On April 11, 2017, the United States Court of Appeals for the District of Columbia Circuit canceled oral argument, which had been scheduled for April 19, in several consolidated cases challenging EPA’s 2015 revision of National Ambient Air Quality Standards (NAAQS) for ozone. The court took this action, and ordered that the case be held in abeyance, in response to an EPA motion asking that oral argument be continued, to give the appropriate Trump administration officials adequate time to review those standards. EPA’s motion indicated that the new administration is deciding whether to reconsider them.

What is the regulatory significance of the court’s action?

At this time, the 2015 ozone NAAQS remains in effect. Mandatory statutory measures concerning them therefore continue to apply. For example, new applications for Prevention of Significant Deterioration (PSD) permits for major new or modified stationary sources must address the 2015 NAAQS. This means that applicants for such permits must demonstrate that the source to be permitted will not cause or contribute to a violation of that standard.

Furthermore, despite the court’s action, each state must still submit State Implementation Plan (SIP) amendments addressing the requirements of Section 110(a)(1) of the Clean Air Act (Act) to EPA by October 2018. In addition to providing for monitoring of air quality and demonstrating that the state has adequate personnel, funding and authority to implement the NAAQS, these so-called infrastructure SIPs must demonstrate that air pollution within the state is not causing or contributing to a violation, or interfering with maintenance, of the NAAQS in any other state. Preparation of these SIPs requires significant state resources to develop the SIP and thereafter to provide public notice of it to conduct public hearings on it.

Finally, as long as the 2015 NAAQS remains in effect, EPA is under a statutory obligation to designate areas throughout the country as attainment (in compliance), nonattainment (not in compliance) or unclassifiable (available data does not allow a determination of whether the standard is met). Under the Obama administration, EPA said that it intended to make these designations by October 1, 2017. They are not required until somewhat later, however. The statute gives EPA two years after promulgating a NAAQS to make designations for it. Because the effective date of the 2015 NAAQS was December 28, 2015, the agency has at least until December 28, 2017, to sign a notice concerning the designations. Moreover, the Act allows EPA to take an additional year before making designations if it has “insufficient information” at the end of two years. In the past, EPA considered reconsideration and possible revision of a NAAQS to constitute “insufficient information.” Using this approach, designations could be deferred until as late at December 28, 2018. Ultimately, however, unless the 2015 standard is rescinded, EPA will be required to make designations for it. Once those designations become effective, they, in turn, will trigger requirements for states designated nonattainment to prepare, submit to EPA and implement plans consistent with the onerous requirements specified in Section 182 of the Act for bringing nonattainment areas into compliance with the standard.

What happens if EPA decides to reconsider the 2015 rule revision in whole or in part? Again, this would not automatically stay the 2015 NAAQS. Under Section 307(d) (7)(B) of the Act, EPA, however, could stay the effectiveness of the NAAQS for a period of up to three months while reconsidering some or all of it. Although such a stay likely would not be long enough for EPA to reconsider and revise the NAAQS itself, the agency might be able to complete revisions to certain other aspects of the 2015 rule (for example, provisions concerning PSD and the ozone monitoring season) within that timeframe.

Because judicial challenges to the 2015 NAAQS are pending, the Administrative Procedure Act (APA) authorizes a more extended stay. Section 705 of the APA authorizes an agency such as EPA to “postpone the effective date” of an action pending judicial review when “justice so requires.” The postponement may extend to the conclusion of the judicial review proceedings. Given that pending challenges to judicial review of the NAAQS have been placed in abeyance as a result of EPA’s motion to continue oral argument and that, as discussed above, statutory deadlines for implementation of that standard are approaching, justice requires such a stay until judicial review can be completed. That would almost surely mean the stay would extend through completion of any reconsideration proceedings.

In short, the DC Circuit’s postponement of oral argument on challenges to the 2015 ozone NAAQS has no impact on that standard’s effectiveness. Nor does it modify the substance or timing of implementation requirements specified in the Act. Thus, it would be appropriate for EPA to stay the effectiveness of the standard while it considers whether to reconsider it and, if it undertakes reconsideration, until those proceedings have been completed.