New York's top court says the state can require major polluters to restore Superfund sites to the condition they were in before they were contaminated.

In a 5-2 ruling Thursday, the Court of Appeals found that the state Department of Environmental Conservation can mandate what's known as a "complete cleanup" of industrial waste.

In a statement, the DEC said officials are "pleased the Court of Appeals recognized the importance of DEC's authority to require polluters to reach complete cleanup requirements at state Superfund sites. This is a substantial victory for the state’s citizens, land and water," the statement continued.

Environmental groups are also calling the ruling a big win. "The court upheld the authority of the state officials to push, and gave them the flexibility to push, for the highest levels of cleanup that they think they can achieve," says Attorney Mark Izeman from the Natural Resources Defense Council.

The judges said the higher standard is consistent with the state's Superfund law from the 1970s. That statute is separate from the federal Superfund program that's currently overseeing cleanups of the Gowanus Canal and the Newtown Creek in New York City, though federal EPA officials are required to consider the state's regulations.

A group of corporations calling itself the New York Superfund Coalition filed suit against the state in 2007, advocating a lower standard that would have allowed less expensive cleanups that would have allowed polluters to leave some contaminants at certain sites. The corporations argued that state regulations required companies only to do the "best job that is feasible." The difference in those two directives can cost companies hundreds of millions of dollars.