Commenting open: November 13, 2025 12:00AM PT - January 20, 2026 11:59PM PT.
Formal Comment Period: Rulemaking for flame cap kilns and air curtain incinerators
Ecology is conducting rulemaking to address the use of flame cap kilns and air curtain incinerators. This rulemaking adds the definition of “flame cap kilns” to Chapter 173-430 WAC to align rule language with amendments made to the Washington Clean Air Act (RCW 70A.15) by Substitute Senate Bill 6121, signed into law in the 2024 legislative session. The rule is also being amended to address air curtain incinerators. Current technology available for air curtain incinerators makes it difficult to meet some emission limits. Therefore, permit applications for air curtain incinerators require additional consideration and information, which takes more time to issue the necessary permit. With proper criteria and operation standards, air curtain incinerators may be less harmful to air quality than open burning. This rulemaking will add language to streamline the permitting process for both applicants and Ecology staff. The anticipated adoption date of this rule is Spring 2026.
Please submit your formal comments for this rulemaking on Chapters 173-425, -430, -400 WAC. Please note, any information (e.g., personal or contact) you provide in a comment or in an attachment may be publicly disclosed and posted on the Internet
Contact Information
*Indicates Required Fields
Thank you for subscribing to the Formal Comment Period: Rulemaking for flame cap kilns and air curtain incinerators mailing list.
Ecology is conducting rulemaking to address the use of flame cap kilns and air curtain incinerators. This rulemaking adds the definition of “flame cap kilns” to Chapter 173-430 WAC to align rule language with amendments made to the Washington Clean Air Act (RCW 70A.15) by Substitute Senate Bill 6121, signed into law in the 2024 legislative session. The rule is also being amended to address air curtain incinerators. Current technology available for air curtain incinerators makes it difficult to meet some emission limits. Therefore, permit applications for air curtain incinerators require additional consideration and information, which takes more time to issue the necessary permit. With proper criteria and operation standards, air curtain incinerators may be less harmful to air quality than open burning. This rulemaking will add language to streamline the permitting process for both applicants and Ecology staff. The anticipated adoption date of this rule is Spring 2026.
Please submit your formal comments for this rulemaking on Chapters 173-425, -430, -400 WAC. Please note, any information (e.g., personal or contact) you provide in a comment or in an attachment may be publicly disclosed and posted on the Internet
Contact Information
*Indicates Required Fields