On Friday, July 19th, the Tenth Circuit issued a much-anticipated decision in the lawsuit over regional haze requirements in Oklahoma.  In a split decision, with three judges writing three separate opinions, the majority of the Tenth Circuit panel deferred to EPA’s position instead of respecting the state authority granted to Oklahoma under the Clean Air Act.

Key to the case was the fight over how to analyze the expected cost of additional emission controls at three facilities subject to “best available retrofit technology” requirements.  EPA claimed that all states must use a 2002 “Cost Manual” to determine costs and claimed that the manual required an assumption that state-of-the-art control devices can be installed “overnight.”  Since Oklahoma had taken a more reasonable, real-world approach, and recognized that the utilities at issue would incur significant financing, overhead, and other indirect costs to install controls that take years to build, its cost estimates were several times higher than EPA’s estimates.  As a result, Oklahoma determined that control devices known as “dry scrubbers” would not be cost-effective in addressing visibility concerns at nearby national parks and wilderness areas.

However, the court deferred to EPA, and the consultant that prepared EPA’s analysis (Dr. Phyllis Fox), thus allowing EPA to impose much more costly emission controls and more stringent emission limits on seven utility units in Oklahoma.  The court’s decision is particularly important given the significant number of similar lawsuits currently underway to address EPA’s rejection (or approval) of western states’ regional haze plans.

A copy of the Tenth Circuit’s decision is available here: Oklahoma v. EPA.