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Originally published in the December 2023 issue of Bench & Bar of Minnesota Environmental Law Update, Minnesota State Bar Association.

On July 21, 2023, the U.S. EPA published a final rule titled “Removal of Title V Emergency Affirmative Defense Provisions from State Operating Permit Programs and Federal Operating Permit Program” 88 Fed. Reg. 47029 (2023). The rule removes the “emergency” affirmative defense provisions from the federal Title V operating permit program regulations. EPA has directed state permitting programs with emergency affirmative defense provisions to submit revisions to their rules consistent with the final rule or request an extension by August 21, 2024.


The Clean Air Act (CAA), codified at 42 U.S.C. 7401 et seq., is the comprehensive federal law that regulates air emissions from stationary and mobile sources and seeks to protect human health and the environment from emissions that pollute ambient, or outdoor, air.

In 1990, Congress amended the CAA, adding Title V of the Act, set forth at 42 U.S.C. §§ 7661 to 7661f, which established a national operating permit program for certain stationary sources of air pollution. The first set of regulations, finalized in 1992 and codified at 40 CFR part 70, governed state operating permit programs and directed states to develop and submit to the EPA programs for issuing operating permits for major and certain other stationary sources of air pollution. In 1996, the EPA promulgated a second set of regulations, codified at 40 CFR part 71, which outlined the federal operating permit program. Every source regulated under the Act must have an operating permit, and each permit must contain emissions limitations and standards that set forth how much of which air pollutants a source is allowed to emit.

The EPA first promulgated the emergency affirmative defense provisions when it finalized its Title V regulations for state operating permit programs in 1992 and in the regulations for the federal operating permit program in 1996. The emergency affirmative defense provisions, located in 40 CFR 70.6(g) and 71.6(g), protected facilities from liability for Title V air permit violations that occurred during emergency situations.

These provisions allowed stationary sources to assert an affirmative defense in enforcement actions brought for noncompliance with technology-based emission limits in their Title V permits by demonstrating, among other things, that any excess emissions occurred because of an “emergency,” as defined in the regulations. EPA defined an emergency as “any situation arising from sudden and reasonably unforeseeable events beyond the control of the source, including acts of God, which situation requires immediate corrective action to restore normal operation, and that causes the source to exceed a technology-based emission limitation under the permit, due to unavoidable increases in emissions attributable to the emergency.”

The emergency affirmative defense provisions are not required program elements. States have never been obligated to include the § 70.6(g) affirmative defense provision in their part 70 operating permit programs. Similarly, although the emergency affirmative defense provision is located within the “Permit Content” section of the part 70 and part 71 regulations, the EPA does not consider the provision to be a required permit term.

Thus, the EPA considers the emergency provision to be a discretionary element of both state permitting programs as well as individual operating permits.

The Final Rule

The EPA previously proposed repealing the affirmative defense in 2016 but did not finalize the removal. The Biden Administration renewed the proposal to repeal the defense in March of 2022.

In its final rule, the EPA explained that the emergency affirmative defense provisions, which are a discretionary element of both state permitting programs as well as individual operating permits, “are inconsistent with the EPA’s interpretation of the enforcement structure of the [Act] in light of prior court decisions from the U.S. Court of Appeals for the D.C. Circuit.” The EPA also stated that removal of the provisions is consistent with other recent EPA actions involving affirmative defenses and would harmonize the EPA’s treatment of affirmative defenses across different programs under the Act.

According to the EPA, the removal of emergency affirmative defense provisions will not restrict a source’s ability to defend itself in an enforcement action, since sources can instead assert affirmative defenses based on malfunctions, which were not addressed in this final rule.

EPA’s final rule took effect on August 21, 2023. Shortly after, on September 19, 2023, SSM Litigation Group, whose members include the American Petroleum Institute, the Corn Refiners Association, and the Council of Industrial Boiler Owners, filed a lawsuit challenging the rule in the U.S. Court of Appeals for the District of Columbia Circuit.

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