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15 July 2003 AGE-NC Project No 95-0109 ' Page 4 of 5 • One or more BTEX compounds were detected in the same samples at concentrations as high as 18 µg/l benzene(MW-14),2 0 µg/1 toluene(MW-14), 130µg/1 ethylbenzene(MW-9)and 150 �Lg/l total xylenes (MW-8) ' TPH-g and BTEX compounds were not detected in any of the newly installed wells(MW-15 through MW-19) The lateral and vertical extent of petroleum hydrocarbon-Impacted ground water has been defined • 1,2-DCA was detected in samples collected from wells MW-7,MW-8,MW-9,MW-14 and MW-16 at concentrations ranging from 2 5 gg/l (MW-8) to 65 µg/l(MW-9) 1,2-DCA was not detected in any of the newly installed deeply-screened wells The vertical extent of the 1,2-DCA contamination appears to be defined 1,2-DCA was detected in well MW-16 (screened from 50 to 70 feet bsg),which is the most southern well in the network Therefore, ' the lateral extent of 1,2-DCA-impacted ground water has not been fully defined toward the south of well MW-16 However, 1,2-DCA concentrations in well MW-16 have decreased each quarter from 31 µg/1 in December 2002 to 3 0 gg/l in the sample collected on 30 June ' 2003 • The extent of petroleum hydrocarbon-impacted groundwater appears to be contained within ' the current on-and off-site well network The southern lateral extent of 1,2-DCA-Impacted ground water is not fully defined 5.0.t RECOMMENDATIONS ' Based upon data collected from the site, AGE recommends' • Continued quarterly ground water monitoring as required by Clean-up and Abatement Order ' No 93-701 The next groundwater monitoring event will be scheduled for September 2003 • If 1,2-DCA concentrations do not continue to decrease in well,MW-16 in subsequent ' sampling events, AGE recommends installation of an additional shallow-screened ground water monitoring well south of MW-16 to define the lateral extent of dissolved 1,2-DCA as required by Clean-up and Abatement Order No 93-701 ' 6.0. . LIMITATIONS T Our professional services were performed using that degree of care and skill ordinarily exercised by ' environmental consultants practicing in this or similar localities The findings were based upon field • measurements and analytical results provided by an independent laboratory Evaluations of the geologic/hydrogeologic conditions at the site for the purpose of this investigation are made from a Advanced GeoEnvironmental,Inc.