Types of air permits

In general, the kind of permit a facility is required to apply for will depend on how much air pollution the facility could potentially cause based on the kinds of equipment or processes the facility operates.


Federal operating permits required under Title 5 of the Clean Air Act (CAA) are often interchangeable referred to as “Title 5” permits or “Part 70” permits (Part 70 of the code of federal regulations is where the CAA permit requirements are codified). These permits are required for the larger emitters of air pollutants. The CAA permit program is implemented nationwide under the same basic principles and guidance. The EPA evaluates and approves state programs that serve to implement these federal requirements.

  • Individual Total Facility — Typically a facility requiring a Part 70 permit must apply for an individual permit, which is written specifically for the activities (emission units, controls, etc.) at the facility and includes only those requirements applicable to the facility.
  • General — One Part 70 general permit, for manufacturing facilities, is currently available. General permits are pre-written to cover a range of operating scenarios and applicable requirements, so they require less processing by the MPCA. Because of this, a general permit may be quicker to obtain than an individual total facility permit.


State operating permits are required for some facilities that are not required to have a federal operating permit but still meet permit requirements under state rules and statutes. In Minnesota, these permits are the result of state specific strategies approved by the federal government to regulate minor sources of air emissions and to attain compliance with broader air quality federal laws and regulations.

  • Individual Total Facility permits at the state level are similar to the federal-level individual permit. However, at the state level, there are more alternatives available to the individual permit.

  • Registration permits are for facilities with low actual emissions (i.e., what actually comes out the stack) versus their potential emissions. In general, the facility's actual emissions must be less than 50 percent of the federal thresholds. There are other requirements. These are single page permits with requirements specifically outlined in rules, and allow modifications to be made as long as the facility continues to qualify for the permit.

  • Capped emission permits are state permits intended for noncomplex facilities that do not qualify for a registration permit and do require site-specific permit conditions. The facility’s actual emissions must be less than 75 to 90% of the federal thresholds. Similar to registration permits, these are single page permits with requirements specifically outlined in rules, and allow modifications to be made as long as the facility continues to qualify for the permit.

  • General permits are similar to the federal general permits except that the PTE for these facilities are below the federal thresholds. One state general permit option (non-metallic mineral processing) is currently available.

The U.S. EPA requires that Title V permits be renewed every five years. State permits generally do not expire, although MPCA does have authority to make a state permit expiring in certain circumstances. All individual total facility permits must be put on public notice for 30 days. Federal individual total facility permits are also subject to a 45-day EPA review period before they can be issued. It can take anywhere from six months to a year or longer to issue individual total facility permits, depending on the number of complicated issues involved.

What about modifications?

If a facility wants to make changes at its facility after receiving a total facility permit, it should first determine if it will need an amendment to its permit. General permits, registration Permits, and capped permits preauthorize modifications, provided the modified facility still qualifies for the same permit. To determine if its individual permit must be amended, the facility must: calculate the PTE of the modification, review the applicable state and federal rules and regulations, and determine the applicable amendment type (if one is necessary). These items should all be done before starting construction on the modification because some amendment types require that the permit amendment be issued before construction commences on the modification. The permit amendment types are differentiated based on threshold levels of emissions and/or the applicability of certain Federal programs. The types of amendments are: administrative, minor, moderate, major. Some changes can be made without a permit amendment, including those qualifying as an insignificant modification, changes contravening permit terms, and certain replacements. Major amendments must be placed on public notice, can take as many as six months or more to issue, and generally involve the consideration of Federal programs and other changes that have the potential to significantly affect air quality.

How are permits processed?

The degree of involvement by the MPCA with a permit action depends on the type of permit; the more significant the potential impact to air quality a permit or permit amendment has, the more detailed the involvement by MPCA staff. Individual total facility permits, and all amendments except administrative amendments go to permit teams made up of a permit writer/engineer and compliance and enforcement staff who work together to draft the permit.

How does the MPCA prioritize its permitting effort?

In general, the MPCA gives priority to facilities that need their permits to begin construction or operation of either a modification or a totally new facility.

  • Construction permits: Applications for permit amendments needed before construction can begin are put in a queue, to be worked on as staff become available. There is also an expedited permit program where facilities pay to have staff work overtime to draft their permit. This is only useful when the queue is large. Total facility operating permits for new (not yet constructed) facilities are also put in this queue.
  • Total Facility Operating permits: This includes reissuance of federal permits issued five or more years ago. These applications are worked on based on the priorities set by the AQ permit management. At this point in time, most facilities in Minnesota who require one have received their total facility operating permit. While still keeping up with permits and amendments required for construction projects, the goal is to manage the reissuance of federal permits to minimize the backlog.

What about sources with very low emissions?

A permit may not be required for certain sources that have potential emissions that exceed permit thresholds but have very low actual emissions. These sources are called conditionally exempt sources, and could include auto body, coating, woodworking, gasoline service stations, and concrete manufacturers. In order to qualify, the sources are required to follow technical standards and submit a notification.


For assistance with air permits in Minnesota, contact the MPCA at 651-296-6300 or 800-657-3864 and ask for Business Assistance.