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PCBs SUPERFUND SITE
Cq^ ppQ-^jy Pe9'on 2:	M Broadway, New York, NY 10007
EPA Technical Requirements for
Phase 2 of Hudson River
Dredging Project
Factsheet
December 2010
The U.S. Environmental Protection Agency
(EPA) has provided the General Electric
Company (GE) with detailed requirements
for the next phase of the project to remove
sediment contaminated by polychlorinated
biphenyls (PCBs) from the bottom of the
Hudson River. PCBs are probable human
carcinogens and can also affect the
immune, reproductive, nervous, and
endocrine systems. EPA developed the
plans for the second part of the two-phased
dredging project after a scientific review of
data and information from the first phase of
dredging by a group of independent
scientific experts, and extensive input from
a broad range of stakeholders.
Two hundred miles of the Hudson River are on the federal Superfund list of the most hazardous waste
sites in the country. Approximately 40 miles of the upper Hudson River from Hudson Falls to Troy
contains the most contaminated areas of river bottom. In 2002 EPA made a formal decision to dredge
areas of this stretch. The cleanup project was divided into two phases to allow time to evaluate
information from the first phase to make improvements before proceeding with Phase 2.
Enhancements, refinements and improvements made to Phase 2 from Phase 1 include:
Improved Sampling
•	In advance of Phase 1, GE took some 50,000
samples of river sediment in order to delineate
and design the dredging project. Unfortunately,
many of the samples turned out to be
incomplete or otherwise inadequate for the
intended purposes
•	The result was that the quantity and depth of
PCBs in the areas to be dredged was often
underestimated. Phase 1 operations required
multiple dredging passes in most areas.
•	Phase 2: With the experience gained from
Phase 1 sampling, GE is resampling using
improved methodology to give more accurate
and complete information on the extent of the
contamination in the areas to be dredged. GE
began this resampling effort this past summer.
Improved Dredge Design
•	The Phase 1 dredging design consistently
underestimated the "depth of contamination"
(DoC), which is the depth of cut that the dredge
operators must make on each pass. As a
result, multiple dredging passes were needed
in Phase 1.
•	Underestimating DoC led to a less efficient
dredging program that took longer than
necessary.
•	The reasons for the underestimation of DoC
include the incomplete samples described
above, but also the inadequate accounting for
a high degree of variability in the contaminated
sediment layer.

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Improved Dredge Design (cont.)
•	Phase 2: GE wiii be required to adjust the DoC
calculations to take into account this variability.
This means the dredger will dig deeper in
certain locations in order to give greater
assurance that all the PCB-contaminated
sediments will be captured.
Fewer Dredge Passes
•	In Phase 1, the plan allowed for multiple
dredging passes—typically three to tour—to
capture as much of the PCB-contaminated
sediments as possible.
•	One consequence of the multiple dredge
passes approach was that areas that had been
dredged often stayed "open" (uncovered) for
months while repeated re-sampling and re-
dredging took place. During this time the
exposed sediments were able to get back into
the water column and/or were re-deposited on
the river bottom.
•	Phase 2: A maximum of two dredge passes will
be used. In very rare circumstances, when a
particularly high concentration of PCBs is
unexpectedly discovered after the second pass,
EPA will require a third.
Significantly Less Capping
•	GE will be required to design the dredging
project to achieve the cleanup target of 1 part
per million of the most toxic PCBs, referred to as
"Tri • PCBs," in all of the dredge areas.
•	Due to certain physical constraints in the river
(bedrock, clay and shoreline stability
considerations) and other realistic limitations on
the ability of dredging to achieve the cleanup
target in all areas, there will be some areas that
require a cap to isolate the relatively small
amount of PCBs that remain after dredging
occurs.
•	Even in areas that require a cap, the vast
majority of the PCBs wiii be dredged before the
area is capped.
•	Phase 2: EPA will limit capping at 11 percent of
the total project area, not counting those
bedrock/clay/shoreline areas where capping is
the only option. In addition, within this 11
percent maximum of dredged area that may be
capped under this performance standard,
another lower limit of 3 percent has been
established to even more stringently limit
w

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capping over areas where significant PCB
contamination remains below the top six inches
of sediment after two dredging passes. By
comparison, in Phase 1, 22 percent of the total
acreage dredged was capped, not counting
bedrock, clay and shoreline areas.
Increased Productivity
•	During Phase 1, a total of 283,000 cubic yards
of sediment were dredged by GE.
•	Phase 2: The target for the second phase of
the project is to dredge a minimum of 350,000
cubic yards of sediment each year. EPA.
expects that GE will be able to achieve even
higher productivity, up to 500,000 cubic yards a
year or more.
Protective Limits on Resuspension
•	A fundamental goal of the project is to achieve
a quick and significant reduction in PCB levels
in fish tissue. Since the conclusion of Phase 1,
fish samples collected in the fall of 2009
showed that —as always expected—there was
a short-term increase in fish tissue PCB levels
during and immediately after dredging
operations. But fish samples collected in the
spring and fall of 2010 showed no appreciable
change from pre crecging levels, also
confirming EPA's predictions.
•	Updated modeling and other projections
provide strong evidence that anticipated rates
of resuspension wiil not jeopardize the goals of
the project; on the contrary, once the project is
completed, fish are projected to show speedy
and dramatic improvements as a result of the
dredging.
•	Phase 2: EPA is setting resuspension
standards that take into account both the
concentration of PCBs in the river water and the
amount of PCBs moving downstream.
- Both measurements are made at specified
locations along the 40-mile stretch of the
Upper Hudson in which the project is being
carried out.
If, at a designated measuring location, the
concentration exceeds 500 parts per trillion
of PCBs (equal to the maximum amount
allowed in drinking water) for five days out of
any seven, then GE may be required to take
various steps. These steps include a
temporary slowdown of operations or, in the
unlikely event of a particularly high
exceedance, a possible temporary shutdown
of operations.
The amount of PCBs allowed to travel down
the river will not be allowed to exceed 2% of
the total amount of PCBs actually excavated
from the river bottom, as measured at
designated locations downstream of where
the dredging is taking place.
At Waterford. the farthest downstream
measuring station, the load may not exceed
1 % of the amount excavated. If these limits
are exceeded for specified periods of time,
then GE may be required to take various
steps, including a temporary slowdown of
operations.

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- These standards, particularly the load
standard at Waterford, will be re-evaluated,
and may need to be adjusted and updated
as dredging operations move from the
uppermost portions of the 40-mile stretch of
river into areas much further downstream.
Flexibility to Make Changes
• As the Hudson River Peer Review Panel
recommended to EPA, the plan for Phase 2 calls
for constant evaluation of new data, and
provides for adjustments as the project moves
forward if needed to improve operations and
meet project goals. EPA will make these
determinations based on scientific data.
These and other improvements to the second
phase of the Hudson River dredging project will
ensure that the momentum of the cleanup work
in the river continues and that the biggest
sources of ongoing contamination are
addressed.
For more information or to view the technical
documents that contain the details of Phase 2,
visit www.eoa.gov/hudson. Copies of the
documents can also be viewed at EPA's
Hudson River Field Office located at 421
Lower Main Street, Hudson Falls, NY
EPA Contacts:
Dave King, Director and Projects Coordinator
EPA Region 2
Hudson River Field Office
421 Lower Main Street
Hudson Falls, NY 12839
(518) 747-4389
king.david@epa.gov
Larisa Romanowski, Community Involvement Coordinator
EPA Region 2
Hudson River Field Office
421 Lower Main Street
Hudson Falls, NY 12839
(518) 747-4389
romanowski.larisa@epa.gov

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