PFAS in West Plains private wells

We are working with the Environmental Protection Agency (EPA), Washington Department of Health, Spokane Regional Health District, Eastern Washington University, and the West Plains Water Coalition on per- and polyfluoroalkyl substances (PFAS) contamination in groundwater in the northeast West Plains near Spokane.

In March and June 2024, the EPA sampled 411 private wells in the eligible sampling area, and 236 wells, or 57%, had PFAS above safe drinking water standards. We are providing bottled water to these homes upon request.

We invite you to share your results with us, even if PFAS wasn't detected in your water. The results will help us better understand where PFAS came from and where it is going in the West Plains. The EPA will not share your drinking water results with us to protect your personally identifiable information (your name, address, and phone number) under the Privacy Act.

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March and June results from 411 private wells

Thank you to everyone who participated in the sampling events in March and June.

We held an in-person meeting with the EPA on May 21 and an online, recorded meeting on June 6 to help people understand their sampling results.

Download the presentation slides
View the online meeting recording (YouTube)

Summary of the March and June 2024 PFAS sampling results

Sample results	Number of locations	Percent of locations
Wells that don't have PFAS	111	27%
Wells with PFAS below drinking water standards	64	16%
Wells with PFAS above drinking water standards	236	57%
Total	411	100%

See "Geographic summary" below for a text description of this results map.

The areas north of Highway 2 had the highest levels of PFAS. Some more than 20 times the drinking water standard.
The small number of samples taken south of the Spokane International Airport mostly did not have PFAS; however, directly east of the airport and south of Interstate 90, some wells had PFAS up to five times the drinking water standard.
Samples taken south and west of the Fairchild Air Force Base were below drinking water standards for PFAS.

The EPA created this map to summarize where samples were taken without showing private well locations. The boxes on the map are Public Land Survey System quarter-sections. The pie charts show the percentage of sampled wells within an area where PFAS was over drinking water standards, and by how much. The size of the circle indicates how many wells in that area were sampled. The smallest circle is one well; the largest is 40.

How to interpret your results

How it looks*	What it means
0.0	A black box with white text means that samples were ABOVE the drinking water standard. You should use an alternate source for drinking and cooking water or use a filter certified to remove PFAS.
0.0	A bolded number means that the PFAS compound was found in the sample, but it is below the drinking water standard (if one has been set).
0.0 U	The U next to a number means that is the lowest level the analysis can measure accurately and the test didn't find the PFAS compound (non-detect).

*Numeric values (0.0) are examples. Cell formatting and "U" are how to interpret your results.

How long do results last?

A sampling event is a snapshot in time. Because contamination and groundwater are constantly moving, we cannot know future levels at any location based on one sample.

We are working toward identifying sources so that any parties responsible for contamination can monitor groundwater regularly and provide whole-house water treatment systems as needed. The area-wide groundwater study with the City of Medical Lake will help us understand how groundwater and contamination are moving by taking samples from the same 30 locations four times a year.

Share your results to receive no-cost bottled water and help our investigation

Ecology invites you to share your results with us, even if PFAS wasn’t detected in your water. The results will help us better understand where PFAS came from and where it is going in the West Plains.

Sharing your results is completely voluntary. Data you provide to Ecology may be subject to public records requests and disclosure.

How to request bottled water

If your results show PFAS concentrations above safe drinking water standards, Ecology will provide no-cost bottled water to ensure you have safe drinking and cooking water. The bottled water will be delivered twice a month.

When you submit your sample results to Ecology, please include the necessary information to set up your bottled water delivery:

How many people live in the household
Contact person
Phone number
Delivery address

The Washington Department of Health is working on providing point-of-use filtration (POU) systems to replace bottled water. Bottled water and POU filters can help until investigation and cleanup of PFAS sources provide more permanent solutions, such as whole-house treatment systems paid for by the party responsible for the contamination.

How Ecology chose the sampling area

Initially we selected the sampling area based on our understanding of groundwater flow direction and the sample results people had shared with us prior to the sampling in March 2024. We understand that groundwater flows north to northeast in this area. As a result, the sampling area did not focus south of Interstate 90 in the first round of sampling.

After reviewing the March 2024 sampling information, we expanded the sampling area to the southeast to include the area between Interstate 90, Highway 195, and Thorpe Road.

Two potential PFAS sources in the northeast West Plains have been identified:

Fairchild Air Force Base (FAFB) is investigating PFAS in groundwater and monitoring offsite drinking water wells in the cross-hatched area in the above map (the area west of Hayford road). FAFB provides in-home treatment or alternative water to homes with PFAS above federal drinking water standards.

Spokane International Airport has PFAS contamination, and Ecology is requiring the airport to investigate whether PFAS is leaving its property.

Some drinking water tests from properties outside the FAFB monitoring area and the airport property boundaries have PFAS above safe drinking water standards.

Results from the well sampling will inform community members about the quality of their sole source of drinking water and provide the agencies with necessary data to help inform future cleanup efforts.

Ecology awarded the City of Medical Lake an area-wide groundwater investigation grant to develop a model of PFAS contamination in groundwater in the West Plains. The project includes public outreach, groundwater sampling and analysis, and identification of PFAS sources using geochemical fingerprinting.

Groundwater samples will be taken from 30 locations four times a year to develop the model, which will help us understand where PFAS came from and where it is going in the West Plains. Sampling began in spring 2024. Sample results people share with us will also be added to the model. To calibrate the model, another 50 locations will be sampled once in fall 2024. Calibration will help ensure the accuracy of the model.

Ecology is working with the Air Force, City of Medical Lake, Spokane County, Spokane Regional Health District, and Eastern Washington University on the groundwater model.

Contact information

Erika Beresovoy (she/her)
Public Outreach Coordinator
WestPlainsPFAS@ecy.wa.gov
509-385-2290