Eleven of the 13 units have recently shut down, and under this settlemen,t those shutdowns become a permanent and enforceable obligation. At the remaining two units, Duke must continuously operate pollution controls and meet interim emission limits before permanently retiring them. In addition, the settlement requires that Duke retire another unit at the Allen plant, spend a total of $4.4 million on environmental mitigation projects, and pay a civil penalty of $975,000.

Co-plaintiffs Environmental Defense, the North Carolina Sierra Club and Environment North Carolina joined the United States in the settlement. The United States initially sued Duke in 2000, and the trial was set to begin in October following years of pre-trial litigation, including a landmark 2007 Supreme Court decision agreeing with the EPA’s interpretation of the relevant Clean Air Act regulations.