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, 23 October 1998 AGE-NC Project No 95-0184 ' Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in each well sampled, with concentrations as high as 150,000 parts per billion ' (ppb, reported as micrograms per liter) Benzene was detected at concentrations as high as 46,000 ppb TPH-d was detected in the sample from MW4 at a concentration of 28,000 ppb DIPS was detected in the sample from MW-3 at a concentration of 4 4 ppb MTBE was detected in samples ' collected from VW-2B, VW-3 and VW-4 at concentrations of 1,200 ppb, 1,000 ppb and 990 ppb, respectively. 1,2-Dichloroethane (DCA) was detected in three of the ten wells sampled at concentrations as high as 2,500 ppb (VW-2B) Four additional constituents were detected with EPA ' Method 8260 at concentrations as high as 3,100 ppb (1,2,4-tnmethylbenzene, MW-4) Analytical results are summarized on Tables 2 and 3 The laboratory report (MAI sample Nos 92680-92689) ' and chain-of-custody forms are included in Appendix B a Hydrocarbon concentrations detected in samples collected from MW4,VW-2B, VW-3, VW-4 and ' VW-5B are indicative of the presence of free product Lower hydrocarbon concentrations were detected in MW-7, located between MW4 and the remaining wells The lower hydrocarbon concentrations detected in samples collected from MW-1,MW-2 and MW-3 are probably due to the i deep drowning of these wells (22 feet). ' 4.0. DISCUSSION AND CONCLUSIONS Based upon data collected from the site, AGE concludes the following • Petroleum hydrocarbons were detected in each well sampled, at concentrations as high as ' 150,000 ppb Although not measurable in the wells, free product appears to remain at the site Additional monitoring wells will be necessary to delineate the horizontal extent of hydrocarbon-impacted ground water ' Concentration�of hydrocarbons detected at the site have generally remained stable • The inferred ground water flow direction was toward the northeast during the July 1998 ' monitoring event The inferred flow direction has generally been toward the east to southeast at the site ' Ground water is approximately 22 feet above the screened interval in monitoring wells MW- 1 through MW-3,twelve feet above the screened interval in MW4 and seven feet above the screened interval in MW-7 These wells recharge rapidly, possibly preventing significant ' drawdown during purging The hydrocarbon concentrations detected in these `drowned' wells may not be representative of shallower ground water where the maximum hydrocarbon impact would be expected Advanced GeoEnvironmentat,Inc.