## Facts

- Environmental organizations sued the EPA Administrator under the Clean Air Act’s citizen-suit provision, alleging a failure to perform a nondiscretionary duty in reviewing state implementation plans (SIPs).
- States submitted SIPs to attain and maintain national ambient air quality standards, including secondary (welfare-based) standards.
- EPA adopted the position, reflected in testimony and a regulation, that it lacked authority to require SIP provisions preventing air quality deterioration in areas already cleaner than national secondary standards.
- Plaintiffs alleged that allowing “clean air” areas to degrade up to the secondary standard would invite industrial relocation and rapid deterioration of existing air quality.
- Plaintiffs sought to enjoin EPA from approving SIPs that permitted significant deterioration in currently clean areas and to require EPA to demand non-degradation measures.
- After a hearing on a preliminary injunction, the court granted preliminary injunctive relief; the dispute was presented as purely legal, with no material factual conflicts.

## Issues

1. Whether the district court had jurisdiction under the Clean Air Act citizen-suit provision to hear a pre-approval claim that EPA failed to perform a nondiscretionary duty, rather than requiring plaintiffs to wait for SIP approval and pursue statutory review of final agency action.
2. Whether the Clean Air Act of 1970 required EPA to prevent significant deterioration of air quality in areas already cleaner than national standards, making EPA’s contrary interpretation and regulation unlawful.

## Decision

- The court held it had jurisdiction under the citizen-suit provision to address an alleged failure to perform a nondiscretionary duty without requiring plaintiffs to wait for SIP approval.
- The court held the Administrator’s interpretation that EPA lacked authority to require protection of clean-air areas was legally erroneous.
- The court held EPA’s regulation permitting SIPs to allow significant deterioration in clean areas (so long as national standards were met) was invalid under the Clean Air Act.
- The court granted a preliminary injunction barring EPA from approving SIPs that would allow significant deterioration of air quality in cleaner-than-standard areas.

## Legal Principles

- The Clean Air Act’s mandate to “protect and enhance” air quality requires more than compliance with minimum national standards where existing air quality is better than those standards.
- EPA has a nondiscretionary duty in SIP review to ensure state plans comport with the Act’s protective requirements, including preventing significant deterioration of existing clean air.
- The citizen-suit provision authorizes district court jurisdiction to compel performance of a nondiscretionary duty when the Administrator adopts a legally incorrect view of statutory obligations, even before final SIP approvals occur.
- Agency regulations and approval practices that allow deterioration of cleaner-than-standard air based on an asserted lack of authority are unlawful when inconsistent with statutory purpose and structure.

## Conclusion

The court enjoined EPA from approving SIPs that permitted significant deterioration of already clean air, holding that the Clean Air Act required EPA to insist on non-degradation protections and that citizen-suit jurisdiction was available to challenge EPA’s failure to carry out this nondiscretionary duty before SIP approvals occurred.


Sierra Club v. Ruckelshaus, 344 F. Supp. 253 (D.D.C. 1972)