What Are Per- and Polyfluoroalkyl Substances (PFAS)?

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Skagit PUD's drinking water remains safe and protected from contaminants, including the group of human-made chemicals labeled PFAS (per- and polyfluoroalkyl substances). PFAS are manufactured for a variety of industrial purposes. If detected in drinking water, PFAS can potentially raise health concerns.

About PFAS

PFAS are chemicals used in industrial and consumer products, such as carpeting, clothing, upholstery, food paper wrappings, fire-fighting foams, and metal plating worldwide since the 1940s.

Some epidemiological studies suggest that exposure to PFAS increases cholesterol levels, reduces birth weight, and may increase rates of some types of cancers (kidney and testicular cancer).

The 2019 movie Dark Waters,” which is based on a true story, focuses on the use of PFAS in the United States and how these “forever chemicals” are found in everything from clothing to drinking water and, subsequently, the human bloodstream. The chemicals do not biodegrade, can accumulate in water bodies, and have potentially serious health consequences.

Monitoring Efforts

Currently, PFAS are not regulated contaminants, and routine monitoring is not required. Still, Skagit PUD monitored for six types of PFAS in 2014-2015 (under the Environmental Protection Agency’s third Unregulated Contaminant Monitoring Rule) in our Judy Reservoir water system serving Mount Vernon, Sedro-Woolley, and Burlington. Test results show no detection (ND) of these chemicals in the Judy Reservoir water.

Perfluorinated Compound Name Acronym Unit 08/2014 Results 11/2014 Results 02/2015 Results 05/2015 Results
Perfluorooctanesulfonic acid PFOS ug/L ND ND ND ND
Perfluorooctanoic acid PFOA ug/L ND ND ND ND
Perfluorononanoic acid PFNA ug/L ND ND ND ND
Perfluorohexanesulfonic acid PFHXS ug/L ND ND ND ND
Perfluoroheptanoic acid PFHPA ug/L ND ND ND ND
Perfluorobutanesulfonic acid PFBS ug/L ND ND ND ND


  • Washington Department of Health has proposed to adopt a state action level for PFAS and is currently open for stakeholder comments.
  • Detailed information regarding PFAS can be found on the EPA website.
  • Skagit PUD is committed to protecting the Judy Reservoir watershed and prohibiting any activities that can introduce PFAS compounds or other contaminants in the source water.
  • Map of PFAS Contamination in the U.S.