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21 May 2003
<br /> AGE-NC Project No 95-0130
<br /> Page 5 of 16
<br /> I (Interval A),50 and 55 feet bsg(Interval B),70 and 75 feet bsg(Interval C), 100 and 110 feet
<br /> bsg(Interval D)and between 125 and 142 feet bsg(Interval E) TPH-g and BTEX-impacted
<br /> water was detected from both wells at sampling intervals B, C,D and E at concentrations as
<br /> high as 160,000µg11,MTBE-impacted water was detected from MW-6(B and C)and MW-7
<br /> (B, C and D) at concentrations as high as 420 gg/l, 1,2-DCA was detected in samples
<br /> collected from MW-6(B and C)and from MW-7B at concentrations as high as 210µg11 Soil
<br />' and ground water analytical results are summarized in Tables 2 and 3 Results of the
<br /> September 2001 investigation were reported in Multi-Level Monitoring Well Installation
<br /> Report- Third Quarter 2001, dated 01 March 2002, prepared by AGE
<br />' September 2002 - AGE performed a `Ground Water Extraction Capture Zone Analysis' to
<br /> estimate the theoretical area that would be influenced during ground water extraction
<br />' activities at the site Based on the analysis, a theoretical down-gradient capture zone of
<br /> 54 feet was calculated, upgradient from the extraction well, the capture zone would extend
<br /> 1.70 feet to each side of the stream line moving directly toward the extraction well(Figure 3)
<br />' Between January 1995 and March 2003, thirty ground water monitoring events were performed at
<br /> the site to monitor dissolved petroleum hydrocarbon concentrations in ground water and to
<br />'0 characterize ground water flow direction and gradient on the site (Table 3) Generally, TPH-g and
<br /> BTEX was detected in water samples collected from wells MW-1, MW-2,MW-3,MW-6 (A,B, C,
<br /> D and E), MW-7 (B, C, D and E), VW-1 (B and C), VW-2 (A and B) and VW-3 (A and B) at
<br />' concentrations as high as 390,000 pLgd and BTEX compounds as high as 92,000 gg/l Generally,
<br /> MTBE was detected in the same wells at concentrations as high as 440,000 gg/l, low concentrations
<br />' of tert-amyl methyl ether (TAME), tert butanol (TBA), ethylene dibromide (EDB) and
<br /> 1,2-dichloroethane (1,2-DCA)were detected from wells MW-1, MW-2,MW-3, MW-6 (B and C),
<br /> MW-7B,VW-i (B and C),VW-2(B and C)and VW-3A on isolated occurrences Analytical results
<br />' of ground water sampling events performed at the site are summarized in Tables 3
<br />' 3.0. SCOPE OF WORK
<br /> Based on the results of the above-referenced ground water extraction Capture Zone Analysis for the
<br />' site in September 2002, and based on an SVE pilot test performed at the site in January 1996,AGE
<br /> proposes to install, operate and maintain (1) an interim ground water pump-and-treat remediation
<br /> system utilizing two new ground water extraction wells(EW-1 and EW-2) and dedicated low-flow
<br />' groundwater submersible pumps,and(2)an interim SVE remediation system utilizing existing SVE
<br /> wells VW-1, VW-2 and VW-3
<br />' Drilling and interim remediation field activities will consist of the following tasks
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<br /> tAdvanced GeoEnvironmentai,Inc
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