WASHINGTON, D.C. — The U.S. Environmental Protection Agency issued stringent emissions regulations for boats and trains last week, drawing praise from industry and environmental groups alike.

Harbor tugs, ferries, barges, recreational boats and trains will be forced to use cleaner fuel to reduce soot by 90 percent and nitrogen oxide, which causes smog and contributes to climate change, by 80 percent. New engines must meet these standards by 2015.

It could take more than 20 years for most engines to be refurbished to meet the new standards. And the technology needed to meet the new cleaner engine requirements don't entirely exist yet.

"Today's final rule establishes difficult stretch goals for the industry," said Jed Mandel, president of the Engine Manufacturers Association. "But, we are prepared to meet the challenge. It will not be an easy task. Application of advanced diesel emission reduction technology in marine vessels is very challenging due, among other things, to the constraints imposed by the marine environment. There also are big challenges in adapting clean diesel technology to locomotives."

The EPA has in recent weeks come under fire for a lax smog regulations decision and for rebuffing California's efforts to regulate greenhouse gas emissions. The new regulations don't include large ships.