A U.S. appeals court has upheld a federal plan limiting pollution in the Chesapeake Bay despite objections from farmers who accuse the Environmental Protection Agency of abusing its power.

The ruling Monday upholds restrictions on farm and construction runoff and wastewater treatment and is a clear win for environmentalists.

Six states have agreed to the pollution limits: Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia, along with Washington, D.C.,

The American Farm Bureau Federation and others fought the restrictions. They argued that the EPA was usurping state authority to regulate waterways.

The EPA says animal waste and fertilizer that moves from streams into the Chesapeake is the single largest source of bay pollution.

Third Circuit Judge Thomas Ambro says Chesapeake Bay pollution is a complex problem that affects more than 17 million people.