Reducing the amount of toxic PCBs resuspended into the upper Hudson River during the second phase of the dredge project is a major concern of an independent peer review panel studying the project’s first phase.
The large-scale environmental dredging project had to be shut down several times last summer when PCBs — stirred up by dredges and tug boats — increased in river water beyond the federal drinking water standard of 500 parts per trillion.
But General Electric Co. and U.S. Environmental Protection Agency consultants had very different views about the resuspension problems during the first day of a three-day peer review panel session at the Queensbury Hotel in Glens Falls.
The panel is studying results of last year’s test dredging at PCB “hot spots” on the river about 40 miles north of Albany. The panel will make recommendations this summer for the second phase of the dredging, a project that the EPA wants to start next year.
GE’s experts said there isn’t too much more that their engineers can do to reduce resuspension. The EPA’s experts disagreed, saying there are a variety of ways to reduce the amount of PCBs stirred up.
“We suspect we can work around the edges,” said John Connolly, a GE consultant.
Connolly said that by changing some techniques the dredges may be able reduce the PCB resuspension rate from the about 3 percent seen last year to 2.5 percent in the dredge project’s second phase, which is expected to start next spring.
“We can adjust things and make things better,” said Edward Garvey, an EPA consultant, in answer to a peer group question.
“There is definitely room for improvement,” Garvey said, but he told the panel he could not specify how much resuspension could be reduced.
The EPA on Monday released a 200-page addendum to its evaluation of the dredge project’s first phase. In it, the EPA listed six ways to reduce resuspension and also criticized some of GE’s techniques.
Some of the ways to reduce resuspension cited by EPA were reducing tug boat traffic around the dredging; modifying the way the sediment is scooped up so less sediment is dropped back into the water; and improving the methods of backfilling the areas freshly dredged with clean fill.
But Connolly said GE doesn’t think vessel traffic is a major cause of the resuspension.
In the EPA addendum, the EPA criticized some of General Electric’s sampling methods and the way GE uses the sampling results.
This new critical attitude by the EPA toward GE is a departure from the past few years when the government agency and large corporation seemed to be cooperating.
Mark Behan, a GE spokesman, said Tuesday that the EPA has approved all the sampling and testing methods that GE uses, including 50,000 river core samples and 18,000 tests done during the first phase.
“The EPA relies on GE data except when it doesn’t support their preordained positions,” Behan said about critical comments about GE in the EPA publication.
David King, director of the EPA’s Hudson River Field Office in Fort Edward, said some of the river water testing done by GE in March that showed large spikes in PCBs are suspect because four of five monitors at the Thompson Island pool test site were plugged with mud and river vegetation.
“Our position is that the first phase was good, it taught us a lot,” King said. “The idea that we can’t make improvements is a little fatalistic.”
GE officials noted that the EPA is considering exceeding the 500 parts per trillion PCB drinking water standard during dredging.
During the project’s first phase, if the resuspension water levels reached 500 parts per trillion, the project was stopped until the PCB levels went down. King said now that the EPA is paying the towns of Waterford and Halfmoon to be on Troy water through at least 2012, if the resuspension levels exceeded 500 parts per trillion it wouldn’t matter as much because no nearby community was taking their drinking water from the Hudson.
The seven-member panel of independent scientists and engineers studying the first phase is expected to make final recommendations for changes by July.
GE is conducting and paying for the estimated $780 million dredge project. GE estimated on Friday that the first phase of the dredging project has already cost $561 million.
GE has not yet indicated publicly that it wants to stop the dredging project, but it has said it wants to alter the way dredging is done, including capping the more deeply embedded PCB-contaminated soil.
GE is on orders from the federal government to remove PCBs (polychlorinated biphenyls, a probable carcinogen) from the river bottom between Fort Edward and Troy.
The second, larger phase of the dredge project is expected to last five years. However, King said Tuesday that if the project has to be extended a sixth year it would. This is a departure from the EPA’s and GE’s plan to keep the second phase to five years.
The peer review panel will resume its deliberations today and complete them Thursday afternoon.