November 14, 2022

Proposal Would Include Fugitive Emissions in All NSR Major Modification Determinations

On October 14, 2022, EPA proposed revisions to the new source review (NSR) program related to fugitive emissions and major modifications. [87 FR 62323] The rule would make two specific changes. First, all existing major sources would be required to count fugitive emissions when determining whether a change or project at the source would be considered a major modification. Second, all sources would be required to count fugitive emissions when determining whether a modification by itself constitutes a major source. Under a deadline extension, comments may be submitted through February 14, 2022 via Docket ID No. EPA-HQ-OAR-2004-0014. [87 FR 68119]

Fugitive emissions are those emissions which could not reasonably pass through a stack, chimney, vent, or other functionally equivalent opening. When making an NSR major source determination, a source does not include fugitive emissions unless it belongs to one of 28 listed source categories (e.g., iron and steel mills, petroleum refineries) referenced in §52.21(b)(1)(iii). Similarly, a 1980 rule exempted sources not on the list of 28 from including fugitives when determining whether a modification would be considered 1) a major source by itself, or 2) a major modification (which is not the same thing).

This fugitive emissions exemption for modifications has been subject to substantial litigation over the previous four decades, and EPA proposes to remove it completely, along with parallel language found in Part 51. If finalized, fugitive emissions still may be excluded by non-28-listed sources when making a major source determinations. However, those same sources must include fugitive emissions when evaluating modifications to determine if they are major sources by themselves or major modifications. Fugitive emissions already must be included when conducting BACT and ambient air analyses.

Given the past legal challenges, the agency believes the proposal would eliminate the uncertainty surrounding fugitive emissions within the context of major modification determinations. Additionally, EPA noted the impact on regulated sources would be limited as the proposal affects only non-28-listed existing major sources. If finalized, the rule would eliminate an exemption, and any state implementation plans (SIPs) containing these fugitive emissions exemptions would become less stringent than the required minimum program elements and thus require revision. If EPA determines SIP revisions are necessary, states would be required to submit those revisions within three years of the final rule’s effective date. [87 FR 62334-5] A fact sheet summarizing the proposal and background information is also available.


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