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• 25 October 2002 AGE-NC Project No 02-0964 Page 3 of 8 detected at maximum concentrations of 1,900 gg/l benzene,4,100 gg/1 toluene and 3,600 gg/l mg/kg ethylbenzene in sample A and 35,000 gg/l xylenes In sample B On 31 January 2002, three additional soil pi obe borings were advanced, two borings wei e advanced on-site to a depth of 90 feet bsg (I and J), while boring H was established off-site across California j Street to a depth of 50 feet bsg Laboratory analysis indicated i • TPH-g and TPH-d were detected in grab ground water samples collected during the soil boring operations at concentrations as high as 120,0OOgg/l and 190 Ag/l,respectively, in the sample fr om boring J at a depth of between 46 and 50 feet bsg Dissolved BTEX compounds were detected at maximum concentrations of 650 µg/l benzene in sample I at a depth of between 46 and 50 feet bsg and 9,000 µg/1 toluene,2,900 µg/l mg/kg ethylbenzene and 9,000 µ.g/1 xylenes in sample J at a depth of between 46 and 50 feet bsg On 02 August 2001, three ground water monitoring wells (MW-1, MW-2 and MW-3), screened between 20 and 40 feet bsg, were installed at the site (Figure 2) Well MW-1 was Installed at the northeast corder of the site, and wells MW-2 and MW-3 were Installed at the southern edge of the dissolved plume area Two gr ound water monitoring events have occur ed to date, the last one In January 2002 • Ground water elevation at the site is approximately 15 feet below mean sea level Ground watel at the site is Inferred to flow north-northeast • TPH-g,TPH-d and BTEX compounds have not been detected in ground water samples fn om wells MW-2 and MW-3 • TPH-g and TPH-d have been detected In well MW-1, the highest concentrations were detected dun tng the January 2002 monitoring event at 18,000 µg/l and 9,000 gg/l, I espectrvely • BTEX compounds were detected In well MW-1 during the January 2002 monitoring event at concentrations of 360 µg/l benzene, 1,600 gg/l ethylbenzene and 4,700 µg/1 xylenes, toluene was not detected during the January 2002 monitoring event, but was detected during the preceding September 2001 monitoring event at 160 gg/1 • MTBE was detected In the monitoring well sample from well MW-2 at a maximum concentration of 9 3 gg/1 The lateral and vertical extent of pets oleurn hydrocarbon-impacted soil and ground water to the northeast, east and southeast have not been delineated • Advanced GeoEnvnronmental,Inc