In its on-going campaign over what it sees as illegal modifications to grandfathered coal-fired plants, that is, those exempt from the Clean Air Act, the EPA has recently been set back.

The Agency has been forced to crack down on emissions in the Northeast following a legal challenge by Midwest power producers. The EPA had blamed Midwest coal-fired plants for preventing Northeastern states meeting air quality ozone standards, but under a consent agreement, it will now impose federal reductions in six Northeastern states from May next year.

American Electric Power (AEP) has also reacted to the moves by attempting to have the bulk of the EPA claims rejected on the grounds that they fall beyond the five-year limitations period. According to AEP, the move was made in order to simplify the case as it is confident of winning any challenge. An EPA response is due within the next few weeks, but the case is not expected to be resolved until autumn.