Cleaning up: Addressing PFAS contamination at Paine Field Airport

2024 installation of monitoring wells at the Paine Field Fire Training Pit PFAS site

Like other airports in Washington and across the nation, Paine Field Airport is addressing per- and poly-fluoroalkyl (PFAS) contamination from decades of activities that involved their use. Known as forever chemicals, PFAS are a family of thousands of different manufactured chemicals. They take a very long time to break down in the environment and are linked to negative health impacts.

In the past, Paine Field and local fire

departments used firefighting foam with PFAS during required training activities, which released PFAS to the soil and groundwater. At that time, the impact of PFAS on people and the environment was unknown. Today, training activities prevent firefighting foam from contacting the ground, and regulations are in place to manage firefighting foams with added PFAS.

Paine Field Fire Training Pit PFAS site map

In 2018, before PFAS was regulated, Snohomish County proactively began investigating the extent of PFAS contamination at Paine Field. The Paine Field Fire Training Pit PFAS cleanup site was identified with high concentrations of PFAS in soil, groundwater, and surface water —including in a stormwater pond and wetlands on the site. However, there is no impact to drinking water. We are now beginning oversight of the cleanup of this site under the formal cleanup process, with the signing of a legal agreement with Snohomish County. 

Public comment period

The public comment period for this site opens Aug. 11 and closes Sept. 10. We invite you to provide feedback on the following documents: 

• Agreed Order: Legal agreement between Ecology and Snohomish 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. 

Please review these documents online or at the Mukilteo Library. 

There are three ways to comment:

1. Comment online
2. Email a comment to David.Unruh@ecy.wa.gov
3. Mail a comment to: 
   David Unruh, Site Manager
   WA Department of Ecology
   PO Box 330316
   Shoreline, WA 98133-9716

Other Paine Field PFAS cleanup sites

We are also aware of two other PFAS cleanup sites at Paine Field: 

These sites have lower concentrations of PFAS than the Paine Field Fire Training PIT PFAS cleanup site. As a result, Snohomish County will investigate them more in the future, when additional funding is available.