How did PFAS reach drinking water in Airway Heights and the West Plains?

Which sources does this page cover?

Washington's Department of Ecology names three main sources of PFAS in West Plains groundwater. Groundwater there flows from southwest to northeast. Ecology splits the area at Hayford Road.

* Ecology's fact sheet on the airport from April 2026 dates the order to 2023. Ecology's site record lists March 29, 2024. We use the site record, because it links the order itself.

On the base, the Air Force lists five main areas where foam was released. They are a fire truck testing area, two aircraft crash sites, a fire station and a fire training area. Its investigation found one more area, near a former hangar.

The parties disagree about where the PFAS comes from. In April 2026, Ecology rejected the view that it comes only from the base. Ecology called that view "not scientifically justifiable".

What happened, and what has been done since?

Foam use and contamination found   Steps that ended or treated it

1. 1970The Air Force began using firefighting foam, according to its own timeline. Air Force
2. 1989The base was placed on the federal Superfund list. Air Force
3. 2015The Air Force completed a first assessment of PFAS on the base. Air Force
4. 2016 or 2017PFAS were found in the city's wells and in nearby private wells. The records differ on the year; see the note below. ATSDR
5. 2017For a time, residents were told not to drink city water or cook with it. Bottled water was handed out. The city took its wells out of use and drew water from Spokane. In June it declared the water safe to drink. ATSDR
6. 2018A temporary carbon filter was installed at city well 9. The Air Force began installing filters in homes. Air Force
7. 2019Treatment at city wells 1, 4 and 9 was chosen. In November, ATSDR tested the blood of residents. Air Force · ATSDR
8. 2021–2025The Air Force investigated the base from June 2021 to March 2025. Its report was finalized in 2025. Air Force
9. 2024In March and June, the EPA sampled 411 private wells in the West Plains. Ecology
10. 2024On March 29, Ecology ordered the airport to investigate. Ecology The Air Force finished switching its fire trucks to foam without fluorine. Air Force
11. 2026In January, the City and County of Spokane joined the airport investigation. In February, Ecology required emergency steps. Ecology

What was measured in the city wells in 2017?

Air Force tests showed PFAS in all three wells the city then used. The highest result from a well in use was 1,520 ng/L. That is 1,200 ng/L of PFOS and 320 ng/L of PFOA combined. The same well held 1,500 ng/L of PFHxS.

ATSDR says that by 2017, city water met the EPA's health advisory for PFOA and PFOS. That advisory was the guide value at the time. Today's limits are far lower; see how today's limits compare.

The 2017 results are in the ATSDR report, page 4. ATSDR does not name the wells.

What has the Department of War measured off base since 2021?

The Department of War publishes its test results for off-base drinking water. For Fairchild, it lists 3,418 samples from October 2021 to February 2026. Each sample carries a label for treatment. That gives three groups: no treatment system, before treatment and after treatment.

Highest results, in ng/L. "J estimate" is a value the laboratory flagged as estimated:

The first column per group is the highest result without a laboratory qualifier. Several times, an estimate is higher than that. That is why estimates get their own columns. A dash means not detected. HFPO-DA was tested in fewer samples than the other chemicals.

What does "before treatment" mean here?

These samples come from homes with a treatment system. They were taken before the water reached the tap. Up to May 2024, the numbers of samples before and after treatment were similar. From August 2024, there were about three before for every one after. In the February 2026 round, sample numbers run in short groups. Each group ends with the sample after treatment. Before it, results often fall step by step, for example 135, then 2.84, then nothing detected. We think some samples were taken between filter stages. The data does not say. So for this group we show highest values only, and no counts.

Why do the highest results without a treatment system stand out?

The two highest PFOS results come from one laboratory report of October 7, 2022: 671 and 631 ng/L. The next two, 424 and 404 ng/L, come from one report of October 7, 2021. Without these two reports, the highest results are 80 ng/L for PFOS, 174 for PFHxS and 72 for PFOA. Within the two reports, high results and results with nothing detected alternate. We cannot tell why. We show the values as they are.

What did the samples after treatment show?

PFOS was detected in 117 of the 949 samples after treatment. Nine of these samples reached the action level for at least one chemical. One reached it with estimated values only. The highest was 285 ng/L of PFOS, in September 2022. The data does not say what happened at those homes afterwards.

Some short-chain PFAS were found at higher levels after treatment. PFBA reached 520 ng/L and PFPeA 420 ng/L, both in 2024. The federal drinking water limits do not cover these two; see the limits.

What else did the tests find?

HFPO-DA was found 45 times, all in 2024. The highest result, 330 ng/L, was taken before treatment on December 8, 2024. The data does not say where it came from.

How do these results compare with today's limits?

Washington changed its state action levels for PFAS on January 15, 2026. They are now 4 ng/L for PFOA and PFOS, and 10 for PFHxS, PFNA and HFPO-DA. Before, they were 10 for PFOA, 15 for PFOS, 65 for PFHxS and 9 for PFNA. They apply to the public water systems the rule calls Group A, on a running annual average. A single result from a private well does not break them in the legal sense.

Federal limits and the Department of War's action level for private wells may change. We keep them on one page: How do PFAS results compare with the limits? None of these values decides whether someone has a legal claim. What the lawsuits ask for is a separate question.

How many samples reached the action level for a single chemical?

We counted only samples without a treatment system. A sample counts if at least one chemical reached its own action level. Without estimates: 380 of 826. Including estimates: 383. For samples before treatment we give no count, for the reason above.

The Department's memo sets the action level at or above three times the federal limits. For PFOA or PFOS, that is 12 ng/L. For PFHxS, PFNA or HFPO-DA, it is 30 ng/L, each on its own. The action level also includes a hazard index for mixtures. In this group, it added no further samples.

What did the EPA find in other West Plains wells?

In March and June 2024, the EPA sampled 411 private wells in the northeast West Plains. 236 of them, or 57 %, had PFAS above drinking water standards. 111 had none detected. Wells north of Highway 2 had the highest levels, some more than 20 times the standard. Wells south and west of the base were below the standards.

These results are not part of the Department of War's data. Ecology's page does not say which standard it used.

Which public water system serves Airway Heights?

Your provider's name was on your bill. Each public system also has a PWSID. The table shows what the latest report says:

What does the city's 2025 report say about PFAS?

The city's report for 2025 lists PFOA as not detected. Under additional monitoring the EPA requires, it lists four more: PFOS 4.92, PFHxS 4.91, PFBS 5.14 and PFHxA 38.2 ng/L. For PFOS, it gives a single result. The report does not say where or when the samples were taken. It lists no violation.

The PFOS value is just above the federal limit of 4 ng/L. That limit applies as a running annual average, with a deadline still years away; see the limits. One result does not show a violation.

The report gives its PFAS values in milligrams per litre. We converted them to ng/L. The City of Spokane publishes its own report for the water it supplies.

What does this mean for today's water?

For the city, its annual report is the current record. For private wells, the Department of War starts interim action at or above its action level. That applies where it is the known source. Ecology offers free well sampling in parts of the West Plains. For a well that was never tested, a test is the only way to know.

What did health agencies conclude for this area?

In November 2019, ATSDR tested the blood of 333 people in Airway Heights. They had used city water and lived west of Hayford Road for at least a year before June 8, 2017. ATSDR published the results in March 2022.

After adjusting for age, PFHxS levels were 56 times the national level. PFOS was about 8 times and PFOA about 6 times the national level. ATSDR says the higher levels may be linked with past drinking water contamination.

The comparison is on page 20 of the ATSDR report. The averages are in Table 7 on page 21.

What about showering and cancer ratings?

Drinking and cooking are the routes that matter most. The EPA says showering and washing are unlikely to add much to your risk. The IARC has rated both chemicals. It classifies PFOA as carcinogenic to humans and PFOS as possibly carcinogenic. The wider research, and where it is unsettled, is on one page: What does PFAS exposure do to health?

How do the AFFF lawsuits apply here?

Firefighting foam of this kind is called AFFF. The AFFF cases are grouped before one federal judge as MDL 2873. Handling the foam at work and drinking contaminated water are separate exposure routes. Near this base, both can apply.

Which conditions the lawsuits cover, and which are under review, is kept on one page: What are the AFFF lawsuits? What the work route asks for is explained under What if you handled the foam at work?

Which other PFAS sites have we documented?

• Peterson Air Force Base, Colorado — Security, Widefield, Fountain, the Security Mobile Home Park and private wells
• Willow Grove and Warminster, Pennsylvania — Horsham, Warminster, Warrington, North Wales, Aqua and private wells

Every place page uses the same method. We use the Department of War's own test results and name public water systems by PWSID. Dates are as precise as the record.

Where does this page's information come from?

• ATSDR — PFAS Exposure Assessment: Spokane County, Washington
  First detection in May 2017, who took part, the blood results in short.
• ATSDR — PFAS Exposure Assessment, Spokane County, report, March 2022 (PDF)
  City wells in 2017 and the switch to Spokane water on p. 4. Blood comparison on p. 20, Table 7 on p. 21. Page numbers as printed in the report.
• Air Force — Fairchild open house posters, April 2026 (PDF)
  Timeline, source areas on the base and the investigation. Wells sampled and treated as of December 29, 2025. Schedule as of March 2026.
• Air Force — Fairchild AFB continues comprehensive response to PFAS contamination
  Wells tested and systems installed as of late 2025, single-tap filters, wider testing from 2026.
• Air Force — Preliminary groundwater sampling results indicate contaminants in Airway Heights
  Sampling in late April, advice not to drink city water, public meeting on May 23. The page shows no year.
• Washington Department of Ecology — PFAS in West Plains private wells
  The three sources, the two areas, help for residents, filters and state funding.
• Washington Department of Ecology — EPA and Eastern Washington University sampling results
  The EPA's private well sampling in 2024.
• Washington Department of Ecology — Spokane International Airport PFAS, site record
  Order of March 29, 2024, agreement of January 20, 2026, emergency steps and notice of non-compliance in 2026.
• Washington Department of Ecology — Focus on: Spokane International Airport PFAS Investigation, April 2026
  Ecology's view on the sources. Dates the order to 2023, unlike the site record.
• City of Airway Heights — Water quality information
  The city's water sources and its account of the 2017 contamination.
• City of Airway Heights — Water reports, including the 2025 report
  PWSID, sources in winter and summer, the carbon filter at well 9, PFAS results for 2025.
• Washington State Board of Health — rule 26-01-082 in the Washington State Register, effective January 15, 2026
  The old and new state action levels for PFAS.
• Department of War (then Defense) — Memorandum on implementing the EPA limits, September 3, 2024 (PDF)
  The action level for private wells where the Department is the known source, on p. 2.
• Department of War — Off-Base Drinking Water PFAS Testing Results
  The measurement data for the base. Query results have no permanent link, so the query is stated on this page. Retrieved October 4, 2026. Our copy of the file can be downloaded.
• EPA — Steps you can take to reduce your risk
  Showering and washing.
• IARC — Monographs Volume 135: PFOA and PFOS
  Cancer classification of PFOA and PFOS.
• US District Court, District of South Carolina — MDL 2873
  The court's page for the AFFF lawsuits. Conditions, exposure routes and proof requirements are set out on the PFAS topic page.

We link a source at the point each claim is made. One set of figures has no permanent link at its source: the Department of War's data. So we state the query and publish our copy of the data. If a link is broken or a source has been superseded, tell us.