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' 24 June 2005 l• AGE-NC Project No 95-0103 ' Page 8 of 12 • Other fuel additives detected in well VE-1 Include 1,2-DCA at 53 µg11,TAME at 75 µg/1 and DIPS at 8 6 Fuel additives detected in well EW-3 Include 1,2-DCA at 9 8 µg/1, TAME at 16 µg/1 and D1PE at 8 2 i 3 2 4 Analytical Results of Full-Purge Ground Water Samples A t x samples were collected on 11 May from monitoring wells MW-3, MW-4 and vapor total of sI amp y g well VE-6 and extraction wells EW-1, EW-2 and EW-3 for hydrocarbon analysis during the full purge sampling event • TPH-g was detected from all six referenced well locations The highest concentration was detected in sample EW-3 at a concentration of 8,300 µg/l,however, all six of the Impacted wells contained TPH-g at concentrations greater than 1,000 µg11 BTEX compounds were detected from all six well locations, the highest BTEX concentrations were detected from well EW-3 at 400 µg/1 benzene,32 µg/1 toluene(34 µg11 toluene in well MW-4),480µg/l ethylbenzene and 1,500 µg11 total xylenes Benzene was not detected in the off-site monitoring well MW-3 • The fuel additive MTBE was not detected in samples i 3 2 5 Natural Attenuation- Geochemical and Geophysical Results Geochemical parameters were generally consistent between on-site and off-site wells during the May 2005 monitoring and sampling event r • The pH values were almost stable or equal between all wells monitored (6 521-6 945) Conductivity was lowest in the southern and eastern plume area(1,460µmho/cm)and highest in the plume area (VE-1=2,352 µmho/cm) and directed north in the off-site well sample MW-2 (2,480µmho/cm) Alkalinity was highest off-site (MW-2=900 milligrams per liter mg/1) and lowest within the down gradient edge of the plume at well EW-1 (540 mg/1) Redox and dissolved oxygen measurements were significantly greater than detected during the purging process and not reliable when comparing the sample set However,the lowest ' DO values were down gradient of the former release area(EW-1=3 0 and MW-2=5 8) • Nitrate values were highest off-site at well MW-3 (2 6 mg/l) and within the core of the i dissolved plume at well EW-3 (2 4mg/l) The highest detection of sulfate was detected iri well VE-1 (230 mg/1),while the lowest concentration was detected was at well EW-1 down- gradient of the former release area (140 mg/1) and off-site detections were average Advanced GeoEnvyronmental,Inc i Y