EPA Finalizes Rule Clarifying “Applicable Requirements” Under Title V Program

On September 25, 2026, EPA published a final rule that codifies its existing interpretations regarding when and whether “applicable requirements” established in other Clean Air Act (CAA) programs may be reviewed, modified, and/or implemented through the Title V operating permit program. 91 Fed. Reg. 61026 (Sept. 25, 2026). In particular, the final rule clarifies (1) the limited situations in which requirements under the New Source Review (NSR) preconstruction permitting program would be reviewed using the EPA’s Title V oversight authorities, and (2) the EPA’s “well-established” position that the CAA’s General Duty Clause is not an “applicable requirement” implemented through the Title V program.

Background

Title V of the CAA requires major sources of air pollution to obtain operating permits that consolidate applicable air pollution control requirements into a single permit: “Each permit issued under this subchapter shall include enforceable emission limitations and standards … and such other conditions as are necessary to assure compliance with applicable requirements of this chapter….” CAA § 504(a).

These permits generally incorporate requirements established under other CAA programs, but disputes have arisen over whether Title V provides a mechanism to revisit requirements established under other CAA programs, such as NSR, or to incorporate obligations arising under other CAA provisions, such as the General Duty Clause. 

Key Provisions of Final Rule

First, EPA is clarifying that, provided a source obtains an NSR permit under EPA-approved (or EPA-promulgated) Title I rules with public notice and the opportunity for comment and judicial review, the NSR permit (and not the Title V permit) establishes and defines the relevant applicable requirements of the State Implementation Plan (SIP) or Federal Implementation Plan (FIP) for purpose of Title V. In other words, “EPA will not reevaluate those NSR decisions through the title V process, which is not designed to authorize or require permitting authorities to second-guess prior NSR decisions when implementing title V.” 

However, there are “limited situations” when the Title V permitting process is the appropriate venue to ensure that the Title V permit assures compliance with all NSR-related requirements, “including relatively rare situations in which the applicable SIP requirements governing a construction project have not been conclusively established outside of the title V permitting process, or limited examples in which NSR issues and title V issues involve substantive overlap.” An example of this overlap includes situations in which a state’s Title I SIP and Title V program rules both explicitly require consideration of NAAQS impacts in a Title V permit proceeding. This aspect of the rule marks EPA’s latest development related to NSR, following the reinstatement of its “no-second guessing” policy, recission of its reactivation policy, and promulgation of its proposed rule clarifying the scope of construction activities that may proceed without obtaining an NSR permit.

Second, EPA is clarifying that the General Duty Clause of CAA § 112(r)(1), which generally requires owners and operators to identify hazards associated with accidental releases of hazardous substances and take steps to prevent such releases, is not an “applicable requirement” that must be implemented through Title V permitting.

Takeaways

EPA characterizes the rule as a primarily procedural measure that imposes no direct requirements on affected stakeholders and is not expected to generate additional impacts with respect to either NSR or the General Duty Clause. EPA explains that the rule codifies its existing NSR interpretations, in place since 2017, and clarifies the longstanding understanding of the General Duty Clause under the Title V program, which has been consistently applied since the program’s inception in the 1990s.

However, the rule does not eliminate NSR requirements or affect the General Duty Clause obligations, and facilities must ensure compliance with applicable requirements under those programs.