## Facts

- The Association of Irritated Residents (AIR), a California nonprofit with members in the San Joaquin Valley, challenged EPA’s approval of portions of California’s ozone State Implementation Plan (SIP) for the San Joaquin Valley nonattainment area.
- Clean Air Act (CAA) SIPs for nonattainment areas must include contingency measures that automatically take effect if reasonable further progress or attainment is not achieved.
- EPA approved the SIP, including a single contingency measure expected to yield relatively small emissions reductions and an “Enhanced Enforcement Activities Program.”
- AIR petitioned for review, arguing EPA unlawfully approved an inadequate contingency measure and improperly approved the enforcement program.

## Issues

1. Whether AIR had Article III standing and whether its claims were ripe for review.
2. Whether EPA’s approval of the SIP’s contingency measure was arbitrary and capricious under the Administrative Procedure Act because the measure did not satisfy the CAA’s contingency-measure requirements.
3. Whether EPA unlawfully approved California’s Enhanced Enforcement Activities Program under the CAA.

## Decision

- The Ninth Circuit granted the petition in part and denied it in part.
- The court held AIR had standing and the petition was ripe.
- The court remanded EPA’s approval of the contingency measure as arbitrary and capricious because EPA did not acknowledge or explain a change in its approach to what constitutes “reasonable further progress” for contingency measures.
- The court rejected EPA’s rationale that a weak contingency measure could be justified by assuming it likely would not be triggered.
- The court denied AIR’s challenge to EPA’s approval of the Enhanced Enforcement Activities Program, concluding the program did not make any emission limitation less stringent than one already in the SIP.

## Legal Principles

- A nonprofit may establish Article III standing in environmental cases through members’ injuries tied to air quality in the regulated area, and such challenges can be ripe when directed at final EPA SIP approvals.
- CAA contingency measures must be meaningful automatic backstops; EPA cannot approve minimal contingencies based on speculation that they will never be needed.
- When an agency changes a prior policy or interpretive position, it must recognize the change and give a reasoned explanation; failure to do so renders the action arbitrary and capricious.
- A state enforcement initiative may be approvable under the CAA where it does not relax existing emission limitations or make them less stringent.

## Conclusion

The Ninth Circuit required EPA to provide a reasoned, transparent justification for approving a low-reduction SIP contingency measure, remanding that approval as arbitrary and capricious, while leaving intact EPA’s approval of California’s enhanced enforcement program.


Ass’n of Irritated Residents v. U.S. Env’t Prot. Agency, 10 F.4th 937 (9th Cir. 2021)