Air quality trends in Missouri

The Missouri Department of Natural Resources works with federal and local governments to improve Missouri’s air quality for all citizens. One of the main ways we do this is through implementing and enforcing environmental laws and regulations.

Federal Laws and Regulations

The U.S. Environmental Protection Agency (EPA) develops regulations that explain the technical, operational and legal details necessary to implement federal environmental laws. These federal regulations also form the underlying basis for state regulations. Federal regulations developed under federal laws are codified in the U.S. Code of Federal Regulations (CFR), Title 40. For information about the federal rulemaking process, visit EPA's Regulations webpage.

EPA is charged with administering the federal Clean Air Act, which was enacted in 1970. This federal law regulates air emissions from stationary and mobile sources. Among other things, this law authorizes EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and public welfare and to regulate emissions of hazardous air pollutants by setting standards.

State Laws and Regulations

EPA can authorize states to carry out all or part of the federal regulatory requirements under state equivalent programs, in lieu of the federal program. To receive authorization, the state regulations must be at least as strict as the federal regulations and the state must demonstrate that it has the resources to effectively carry out its regulatory programs in lieu of EPA. Federal regulations that Missouri has adopted are incorporated by reference in the Code of State Regulations. EPA retains its regulatory oversight and enforcement authority for federal regulations that Missouri has either not yet adopted or has adopted but EPA has not yet given Missouri temporary or final authorization to administer. In those cases, EPA retains its regulatory oversight and enforcement authority for the requirements until EPA grants state authorization.

The Missouri Air Conservation Commission has the authority to adopt, amend or repeal rules and regulations to implement, enforce and carry out the provisions of the Missouri Air Conservation Law (Chapter 643, RSMo). The department's Air Pollution Control Program administers the state's air conservation law, which ensures the state’s air quality meets federal standards. The department issues air emission permits to make sure sources of air pollution meet all federal and state regulations. We inspect facilities and ensure compliance with these regulations, receive emissions data from facilities, monitor air quality and develop state implementation plans to ensure Missouri will meet federal standards for six criteria pollutants.