Discovery of PFAS Contamination in Groundwater at the Yakima Training Center (YTC)

Some wells on or near the Yakima Training Center have recently been identified as contaminated with Per- and Polyfluoroalkyl Substances (PFAS). Below are resources to help you get your well tested and find more information on this event. 


The U.S. Army Yakima Training Center (YTC) has assumed full responsibility and oversight for the PFAS response, including well testing, monitoring, mapping, and providing clean drinking water for those affected.

Yakima County has offered its full support to proactively assist the YTC by:

  • Opening our wells for sampling
  • Providing water system maps
  • Participating in DOH’s testing
  • Offering our assistance and cooperation in finding short- and long-term solutions
  • Participating in public meetings and offering our full support to ensure the protection of groundwater in Yakima County


What you can expect from Yakima County

  • Prompt and full updates as we receive them from the Yakima Training Center (YTC)
  • Coordination and communication with the YTC on long-term solutions
  • Ensuring the integrity of our water systems


Submit Your PFAS Results to Yakima County

If the U.S. Army has recently tested your domestic well for PFAS, and you would like to share your test results with Yakima County, please complete  this form

How is Groundwater Contamination Traced?

The military is currently undergoing PFAS contamination tracing for the firing center. The exact process the military is following and what tools the military is using has not yet been shared, but groundwater tracing generally follows some standard guidelines.


When groundwater contamination is discovered often several questions are immediately asked. What is the probable source of the contamination? What is the extent of the contamination? What is the predicted impact of different mitigation scenarios?


To begin to try to answer these questions typically a collection of groundwater wells are tested around the suspected source of the contaminate. This growing network of monitoring wells help to provide access to groundwater, determine which pollutants are present and in what concentrations, and determine the distribution of pollutants both over an area horizontally and vertically. As water flows from higher gradient to lower gradient, the growing area of pollution can be mapped and future flow predicted. Other pollution tracing techniques, such as predictive computer models, may be applied to help investigate the origin of groundwater pollution and the extents. Wells that test above the reporting limit are mapped as a “plume.”


Groundwater plume means groundwater that has been polluted by a release of the contaminant (in this case PFAS) above the reporting limit. This is used to identify the spatial distribution of the groundwater impacted by the release of the contaminant of concern.


The quickest and most cost-effective means of finding the boundary and shape of a groundwater plume is testing outward from the suspected source until the boundaries of contamination are found.


Sample plume map 

Sample plume animation 

(Note: These are only illustrative examples and not from the firing center):



Resources: