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1 <br />' 05 December 2002 <br /> . AGE-NC Protect No 02-0964 <br />' Page 3 of 7 <br /> detected at maximum concentrations of 1,900 gg/l benzene, 4,100 µg/1 toluene and <br /> 3,600 gg/l mg/kg ethylbenzene in sample A and 35,000 µg/1 xylenes In sample B <br />' On 31 January 2002,three additional soil probe borings were advanced,two bonngs were advanced <br /> on-site to a depth of 90 feet bsg Q and J), while boring H was established off-site across California <br />' Street to a depth of 50 feet bsg Laboratory analysis indicated <br /> • TPH-g and TPH-d were detected In grab ground water samples collected during the soil <br /> boring operations at concentrations as high as 120,000µg/1 and 190 gg/l,respectively,in the <br />' sample from boring J at a depth of between 46 and 50 feet bsg Dissolved BTEX compounds <br /> were detected at maximum concentrations of 650 µg/1 benzene In sample I at a depth of <br /> between 46 and 50 feet bsg and 9,000µg/1 toluene,2,900µg/1 mg/kg ethylbenzene and 9,000 <br />' gg/l xylenes in sample J at a depth of between 46 and 50 feet bsg <br />' On 02 August 2001, three ground water monitoring wells (MW-1, MW-2 and MW-3), screened <br /> between 20 and 40 feet bsg, were installed at the site (Figure 2) Well MW-1 was installed at the <br /> northeast corner of the site, and wells MW-2 and MW-3 were installed at the southern edge of the <br /> dissolved plume area Two ground water monitoring events have occurred to date, the last one in <br /> January 2002 <br />' • Ground water elevation at the site is approximately 15 feet below mean sea level Ground <br /> water at the site is inferred to flow north-northeast <br /> • TPH-g,TPH-d and BTEX compounds have not been detected In ground water samples from <br />' wells MW-2 and MW-3 <br /> • TPH-g and TPH-d have been detected In well MW-1, the highest concentrations were <br />' detected during the January 2002 monitoring event at 18,000 µg/l and 9,000 µg/1, <br /> respectively <br />' • BTEX compounds were detected in well MW-i during the January 2002 monitoring event <br /> at concentrations of 360 gg/l benzene, 1,600 µg/1 ethylbenzene and 4,700 µg/1 xylenes, <br /> toluene was not detected during the January 2002 monitoring event,but was detected during <br /> Ithe preceding September 2001 monitoring event at 160 gg/l <br /> • MTBE was detected in the monitoring well sample from well MW-2 at a maximum <br /> concentration of 9 3 µg/1 <br /> I <br /> The vertical extent, and the lateral extent of petroleum hydrocarbon-Impacted ground water to the <br /> most northeast section of the release area has not been delineated <br /> i <br /> IAdvanced GeoEnvironmental,Inc <br />