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' 13 February 2003 AGE-NC Project No 99-0624 Page 3 of 5 The general ground water gradient in the area of wells MW-1 through MW-4 was calculated to be ' approximately 0 002 ft/ft or less, or approximately 11 feet per mile and inferred to be flowing towards the south � M ' 32 LABORATORY RESULTS OF GROUND WATER SAMPLES ' A total of four ground water samples were submitted to a DHS-certified laboratory TPH-g was detected in water samples collected from wells MW-2 and MW-3 at concentrations of 830 micrograms per liter (,ug/l) and 52,ug/l, respectively The laboratory Indicated that the sample ' chromatograms from MW-2 and MW-3 had significant unmodified or weakly modified gasoline BTEX compounds were detected in ground water samples collected from wells MW-1,MW-2 and MW-3 Benzene was detected In samples MW-1, MW-2 and MW-3 at concentrations of between 18 ,ugll (MW-3) and 19 ug/l (MW-2) Ethylbenzene and xylenes were detected only in sample ' MW-2 at concentrations of 18 ,ug/l and 21 pg/l, respectively MTBE was detected(EPA 8260)in ground water samples collected from wells MW-1, MW-2 and MW-3 at concentrations ofbetween 17 pg/1(MW-1)and 17,000µg/l(MW-2) No other constituents of concern were detected above laboratory reporting limits in the analyzed samples Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports (McCampbell Analytical Inc Lab T D No 0212016) and chain-of-custody forms are presented in Appendix B 4 0. SUMMARY AND CONCLUSIONS The implications from the findings of the November 2002 investigation are • The depth to ground water at the site was approximately 54 feet below surface grade; or approximately 15 feet below mean sea level • Ground water flow direction in the area of wells MW-1 through MW-4 was inferred to be towards the south at an approximate gradient of 0 002 ft/f1 Due to the low hydraulic gradient at the site,slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify the inferred ground water flow direction ' • TPH-g was detected In ground water samples from wells MW-2 and MW-3, the'highest concentration was detected In the sample collected from MW-2 at 830 µg/1 • Benzene, ethylbenzene and xylene compounds were detected in the water sample collected . from MW-2,and low concentrations of benzene were detected in the water samples collected Advanced GeoEnvironmental,Inc