Frequently Asked Questions: Air Permits

What is an air permit?

An air permit is a legal document for air emissions sources. Permits itemize the construction, operation and record keeping requirements needed to comply with both federal and state rules.

Prior to issuing a permit to a new source or currently operating source, Department of Natural Resources staff write a "Preliminary Determination" document to make an internal decision on whether to allow this type of operation to start or continue to operate. Staff usually perform source specific modeling of the pollutants listed in the permit application before issuing a permit for a source. All these documents are public and can be viewed at the local Air Management office. Copies are also available for a small photocopying fee.

The public has the right to comment on a permit prior to issuance. A public notice is printed in the local newspaper in the area where the facility is located, which starts a 30-day public comment period. Operation permits are scheduled to be renewed every five years.

Why do some facilities have permits and others don't?

All facilities that emit air pollution are required to have an air pollution control permit unless they can show they are exempt. A facility may be exempt from permit requirements based on the amount of air pollution they emit or because of their individual manufacturing or production operations. In general, air permits are divided into construction permits and operation permits. A new facility needs a construction permit before they can even begin breaking ground or before an existing facility can modify or make changes to their equipment. Construction permits authorize construction projects for up to 18 months before they expire. Once a facility is constructed or modified, the construction permit then is transferred into an operation permit that covers the continued operation of the entire facility. Operation permits contain the all the regulations that apply to the new or modified equipment as well as any existing equipment. For additional information on determining if a permit is needed, please access DNR's Permit Primer, or contact your local DNR regional office and ask for an Air Management staff person.

What about facilities that have indirect emissions?

There are situations when new sources will not directly emit air pollutants yet may still have an impact on surrounding air quality. For instance, parking lots have the potential to generate air contaminants as a consequence of motor vehicle exhaust released on the site. Indirect source modeling is conducted for these types of situations as part of the air permit review process.

Last Revised:Last Review Date: September 28, 2006
Next Review Date: September 28, 2007
Thursday September 11 2008