Spokane International Airport PFAS

Ecology is requiring SIA, the City of Spokane, and Spokane County (responsible parties) to provide safe drinking water to residents and businesses with PFAS-contaminated wells in the affected area shown at left. We notified them Feb. 10, and included a scope of work and schedule for providing:

• Bottled water and/or point-of use (POU) filtration systems (short-term interim action)
• Well testing and treatment system maintenance
• Point-of-entry treatment (POET) systems or connection to city water where possible (long-term interim action)

Short-term plan to provide bottled water or POU filters and offer well testing

The draft short-term interim action work plan is due Feb. 24. This plan will detail how the responsible parties will supply bottled water or POU filters to people with contaminated wells in the affected area.

Ecology is sharing the well testing results we have to aid this process. The responsible parties will be offering testing to private wells within the affected area. Your participation is voluntary, but we encourage you to respond if services are offered.

We expect the work to begin in mid- to late March. We will hold a 60-day public comment period and public meeting for the short-term interim action work plan.

Long-term plan to provide POETs or city water, periodic well testing, and treatment system maintenance

The responsible parties will submit a draft long-term interim action work plan by May 11. This plan will detail how the responsible parties will supply POETs to people with contaminated wells or connect them to city water where possible. The work will include maintaining the treatment systems and periodically testing wells and filtered water.

We expect the work to begin later this year. We will hold a 60-day public comment period and public meeting for the long-term interim action work plan.

What if I'm not in the affected area?

For now, the work will be limited to the area in the map above. However, Washington's cleanup law requires responsible parties to find the full extent of contamination. As the investigation continues, the area may expand based on groundwater sampling results.

We based the current boundaries of the affected area on:

• Data in the draft Initial PFAS Investigation Report
• Historical data from the airport property
• Well-established and published characteristics of regional geology and hydrogeology
• Very low to non-detect levels of PFAS in groundwater upgradient of the airport's property
• High levels of PFAS in groundwater immediately downgradient of the airport's property
• Documented PFAS impacts to drinking water wells further downgradient from the airport's property

SIA submitted the draft Initial PFAS Investigation Report on January 15. We are reviewing it, will provide SIA comments as needed, and post the final report after our comments have been addressed. We will also share the final report through the West Plains PFAS Updates email list.

Groundwater samples were collected from 52 monitoring wells. Soil samples were collected from 57 locations at multiple depths below the ground surface. The report includes maps and preliminary analyses of soil and groundwater data. The results will be used to develop a Remedial Investigation Work Plan.

On July 31, Ecology received a request from SIA to modify the schedule by extending the deadline for submitting the Remedial Investigation Work Plan by 120 days. This extension affects all the other deliverables, as they are based on the submittal of the previous one.

Ecology compromised by granting a 60-day extension, and we amended the order. We will share the draft Remedial Investigation Work Plan when it's final.

As part of the schedule modification, we are requiring quarterly groundwater monitoring and the submittal of groundwater monitoring reports to occur sooner than the Enforcement Order originally required. Quarterly groundwater monitoring was going to start after the Remedial Investigation Work Plan was finalized; however, SIA and Ecology agreed to change the schedule, and monitoring should start by the end of the year.

SIA submitted the final Initial PFAS Investigation Work Plan, Sampling and Analysis Plan, Health and Safety Plan, and Inadvertent Discovery Plan on December 13, 2024. Ecology reviewed and commented on a draft submitted September 19. Following SIA's revision, we approved it noting a few of our comments were not fully incorporated in a cover letter attached to the work plan. SIA responded to our conditional approval letter.

Work plan summary

The Initial PFAS Investigation Work Plan explains where and how preliminary groundwater and soil samples will be collected on SIA's property, focusing on areas with potential or known PFAS releases (click image above to enlarge and view the areas). The field work detailed in this work plan was completed in January 2025. 

March 2024 groundwater sampling results

Appendix A of the work plan is the results of groundwater samples taken in March 2024. Based on Ecology’s review, the results are generally consistent with SIA’s past sampling and indicate several areas within the airport property had PFAS. Highest concentrations were observed in the Joint Fire Training Area, with one type of PFAS (PFHxS) at 16,000 parts per trillion (ppt), which is 1,600 times the drinking water standard of 10 ppt.

Learn more

• Download the Initial PFAS Investigation Work Plan, includes Ecology's conditional approval letter (read SIA's response) and figures showing March 2024 and planned sampling locations
• Download the work plan appendices, which are as follows:
1.  March 2024 Groundwater Sampling Data
2. Quality Assurance Project Plan / Sampling and Analysis Plan
3. Health and Safety Plan
4. Inadvertent Discovery Plan (for if historical artifacts are found during the investigation)
5. Groundwater Monitoring Well Boring Logs
• Read Ecology's summary

After Ecology review and comment, SIA made revisions and the Site Assessment Report for PFAS was approved as final in August 2024. The report includes the following sections:

• SIA description (current and past operations and land use, geology and hydrogeology, groundwater and surface water) 
• Records review (personnel interviews, incident records)
• Fire emergency training response system information
• Waste related to SIA operations
• Other potential sources of PFAS
• SIA's historical PFAS data

The report lists areas that could be PFAS sources where firefighting foam was stored or used, and areas where PFAS was previously found in groundwater:

• Airplane crash that resulted in a fire – 1994
• Joint Fire Training Area and Military Burn Pit, Air Force, SIA, and Air National Guard training with firefighting foam
• Triangle Ramp training area
• Historical SIA Fire House, previous firefighting foam storage and firefighting training area
• Current SIA Fire House, firefighting foam storage and firefighting training area
• FAA inspections and testing (Taxiway K)
• Hanger 725, firefighting foam storage
• Field Maintenance Building, firefighting foam storage and equipment maintenance
• Air National Guard Operations Area, previous firefighting foam training
• Park Drive waste disposal area and Waste-to-Energy Plant borrow pit, unknown source
• Stormwater recovery area, collects stormwater that may contain PFAS
• Southeast area of business park, no known firefighting foam activities in the area, further investigation needed

In addition to reading the report, you can learn more in Ecology's summary.

The Enforcement Order and Public Participation Plan were open for public comment March 29 through May 27, 2024. We held a public meeting May 6 (download the slides) that was attended by more than 100 people. We appreciate the community’s input and interest and thank the 21 people who submitted comments. We considered and responded to all the comments we received. 

The order requires SIA to complete a remedial investigation and feasibility study. The remedial investigation will determine the full extent PFAS and other contamination in soil and groundwater, and the feasibility study will assess cleanup options. The order includes a scope of work and schedule for completing the investigation and study. The Public Participation Plan describes how you will be informed and can comment during the cleanup process. You can learn more in the public notice that was mailed to the community and by reviewing the order and plan.

If you would like to be added to the postal mailing list, please send your mailing address to Erika Beresovoy at erika.beresovoy@ecy.wa.gov or call her at 509-385-2290. The postal mailing list will notify you about open public comment periods for the Spokane International Airport PFAS site.

To join the West Plains PFAS updates email list, you can subscribe online, or email or call Erika to request to be added. The email list will notify you about open public comment periods for the Spokane International Airport PFAS site, as well as other PFAS-related topics relevant to the West Plains, including the Area-wide Groundwater Investigation we're funding. You can also find more information on our PFAS in West Plains private wells webpage.

In October 2017, SIA hired an environmental consultant to drill two new groundwater monitoring wells in the northeast part of the airport property. In November, these wells and an existing well were sampled to determine if PFAS were in groundwater. Sample results for all three wells had levels of PFAS above Washington’s recommended health safety levels.

PFAS contamination had been identified in wells in and around the nearby Fairchild Air Force Base earlier in 2017. PFAS, a known human health hazard, are in firefighting foam used to control petroleum fires at airports and military installations.

In March 2019, SIA hired another consultant to sample groundwater monitoring wells for PFAS in an area that had been used for fire training drills in the southwest portion of the airport property. Sample results for three wells had levels of PFAS above Washington’s recommended health safety levels.

Ecology received the 2017 and 2019 sampling results in early 2023 from a third party who had obtained them through a public records request. Ecology completed an initial investigation, and then added the airport to the Contaminated Sites List.