 ' µg/1 ethylbenzene and 680 µg/1 xylenes, respectively, from well MW-2, benzene was not detected in any water samples ' No other fuel components were detected by laboratory analysis Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory ' reports (Cal Tech Environmental Laboratories I D 0503-256), quality assurance/quality control (QA/QC)and chain of custody forms are presented in Appendix C,GeoTracker confirmation pages • of the submitted laboratory electronic deliverable format (EDF) files are included in Appendix G ' Advanced GeoEnvironmental,Inc I i