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Air Quality Program

Air Quality Rules in Washington’s State Implementation Plan

Chapter 173-400 Washington Administrative Code (WAC) is Washington’s general air quality regulation, developed by the Ecology. Other agencies with air quality responsibilities in Washington either have their own regulations, or rely on Ecology's regulations to control air pollution from facilities and industries in their jurisdiction. These state and local regulations are a major part of Washington's program to meet federal air quality standards. The main purpose of these standards is to protect human health.

Washington's SIP is a statewide plan for meeting and maintaining air quality standards. It is required by the federal Clean Air Act (CAA). Air quality regulations are an important part of Washington's SIP.

Periodically, state and local air quality agencies revise their regulations for meeting and maintaining air quality standards. Revisions may be in response to changes in state law or changes in federal regulations. Revisions that modify existing portions of the SIP must be submitted to EPA. One approved, the revised rules are added to the SIP. These rules are then federally enforceable.

Ecology amended Chapter 173-400 WAC to make it consistent with federal requirements. This is needed for EPA to approve Washington's new source review and prevention of significant deterioration permitting programs into the SIP. SIP approval helps ensure that Washington is consistent with federal law while attaining and maintaining good air quality and protecting citizen's health.

Washington's air quality agencies


Ecology is the state air quality agency. It regulates:

  • air pollution sources where there is no local air quality agency, and
  • all statewide major sources subject to Prevention of Significant Deterioration (PSD) permits.

Local air quality agencies

There are seven local air quality agencies in Washington. These local agencies regulate air pollution sources in their jurisdictions. Chapter 173-400 WAC applies statewide, except where a local agency has adopted and implemented its own rules. The exception to this is that Ecology always regulates sources subject to the Prevention of Significant Deterioration (PSD) program.

Energy Facility Site Evaluation Council (EFSEC)

EFSEC regulates major energy facilities in Washington. EFSEC contracts with Ecology to write the air quality permits that are jointly issued by EFSEC and EPA.

The proposed update to the SIP

Ecology has revised Chapter 173-400 WAC several times since it was last approved into the SIP in the 1990s. Ecology is now asking EPA to review and approve most of its updated regulation in the SIP. This update will:

  • replace old regulation language with current language,
  • remove outdated requirements,
  • update references to federal requirements, and
  • renumber sections of the regulation.

Is Ecology proposing to revise the regulation again?
No. Ecology is only proposing to include in the SIP the revisions to the regulations that have already been done. A SIP approval does not change the state's regulations. It just makes the regulations federally enforceable.

Which version of Chapter 173-400 WAC is being proposed for inclusion in the SIP?
The version of Chapter 173-400 WAC that was adopted in November 2012 is the regulation Ecology proposes to include in the SIP.

Will the entire regulation be in the SIP?
No. Only the parts used to protect and maintain federal air quality standards are proposed to be included be in the SIP.

What are the main differences between the revised regulation and the one currently in the SIP?

  • The most significant differences are in the new source review program. The regulations currently in the SIP list the facilities and industries required to apply for a new source review permit. If a facility or industry is not on the list, or if an air quality agency Director or control officer determines it does not need a permit, the facility or industry is exempt from permitting. The revised regulations no longer list facilities that need a permit. They now list facilities and industries that are exempt from permitting requirements. All facilities not on this list must apply for a permit.
  • The revised regulations contain several streamlining options, including a process for issuing a General Order of Approval and a process for permitting portable sources.
  • The revised regulations also include PSD and nonattainment area permitting regulations that meet federal requirements. If EPA approves the PSD regulations, Washington will have its own SIP-approved state PSD program, instead of being delegated authority to issue PSD permits under the federal program. The nonattainment area permitting regulations are needed for permitting in current and potential nonattainment areas.

These and other changes are described in detail in the SIP submittal package, and were available for the public to review and comment on before Ecology submitted the package to EPA in January 2014.

What is in package Ecology submits to EPA?
The submittal package contains:

  • the sections of Chapter 173-400 WAC that Ecology is proposing to include in the SIP, and
  • supporting documents describing the proposed changes and their effects.

How can I learn more and comment?
Ecology held a formal public comment period from August 9, 2013 through September 20, 2013. A public hearing on the proposal was held on September 11 at 6 pm at Ecology’s office in Lacey. Ecology received comments. They are addressed in Response to Comments in the Appendix F of the final SIP submittal package. EPA will be accepting comments on the proposal before making their final decision.

If you would like to receive e-mail notifications about this project, please subscribe here. For more information, contact Anya Caudill at (360) 407-6630.

Local and EFSEC Regulations

Since the SIP is a statewide plan, other agencies in Washington with air quality jurisdiction participate in the process. Washington's seven local air quality agencies and EFSEC are now in the process of evaluating their regulations to determine what may need to be revised. As each agency revises its regulations and determines what is required to be included in the SIP, Ecology will provide opportunities for public comment. The process of submitting Ecology, EFSEC, and local agency regulations to EPA will probably take about two years.

Steps in the process

Below is a general idea of how we expect the process to take place:

  • EFSEC and each local air quality agency will develop revisions to their regulations. EPA and Ecology staffs are available to work with each agency to ensure the draft language is appropriate for the SIP.
  • Each agency will adopt its regulations according to its agency process and the state Administrative Procedures Act.
  • Each agency will develop a SIP submittal package that includes the portions of their regulations to be included in the SIP, along with supporting documentation.
  • Ecology will hold a public comment period and a public hearing on individual agency regulations. If possible, Ecology will hold a SIP revision hearing the same day the agency adopts its regulation. Otherwise, Ecology will schedule a hearing at another time. If time allows, Ecology may schedule a SIP hearing for several agencies' regulations at the same time.
  • Ecology will submit regulations to EPA in groups as agencies complete their regulation adoption and SIP revision hearing processes.
  • EPA will review the submittals and publish a proposed action in the Federal Register. A 30-60 day public review and comment period begins when this notice is published.
Opportunities for input

EFSEC and local agencies will offer a public comment period and hold a public hearing when they revise their regulations. You can comment in person at public hearings, or in writing to the appropriate agency at any time during the public comment period. Each agency will respond to comments about its own regulation.

EFSEC and local agencies will prepare SIP submittal packages, which will also have public comment periods and hearings. Ecology conducts these hearings on SIP submittal packages. A SIP hearing may be held at the same time as the regulation adoption hearing, or later. Ecology, with the help of the agency revising its rules, will respond to comments received on the SIP revision.

Air quality agency contacts

  • Ecology
    (Washington State; Adams, Asotin, Chelan, Columbia, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Pend Oreille, San Juan, Stevens, Walla Walla, Whitman counties)
    Anya Caudill;
  • EPA Region 10
    Donna Deneen;
  • Energy Facility Site Evaluation Council
    Jim La Spina;
  • Benton Clean Air Agency
    (Benton County)
    Robin Priddy;
  • Northwest Clean Air Agency
    (Island, Skagit, and Whatcom counties)
    Mark Buford;
  • Olympic Region Clean Air Agency
    (Clallam, Grays, Jefferson, Mason, Pacific, and Thurston counties)
    Mark Goodin;
  • Puget Sound Clean Air Agency
    (King, Kitsap, Pierce, and Snohomish counties)
    Steve Van Slyke;
  • Spokane County Clean Air Agency
    (Spokane County)
    April Westby;
    509.477.4727, ext. 105
  • Yakima Regional Clean Air Agency
    (Yakima County
    Hasan Tahat;
    509.834.2050, ext. 105

Contact Us


Final Documents Submitted to EPA in January, 2014:


Proposal Documents:

Public hearing notice

Press Release