Chapter 173-407 WAC

On February 21, 2018, Ecology amended Chapter 173-407 WAC, Greenhouse Gas Mitigation Requirements and Emissions Performance Standard for Power Plants (formerly called 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.
  • Develop and implement plans or programs to reduce greenhouse gases as approved by Ecology.

This rule also describes Ecology’s consultation with Washington 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

Ecology's meetings with stakeholders

Date Documents Location
April 13, 2017
draft rule (3/31/17)
meeting summary
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.  We accepted comments the following ways:

  • Comment online. View comments.
  • Attend a public hearing (in person and webinar):

           November 7, 2017
           Department of Ecology
           300 Desmond Drive SE
           Lacey, WA  98503

  • Mail to:  Jean-Paul Huys
                  Department of Ecology
                  P.O. Box 47600
                  Olympia, WA 98504-7600


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.