NWCAA: Serving Island, Skagit and Whatcom Counties

Air Operating Permits

The 1990 Federal Clean Air Act Amendments mandated an operating permit program for the largest sources of air pollution. An air operating permit — or Title V permit — combines operational and procedural requirements — including monitoring and reporting — emission standards and other regulatory requirements into one comprehensive document.




facilities that need an air operating permit

A facility is required to get an air operating permit if it has the potential to emit:

  • More than 100 tons per year of any pollutant.

  • More than 10 tons per year of any hazardous air pollutant.

  • More than 25 tons per year of a combination of hazardous air pollutants.

When actual emissions are less than potential

Facilities that have the potential to emit more than these thresholds but actually emit less, can ask for a legal order from the Northwest Clean Air Agency that limits emissions to below the thresholds.  These sources are considered "synthetic minors." 

What Air operating permits are and what they do

Air operating permits help facilities know what they need to do to follow air quality laws and regulations - and help our agency enforce them.


Air operating permits DO:

  • Collect and record a facility's air pollution control requirements in one document. This gives the public, regulators and the facility a clear picture of what the facility is required to do to keep its air pollution under the legal limits.
  • Require the facility to report regularly on how it is tracking its emissions and the controls it is using to limit its emissions.
  • Clarify monitoring, testing and record keeping requirements.
  • Require the source to certify each year whether it has met the permit’s air pollution requirements.
  • Make the terms of the air operating permit federally enforceable. This means that the U.S. Environmental Protection Agency, state Department of Ecology, Northwest Clean Air Agency and the public can enforce the terms of the permit.

What air operating permits are not, and what they don't do


Air operating permits DON'T:


  • Increase emission limits for a facility.
  • Add new requirements for a facility.
  • Permit or approve new construction. Many projects, such as new boilers at a refinery and new dryers at a plywood manufacturer, require construction permits, called orders of approval to construct. Those are issued separately from the air operating permit and added to the air operating permit later.
  • Get an environmental impact statement or other review under the State Environmental Policy Act.


What you can do


You can review our air operating permits and comment on them during public comment periods and hearings. We renew air operating permits every five years to keep them updated. We'll solicit public comment for all air operating permit renewals and some modifications.


EPA has more information about public participation in the air operating permit process, or you can call us at 360-428-1617.