From the new York Times' Green blog:
General Electric began the second phase of its cleanup of the Hudson River on Monday under tightened federal requirements, including a limit on how much contamination could be sealed on the riverbed rather than removed.
Two dredges began operations in the Upper Hudson south of Rogers Island in Fort Edward, N.Y., with one assigned to remove sediment and the other debris, a spokesman for G.E., Mark Behan, said. He said that operations would continue 24 hours a day, six days a week through October, weather permitting.
As many as four dredges, four backfill platforms, 17 tugboats and more than 25 barges will be operating in the Upper Hudson during the cleanup, Mr. Behan said.
The project is intended to remove PCBs, or polychlorinated biphenyls, that were discharged by two G.E. factories into the river over a 30-year period ending in 1977. It will continue to unfold for five to seven more years over a 40-mile stretch of river north of Albany.
General Electric carried out the first phase of the cleanup along a six-mile stretch of the Hudson from May to November of 2009. In the second phase, the company is following new requirements issued last December by the Environmental Protection Agency, which is overseeing the effort under its Superfund program for redressing toxic contamination.
Under the more stringent rules, G.E. is allowed to cap only 11 percent of the total project area, which stretches from Hudson Falls to Troy, N.Y., on the riverbed. That does not include areas where capping is unavoidable because of physical barriers in the river, which could amount to an additional 10 percent of the project, the E.P.A. said.
By contrast, the company capped nearly 37 percent of the pollution that it treated in
the first phase, the agency said.
In the current phase, E.P.A. officials are also requiring a maximum of three passes by dredging vessels with the aim of limiting recontamination of the river. They have also required more rigorous sampling to determine the extent of the contamination.
G.E. officials have said the new standards reflect a consensus for ensuring a practical and cost-effective project. At least 95 percent of the PCBs in the dredging area are expected to be removed under the new standards.
Updates on the dredging will be posted at www.hudsondredging.com.