EPA argued before the DC Circuit that emissions limits covering industrial boilers should be left in place while they work to address legal flaws identified by a federal appeals court, the agency said in a court filing. The U.S. Court of Appeals for the District of Columbia Circuit in July found that the EPA erred when it excluded certain high-performing units from its calculation of minimum emissions standards, known as MACT floors, for different subcategories of boilers. That decision, which included several victories for environmental organizations, also rejected all arguments raised by U.S. Sugar Corp., the American Chemistry Council and other industry petitioners.

The D.C. Circuit panel's opinion in U.S. Sugar Corp. vacated the emissions standards for all major boiler subcategories that would have been affected had the EPA considered all sources, rather than excluding certain units from its analysis. The EPA petitioned the court Sept. 12 to instead leave the emissions limits in place while the agency works to address the D.C. Circuit's ruling.

The maximum achievable control technology standards for major source boilers, commonly referred to as Boiler MACT, apply to more than 14,000 boilers found at petroleum refineries, chemical plants and other industrial facilities. The EPA estimated it would cost industry $1.6 billion annually to comply with the emissions standards.

In the U.S. Sugar ruling, the D.C. Circuit panel rejected an industry argument that the EPA's approach to rely on enforcement discretion to address violations of the Boiler MACT standards caused by malfunctions represents a violation of a Clean Air Act requirement that the standards must be achievable.

“The panel decision upholds an EPA regulation that requires the impossible: perfect performance that even EPA admits is neither achieved nor achievable because malfunctions are an inevitable fact of industrial life,” the Ohio-based utility said in its petition. “Unless corrected, this decision will be felt in dozens of impending rulemakings impacting a broad swath of the American economy while generating a slew of unnecessary lawsuits in federal district courts nationwide.”