Illinois Air Cleared: No More Ozone Paperwork for St. Louis
Published Date: 2/26/2026
Proposed Rule
Summary
The EPA says the Illinois part of the St. Louis area is now meeting clean air rules for ozone pollution based on recent air quality data. This means Illinois won’t have to submit extra pollution control plans as long as air stays clean. People living and working in the area can expect better air without new costly rules, and public comments are open until March 30, 2026.
Analyzed Economic Effects
3 provisions identified: 2 benefits, 1 costs, 0 mixed.
Illinois St. Louis Area Meets Ozone Standard
If you live in the Illinois portion of the St. Louis area, the EPA proposes that the area attained the 2015 ozone standard based on certified monitoring for the 2023-2025 period with a 3-year design value of 0.070 ppm. If finalized, the EPA would suspend Illinois' obligations to submit attainment demonstrations and associated RACM, RFP plans, contingency measures, and other SIP planning related to the 2015 ozone NAAQS for as long as the area continues to attain the standard.
No New Small-Entity Requirements
The EPA states this proposed clean data determination "will not have a significant economic impact on a substantial number of small entities" and "will not impose any requirements on small entities beyond those imposed by state law." If you run a small business in the Illinois portion of the St. Louis area, the proposed action does not directly regulate your business or create new federal obligations.
Final Approval Depends on Missouri
The EPA will not finalize the clean data determination for the Illinois portion of the St. Louis area unless the Missouri portion of the multi-state St. Louis area is also determined to be attaining the 2015 ozone NAAQS. That means any suspension of Illinois' planning obligations only takes effect if the EPA also finalizes a similar finding for Missouri.
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Key Dates
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