## Facts

- Under the Clean Air Act (CAA), EPA sets National Ambient Air Quality Standards (NAAQS), and transportation activities receiving federal approval or funding must “conform” so they do not worsen NAAQS compliance.
- EPA issued transportation-conformity guidance in 2010, after notice and comment, identifying a preferred modeling methodology while allowing alternatives on a case-by-case basis.
- In 2015, EPA issued revised guidance that changed the preferred modeling approach but again stated it would consider alternative methods case-by-case.
- EPA issued the 2015 guidance without notice-and-comment rulemaking.
- Sierra Club and other organizations petitioned for review, asserting the 2015 guidance effectively altered substantive conformity criteria and therefore required notice and comment under the Administrative Procedure Act (APA) and the CAA.

## Issues

1. Whether EPA’s 2015 transportation-conformity modeling guidance constituted “final agency action” (and a reviewable “final action” under the CAA) subject to direct appellate review.
2. If reviewable, whether issuing the 2015 guidance without notice and comment violated the APA and the CAA.

## Decision

- The court dismissed the petition for lack of jurisdiction.
- The 2015 guidance was not final agency action because it did not determine rights or obligations and did not itself create legal consequences.
- Any legal effects would arise only from later, project-specific conformity determinations applying statutes and regulations, not from the guidance document.
- Because the action was not final and reviewable, the court did not reach the notice-and-comment challenges on the merits.

## Legal Principles

- An agency document is not final agency action unless it both reflects the consummation of the agency’s decisionmaking process and determines rights or obligations or produces legal consequences.
- Nonbinding guidance that states an agency’s preferred approach while preserving case-by-case flexibility generally lacks independent legal effect and is not directly reviewable under the APA.
- The CAA’s provisions for direct court-of-appeals review cover EPA “final actions” of the type that carry binding legal effect; informal methodological guidance that neither approves/disapproves a SIP nor alters binding standards typically falls outside that channel.
- Challenges to methodological choices may be premature when directed at guidance rather than a later concrete application that imposes legal consequences.

## Conclusion

The D.C. Circuit held that EPA’s 2015 transportation-conformity guidance was an advisory, nonbinding statement lacking independent legal consequences, so it was not a reviewable final agency action; the court therefore dismissed the petition and did not decide whether notice and comment was required.


Sierra Club v. EPA, 873 F.3d 946 (D.C. Cir. 2017)