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t 16 March 2005 AGE-NC Project No 99-0657 Page 3 of 4 ' 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the water samples collected from wells MW-1, MW-2, MW-4 and MW-5 ' at concentrations ranging from 200 micrograms per liter (V.g/l) (MW-5) to 3,300 µg/l (MW-1) Benzene and xylene were each detected in one water sample this quarter, 52 µg11 benzene in well ' MW-4 and 920 �tg/l total xylenes in well MW-1 Ethyl-benzene and toluene were not detected this quarter in any ground water samples this quarter ' MTBE was detected in water samples collected from wells MW-1, MW-2, MW-4, and MW-6 at concentrations ranging from 73 µg/l (MW-6)to 1,600 gg/1 (MW-2) ' No additional target analytes were detected at or above laboratory reporting limits in the ground water samples analyzed Analytical results of the ground water samples collected in July 2004 are summarized in Table 2 The laboratory report (CTEL Project No CT214-0410153), quality rassurance/quality control(QA/QC)reports,and chain of custody forms are included in Appendix C Documents confirming the upload of laboratory electronic deliverable format(EDF)files and depth to water measurements to GeoTracker are included in Appendix D 4.0. SUMMARY AND CONCLUSIONS The following conclusions were drawn from the results of this investigation • The ground water elevation averaged approximately 4 98feet above MSL Ground water is inferred to be flowing toward the southwest under an average ground water gradient of 0 005 ft/ft which is consistent with previous monitoring events • The highest concentrations of dissolved hydrocarbons occurred in monitoring wells MW-1, MW-2, and MW-4, which are located at or down-gradient of the UST area Concentration maps depicting the approximate distribution of dissolved TPH-g and MTBE are presented as Figures 4 and 5, respectively • Concentrations of dissolved TPH-g decreased this quarter in all monitoring wells with exception to MW-1, TPH-g was detected again in parameter well MW-5 Concentrations of BTEX compounds have remained consistent, though only benzene (52 µg11 in MW-4) and xylene(920 pg/l in MW-1) were detected MTBE concentrations increased in wells except MW-2, where a sight decrease was recorded • The lateral extent of petroleum hydrocarbon contamination in ground water has been defined to the east,west,southeast and north(CPT-1)of the UST area The lateral extent of impacted soil in the vadose zone has been defined Advanced GeoEnvironmental,Inc I