Air Plan Approval; Michigan; Determination of Attainment by the Attainment Date for the 2015 Ozone Standards
Key claim: The EPA proposes to determine that the Detroit, Michigan nonattainment area attained the 2015 ozone NAAQS by the August 3, 2024 Moderate attainment date, based on concurrence of an exceptional events request from Michigan EGLE.
Abstract
(Proposed Rule · Environmental Protection Agency) The Environmental Protection Agency (EPA) is proposing to determine under the Clean Air Act (CAA) that the Detroit, Michigan nonattainment area (“Detroit area” or “area”) attained the 2015 ozone National Ambient Air Quality Standards (NAAQS) by the applicable attainment date. This determination relies on the EPA’s concurrence on an exceptional events request submitted by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) on February 19, 2026, and concurred on by the EPA on March 24, 2026. Therefore, the EPA is proposing to take final agency action on Michigan’s exceptional events request. This action, if finalized, will fulfill the EPA’s statutory obligation to determine whether the Detroit area attained the 2015 ozone NAAQS by the Moderate attainment date of August 3, 2024.
Why this matters
Attainment-date determinations govern whether a nonattainment area avoids mandatory reclassification (a ‘bump-up’) to a higher classification with stricter SIP, RACT, and offset obligations. The Detroit proposal is notable because it rests on EPA’s concurrence with an exceptional events demonstration under 40 CFR 50.14 — a mechanism whose use directly affects which monitored ozone exceedances count toward attainment, with tangible permitting and compliance-cost consequences for regulated sources in southeast Michigan.