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Composting converts organic solid waste into enriched organic soil. Compost production can be done on many levels: from the backyard bin to large commercial operations which produce composted material for sale.




We regulate commercial composting operations through the Notice of Construction (NOC) permit application process and registration program. The NOC is a pre-construction review by our agency engineers. These engineers can issue an Order of Approval for the operation that may contain site-specific conditions as a required part of the Approval.

The Registration program requires permitted operations to register with us annually, to assure the agency that they continue to comply with all applicable permit approval conditions.

Click here for more information about the NOC and Registration programs.


 Composting Facilities


We require permitted composting operations to register with us on an annual basis to confirm compliance with approval conditions.

A variety of technologies, operational condition, and approval conditions are included in the Notice of Construction (NOC) reviews below.  These details can be seen in the final Order of Approval which covers each site’s operations.

Facility ID No. Source Name Location County NOC Order of Approval(s)

Bailey Compost

12711 Springhetti Rd

Snohomish Snohomish 7487

Cedar Grove- Everett

3620 36th Pl NE

Everett Snohomish 10455

Cedar Grove- Maple Valley

17825 Cedar Grove Rd

Maple Valley King 10456

Lenz Enterprises Inc

5212 SR 532

Stanwood Snohomish 9386

​Misich Farms Riverside Topsoil

7404 Lowell-Snohomish River Rd

​Snohomish ​Snohomish ​7662

​Monroe City of Biosolids Composting Facility

Monroe Reformatory

​Monroe ​Snohomish ​8147

​Monroe City of Biosolids Composting Facility

18117 203rd St SE

​Monroe ​Snohomish ​10164

​Pacific Topsoils Inc

8616 219th St SE

​Woodinville ​Snohomish ​9103

​Pierce Co Recycling Composting and Disposal LLC

14515 54th Ave NW

​Gig Harbor ​Kitsap ​N/A
​21331 ​Pierce Co Recycling Composting and Disposal LLC ​Puyallup ​Pierce 6970

 Frequently Asked Questions


What is the Clean Air Agency doing about composting odors?

We take odor complaints very seriously and follow the protocols established through our regulations which state that it is against the law to emit any air contaminant that unreasonably interferes with enjoyment of life and property.

How does the Clean Air Agency investigate and respond to odor complaints?

We prioritize our response based on the number of complaints and likelihood of the smell still being present. You must be willing to provide a written statement describing how the smell is impacting your life and or property (at this moment) and agree to testify under oath later if any enforcement action taken by the agency is appealed.

Once on site, our inspector must be able to detect an odor that is distinct, definite and unpleasant, and be able to trace the odor back to its source. 

What should I do when odor is impacting me at my home or place of business?

When you detect an odor that interferes with your enjoyment of life and/ or property, please register your complaint with us as soon as possible. Our inspectors will evaluate the information and will respond if resources are available. It is important to submit a complaint while the odor is actually occurring. Please visit the Complaint​ section of our website for instructions.  Our online complaint process is the most efficient way to file a complaint.

Has any enforcement action been taken against Cedar Grove Composting for odor issues?

Yes. We have issued several civil penalties to Cedar Grove for nuisance odor violations at both of its facilities.

Who is ERMAS?

ERMAS (Environmental Reporting, Monitoring and Solutions) is a consulting firm hired by Cedar Grove to respond to and investigate odor complaints in the SE King County and Marysville/ Everett areas. The agency does not work with ERMAS.

What is the status of the community odor monitoring study in the Marysville/ Everett area?

The study is complete. View the ​Report Summary or full Final Report​ for details.

Does the Agency work with Facts On Composting?

No, but the agency does take interest in organizations that communicate odor related information to the public. The Facts on Composting (FOC)​ website was funded by a public participation grant from the Washington Department of Ecology (DOE), but is not necessarily endorsed by DOE. According to FOC, the goal of the grant is to provide community outreach to address potential health threats from emissions from large scale composting facilities in Western Washington.​