The Cresson area in particular is no stranger to pollution. The Department of Environmental Protection previously reported Cresson had extremely high levels of mercury in the soil because Cresson is downwind from 13 different coal-fired power plants.

Thursday, a study released out of Washington, D.C., listed the 50 dirtiest power plants in the nation, and three of them are in Pennsylvania.

The fifth on the list is the Reliant Power Plant in Shawville, Clearfield County, one of the plants believed to be responsible for the high mercury levels in Cresson.

Some residents said they aren't surprised by the results.

"We're a coal community and when there's coal, there's dirt," said Margaret Cnoel. "I think the people who are causing the pollution should clean it up."

The report not only measured mercury emissions from the plants, but also took readings on sulfur dioxide, carbon dioxide and other emissions.

The other two Pennsylvania power plants on the list are owned by Allegheny Energy, but are not locally run.