2026-03845Proposed RuleWallet

Missouri's Air Gets EPA Green Light: St. Louis Ozone Win

Published Date: 2/26/2026

Proposed Rule

Summary

The EPA says the Missouri part of the St. Louis area has cleaned up its air enough to meet the 2015 ozone pollution rules. This means Missouri won’t have to do some extra pollution control planning as long as the air stays clean. People living and working in the area can expect better air quality, and the state can save time and money on extra paperwork.

Analyzed Economic Effects

3 provisions identified: 3 benefits, 0 costs, 0 mixed.

Missouri St. Louis Meets 2015 Ozone Standard

The EPA proposes to find that the Missouri portion of the St. Louis nonattainment area attained the 2015 8-hour ozone standard based on the 2023-2025 design value of 0.070 parts per million (ppm). This proposed Clean Data Determination is based on quality-assured, certified monitoring data for 2023-2025 and EPA concurrence on part of Missouri's exceptional events request (concurrence date January 27, 2026).

EPA Concurred on Wildfire Exceptional Days

The EPA concurred (on January 27, 2026) that certain ozone monitor days in 2023 were influenced by Canadian wildfire smoke and may be excluded from regulatory design-value calculations. The concurred exclusions are: West Alton (AQS ID 29-183-1002) for May 24, June 3, June 6, June 10, June 17, and June 24, 2023; and Maryland Heights (AQS ID 29-189-0014) for June 6, 2023.

State Planning Submissions Suspended If Finalized

If the EPA finalizes the Clean Data Determination, the requirements for the Missouri portion of the St. Louis area to submit attainment demonstrations and associated reasonably available control measures (RACM), reasonable further progress (RFP) plans, contingency measures, and other attainment-related plan elements under 40 CFR 51.1318 would be suspended for as long as the area continues to attain the 2015 ozone NAAQS.

Your PRIA Score

Score Hidden

Personalized for You

How does this regulation affect your finances?

Sign up for a PRIA Policy Scan to see your personalized alignment score for this federal register document and every other regulation we track. We analyze your financial profile against policy provisions to show you exactly what matters to your wallet.

Free to start

Key Dates

Published Date
Comments Due
2/26/2026
3/30/2026

Department and Agencies

Department
Independent Agency
Agency
Environmental Protection Agency
Source: View HTML

Related Federal Register Documents

Previous / Next Documents

Back to Federal Register

Take It Personal

Get Your Personalized Policy View

Start a Free Government Policy Watch to see how policy affects your household, then upgrade to PRIA Full Coverage for year-round monitoring.

Already have an account? Sign in