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Chapter 173-401 WAC

Overview of Rulemaking



Jason Alberich
(360) 407-6082


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Washington Clean Air Act

On February 3, 2016, Ecology adopted amendments to Chapter 173-401 WAC Operating Permit Rule. The amendments:

  • Update language for the complexity portion of Ecology’s air operating permit (AOP) fees to allow for fair fee distribution to Ecology AOP sources.
  • Revise audit provisions.
  • Clarify applicability requirements.
  • Clarify rule provisions, update language to be consistent with state and federal rules, and correct errors.

What is Chapter 173-401 WAC, Operating Permit Regulation?

Title V of the federal Clean Air Act requires states to develop and implement an air operating permit program for facilities that are the largest sources of air pollution. These operating permits are often referred to as Air Operating Permits (AOPs), Title V Permits, or Part 70 Permits. They combine into one document the requirements for operations, procedures, applicable rules, emissions standards, monitoring, recordkeeping, and reporting. The purpose of the AOP is to make it easier to comply with and enforce air pollution laws.

Chapter 173-401 WAC establishes Washington’s air operating permit program. The rule requires a facility to have an AOP if it has the potential to emit any of the following:

  • More than 100 tons per year of any pollutant such as nitrogen oxides (NOx), volatile organic compounds (VOCs), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter (PM). Lower thresholds may apply in nonattainment areas;
  • More than 10 tons of any hazardous air pollutant (HAP) as listed in subsection 112(b) of the federal Clean Air Act; or
  • More than 25 tons per year of a combination of any HAPs.

A facility may also be required to have an AOP if it is subject to certain federal air quality requirements, including:

  • Title IV Acid Rain Program;
  • New Source Performance Standards (NSPS); or
  • National Emission Standard for Hazardous Air Pollutants (NESHAP).

Who does this rule affect?

It affects a broad range of industries and facilities required to have an AOP as defined in Chapter 173-401 WAC.

Appeal Procedures

This adoption can be appealed under procedures described in the Administrative Procedure Act (RCW 34.05.330).  For more information about appealing this rule adoption, please contact Bari Schreiner, Agency Rules Coordinator, at (360) 407-6998 or bari.schreiner@ecy.wa.gov.