Chapter 173-407 WAC

On February 21, 2018 the Department of Ecology adopted amendments to Chapter 173-407 WAC Greenhouse Gas Mitigation Requirements and Emissions Performance Standard for Power Plants (formerly named Carbon Dioxide Mitigation Program, Greenhouse Gases Emissions Performance Standard and Sequestration Plans and Programs For Thermal Electric Generating Facilities). 

This rule requires power plants and units to reduce carbon dioxide emissions, meet the greenhouse gas emissions performance standard, and develop and implement plans or programs to reduce greenhouse gases as approved by Ecology. This rule also describes Ecology’s consultation with Utilities and Transportation Commission and consumer-owned utilities.

Rulemaking timeline


Announcement phase (CR-101)

Filing date:
Feb. 7, 2017

Announcement documents

Rule development phase

February 7, 2016 - October 4, 2017

Public input & involvement

Stakeholder Meeting and Informal Comment Periods 
Ecology held a stakeholder meeting to discuss possible revisions to the rule. Ecology also had three informal comment periods to give stakeholders opportunities to review and provide informal comments before official public comment period starts. The stakeholder meeting and informal comment periods schedule with supporting documents are listed below:
Date Time Documents Location
Thursday, April 13, 2017 1 p.m. - 3 p.m. draft rule (3/31/17)
meeting summary
Ecology / phone
comments due by Friday, May 12, 2017   draft rule (4/11/17) no meeting
comments due by Friday, June 16, 2017   draft rule (5/26/17) no meeting
comments due by Friday, July 28, 2017   draft rule (7/17/17) no meeting

Rule proposal phase (CR-102)

Filing date:
Oct. 4, 2017

Rule proposal documents:

Comment period

Comments were due by November 14, 2017. Comments were received through the following methods: Ecology will review all comments received and plan for adoption February 2018. 
Hearing location(s):  
Time: Location: Comment: 
2:00 pm Webinar and in person at Department of Ecology Headquarters, 300 Desmond Drive SE, Lacey WA 98503 Presentation, question and answer session followed by the formal public hearing.
We are also holding this hearing via webinar. This is an online meeting forum that you can attend from any computer using internet access.

To join the webinar click on the following link for more information and instructions: For audio only, call US toll number +1-240-454-0887 and enter access code 809 694 382. Or to receive a free call back, provide your phone number when you join the event. 

Rule adoption phase (CR-103)

Adoption date:
Feb. 21, 2018

Rule effective date:
March 24, 2018

Rule implementation information:

Additional languages

Español (Spanish) 中文 (Chinese) Tiếng Việt (Vietnamese) 한국어 (Korean)


To request ADA accommodation for disabilities, or printed materials in a format for the visually impaired, contact Ecology's ADA Coordinator by email at, or call 360-407-6831. People with impaired hearing may call Washington Relay Service at 711. People with speech disability may call TTY at 877-833-6341.