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12 August 2002 AGE-NC Project No 95-0103 Page 10 of 11 ' 4.0. SUMMARY/CONCLUSIONS Based on the results of ground water remediation activities, AGE concludes the following Ground water remediation was initiated at the site in early April 2002 Between 02 April and 30 May 2002, the pump-and-treat system was in operation for approximately 60 days and ' processed approximately 226,147 gallons of water AGE estimates that an average 3,800 gallons of water was discharged per day during this time • Dissolved hydrocarbons were detected from ground water samples collected at the influent end of the treatment system on 24 April and 30 May 2002 Based on the amount of ground water processed and laboratory analytical results, approximately 1 53 lbs of benzene and 27 lbs of TPH-g were removed from the extracted ground water between 02 April and 30 May 2002 (Table 1) ' Based on the results of the 30 May 2002 quarterly monitoring event, AGE concludes the following The average ground water level was approximately 12 8 feet below the top of the casing, a ground water decrease of approximately 0 8 feet since the monitoring event in February The map of ground water contours indicates a general ground water flow toward the southeast • The ground water table in monitoring wells MW-2 through MW-4 was approximately one to three feet above the top of the screened interval, these wells may not yield samples fully representative of shallow ground water conditions ' • Benzene was detected In sample MW-4 at 3,800µg/l,which is considerably above the DHS' Maximum Contaminant Level of 1 0 �Lg/l in drinking water t5.0 RECOMMENDATIONS Based upon the results of the second quarter 2002 AGE recommends ' • Continued quarterly ground water monitoring at the site The next monitoring event should be scheduled for late August 2002 ' Continued operation and maintenance of the groundwater extraction and treatment system Advanced GeoE nvi ron mental,Inc 1 `