ALBANY, N.Y. — At the urging of environmental groups, the U.S. Environmental Protection Agency has agreed to speed up its study of whether General Electric's six-year dredging project on the Hudson River was effective in cleaning up PCB contamination.

In a Dec. 18 letter to green groups that met with him in Washington, D.C., earlier this month, Mathy Stanislaus, who oversees EPA's Superfund cleanup programs, agreed to begin the review early in 2016 instead of 2017.

But he said the EPA won't stop GE from dismantling the plant it used to process sediment dredged from a 40-mile stretch of the river north of Albany.

GE has said it successfully completed removing PCB it released into the river before 1977 and the EPA agreed. Environmental groups contend contamination remains at unsafe levels.

There was no immediate comment Tuesday from GE.