US: The Court of Appeals for the D.C.Circuit Largely Upholds 2015 Ozone Standards

In a decision published on August 23, 2019, the Court of Appeals for the D.C. Circuit upheld the Environmental Protection Agency’s (EPA’s) primary national ambient air quality standard (NAAQS) for ozone. The Court remanded the secondary standard to EPA for reconsideration and vacated the grandfathering provision.

EPA’s 2015 primary and secondary NAAQS for ozone were set at 70 ppb. The Court upheld the primary standard but ordered EPA to revisit its secondary standard. EPA was found to have arbitrarily declined to have set a level that would protect against adverse welfare effects associated with visible leaf injury.

The Court rejected industry challenges that argued EPA erroneously excluded the “overall adverse economic, social, and energy impacts” when revising the standard, that EPA is required to consider the impact of background ozone on the ability of states to attain the standard, and that EPA must consider background ozone.

While reviewing the 2015 standards, EPA also revised the regulations for the Prevention of Significant Deterioration (PSD) program. EPA was unsure how to handle completed PSD permit applications where sources would have complied with the 2008 standards in effect at the time of filing, but where the NAAQS were revised before the permit was approved. Under the Clean Air Act, the permitting authority must grant or deny the completed application within one year. To address this, EPA created a grandfathering provision for pending permit applications that satisfied one of two criteria. The two categories were: (1) permit applications deemed complete on or before the signature date of the final rule revising the ozone NAAQS; and (2) permit applications “for which the reviewing authority has first published a public notice of the draft permit or preliminary determination before the effective date of the NAAQS. If the application met either criteria, the owner or operator could demonstrate compliance with the 2008 NAAQS instead of the 2015 NAAQS. The Court held that there was no conflict with the PSD program and the revised NAAQS, as the PSD program does not require that a permit be approved within one year, only that it be granted or denied. If the permittee cannot comply with the revised NAAQS, the permitting authority can deny the permit within one year.


Murray Energy Corp. v. EPA, No. 15-1385