Approved Air Quality Implementation Plans in Region 8
This site contains information about air quality regulations called State Implementation Plans (SIPs), Federal Implementation Plans (FIPs), and Tribal Implementation Plans (TIPs) approved by EPA Region 8.
State Implementation Plans
Federal Implementation Plans
Uintah and Ouray Indian Reservation
The following links exit the site EXIT
- Regional haze in Montana
- Sulfur Dioxide in Billings/Laurel, Montana
- Regional haze in North Dakota
- Regional haze in Wyoming
Fort Berthold Indian Reservation (Madan, Hidatsa, and Arikara Nations)
Tribal Implementation Plans
Region 8 currently has no approved TIPs.
About this website: The official SIPs, TIPs, and FIPs are contained in regulations promulgated in the Federal Register and codified in the U.S. Code of Federal Regulations (CFR). EPA’s web-versions of the approved SIPs, TIPs, and FIPs are for reference. While we make every effort to maintain the accuracy of the files accessible here, inconsistencies may occur. Please contact us using the link below if you find any errors in these files.