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' 30 June 2003 • AGE-NC Project No 95-0103 Page b of 7 ' 4.0. SUMMARYICONCLUSIONS Based on the results of ground water remediation activities, AGE concludes the following ' • Between 27 December 2002 and 15 April 2003, the pump-and-treat system processed approximately 461,765 gallons of water The total volume of ground water treated equals 2,139,002 gallons • Dissolved hydrocarbons were detected from ground water samples collected at the Influent end of the treatment system Based on the amount of ground water processed and laboratory analytical results,approximately 0 858 lbs of Benzene and 27 78 lbs ofTPH-g were removed from the extracted ground water (Table 1) Cumulative totals of 5.15 lbs of Benzene and 123 68 lbs of TPH-g are estimated to have been extracted since ground water treatment began on 02 April 2002 • TPH and the remaining BTEX compounds concentrations have decreased in the monitoring well samples over the remediation period The overall reduction of benzene on-and off-site Indicates successful removal of dissolved hydrocarbons and capture of the off-site dissolved ' . hydrocarbons • MTBE concentrations have increased noticeably in groundwater samples MW-3,MW-4 and MW-5, MTBE was detected for the first time in well MW-5 since momtonng was initiated ' in December 1997 The MTBE distribution pattern suggests that ground water extraction is successfully beginning to draw the off-site MTBE back towards the site ' • The cost for ground water extraction over the last one-year period was a net $115,680, the cost translates to $953 per pound of gasoline and $22,462 per pound of benzene ' Based on the results of the April 2003 monitoring event, AGE concludes the following • The average ground water level was approximately 14 feet below the top of the casing, a ' ground water increase of approximately 0 6 feet since the monitoring event in January 2003 The map of ground water contours indicates a general ground water flow toward the northwestern portion of the site • The ground water table in monitoring wells MW-3 through MW-7 and vapor well VE-5 was at the top of the screened interval,these wells should yield samples representative of shallow ' ground water conditions • The concentrations of TPH-g continue to decline in wells MW-1 to MW-5, TPH-g was not ' detected in sample MW-7 in the first quarter 2003 ' Advanced GeoEnvironmental,Inc t