in effect
This is a technical correction to an EPA final rule, not a new policy. The underlying rule (published February 24, 2026, at 91 FR 9088) finalized the repeal of certain amendments that had been made on May 7, 2024, to the Mercury and Air Toxics Standards (MATS) for coal- and oil-fired power plants. This document fixes typographical errors and missing text in that rule; the EPA states it does not change any of the rule’s substantive requirements.
Two pieces of regulatory text are corrected. In Table 5 to Subpart UUUUU (entry 3.e.1(D)), an equation that had been cut off is completed to read “Reported Result = (Measured Concentration in Stack)/(%R)x100.” In Appendix E, section 31.0, the word “data” is inserted so the text reads that supporting documentation must be submitted “in a PDF file submitted concurrently with the data file.” The correction takes effect April 27, 2026. The EPA issued it without prior public notice and comment, citing the “good cause” provision of the Administrative Procedure Act (5 U.S.C. 553(b)(B)), on the basis that the changes are minor, noncontroversial technical corrections.
The corrected text applies to owners and operators of coal- and oil-fired electric utility steam generating units subject to the MATS performance-testing and data-reporting requirements. For those parties, the corrections clarify the exact wording of a test-result equation and a data-submission instruction; the EPA states the substantive obligations of the underlying rule are unchanged.