EPA Approval of Missouri's Plan to Reduce Ozone Pollution in the St. Louis Area
Official: Air Plan Approval; Missouri; Moderate Attainment Plan Elements for the 2015 8-Hour Ozone Standard for the Missouri Portion of the St. Louis Nonattainment Area
Reading: The EPA is approving an existing state implementation plan framework for ozone attainment without introducing new or stricter requirements beyond what the Clean Air Act already mandates for Moderate nonattainment areas.
Louis region.
In clear language
The EPA is approving Missouri's plan to reduce ground-level ozone pollution in the St. Louis area to meet federal air quality standards. The plan includes vehicle inspection and maintenance programs, rules for new pollution sources, and requirements for major factories to use cleaner technology. This approval applies to the Missouri side of the bi-state St. Louis region.
How does this affect you?
Pick the type of resident or organization you most identify with — we'll generate a plain-language breakdown of what changes for you and what you can do about it.
Who does this affect?
- Residents in the Missouri portion of the St. Louis metropolitan area who breathe the air and may have health issues from ozone pollution
- Vehicle owners in Missouri who will need to comply with vehicle inspection and maintenance programs
- Factories and large industrial facilities in the region that emit volatile organic compounds or nitrogen oxides
- Businesses planning to build or expand operations in the nonattainment area, which will face stricter permitting requirements
What can you do?
- Keep your vehicle well-maintained and pass required emissions inspections to reduce pollution from cars and trucks
- Check the EPA or Missouri Department of Natural Resources website for air quality alerts and limit outdoor activities on high ozone days
- Support local policies that encourage electric vehicles, public transit, and reduced vehicle emissions in your community
Timeline
- September 6, 2023 (Missouri submitted its state implementation plan revision)
- August 14, 2026 (EPA published this proposed approval)
No New Jersey official has a verified action on this policy yet.
Related policies
- Federal RegisterAug 20, 2026EPA Approves Wisconsin's Plan to Improve Air Quality in Three Areas
The EPA has approved Wisconsin's air quality improvement plan for three regions (parts of Chicago, Milwaukee, and Sheboygan areas) that currently do not meet federal ozone standards. The plan includes measures to reduce emissions from cars and trucks, vehicle inspection programs, and rules for new industrial sources. This approval means Wisconsin can move forward with implementing these strategies to bring air quality into compliance with federal requirements.
- Federal RegisterAug 20, 2026EPA Approves Arizona's Plan to Reduce Sulfur Dioxide Pollution in the Hayden Area
The EPA has approved Arizona's plan to reduce sulfur dioxide (SO₂) pollution in the Hayden area to meet federal clean air standards set in 1971 and 2010. The plan includes steps Arizona must take to bring the area into compliance, such as requiring pollution controls on sources and monitoring progress toward cleaner air. This approval means Arizona can now implement the measures outlined in the plan to improve air quality.
- Federal RegisterAug 14, 2026EPA Approving Iowa's Plan to Prevent Sulfur Dioxide Pollution from Crossing State Lines
The EPA is approving Iowa's plan to prevent sulfur dioxide air pollution from traveling across state lines and harming air quality in neighboring states, including New Jersey. This approval ensures Iowa is meeting federal Clean Air Act requirements that every state must limit the pollution it sends to other states. The rule applies to a 2010 federal air quality standard for sulfur dioxide.
- Federal RegisterAug 14, 2026EPA Approves Virginia's Plan to Keep Air Quality Clean Around Shenandoah National Park
The EPA is approving Virginia's plan to maintain clean air standards in the Madison and Page Counties area around Shenandoah National Park for the next 10 years. Virginia submitted a detailed plan showing how it will keep ozone pollution at safe levels in that region. This approval means Virginia can continue its current air quality management approach in this area.