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30 March 1999
<br /> • AGE-NC Project No 95-0173
<br /> Page 3 of 5
<br /> October 1998 and the January 1999 ground water monitoring events The ground water elevation
<br />' data for MW-I through MW-12 and VW-I during the January 1999 ground water monitoring event
<br /> is depicted in Figure 3
<br /> Ground water monitoring data collected to the area of wells MW-1, MW-2, MW-3, MW-6, MW-8,
<br /> MW-9, MW-10, MW-11, MW-12 and VW-I indicated that the ground water flow direction was
<br /> generally toward th northeas t a gradient of 0 003 ft/ft, or approximately 18 feet per mile (Figure
<br /> 3), data collected in t rea of wells MW-4, MW-5 and MW-7 indicated that groan water flow
<br /> direction was generally toward the sou eas t a gradient of 0 003 ft/ft, or approximately 18 feet per
<br />' mile Ground water was approxuna e y o feet above the screened intervals in monitoring wells
<br /> MW-1, MW-2, MW-3 and MW-4, ground water was approximately 24 to 34 feet above the screen
<br /> intervals atm -1B and AW- , therefore, these wells are "drowned", and may not yield samples
<br />' fully representi.-tive of ground water conditions near the top of the saturated zone, where fuel
<br /> hydrocarbons would be expected to have the greatest impact
<br /> 32 LABORATORY RESULTS OF GROUND WATER SAMPLES
<br />'• A total of fifteen ground water samples were submitted to a DHS-certified laboratory in January
<br /> 1999 TPH-g was detected in water samples collected from wells MW-1 through MW-4, MW-6,
<br />' MW-9, VW-1, AW-IB and AW-2B at concentrations ranging up to 260,000 micrograms per liter
<br /> (µg/1) TPH-d was detected in water samples collected from wells MW-1 through MW-4, MW-6.
<br /> MW-8, MW-11, MW-12, VW-1, AW-IB and AW-213 at concentrations ranging up to 19,000 µg11,
<br />' however, the laboratory reported that the diesel chromatograms for the samples did not have typical
<br /> diesel characteristics
<br />' BTEX compounds were detected in ground water samples collected from wells MW-1 through MW-
<br /> 4, MW-6, MW-8, MW-9, MW-10, MW-11, MW-12, VW-1, AW-IB and AW-213 at concentrations
<br />' ranging as high as 69,000 ug/l (toluene, VW-1) The greatest benzene concentration was detected
<br /> from well MW-3 at a concentration of 22,000 µg/l
<br /> MTBE was detected from wells MW-5, MW-8, MW-9 and MW-10 utilizing EPA Method 8020 at
<br /> concentrations as high as 3 5 µg/i, MTBE was not confirmed in any water samples utilizing EPA
<br /> Method 8260, no other fuel oxygenates were detected above laboratory reporting limits
<br /> Analytical results of the ground water samples are summarized in Table 2 The laboratory reports
<br /> (Castle Analytical Laboratory Reference No 1897 and McCampbell Analytical Inc I D No 99876
<br /> through 99883) and chain-of-custody forms are presented in Appendix E
<br />' Advanced GeoEnvi ron mental,Inc
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