Regulations & Permits

Use this portal to filter and search for all of our regulatory information.

We oversee many state and federal laws designed to protect Washington's land, air, and water. See our laws, rules, & rulemaking page for more information about our current rules and rulemaking.

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ZEV Credit Options (WAC 173-423) 04/2022

This is an April 2022 evaluation of credit options for the zero emission vehicles (ZEV) market in Washington.

https://ecology.wa.gov/zev-credit-options-wac-173-423-04-2022

ZEV Credit Options (WAC 173-423) 02/2022

This is an evaluation of credit options for the zero emission vehicles (ZEV) market in Washington.

https://ecology.wa.gov/zev-credit-options-wac-173-423-02-2022

Notice to Withdraw Rulemaking (WAC 173-400) 04/01/19

This is the notice to withdraw rulemaking for Chapter 173-400 WAC, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/withdrawal-notice-wac-173-400-04-01-19

WSPA proposal (WAC 173-400) 01/01/19

This is Western States Petroleum Association's (WSPA) 1/19 proposed rule language for Chapter 173-400 WAC, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/wspa-proposal-wac-173-400-01-01-19

Withdrawal letter (WSR 16-06-072) 02/26/16

This the withdrawal notice for the original CR-102 filed on January 5, 2016.

https://ecology.wa.gov/withdrawal-letter-wsr-16-06-072-02-26-16

Notice to Withdraw Rulemaking and Immediately Refile (WAC 173-455; 173-400) 04/18/18

This is the notice to withdraw the earlier announcement to expand the scope of the rulemaking.

https://ecology.wa.gov/withdrawrefile-wac173-455;wac173-400-041818

Two Rivers Terminal comments (WAC 173-460) 12/18

These are Two Rivers Terminal's 12/18 comments to remove ammonium sulfate from the toxic air pollutant list, Chapter 173-460 WAC.

https://ecology.wa.gov/two-rivers-terminal-comments

Utility Carbon Intensity Calculator (WAC 173-424) 11-28-22

This is the November 28, 2022 spreadsheet of Washington utility carbon intensity calculator.

https://ecology.wa.gov/utility-carbon-intensity-calculator-wac-173-424-11

Utility Carbon Intensity Calculator (WAC 173-424) 06-30-22

This is the June 30, 2022 spreadsheet of Washington utility carbon intensity calculator.

https://ecology.wa.gov/utility-carbon-intensity-calculator-wac-173-424-06

Utility Carbon Intensity Calculator (WAC 173-424) 04/04/22

This is the April 4, 2022 spreadsheet of Washington utility carbon intensity calculator.

https://ecology.wa.gov/utility-carbon-intensity-calculator-wac-173-424-04

WA-GREET electric power final (WAC 173-424) 06-30-22

This is the June 30, 2022 final supporting documentation for electric power pathway in WA-GREET, Washington's version of the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model.

https://ecology.wa.gov/wa-greet-electric-power-final-wac-173-424-06-30-22

WA-GREET electric (WAC 173-424) 06-30-22

This is the June 30, 2022 supporting documentation for electric power pathway in WA-GREET, Washington's version of the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model.

https://ecology.wa.gov/wa-greet-electric-wac-173-424-06-30-22

WA-GREET supplemental (WAC 173-424) 11-28-22

This is the final supporting documentation for WA-GREET, Washington's version of the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model.

https://ecology.wa.gov/wa-greet-supplemental-wac-173-424-11-28-22

WA-GREET supplemental (WAC 173-424) 04/04/22

This is the April 4, 2022 supporting documentation for WA-GREET, Washington's version of the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model.

https://ecology.wa.gov/wa-greet-supplemental-wac-173-424-04-04-22

WA-GREET supplemental (WAC 173-424) 03/08/22

This is supporting documentation for WA-GREET, Washington's version of the Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model.

https://ecology.wa.gov/wa-greet-supplemental-wac-173-424-03-08-22

Washington GREET model (WAC 173-424) 11-28-22

This spreadsheet is the Washington GREET model, fuel carbon intensity calculator for Clean Fuels Program, November 28, 2022.

https://ecology.wa.gov/washington-greet-model-wac-173-424-11-28-22

Washington GREET model (WAC 173-424) 07-15-22

This spreadsheet is the Washington GREET model, fuel carbon intensity calculator for Clean Fuels Program, July 15, 2022.

https://ecology.wa.gov/washington-greet-model-wac-173-424-07-15-22

Utah GREET model (WAC 173-424) 11-28-22

This spreadsheet is the final Utah GREET model, fuel carbon intensity calculator for Clean Fuels Program, November 28, 2022.

https://ecology.wa.gov/utah-greet-model-wac-173-424-11-28-22

Utah GREET model (WAC 173-424) 07-15-22

This spreadsheet is the Utah GREET model, fuel carbon intensity calculator for Clean Fuels Program, July 15, 2022.

https://ecology.wa.gov/utah-greet-model-wac-173-424-07-15-22

Sulfur dioxide air quality designations

We’re deciding if parts of Washington don't meet national air quality standards for sulfur dioxide.

https://ecology.wa.gov/regulations-permits/plans-policies/areas-meeting-and-not-meeting-air-standards/sulfur-dioxide-designations