Chapters 173-442 and 173-441 WAC

Clean Air Rule - Chapter 173-442 WAC 
Reporting of Emissions of Greenhouse Gases - Chapter 173-441 WAC

Map of sites in Washington affected by this rule

Map of greenhouse gas emissions from large facilities



Jason Alberich
(360) 407-6082

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Washington Clean Air Act

Overview of the Clean Air Rule

On September 15, 2016, Ecology adopted emission standards (Chapter 173-442 WAC – Clean Air Rule) to cap and reduce greenhouse gas (GHG) emissions from significant in-state stationary sources, petroleum product producers, importers, and distributors and natural gas distributors operating within Washington.

For more information on the rulemaking process and public involvement, please see the Clean Air Rule Public Involvement and Timeline webpages.

Parties covered under the Clean Air Rule are required to reduce their covered GHG emissions along an emissions reduction pathway or obtain emission reductions from other covered parties, GHG emissions reduction projects, or out-of-state emissions market programs. The Clean Air Rule covers two-thirds of all in-state GHG emissions including a wide array of public and private sector parties.

In addition, Ecology amended Chapter 173-441 WAC (Reporting of Emissions of Greenhouse Gases) to change the emissions covered by the existing reporting program, modify reporting requirements, and update administrative procedures.

Rulemaking Process Overview

The Clean Air Rule reflects comments, concerns, and suggestions from businesses and industry, environmental stakeholders, and the general public. Ecology originally filed the proposed Clean Air Rule in January 2016, but withdrew the filing to continue stakeholder engagement and feedback. Ecology reproposed the Clean Air Rule in May 2016.

We invite you to continue the conversation toward reducing GHG emissions and a healthier Washington by sharing your ideas, opinions, and concerns as the Clean Air Rule is implemented. Here's how you can participate:

Accessibility (ADA)

For special accommodations or documents in alternate format, call 360-407-6800, 711 (relay service), or 877-833-6341 (TTY). Ecology's ADA Accessibility page.

Para información en español acerca del cambio climático global o la Regla de Aire Limpio, favor de contactar a Gretchen Newman, (360) 407-6097 o

For questions in languages other than English or Spanish, please contact, Jason Alberich at (360) 407-6082 and we will connect with you through an interpreter.