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URS Mr. Robert McClellon October 31, 2006 Page 2 vapor extraction pilot test was conducted in December 2005. During this test, vapor samples were collected from the two extraction wells and analyzed for volatile organic compounds (VOCs). The analytical results for the VOC analysis showed that VOCs were present where the total VOC concen- tration in each of the vapor extraction wells was less than 5 ppmv. Based on these results, there was a potential for VOC constituents to be present in groundwater. To assess the presence or absence of VOC constituents in the groundwater, three groundwater monitoring wells were installed at the site on June 12, 2006. Groundwater samples were collected from the three monitoring wells in June 2006. VOCs were detected in two of the three monitoring wells (MW -2 and MW -3). Four VOC constituents (acetone; chloroform; carbon disulfide; and cis-1,2-dichloroethene) were detected in the groundwater samples. When these values were compared to the most conservative established levels (i.e., primary maximum contaminant levels, etc), all of the detected constituents were less than these levels. To address the SJCEHD requirement for controlling methane from leaving the site, a work plan dated July 28, 2006 to install a passive soil vapor extraction trench was transmitted to SJCEHD. SJCEHD provided their approval, and passive soil vapor extraction trench construction activities began on September 5, 2006. FIELD ACTIVITIES The following two sections describe the passive soil vapor extraction trench installation activities and the third quarter of 2006 monitoring activities. Passive Soil Vapor Extract Trench Installation URS installed the passive soil vapor extraction trench at the World Enterprises site (Figure 1) between September 6, 2006 and September 28, 2006. The passive soil vapor extraction trench was installed by ETIC Engineering of Pleasant Hill, California. Mr. Robert McClellon and Ms. Natalia Subbotnikova of SJCEHD were present during the mandatory portion of these activities. A 180 -foot long trench was installed to a depth of 24 feet (5 feet beneath the static groundwater surface at MW -1 of 19 feet below the ground surface [bgs]) with a width of 5 feet. The trench was located along the property boundary, extending from VW -4 to VW -5. The trench was backfilled with gravel to a depth of 7 feet bgs. Slotted piping (4 -inch schedule 40 polyvinyl chloride [PVC]) with vents at 50 -foot intervals was placed on top of the gravel. Two feet of gravel was placed on top of the slotted piping. A filter fabric was placed over the gravel. The excavation was backfilled to 3 feet bgs with the excavated soil approved for use by Mr. McClellon of the SJCEHD. The remaining portion of the excavation was backfilled using site soil located at the eastern central portion of the site. The vents were constructed with PVC piping to a height of 12 feet above the ground surface. Holes were drilled within the top 2 feet of each pipe and the ends were covered with PVC caps. A concrete pad and three bollards were installed at each vent location. Construction details of the passive soil vapor extraction trench are shown on Figures 2 and 3. K:\Wprocess\25532\WorldEnterprise\Quarterly Rpt\3Q06\CovLtrRpt.doc