On December 5, 2025, the Puget Sound Clean Air Agency (Agency) issued Notice of Construction (“NOC”) Order of Approval number 12003 to Ash Grove Cement. Ash Grove Cement is a Portland cement manufacturer in Seattle, Washington. The current fuels for Ash Grove Cement’s manufacturing process include natural gas and used tires. This Order of Approval allows the fraction of fuel that may consist of tires to increase from a daily limit of 30% up to approximately 37%, which will decrease natural gas consumption. As detailed in the Agency’s worksheet for this project, the Agency has determined that this change in tire consumption will not cause an increase in emissions of any regulated pollutant and may decrease some emissions.

Under WAC 173-400-113, the Agency is obligated to issue an Order of Approval if it determines that a Notice of Construction application meets the applicable regulatory requirements. Because this application meets the applicable requirements of WAC 173-400-113, the Agency is obligated to approve the request, subject to the conditions in the Order of Approval.

To verify that emissions do not increase with the adjusted fuel percentage, Ash Grove will be required to test for emissions of particulate matter, arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, selenium, and dioxins/furans. The Agency will compare these emissions to emissions at the old 30% tire limit to verify that the change in tire consumption rate has not caused an increase in emissions. If an increase is observed through these tests, it would be addressed through the Agency’s compliance process. These test results would be available through the public records request process.

Additionally, Ash Grove continuously monitors emissions of carbon monoxide, nitrogen oxides, sulfur dioxide, total hydrocarbons, and mercury, though the Agency’s analysis showed that none of these pollutants is expected to increase.

The Agency accepted comment on draft Notice of Construction Order of Approval number 12003 from December 10, 2024, to March 4, 2025, and conducted a hearing on the draft Order of Approval on March 3, 2025. The Agency has revised this Order of Approval in response to comments that were submitted by the public during the comment period. 

The Agency has also issued a modification to Ash Grove’s Air Operating Permit number 11339. This Air Operating Permit modification only incorporates the provisions of Order of Approval number 12003. The draft Air Operating Permit modification was also open for public comment from December 10, 2024, to March 4, 2025. The Agency sent the proposed Air Operating Permit modification to US EPA on October 8, 2025, and US EPA did not object to the permit modification during its 45-day review period.

The final Order of Approval, Worksheet with response to comments, Modified Air Operating Permit, and Operating Permit Statement of Basis are available at the links below:

Final Worksheet and response to comments

Final Notice of Construction Order of Approval 12003

Final Modified Air Operating Permit 11339

Final Operating Permit Statement of Basis

Comments submitted regarding Draft NOC and Operating Permit

Separately, in the coming days, the Agency expects to issue for public comment a draft renewal of Ash Grove’s Air Operating Permit, which will include all of the applicable regulatory requirements that have not yet been incorporated into the current version of the permit (such as updates to the National Emissions Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry). The draft renewal will be published on the Agency’s Permits Open for Comment page.

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Pursuant to Puget Sound Clean Air Agency's Regulation I, Section 3.17 and RCW 43.21B.310, this NOC Order of Approval may be appealed to the Pollution Control Hearings Board (PCHB). To appeal to the PCHB, a written notice of appeal must be filed with the PCHB and a copy served upon Puget Sound Clean Air Agency within 30 days of the date the applicant receives the NOC Order. The Air Operating Permit or any condition in it may be appealed only by filing an appeal with the PCHB and serving it on the Puget Sound Clean Air Agency within thirty days of receipt, pursuant to RCW 43.21B.310 and WAC 173-401-735. This provision for appeal of the Air Operating Permit is separate from and additional to any federal rights to petition and review found under §505(b) of the federal Clean Air Act.