LANSING, MI \u2014 Michigan regulators are asking the U.S. Environmental Protection Agency to discount several high ozone days tied to wildfire smoke as they seek to ease air quality restrictions in parts of the state.<\/p>\n
The Michigan Department of Environment, Great Lakes and Energy (EGLE) has submitted multiple \u201cexceptional event\u201d demonstrations<\/a> to EPA arguing that smoke from Canadian wildfires in 2023 and 2025 artificially inflated ozone readings at several monitoring sites.<\/p>\n If the EPA agrees, those days would be excluded from calculations and clear the way for Berrien County and part of Muskegon County to be re-designated as meeting the federal ozone standard despite their classification as in \u201cserious\u201d non-attainment.<\/p>\n \u201cThere\u2019s two parallel processes going on in West Michigan,\u201d said Tom Shanley, EGLE air quality evaluation manager. \u201cA few things all kind of came together at the same time.\u201d <\/p>\n In January, the EPA automatically reclassified Berrien and parts of Muskegon and Allegan counties as in \u201cserious\u201d nonattainment after they failed to meet improvement deadlines under the Clean Air Act \u2014 triggering a requirement that Michigan submit a detailed state implementation plan outlining additional pollution controls.<\/p>\n At the same time, EGLE is asking EPA for an \u201cexceptional event\u201d ruling for Berrien and Muskegon counties tied to wildfire smoke during some of the worst ozone days in 2023.<\/p>\n Federal rules allow states to exclude air quality data caused by natural events that are not reasonably controllable or preventable.<\/p>\n According to EGLE documents, dense smoke from Canadian wildfires coincided with unusually high ozone readings at West Michigan monitoring sites on several days in June and July 2023. <\/p>\n In Berrien County, the Coloma monitor recorded some of its highest ozone concentrations of the year during those smoke episodes, while the Muskegon monitor saw similar spikes during the same period.<\/p>\n In Muskegon County, EGLE is also seeking to exclude a single day in July 2025 when smoke from Canadian wildfires again pushed ozone levels above regulatory thresholds.<\/p>\n A \u201cserious\u201d nonattainment designation requires imposition of stricter permitting, additional pollution controls and detailed planning requirements even if much of the ozone comes from outside the region.<\/p>\n If EPA excludes wildfire smoke days, those obligations would no longer apply in Berrien and Muskegon counties because the areas would again qualify as meeting the federal standard.<\/p>\n However, Allegan County would remain subject to the stricter designation because state officials say the area does not meet the ozone standard even after accounting for wildfire smoke.<\/p>\n For Allegan, \u201cthe data does not support re-designation, even if we were to consider wildfire smoke impacts,\u201d said Shanley.<\/p>\n According to EGLE, West Michigan\u2019s ozone problem is largely imported from air pollutants blowing in from upwind states \u2014 especially the Chicago metropolitan area and the broader industrial Midwest.<\/p>\n