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Hot Spots. Samplers identify dredging targets. (Photo courtesy of General

In a consent decree signed October 6, the General Electric Co has agreed to dredge the hottest areas of PCB-contaminated sediment in the Hudson River and to build a sediment transfer and processing facility. The work could cost between $100 million to $150 million and is scheduled for a 2007 completion.

Fairfield, Conn.-based GE, the U.S. Environmental Protection Agency and the U.S. Justice Dept. reached an agreement in federal district court in Albany, N.Y. The pact stipulates that GE will also pay EPA $78 million for past and future enforcement costs. A five-year final clean-up will follow an initial phase 1 performance review. "This is a major breakthrough for all friends of the Hudson River because it commits GE to begin dredging and to remove the contamination," says EPA Region 2 Administrator Alan J. Steinberg. GE has already paid $37 million in a previous settlement.

In compliance with a 2002 Record of Decision, GE had already engaged Quantitative Environmental Analysis, Glens Falls, N.Y., to conduct extensive river bottom sampling program to identify areas for dredging . GE also hired Blasland, Bouck and Lee, Syracuse, N.Y., to lead the engineering work, spending about $100 million to date. "They were under an enforcement decree with EPA and tested 48,000 sediment samples from 2003-2004. We used the results to target areas for remediation," says George Pavlou, EPA Region 2 Superfund division director.

Until 1977 GE had discharged 30-years worth of polychlorinated biphenyls from two upstream manufacturing plants. The contaminants, about 1.1-million pounds in total, turned the Hudson River into a Superfund site. PCBs were used as insulation in capacitors and there is a documented and tested contaminated 40-mile- long stretch running south from Hudson Falls to the Federal Dam in Troy. For the cleanup the run is divided into three segments: 6 miles, 5 miles and 29 miles long. Work in the initial phase will take place in the first segment. Up to seven closed- bucket environmental clamshell dredges could be used on the project.

PCBs are an environmental and health hazard. Total river cleanup costs are estimated at around $460 million to remove 2.65 million cu yds containing about 150,000 pounds of PCBs. About 10% of total volume will be cleaned in the first phase located around Rogers Island and Griffin Island, near Ft. Edward, the source of contamination. It contains on average 62.5 parts per million of contamination. Spoils will be cleaned to 1 ppm for triplus PCBs. Those most toxic PCBs have three or more chlorine molecules.

The dewatering facility, located in Ft. Edward, will consist of perhaps five enclosed structures--each 100-ft wide by 400-ft long on concrete slab foundations--a 1,450-ft long marine terminal and 38,000 ft of rail spur. A contractor has not yet been selected. It will process 4,000 cu yds of sediment per day and could be the largest of any treatment facilities in the country. About 2 million gals of water per day will also be treated to state water quality discharge standards. Each week 390,000 tons of process material will be transported off site in 250 rail cars to a site as yet to be determined. According to the EPA, only five states have disposal facilities that can handle the material: Idaho, Michigan, Utah, Texas, and Oregon. "We have submitted an intermediate design report, which is undergoing review. It should be finalized next year. Then the final design will be subject to EPA approval and we will start construction on phase 1 infrastructure," says Mark Behan, GE spokesman. "The dewatering facility will treat more than 1 billion gals of water over the life of the project."

Here is a schematic of the Ft. Edward dewatering facility. (967 kb)