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<br /> 08 October 1999
<br /> AGE-NC Project No 95-0121 Y
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<br /> (Castle Analytical Laboratory Reference No 2343 and McCampbell,Analytical Inc I D 14941 `
<br /> through 14949) and chain-of-custody forms are,,presented in Appendix B
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<br /> 40. DISCUSSION AND CONCLUSIONS
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<br /> The following is a summary based on the findings of the'June 1999 investigation '>
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<br />' Ground water elevation at the site decreased an average 0 52 feet between the March 1999'
<br /> and the June 1999 ground water monitoring events r
<br /> ' • , The ground water surface elevation`at the site is approximately 9 feet to 18 feet Wab'ov' e the
<br />' slotted screen intervals in wells MW-1,MW-2, MW-3, MW-4 and MW-7 The ground water r
<br /> elevation at the site was screened through wells VW-3, VW-4, VW-6 and VW-8
<br /> • TPH-g was detected in water samples collected from wells MW-1, MW-2, MW-3, MW-4,
<br />' MW-7 VW-3 VW-4 VW-6 and VW-
<br /> 8 at concentrations'ranging from 230ug/l to 52,000 7 E
<br /> gg/1
<br /> • TPH-d was detected in water samples collected from wells MW-2, MW-4, MW-7, VW-3,
<br />` VW-4, VW-6 and VW-8 at concentrations ranging from 78 µg/1 to 1,100,ug/l, the laboratory '
<br />' reported that the chromatograms for the samples did not have typical diesel characteristics
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<br /> • Various BTEX compounds were detected in water samples collected from MW-1, MW-2,
<br />' MW-3, MW-4, MW-7, VW-3, VW-4, VW-6 and VW-8 at concentrations ranging between
<br /> 3 6 ,ug/l and 11,000 /.zg/1 (benzene-, MW-3)
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<br /> • Utilizing EPA Method 8020, MTBE was detected I zn water samples collected from wells MW-1, VWA VW-6 and VW-8 at concentrations as'high as 88 µg/1 , utilizing EPA Method
<br /> 8260, MTBE was detected in water samples,collected'from wells MW-1, MW-2, VW-4,;
<br /> VW-6 and VW-8 at concentrations ranging btween 9 1 gg/1 and 170 µg/1 v
<br /> • TBA was detected in water samples collected from wells MW-1, MW-4, VW-4, VW-6 and _
<br /> VW-8 at concentrations as high as 75 µg/1
<br /> • From March 1999 to June 1999, a substantial' decrease in concentrations of dissolved' '
<br /> r petroleum hydrocarbons was quantified in ground water samples collected from well MW'1 ,
<br />' (Table 2)
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<br /> ' Based upon data collected during the June 1999 monitoring;AGE-concludes r
<br /> • The general ground-water gradient in the area bound by wells MW-1, MW-2, MW4, MW-4
<br /> and MW-7 was calculated to be approximately,0 003 ft/ft,and directed towards the northeast
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<br /> Adranced GeoEmironmental,Inc
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