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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Adopted rule language (WAC 173-400) 10/25/18

This is adopted rule language for Chapter 173-400 WAC, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-10-25-18

Adopted rule language (WAC 173-400) 08/16/18

This is adopted rule language for Chapter 173-400 WAC, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-08-16-18

Adopted rule language (WAC 173-405) 04/23/19

This is adopted rule language for Chapter 173-405 WAC, Kraft Pulping Mills.

https://ecology.wa.gov/adopted-rule-language-wac-173-405-04-23-19

Adopted rule language (WAC 173-400) 11/29/21

This is adopted rule language for WAC 173-400, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-11-29-21

Adopted rule language (WAC 173-400) 12/19/22

This is adopted rule language for WAC 173-400, General Regulations for Air Pollution Sources.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-12-19-22

Adopted emergency rule language (WAC 173-443) 10/20/20

This is emergency adopted rule language for WAC 173-443, Hydrofluorocarbons (HFCs).

https://ecology.wa.gov/adopted-emergency-rule-language-wac-173-443-10-2

Adopted rule language (WAC 173-401) 08/16/18

This is adopted rule language for Chapter 173-401 WAC, Operating Permit Regulation.

https://ecology.wa.gov/adopted-rule-language-wac-173-401-08-16-18

Adopted emergency rule language (WAC 173-443) 07/30/19

This is an emergency adopted rule language for WAC 173-443, Hydrofluorocarbons (HFCs).

https://ecology.wa.gov/adopted-emergency-rule-language-wac-173-443-07-3

2024-25 Budget for Air Quality Registration

This is the 2024-2025 budget for air quality registration.

https://ecology.wa.gov/2024-25registrationbudget

Adopted rule language (WAC 173-408) 5-13-24

This is adopted rule language for Chapter 173-408 WAC. Landfill Methane Emissions.

https://ecology.wa.gov/adopted-rule-language-wac-173-408-5-13-24

CyrusOne Data Center notice of construction (NOC) permit and technical support document

This is the August 2024 air quality notice of construction permit (approval order) and technical support document for CyrusOne Data Center.

https://ecology.wa.gov/202420812cyrusonenocpermit

Washington Emissions Inventory Reporting System (WEIRS) training, 1/30/25

This is the presentation for the January 30, 2025 training about Washington Emissions Inventory Reporting System (WEIRS).

https://ecology.wa.gov/20250130weirstraining

Adopted rule language (WAC 173-400) 2-12-25

This is the adopted rule language for Chapter 173-400 WAC, General Regulations for Air Pollution Sources, sections -020, -030, -082, -091, -101, -110, -112, -113, -114, -171, -175, -180, -230, -240, -740, -930.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-2-12-25

Adopted rule language (WAC 173-400, sections 025, 040, 050, 060, 105) 2-12-25

This is the adopted rule language for Chapter 173-400 WAC, General Regulations for Air Pollution Sources, sections 025, 040, 050, 060, 105.

https://ecology.wa.gov/adopted-rule-language-wac-173-400-sections-025-040-050-060-105-2-12-25

Adopted rule language (WAC 173-401, section 925) 2-12-25

This is the adopted rule language for Chapter 173-401 WAC, Operating Permit Regulation, section -925 and repeal of section -645.

https://ecology.wa.gov/adopted-rule-language-wac-173-401-section-925-2-12-25

Adopted rule language (WAC 173-401, sections 200, 300, 400, 500, 600) 2-12-25

This is the adopted rule language for Chapter 173-401 WAC, Operating Permit Regulation, sections -200, -300, -400, -500, -600, -620, -700, -722, -724, -735, -900, -915, -920, -940.

https://ecology.wa.gov/adopted-rule-language-wac-173-401-sections-200-300-400-500-600-2-12-25