The federal Clean Air Act (CAA) establishes programs for the regulation of six common air pollutants known as criteria air pollutants (carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter and sulfur dioxide) and 187 substances U.S. EPA lists as hazardous air pollutants (HAPs). HAPs, which are also known as air toxics, are substances known or suspected to cause cancer and other serious non-cancer health effects. Federal and state air pollution control rules require major emitters of HAPs to obtain air permits for their emissions. As a general rule, a major emitter is a facility that has the potential to release more than 10 tons or more of a single HAP or 25 tons or more of a combination of HAPs in a given year. If there is a public complaint about HAP emissions from a facility, IDEM may perform air toxics modeling to determine the facility’s potential impacts even though the facility is not a major emitter.
The IDEM Air Permits site provides additional information about IDEM’s Air Permitting Process.