EPA Proposes Ozone Attainment Status for Detroit Area and Two Michigan Counties

EPA’s Proposal Would End Years-Long Ozone Nonattainment in Three Michigan Areas

The U.S. Environmental Protection Agency has proposed redesignating Berrien County, Muskegon County and the Detroit metropolitan area as meeting the national standard for ground-level ozone, putting an end to “nonattainment” labels that have been in place since 2018. The move follows a sustained, multi-year effort by federal, state and local partners to reduce nitrogen oxides and volatile organic compounds—the two main precursors to smog-forming ozone.

All air monitors in the three areas now show readings below the federal ozone limit, EPA said, confirming that the regions have achieved the cleaner air required by law. The redesignation would be the formal recognition of that milestone. Under the proposal, the areas would shift to an “attainment” status, though a maintenance plan would remain in effect for at least a decade to lock in the gains.

The announcement was welcomed by Michigan officials as a practical win for economic development. “Reaching attainment will reduce permitting burdens, lower costs, and improve affordability,” said one local representative, noting that lakeshore communities had long balanced clean-air protections with growth. Businesses in the affected counties should see faster, more predictable air permitting once the rule is finalized.

Why the Attainment Shift Matters for Michigan’s Industry and Air Quality

For businesses in the Detroit, Berrien and Muskegon regions, a shift from nonattainment to attainment is more than a badge of cleaner air—it directly changes how new projects are permitted. Under the Clean Air Act, nonattainment areas face stricter requirements for new or modified industrial sources, often necessitating costly emission offsets and longer review times. The proposed redesignation would lift those stricter permitting requirements, reducing both costs and schedule uncertainty for manufacturers, energy projects and other emitters.

What the Redesignation Means for Michigan Industry

Industry groups have long argued that ozone nonattainment designations create a hidden tax on expansion. The Detroit area, in particular, includes a significant industrial corridor in Wayne, Oakland and Macomb counties, where automotive and advanced manufacturing projects could benefit from a streamlined permitting path. While existing emissions controls on power plants, factories and vehicles would remain, the end of nonattainment status removes the obligation for new sources to offset emissions at a ratio greater than one-to-one.

Cooperative Federalism in Action

The EPA’s proposal explicitly credits the partnership between its regional office, the Michigan Department of Environment, Great Lakes, and Energy (EGLE), and private-sector emitters that collectively drove down ozone-forming emissions. This model—described by officials as “cooperative federalism”—gave local entities a central role in designing compliance measures, from tighter permits to vehicle inspection programs. The result is a regulatory framework that, according to EPA, can be replicated in other states striving to meet the same 2015 ozone standard.

Maintenance Plan Locks in Gains

One key detail is that the attainment redesignation does not signal a rollback of air quality protections. Federal law requires a 10-year maintenance plan to ensure ozone levels stay below the standard. That plan will freeze existing emission-reduction strategies and mandate continued monitoring, so the business-friendly benefits arrive without sacrificing the air-quality improvements that made attainment possible.

Political Tailwinds and Remaining Steps

The proposal still needs to go through a 30-day public comment period after publication in the Federal Register. While bipartisan support among Michigan’s congressional delegation and state officials suggests a clear path to finalization, the timing will depend on the incoming administration’s EPA leadership. Any significant delay could push back the expected easing of permitting rules.

What Businesses and Local Governments Need to Know

For businesses with facilities or planned expansions in the affected areas:

• Once the redesignation is final, new or modified emission sources will no longer be subject to the more stringent “nonattainment” permitting thresholds. This can reduce the time and cost of obtaining air permits by eliminating the need for emission offsets and potentially shortening review timelines.
• Review current and upcoming projects in Wayne, Oakland, Macomb, Monroe, St. Clair, Livingston, Washtenaw, Muskegon and Berrien counties to determine if any permitting applications can be sequenced to benefit from the lighter regulatory burden after finalization.

For local governments and economic development agencies:

• Begin preparing the required 10-year maintenance plan in coordination with EGLE. Even though emissions caps are already in place, the plan will formalize the commitments that keep the area in attainment and prevent future backsliding.
• Use the anticipated regulatory certainty as a marketing tool to attract new investment, particularly in sectors where permitting speed is a competitive factor—such as advanced manufacturing, data centers and logistics hubs.

For communities and residents:

• Continued air monitoring will remain in effect. The redesignation means ozone levels are currently below the health standard, but residents with respiratory conditions should still follow real-time air quality alerts, especially during warmer months.