Tuesday, March 8, 2011

Advocacy groups say they have reached a deal with the U.S. Environmental Protection Agency in a legal dispute over discharges of ship ballast water that could contain invasive species.

The agreement was filed Tuesday in the federal appeals court in Washington, D.C. It requires the EPA to issue a new permit regulating ballast dumping by commercial vessels.

A dozen environmental groups went to court in 2009, contending the agency's existing permit isn't strong enough to protect coastal waters and the Great Lakes.

Ballast water is considered the leading culprit in a flood of invasive species such as zebra mussels that have reached U.S. waters in recent decades. They compete with native species for food and cause billions in economic losses.