The Tennessee Valley Authority (TVA), the biggest wholesale power producer in the U.S., filed suit last week to stop the EPA from requiring more pollution controls on its coal-fired power plants. The EPA says that TVA improperly upgraded seven old coal-fired plants without bringing them into compliance with current Clean Air Act standards. Even as TVA was defending its right to pollute, the governors of Georgia, North Carolina, South Carolina, and Tennessee were meeting to discuss how they could clean up the dirty air in the Great Smoky Mountains National Park and other parts of the Southern Appalachians. Last year, the air in the national park violated federal ozone standards on 52 days, a problem that many say stems partly from TVA’s coal-burning plants.