Air operating permit for large sources of air pollution

Commercial and industrial businesses that emit large amounts of air pollution are required to get an air operating permit. An air operating permit is a master document that lists all of the air pollution requirements that apply to a business or industry. We issue these permits along with other clean air agencies in Washington.

Apply for an air operating permit

A business must turn in an air operating permit application 12 months before it has the potential to emit:

  • More than 100 tons per year of any air 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.
Even if a business emits less than these amounts, the U.S. Environmental Protection Agency may decide that it still needs an air operating permit.

The federal rules that might apply include:

A permit is valid for five years. A business must apply for renewal 6-18 months before the current permit expires.

Agencies that issue air operating permits

Agencies that issue air operating permits include:

Permit Register

Twice a month, we publish a Permit Register that lists milestones for air operating permits.

Draft permits and public comment opportunities

To check for a public comment period and review a draft permit:

Budget and fees

Every two years, we prepare a workload model and a budget projection. The projection evaluates the cost of reviewing and tracking air operating permits. When the draft workload analysis and budget have been published, we announce a public comment period in the Permit Register. After the public comment period, we finalize the workload analysis and budget. 

At the end of each fiscal year (July 1 – June 30), we prepare an annual report summarizing air operating permit program work and fees.

We publish the current fiscal year’s fee schedule every year by Oct. 31.


Ecology and outside agencies regularly audit the air operating permit program.

Every two years, the Washington State Auditor’s Office conducts a fiscal audit of Ecology’s and each local clean air agency’s air operating permit program.

Every three years, Ecology and one of the local clean air agencies conduct a routine performance audit and random individual permit review.

Periodically, EPA also reviews the air operating permit program and enforcement program.