MASSENA Remediation crews in the coming years will dredge 109,000 cubic yards of contaminated sediment from the banks of the Grasse River, but it might not be going far.
The river cleanup plan approved by the U.S. Environmental Protection Agency calls for dredging shoreline sediment that exceeds PCB levels of 1 part per million in the top 6 inches of soil, according to Walter Mugdan, director of the EPAs Emergency and Remedial Response Division.
Mr. Mugdan said the contaminated sediment will be drained of water, the water will be treated and returned to the water supply and the soil will be kept at a landfill on the Alcoa West Plant site. He said this landfill is designed for permanent disposal of sediment laced with polychlorinated biphenyls, and it currently contains sediment dredged during the engineering phase of the remediation plan.
Some residents of the St. Regis Mohawk reservation who attended a meeting with EPA and tribal officials last week raised concern about keeping the contaminated sediment in the area, pointing to the landfill at the former General Motors Powertrain site as an example of what they described as hazardous waste being left carelessly in an area that has already suffered from PCB exposure.
However, Ken Jock, director of the tribes Environment Division, said that unlike the GM site, the Alcoa West facility is designed for the safe and long-term disposal of contaminated sediment. According to Mr. Jock and Mr. Mugdan, the Alcoa West landfill is equipped with safety features to monitor and prevent PCBs from contaminating the local environment, such as wells to monitor for PCBs, two liners to prevent PCBs from leaking into the ground soil and a layer of clay, soil and vegetation atop the contaminated sediment.
Its basically the state-of-the-art, best way of dealing with PCBs at the moment, Mr. Jock said. Theres quite a difference between the GM and Alcoa West sites.
Mr. Jock described the material left at the GM site as oily, PCB-contaminated sludge an illegal dump that was never approved by the state Department of Environmental Conservation.
Theres no protection at the GM site, he said. Its a much more secure, highly monitored situation at Alcoa West.
Mr. Jock also pointed out that containment in a landfill is one of few ways to minimize exposure to PCBs, which are believed to cause cancer and other health problems in people exposed to them. He said the most harmful method of exposure is by eating fish contaminated with PCBs, and many say this and other methods of exposure have led to high rates of cancer and other diseases among the Mohawks.
Mr. Mugdan pointed out the problematic nature of the contaminants. PCBs were created because they dont break down. Thats why they were used at Alcoa, he said. Thats the key problem.