Dredging Fox River may be insufficient - Report backs DNR plan to cover toxic sediment
The Wisconsin Department of Natural Resources' approach to cover some of the polluted sediments in the $400 million cleanup of the Fox River in northeastern Wisconsin got support Tuesday from a national, non-partisan scientific panel.
The National Research Council concluded in a report, based on 26 cleanup projects across the country, including the Fox, that dredging is effective at removing contaminated sediments from many waterways.
But such work might not go far enough in some cases to reduce safety risks to humans and wildlife.
The report, issued under the umbrella of the National Academy of Sciences, corroborates the approach being sought by the DNR to remove some sediments and cap others containing high levels of polychlorinated biphenyls, or PCBs.
The Fox project is the largest cleanup of toxins in the United States. Some work has begun, but 90% or more is still in the planning stages.
Bruce Baker, a DNR administrator, said the study supports his agency's thinking that "you are never going to get to this level of cleanup with just dredging."
He likened the cleanup of PCBs to "light, fluffy snow" that falls in a storm but gets kicked up by wind as it's being shoveled.
"In some cases, you just can't get all of it by trying to scoop it up," Baker said.
However, environmentalists remain unconvinced that the DNR's proposal is the best approach.
Emily Green, director of the Great Lakes program of the Sierra Club, said she agrees with the science behind the findings of the National Research Council.
But Green said the research council was analyzing numerous cleanup projects, and she worried the DNR plan is being driven as much by cost containment as it is for protecting the environment.
Capping is generally viewed as a cheaper alternative to removing sediments.
The DNR is poised in the next week or so to update its recommendation for cleanup of the Fox after environmentalists sought changes.
The Fox is polluted with PCBs that paper companies operating along the river used in the manufacture of carbonless paper.
Environmentalists had opposed the DNR's use of capping sediments in some parts of the river, fearing that ever-changing river currents and future dredging for navigation could uncover PCBs and send them flowing downstream.
But the council said some spots were best left capped and the sediments not removed. In other instances, removing PCBs from a river bottom doesn't go far enough.
In its study, it showed progress from a project on Little Lake Butte des Morts that reduced PCBs by 87% in 2005 but still left sediments with PCBs that were 20 times higher than acceptable levels.
Source: JSOnline-Journal Sentinel - By Lee Bergquist
Posted: June 2007
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