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Air Quality

This page provides information for local governments related to the Washington Clean Air Act and examples of local air pollution codes.

It is part of MRSC's series on Nuisances: Regulation and Abatement.

New legislation: Effective June 11, 2020, chapter 70.94 RCW (Washington Clean Air Act) has been recodified as chapter 70A.15 RCW (see SHB 2246 §2010). We have updated the citations below.


The Washington Clean Air Act, chapter 70A.15 RCW, sets forth the state law regarding outdoor air pollution and establishes a system of regional air pollution control authorities to implement federal and state air pollution control regulations. (See the Department of Ecology's Washington Clean Air Agencies page.)

RCW 70A.15.2540 states that the rules and regulations adopted by an air pollution control authority, pursuant to the Washington Clean Air Act, preempt local ordinances for the regulation of air pollution. However, that statute authorizes cities and towns to enact and enforce local "nuisance" provisions and performance standards incorporated in zoning ordinances, so long as such standards relating to air pollution control or air quality are not less stringent than those of the authority.

Many local governments have enacted general nuisance ordinances, which typically contain provisions aimed at such problems as illegal burning, dust, and noxious odors.

Measurement Methods in Local Ordinances

A number of jurisdictions still reference the Ringelmann Smoke Chart (U.S. Bureau of Mines, revised 1967) to set and enforce emissions standards. The chart is a series of shaded illustrations used to measure the opacity of air pollution emissions, ranging from light gray through black. The chart is only useful for dark smoke, not light smoke that is associated with wood smoke. It has been replaced by more technically accurate measures, such as EPA Method 9 and Method 22 procedures, and caution should be exercised when using the Ringelmann Chart.

The testing methods used by the Department of Ecology for specific types of emissions are cited in the Washington Administrative Code (WAC). For details and links, see the Department of Ecology's page on Laws, Rules & Rulemaking (click on "See Our Rules" and then "Air and Climate")

Regulatory References

US Environmental Protection Agency

  • Air and Radiation - Provides topical list of related subjects and links to regulations and statutes
  • Air Quality Planning and Standards - Covers air quality, permits, visibility, major projects, emissions and toxic air pollutants
  • Technical Air Pollution Resources - Provides access to EPA resources with technical information about air pollution prevention, technology, regulation, measurement and science.
  • Air Quality Data and Tools - A collection of EPA resources for reviewing and interacting with air quality monitoring, modeling and emissions data.

Washington State Department of Ecology

  • Air Quality - The Air Quality Program's goal is to safeguard public health and the environment by preventing and reducing air pollution. Washington's main sources of air pollution are motor vehicles, outdoor burning, and wood smoke
  • Washington Clean Air Agencies - Provides links to the seven local Clean Air Control Agencies
  • Air Quality Regulations - List of WACs governing air quality. Select Laws, rules, & rulemaking from the filter category sidebar.

Smoke, Dust and Particulate Matter

Dust is also an element of air pollution and may be regulated by the regional air pollution control agency. Most general nuisance provisions contain some reference to dust.

  • Algona Municipal Code - Zoning - Light Industrial
  • Auburn Municipal Code Sec. 18.31.180 - Performance Standards See F. Odorous Gases and Matter, G. Smoke and Particulate Matter Emissions, H. Dust, Dirt, Fly Ash, or Airborne Solids, and J. Toxic Gases and Matter
  • Ellensburg Municipal Code Sec. 5.40.56 - Excessive Smoke and Fumes Declared Nuisance
  • Enumclaw Municipal Code
  • Everett Municipal Code Sec. 8.24.030 (J) - Public Nuisances Affecting Health
  • Richland Municipal Code Sec. 9.16.046 - Public Nuisance of Allowing Blowing Dust and Dirt Prohibited

Offensive Odors

Open Burning - Air Pollution

Last Modified: April 02, 2021