## Facts

- Congress created the Clean Air Act acid rain program, including NOₓ emission-rate limits for certain existing coal-fired boilers.
- The statute allowed EPA to approve a higher alternative NOₓ limit if a unit could not meet the statutory rate using “low NOₓ burner technology.”
- Congress limited EPA’s authority by barring it from requiring controls beyond “low NOₓ burner technology” to meet the statutory limit.
- EPA issued a final rule defining “low NOₓ burner technology” broadly to include both low-NOₓ burners and overfire air (a separate combustion-control technique).
- EPA’s rule made use of the combined technologies a precondition for obtaining an alternative (higher) NOₓ limit.
- Electric utilities and a coal industry association petitioned for judicial review, asserting the rule exceeded statutory authority and was otherwise unlawful.

## Issues

1. Whether EPA exceeded its statutory authority by interpreting “low NOₓ burner technology” to include overfire air and effectively requiring more than the technology Congress specified.
2. Whether EPA’s failure to promulgate the implementing rule by the statutory deadline postponed regulated entities’ statutory NOₓ compliance obligations.
3. Whether the rule was arbitrary and capricious in its technical determinations and justification.

## Decision

- The court granted the petitions for review and vacated the challenged rule.
- The court held EPA exceeded statutory authority by expanding “low NOₓ burner technology” to include overfire air, thereby raising the statutory technology ceiling.
- The court rejected the argument that EPA’s missed rulemaking deadline automatically delayed regulated entities’ statutory compliance obligations.

## Legal Principles

- When Congress specifies a particular control technology as the means of compliance and as a ceiling on agency demands, the agency may not redefine the term to require additional or different technologies.
- An agency interpretation that effectively rewrites a clear statutory limitation is unlawful and receives no deference.
- Vacatur eliminates the rule’s legal effect and restores the pre-rule status quo; to impose similar requirements, the agency must proceed through a new lawful rulemaking.
- Agency failure to meet a statutory rulemaking deadline does not, by itself, excuse regulated entities from statutory duties or extend statutory compliance timelines; the remedy is to compel agency action rather than revise the statute through litigation.

## Conclusion

The D.C. Circuit vacated EPA’s NOₓ rule because it unlawfully expanded a technology-specific statutory limit by treating overfire air as part of “low NOₓ burner technology,” while also holding that EPA’s delay in issuing the rule did not automatically postpone regulated parties’ statutory compliance obligations.


Alabama Power Co. v. EPA, 40 F.3d 450 (D.C. Cir. 1994)