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URS
<br /> Mr. Robert McClellon
<br /> October 3, 2005
<br /> Page 3
<br /> Boring EW-1 was advanced to a depth of 30 feet below ground surface (bgs). Groundwater was
<br /> encountered between 20 and 25 feet bgs with a static groundwater surface of 18.5 feet bgs. Bentonite
<br /> chips were placed in boring EW-1 from the bottom of the boring (30 feet bgs) to approximately 17
<br /> feet bgs. Boring EW-2 was advanced to a depth of 21 feet bgs. Bentonite chips were placed in boring
<br /> EW-2 from the bottom of the boring (21 feet bgs) to 17 feet bgs. The remaining two borings (VW-9
<br /> and VW-10) were advanced to depths of 16.5 feet bgs each.
<br /> After each boring was advanced to the desired depth, either an extraction well or gas migration
<br /> monitoring probe was constructed within the boring. The wells were constructed with 2-inch Schedule
<br /> 40 polyvinyl chloride (PVC) pipe. The probes were constructed with 1-inch Schedule 40 PVC pipe.
<br /> The screened interval for each well or probe was installed at a depth from 6 feet to 16 feet bgs. The
<br /> annulus between the well or probe casing and the boring wall from 17 (for extraction wells) or 16.5
<br /> (for probes) feet bgs to 5 feet bgs was filled with pea gravel filter pack material. One foot of bentonite
<br /> was placed in the annulus from 5 feet to 4 feet bgs. The remainder of the annulus was filled with neat
<br /> cement. A stove pipe/monument was installed at the top of the each probe. The construction details of
<br /> the probes are provided in the probe's corresponding boring log. Since discolored soil or odorous soil
<br /> was not encountered during our activities, the soil cuttings were placed on the ground surface of the
<br /> site as specified in the approved work plan.
<br /> Quarterly Monitoring Activities
<br /> Quarterly monitoring activities conducted at the site on June 9, 2005, and August 29, 2005, included
<br /> measuring methane, oxygen, and carbon dioxide in each probe and well using a hand-held portable
<br /> landfill gas monitor. Mr. Tasiopoulos was present during the measurement activities. These
<br /> measurements were recorded in a field book.
<br /> RESULTS
<br /> June 9, 2005. The methane concentrations in VW-1, VW-3, VW-7S, VW-8S, VW-8D, VW-9, and
<br /> VW-10 were 0 percent. The methane concentrations in VW-2, VW-4, VW-5S, VW-5D, VW-6S,
<br /> VW-6D, VW-713, EW-1, and EW-2 were 0.1%, 18.4%, 21.3%, 14.2%, 20.4%, 9.5%, 0.1%, 27.6%,
<br /> and 20.1%, respectively. The oxygen concentration in all probes ranged from 0% to 22.5%. The
<br /> carbon dioxide concentration in all probes ranged from 0% to 29.9%. The results for each probe are
<br /> summarized in Table 1.
<br /> August 29, 2005. The methane concentrations in VW-1, VW-8S, VW-813, VW-9, and VW-10 were 0
<br /> percent. The methane concentrations in VW-2, VW-3, VW-4, VW-5S, VW-5D, VW-6S, VW-61),
<br /> VW-7S, VW-713, EW-1, and EW-2 were 0.1%, 0.1%, 15.1%, 17.4%, 10.4%, 16.0%, 8.6%, 0.1%,
<br /> 0.1%, 19.2%, and 13.2%, respectively. The oxygen concentration in all probes ranged from 2.3% to
<br /> 19.9%. The carbon dioxide concentration in all probes ranged from 0.9% to 25.9%. The results for
<br /> each probe are summarized in Table 1.
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