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Air Toxics Program

IDEM Air Toxics > Permits Hazardous Air Pollutant (HAP) Permitting

Most air permitting focuses on criteria pollutants. However, rules do exist which require large emitters of Hazardous Air Pollutants (HAPS) to obtain permits for those emissions. As a general rule, any facility that releases more than 10 tons of a single HAP or a total of 25 tons of all HAPs in a given year is required to obtain a permit. In addition, if there is a public complaint, IDEM may perform additional HAPs modeling as part of the permitting process, though the facility may not require a permit for those emissions.

The IDEM Air Permits webpage provides additional information about IDEM’s Air Permitting Process.