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i30 April 2005 i AGE-NC Project No 99-0624 Page 3 of 4 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in ground water samples collected from wells MW-1 through MW-3 and MW-5 at concentrations of between 130µg/1(MW-5)and 91,000µg/1(MW-2) Benzene was only detected in the samples collected from well MW-2 at a concentration of 4 7 µg11 The fuel additive MTBE was detected in samples from wells MW-1 through MW-3 and MW-5 at concentrations of between 140 µg/1 (MW-5)and 88,000 µg/l (MW-2) TAME was detected in samples from wells MW-2 and MW-3 at concentrations of 330 Vg/1 and 6 4 µg/1 ' No other constituents of concern were detected at or above laboratory reporting limits in the analyzed samples Previous and current analytical results of ground water monitoring well samples are summarized in Table 2 The laboratory report (CTEL Project No CT214-0502119) and chain of ' custody forms are presented in Appendix C Confirmation pages of the laboratory electronic digital format (EDF) files and depth to water measurements submitted to the State of California's GeoTracker website are included in Appendix D • 4.0. SUMMARY AND CONCLUSIONS ' The followingconclusions were drawn from the results of this investigation g • The depth to ground water at the site was between 53 87 feet and 55 11 feet toe, the calculated ground water elevations was ranged between 15 53 feet and 16 85 feet below ' MSL • Ground water flow direction in the area of wells MW-1 through MW-6 was inferred to be flowing towards the south at a calculated gradient of between 0 006 ft/ft 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 collected from wells MW-1 through MW-3, and MW-5 at a maximum concentration of 91,000µg/l (MW-2) The appearance of TPH-g at the same or similar concentrations of MTBE indicates that the reported concentration of TPH-g is actually an isolated MTBE peak, which falls within the same carbon range • The fuel additive MTBE was detected in samples from wells MW-1 through MW-3 and MW-5 at a maximum concentration of 88,000 pg/1 (MW-2) MTBE concentrations have been increasing in site monitoring wells since late 2001/early 2002 ' Benzene was only detected in the samples collected from well MW-2 at a concentration of 4 7 µg/1 ' Advanced GeoEnvironmentai,Inc