From IMA member Mostardi Platt …
There are typically two classifications of air pollution control permits required by the Illinois Environmental Protection Act. Construction permits are required prior to beginning construction of an emission source or air pollution control equipment. Operating permits are required for operation of an emission source once it has been constructed.
Determining whether your business operates a regulated emission unit may be a complicated question that requires interpretation. Similarly, questions requiring interpretation may arise in determining whether or not an “emission unit” qualifies for an exemption, how to calculate emission rates, the type of permit that is required, and if you can utilize the Illinois EPA’s registration of smaller sources (ROSS) program. Failure of a source to know about the applicable requirements does not constitute a valid defense from enforcement.
Does my business have an emission unit?