December 7, 2000
Dredging PCB's Could Be a Cure Worse Than the Disease, G.E. Insists
By ANDREW C. REVKIN
he debate over digging up the Hudson
River's last industrial stain has always centered on a single question:
Is the cure worse than the disease?
And the answer offered by a variety of experts on underwater toxic cleanups
remains a resounding: It depends. They say that new dredging technologies
can effectively attack buried spots of PCB's and, if used carefully, can
keep contaminated silt from spreading and creating new problems.
But often, at least at several dozen other underwater cleanups overseen
by the Environmental Protection Agency around the country, in the end the
river bottom remains contaminated, though perhaps not to the degree it
Also, several experts point out, the proposal for the Hudson dwarfs
anything that has ever been tried before. The amount of mud to be moved,
2.6 million cubic yards, would be more than all the mud moved in all the
other cleanups combined. It would be more than enough mud to fill Giants
Stadium to the brim.
Then there is the matter of cost. "The extra levels of care come with
an increased bottom line dollar sign," said Dr. Richard F. Bopp, a geochemist
at Rensselaer Polytechnic Institute in Troy, who has studied the Hudson
contamination for 21 years.
Still, he and many other experts say, there is little merit in simply
waiting for the river to heal itself. This is the preference of General
Electric, which is responsible for the cleanup under the federal Superfund
law and has steadfastly opposed dredging. The company wants to focus instead
on stanching PCB seeps in cliffs near its old factory sites.
As long as tons of PCB's remain banked in the bottom of the river, there
is the prospect of further releases, said Robert E. Randall, the director
of the center for dredging studies of Texas A&M University.
"Doing nothing doesn't seem to be the right thing to do, because then
you have a continual exposure there, an ongoing risk," Dr. Randall said.
He is one of several dredging experts who said that the technological
options had improved substantially in just the last five years. There are
now variants of the old-style clamshell bucket that are positioned using
satellites accurate to within an inch or so. These remove precise, truck-
size cubes of mud and seal themselves to prevent water from leaking out
as the mud is lifted onto barges.
There are also systems that cut into the bottom with screw-shaped bits
and then vacuum the mud and water onto a barge or into a pipeline. But
these devices can create more problems than they solve, because of the
enormous volumes of water that must be treated before they flow back into
At a news conference yesterday, Carol M. Browner, the E.P.A. administrator,
focused on the hydraulic systems, but other officials stressed that their
Hudson cleanup proposal does not specify a dredging technique, only the
extent of dredging.
For years, General Electric has attacked dredging, pointing to the persistent
surface contamination at other toxic cleanup sites, the unparalleled extent
of the Hudson proposal, which it calculates could take 20 to 30 years to
carry out, and the need to put any dredged material in landfills, where
it may still pose environmental risks. The E.P.A. estimates the dredging
would take five years to complete.
Stephen D. Ramsey, G.E.'s vice president for environmental affairs,
said the E.P.A. was trying to gloss over the project as something that
would not interfere with life along the upper Hudson. Instead, he said,
it would be a huge effort.
Mr. Ramsey also said the agency was putting the cart before the horse,
because it issued its decision before a federal panel of scientists had
released its report assessing ways to clean up PCB's.
The analysis, by the National Research Council, is being reviewed, and
is expected to be released by the end of the year.