The Missouri Department of Natural Resources develops plans consistent with federal regulations related to National Ambient Air Quality Standards under Section 110 or Part D of the Clean Air Act. The department also develops plans to address requirements in other sections of the Clean Air Act. This page provides information on these other plans.
- Regional Haze Plan
All states were required by the Clean Air Act to submit Regional Haze SIPs in order to address visibility in federally protected Class I areas. These SIP elements address pollutants that affect visibility and also those that cause acid rain.
Second Regional Haze Plan
The Regional Haze Rule requires states to update their Regional Haze Plans every 10 years to ensure Class I areas continue to make progress towards their visibility goals.
The department is currently developing its first major revision to its original Regional Haze SIP as required by the federal Regional Haze rule. As part of this effort, the department has identified eight in-state sources of visibility impairing pollution and sent letters requesting information needed to perform and analysis of pollution control potential at these sources. These eight letters are included below.
Second Regional Haze Plan Action Table MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document MoDNR Submittal Date Feb. 7, 2025 MoDNR Action/Document Missouri 2025 Progress Report for the Second Regional Haze Planning Period EPA Date No action required EPA Action/Document No action required MoDNR Submittal Date Aug. 30, 2024 MoDNR Action/Document MoDNR Comments on EPA's Proposed Air Plan Partial Approval and Partial Disapproval; Missouri; Regional Haze EPA Date Pending EPA Action/Document Pending MoDNR Submittal Date Aug. 26, 2022 MoDNR Action/Document State Implementation Plan Revision - Missouri Regional Haze Plan for the Second Planning Period EPA Date July 2, 2024 EPA Action/Document Partial Approval/ Partial Disapproval
First Regional Haze Plan
First Regional Haze Plan Action Table MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document MoDNR Submittal Date July 26, 2017 MoDNR Action/Document Clarification Letter - First Regional Haze Plan EPA Date Sept. 24, 2018 EPA Action/Document Full Approval - Regional Haze Plan
MoDNR Submittal Date Aug. 29, 2014 MoDNR Action/Document First Regional Haze Plan 5-Year Progress Report EPA Date Sept. 29, 2015 EPA Action/Document Approval - 5-Year Progress Report
MoDNR Submittal Date Feb. 3, 2012 MoDNR Action/Document Supplement - First Regional Haze Plan EPA Date June 26, 2012 EPA Action/Document Limited Approval - Regional Haze Plan
MoDNR Submittal Date July 29, 2009 MoDNR Action/Document First Regional Haze Plan EPA Date June 26, 2012 EPA Action/Document Limited Approval - Regional Haze Plan
- Interstate Transport SIPs
Section 110(a)(2)(D)(i)(l) of the Clean Air Act requires states to submit SIPs demonstrating that emissions in their state do not have a significant impact on downwind states’ ability to meet or maintain the National Ambient Air Quality Standards for all criteria pollutants. Typically, ozone and particulate matter are the two criteria pollutants in which long range transport of pollutants and precursors can have a significant impact on downwind states.
Interstate Transport SIPs Action Table MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document MoDNR Submittal Date March 7, 2019 MoDNR Action/Document 10 CSR 10-6.372;
10 CSR 10-6.374;
10 CSR 10-6.376;
These rules can be viewed on the Missouri Secretary of State's website.EPA Date Dec. 4, 2019 EPA Action/Document Approval of 10 CSR 10-6.372 and 10 CSR 10-6.376
MoDNR Submittal Date April 26, 2005 MoDNR Action/Document EPA Date May 8, 2007 EPA Action/Document Approval - Interstate Transport SIP
- Inspection and Maintenance SIPs
When new or revised NAAQS are published the EPA also releases implementation requirements for those new standards that must be included in SIPs. The Inspection/Maintenance Program (I/M) is required for all moderate ozone non-attainment areas. This SIP includes the motor vehicle emission inspection requirements for vehicles registered within the St. Louis ozone non-attainment area. See Gateway Vehicle Inspection Program for more information.
Inspection and Maintenance SIPs Action Table MoDNR Submittal Date MoDNR Action/Document EPA Date EPA Action/Document MoDNR Submittal Date Dec. 6, 2019 MoDNR Action/Document Clarification Letter to Remove I/M in Franklin County EPA Date N/A EPA Action/Document N/A MoDNR Submittal Date Nov. 12, 2019 MoDNR Action/Document 2019 St. Louis I/M SIP Revision EPA Date Pending EPA Action/Document Pending MoDNR Submittal Date Dec. 6, 2007 MoDNR Action/Document 2007 St. Louis I/M SIP Revision EPA Date March 3, 2015 EPA Action/Document Approved - I/M SIP Revision
MoDNR Submittal Date Oct. 1, 2003 MoDNR Action/Document 2003 St. Louis I/M SIP Submittal Letter EPA Date May 13, 2004 EPA Action/Document Approved - I/M SIP Revision
If you are looking for a document that is not available on our website, please submit a Missouri Sunshine Law request.