(CN) - Federal regulators Thursday approved General Electric's plan to shut down the 100-acre plant it has used for six years to dredge carcinogenic pollutants from the Hudson River.
The Environmental Protection Agency's approval to close the site is one of the final steps for GE's cleanup of the upper Hudson River to be declared complete.
The PCB-sediment processing facility in Fort Edward, N.Y., was built to support GE's $1.6 billion Hudson River dredging project which it began in 2009 to remove polychlorinated biphenyls it had dumped into the river at Fort Edward and Hudson Falls from the 1940s until 1977.
PCBs were banned in 1979 as carcinogenic. Until then, they were widely used as coolants, cutting fluids in machining, and in carbonless copy paper.
The cleanup plan, the company's largest environmental remediation ever, was required by a 2006 legal agreement between GE and the EPA.
GE has finished its sixth and final season of dredging and now will dismantle and decontaminate the facility, a process that will continue into 2016.
Critics say that elevated levels of PCBs are still in the river and the infrastructure should not be removed.
"GE's work just isn't done," said Dan Raichel, an attorney with the Natural Resources Defense Council. "Just last month, two other federal agencies - the National Oceanic and Atmospheric Association and the Fish & Wildlife Service - said its cleanup would not be enough to make the Hudson's fish safe to eat for generations to come. GE must clean up the rest of the mess it made."
The EPA acknowledged that it received comments urging it not to allow the demobilization, in case there was an opportunity for additional dredging.
"No such opportunity is imminent," the EPA said in a statement.
The agency said that if an agreement is struck by parties other than the EPA, a temporary processing facility can be built.
Riverkeeper president Paul Galley said the EPA decision has decreased the likelihood of a quick and effective dredging of the remaining 100-plus acres of PCBs in the Hudson River and Champlain Canal.
"To resite, rebuild and remobilize a far smaller 'temporary' dewatering facility, if even possible, will only serve to unnecessarily prolong the damage GE is causing the river, our families and our economy. EPA cannot continue to claim 'success' on a job left unfinished," Galley said.
Contractors for GE removed about 2.75 million cubic yards of sediment containing 310,000 pounds of PCBs from a 40-mile stretch of river bottom. The sediments have been shipped to landfills in Oklahoma, Michigan and Ohio.
The environmental cleanup is not done yet. GE said it will restore underwater vegetation to areas of the river that have been dredged and will monitor environmental conditions in the river for the foreseeable future.
"We are proud of what we have accomplished so far, and look forward to bringing the same standard of excellence to the work that lies ahead," said Ann Klee, GE's vice president of global operations for environment, health and safety.
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