Paine Field Fire Training Pit PFAS

Updated September 2025

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The Department of Ecology is overseeing a cleanup of the Paine Field Fire Training Pit PFAS site, located on the western boundary of Paine Field near South Everett. Per- and poly-fluoroalkyl substances (PFAS) were released to the soil and groundwater from firefighting foam, formerly used at the site during required training activities. There have been no reported impacts to area drinking water sources from the site.

We held a 30-day comment period from August 11 to September 10, 2025, on the following documents for the cleanup of the site:

• Agreed Order: Legal agreement between Ecology and Snohomish County (County) requiring the County to investigate environmental conditions, and complete a remedial investigation, feasibility study, and cleanup action plan for the site.
• Public Participation Plan: Describes how Ecology will inform the community about the site activities and ways to become involved.

During the 30-day comment period, Ecology received four comments and responded to them in our Response to Comments Summary document. No significant changes were made to the documents, and they will be finalized.

As part of the agreed order, the County and Ecology will be responsible for working cooperatively to adequately investigate the site and recommend potential options for cleaning up contamination. The County will complete a remedial investigation, feasibility study, and cleanup action plan. Each of these documents will be available for public review and comment.

The schedule included in the Agreed Order requires Ecology and Snohomish County to prepare a draft remedial investigation (RI) for public comment within approximately two years of the effective date of the Agreed Order. This allows time for us to draft a work plan to detail what activities need to be completed to support the RI, complete the field and office work, compile data, and write the draft RI report.

Depending on the initial results from RI sampling, Ecology and the County may decide that an interim action (early partial cleanup) is necessary to reduce a threat to human health and the environment. If this determination is made, we will request public comment on a draft Interim Action Work Plan to guide this partial cleanup.

Join our email list to receive updates about the Paine Field Fire Training Pit PFAS cleanup site. Email Kristen Forkeutis, Public Involvement Coordinator, at Kristen.Forkeutis@ecy.wa.gov to be added to the list. Unsubscribe at any time.

The Model Toxics Control Act (MTCA) is Washington’s environmental cleanup law. It provides requirements for contaminated site cleanup and sets standards that protect human health and the environment. Ecology enacts MTCA and oversees cleanups. The MTCA site cleanup process is completed in steps over a variable timeline.

Current Paine Field Fire Training Pit PFAS cleanup site Public Participation Plan.

This plan describes how Ecology will share information with the community and how you can share information with us. Ecology will review this plan as the cleanup progresses and amend/update it as necessary.

The Paine Field Fire Training Pit PFAS site is located north of 10727 Bernie Webber Drive in Mukilteo, WA, 98275 and airport taxiway K-6. This 30-acre site is situated on the western boundary of Paine Field in unincorporated Snohomish County between South Everett and Mukilteo. It is zoned for light industrial use. The site is owned by the County and includes the southwestern part of the airport and several aircraft hangars.

Past uses of the site included firefighting training exercises conducted by Paine Field and local fire departments, as well as equipment calibration and compliance testing required by the Federal Aviation Administration (FAA). Training exercises involved filling a pit in the ground with flammable materials like petroleum and igniting the materials. These fires were extinguished using fire suppressants, including aqueous film forming foam (AFFF), which contains PFAS. Fire truck calibration and FAA compliance testing were conducted by spraying AFFF mixtures directly onto the ground near the fire training pit. These practices were modified in 2019 so that AFFF was no longer discharged onto the ground.

Two other cleanup sites are located in this area: Paine Field (CSID 9457) and Snohomish
County Airport Fire Pit (CSID 3234). These sites are associated with releases of petroleum hydrocarbons from underground storage tanks and firefighting training. Ecology determined that petroleum hydrocarbons from the Snohomish County Airport Fire Pit site were cleaned up through the Voluntary Cleanup Program in 2007.

PFAS contamination was also found at two sites near Paine Field: Big Gulch Creek Subbasin 9 (CSID 16778) and Swamp Creek PFAS (CSID 17199). These sites are currently being managed outside of the proposed agreed order.

Initial environmental investigations found the following PFAS contamination in soil, groundwater, and surface water at concentrations greater than WA State screening levels:

• Soil: Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and perfluorohexanoic acid (PFHxA)
• Groundwater: PFOA, PFOS, PFNA, and PFHxS
• Surface Water: PFOA, PFOS, PFNA, and PFHxS

What are PFAS?
PFAS stands for per-and poly-fluoroalkyl substances. PFAS is a family of manufactured chemicals which have been used since the 1940s. They are in many industrial and consumer products because of their unique and useful chemical properties. They are used in firefighting foam and a wide range of consumer products including carpets, clothing, cookware, paper, and packaging.

Why are we concerned about PFAS?
Due to their unique and useful chemical properties, PFAS do not degrade or break down naturally in the environment and can accumulate over time. For this reason, PFAS are sometimes called “forever chemicals.” Some types of PFAS can build up in our bodies when we’re exposed for months to years. Studies show that higher levels of PFAS chemicals in our bodies could increase our risk for negative health impacts. To learn more about PFAS health concerns visit the Washington State Department of Health’s PFAS webpage.  

Are PFAS regulated?
The Washington State Department of Ecology and the U.S. Environmental Protection Agency (EPA) are taking action to address PFAS. To learn more visit Ecology’s PFAS webpage and EPA’s PFAS webpage.

Where can I learn more about PFAS?
Additional resources about PFAS are listed below.

• What Are PFAS Factsheet
• Washington State Department of Health PFAS in Drinking Water  
• Agency for Toxic Substances and Disease Registry (ATSDR) – How PFAS Impacts Your Health 
• National Groundwater Association, PFAS and Private Well Owners Fact Sheet 

Need help or have questions? We offer translation and interpretation services at no cost. If
you need these services, email kristen.forkeutis@ecy.wa.gov or call 425-240-4353. If you call, ask for an interpreter to be connected with one.

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