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Approved Air Quality Implementation Plans in California

EPA’s Pacific Southwest (Region 9) implements and enforces federal environmental laws in Arizona, California, Hawaii, Nevada, the Pacific Islands, and 148 tribal nations.

This site contains information about air quality regulations called State Implementation Plans (SIPs) and Federal Implementation Plans (FIPs) approved by EPA within California. To find the status of SIP submittals, visit SIP Status Reports.

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.