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NASA Langley begins Tabbs Creek cleanup
NASA Langley Research Center in Hampton, Va., has begun the
cleanup of Tabbs Creek, which is contaminated by
PCBs (Polychlorinated Biphenyls) and PCTs
(Polychlorinated Terphenyls).
Tabbs Creek is a meandering creek that, along with more than 20
tributaries, and flows into the northwest branch of the Back
River.
"We've worked long and hard to prepare for a safe and thorough
cleanup of Tabbs Creek," said Greg Sullivan, an environmental
engineer and NASA Langley's remedial project manager. "This is a
site that has been studied for several years. We're happy, finally,
to be moving forward with the actual cleanup."
Four storm sewers from NASA and the Air Force base discharge
into the upper portions of Tabbs Creek from NASA's west area. PCBs
and PCTs were inadvertently discharged into NASA Langley storm
sewers and eventually deposited in Tabbs Creek.
NASA cleaned up the contamination source and the storm sewers in
1997. The agency also conducted several investigations in Tabbs
Creek to determine the exact nature and extent of the contamination
and the potential human health and ecological risk posed from
contamination.
NASA's cleanup goal is to reduce levels of PCBs and PCTs in
sediments to levels that are even less than those set by the U.S.
Environmental Protection Agency (EPA) to be protective of
human health. Sullivan said the cleanup will take six to eight
months.
In the late 1980s, NASA and the Langley Air Force Base (LAFB)
conducted site inspections and identified potentially contaminated
sites.
In 1994, NASA Langley and the base were co-listed on the
National Priority List as a Superfund site.
Since then, NASA, with the Virginia
Department of Environmental Quality (VDEQ) and the EPA have
formulated the cleanup plan for Tabbs Creek in a
"Record of Decision."
The results of the site studies and the cleanup plans were made
available for public review and input. NASA has developed a
comprehensive plan for carry out the cleanup and complying with
state and local permit requirements.
"EPA Region III, as the lead regulatory agency in the Superfund
cleanup, has coordinated with the U.S. Fish and Wildlife Service
and National Oceanographic and Atmospheric Administration (NOAA) to
help NASA prepare a cleanup plan that meets the needs of all
regulatory agencies and the VDEQ," said the EPA's Stacie Driscoll,
remedial project manager, Federal Facilities Section, Hazardous
Site Cleanup Division. "EPA believes this action will minimize or
eliminate the risk to Tabbs Creek."
The cleanup is happening in three steps: mobilization, sediment
removal and demobilization. Foster Wheeler Environmental Corp.,
hired by NASA, took the first step in late summer. A big part of
the cleanup involves gaining access to the creek so contaminated
sediments can be removed.
"Work crews have cleared and prepared areas where we must access
the creek," said Sullivan. "We constructed a temporary road so that
the vehicles and machines can get to the contaminated areas. Office
and laboratory trailers have been brought to the site and we've
constructed a temporary building, which we will use to dry and
process the sediment before it is loaded onto trucks for
transportation to an off-site landfill."
Included in the cleanup plan are procedures that work crews will
follow for minimizing disturbances to the community during the
excavation of sediment and transportation of the waste.
"We will also follow a strict health and safety plan and conduct
environmental monitoring throughout the cleanup," said
Sullivan.
The actual cleanup involves excavating sediment, a mechanical
process that scoops up the soil from the bottom of the creek.
Excavating will remove about 7,500 cubic yards of contaminated
sediment.
"Our work plan outlines strict procedures for the protection of
the wetlands surrounding the creek. We will exercise extreme care
during the cleanup to minimize any impact on this vital ecosystem,"
said John Lee, acting head of NASA Langley's Office of Security and
Environmental Management.
The last stage, or demobilization, occurs when the contaminated
sediment has been removed. The final step will be to remove the
equipment and buildings and restore the creek bed.
"We recognize that Tabbs Creek is an important resource for the
community," said Sullivan. "NASA is committed to completing the
cleanup process in the safest and most thorough manner
possible."
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