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D.C. Circuit Closes Book on Ozone Standards Litigation

Oct. 28, 2019, 5:38 PM

Opponents of the Obama administration’s 2015 ozone standards aren’t asking a federal court to revisit a recent decision that largely upheld them.

The U.S. Court of Appeals for the District of Columbia Circuit issued a formal mandate Oct. 28 in Murray Energy Corp. v. EPA, potentially cementing a ruling that rejected challenges from energy companies and states. D.C. Circuit mandates, which formalize the court’s decisions, are issued after the window closes for parties to seek rehearing.

The D.C. Circuit’s action could mark the end of litigation that has dragged on for four years, led by Murray Energy Corp., other energy producers, and a coalition of mostly Republican-led states.

Any party to the case has until Nov. 21 to ask the Supreme Court to review the issue.

“Although there is still the possibility of seeking Supreme Court review, we hope that EPA will focus instead on complying with the Court’s ruling and adopting stronger protections against dangerous smog pollution,” Earthjustice attorney David Baron, who represented environmental groups in the case, said in an email.

The EPA and two of the lead litigants in the case, Murray Energy and Arizona, didn’t respond to questions about the potential for Supreme Court petitions.

D.C. Circuit Ruling

The Environmental Protection Agency’s 2015 primary ozone standard required levels of the air pollutant to be capped at 70 parts per billion to safeguard public health.

The Trump administration defended the threshold in court last year, pushing back on arguments from Murray and other challengers that the standard was impossible to achieve.

The D.C. Circuit sided with the EPA, rebuffing the opponents’ contention that the agency should have considered “adverse economic, social and energy impacts.” Supreme Court precedent bars the EPA from considering costs when setting ozone standards.

The appeals court ruled against the EPA on another part of the 2015 rule, a secondary ozone standard—also 70 parts per billion—designed to protect plants and animals.

A three-judge panel agreed with environmental groups that agency officials failed to justify their selection of a threshold that was weaker than what science advisers recommended.

The case is Murray Energy Corp. v. EPA, D.C. Cir., No. 15-1385, mandate 10/28/19.

To contact the reporter on this story: Ellen M. Gilmer in Washington at

To contact the editors responsible for this story: Gregory Henderson at; Renee Schoof at; Rob Tricchinelli at