EPA Removes Detroit from SO2 Nonattainment as Pollution Drops 57%

The U.S. Environmental Protection Agency (EPA) announced on April 3, 2026, that the Detroit area has been redesignated as being in attainment for sulfur dioxide emissions. This designation indicates that the region now meets the national health-based air quality standards for the pollutant.

The EPA had previously designated the region along the Detroit River, extending from downtown Detroit to Lake Erie, as being in nonattainment in 2013. This status was triggered because air monitoring readings exceeded the health-based limits established under the Clean Air Act.

Emission Reductions and Industrial Controls

Federal regulators reported that airborne sulfur dioxide levels in the area dropped by more than 57% over a period of 13 to 15 years. This reduction was achieved through a combination of state and federal efforts and the implementation of significant emission controls at several industrial facilities.

Key contributors to the improved air quality include:

• The installation of emission controls at U.S. Steel, EES Coke Battery, and Dearborn Industrial Generation.
• The closure of coal power plants operated by DTE Energy, specifically the River Rouge and Trenton Channel facilities.
• Collaborative work between the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and local industrial sources.

EPA Regional Administrator Anne Vogel stated that the redesignation supports economic development and protects families in Michigan. She noted that the progress was made possible through partnerships between the EPA, state leaders, and industry representatives.

Health Impacts and Regulatory Oversight

Sulfur dioxide is one of six criteria pollutants regulated under the Clean Air Act. Short-term exposure to the gas can trigger asthma attacks and cause other respiratory problems. Sulfur dioxide can react with other compounds to create fine particulate matter (PM 2.5), which is linked to premature mortality and cardiopulmonary issues.

Under the previous nonattainment designation, polluters in the Detroit area were subject to stricter regulatory oversight. With the shift to attainment, the EPA stated that air permitting will become faster and more predictable.

Criticism of the Timeline

Despite the improvement in air quality, some environmental advocates have criticized the length of time it took to reach attainment. Nick Leonard, the executive director of the Great Lakes Environmental Law Center, told Planet Detroit that the process took too long for residents who are highly vulnerable to air pollution.

These things aren’t supposed to take this long. If you were a kid born in 2010, you’ve essentially never had safe air to breathe.

Nick Leonard, Executive Director of the Great Lakes Environmental Law Center

Advocates argue that the 13-year timeline underscores a need for faster government and industrial action to protect residents from the health risks associated with breathing polluted air.

Future Monitoring and Compliance

The EPA confirmed that strong health protections will remain in place following the redesignation. Existing monitoring systems and emission controls will continue to operate to ensure that air quality does not deteriorate.

The state of Michigan is required to act quickly if air monitoring shows that sulfur dioxide levels approach or exceed the national health-based standards again.