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The City of Portland, Oregon

Portland Water Bureau

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Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)

Portland Water is closely tracking the news about detections of PFAS in drinking water around the country. Fortunately, Portland’s drinking water is at low risk for PFAS and PFAS have not been detected in Portland’s drinking water sources, the Bull Run Watershed and the Columbia South Shore Well Field. Portland Water will continue to monitor its drinking water sources for PFAS and maintain its robust source water protection programs.

What are PFAS?

PFAS are a large group of human-made chemicals that have historically been used in a variety of ways, including in firefighting foams or to make consumer goods non-stick, water-repellent, or stain-repellent. Some of these chemicals are now known to be harmful to human health

What are the sources of PFAS in drinking water?

Around the country, PFAS contamination of drinking water sources has typically been due to a specific location where large amounts of PFAS have been released into the environment over time. This includes industries that manufacture PFAS or apply PFAS to consumer goods, and facilities that use certain types of firefighting foam, such as airports, military bases, and fire department training facilities. 

Are there known sources of PFAS near Portland’s water supplies?

Portland Water’s primary source of drinking water, the Bull Run Watershed, is highly protected with no known sources of PFAS in or around the watershed.

Portland Water is aware of three sites in or near the Columbia South Shore Well Field that have historically used firefighting foams that contain PFAS: Portland International Airport; Portland Air National Guard Base; and a Portland Fire and Rescue training facility. PFAS have been found in the shallow groundwater aquifers just below the surface at all of these sites. Portland Water does not use the aquifers in the areas where PFAS have been found as sources of drinking water.

The Portland International Airport and Portland Air National Guard sites are outside of the Columbia South Shore Well Field wellhead protection area and pose a low risk to Portland’s drinking water. The Portland Fire and Rescue training facility is located within the Columbia South Shore Well Field but is also considered to pose a low risk to Portland’s drinking water. Drinking water from this area of the well field is drawn from deeper aquifers that are physically separated from the shallow aquifers by thick layers of silt and clay, called confining units. The PFAS in the shallow groundwater at this site are not expected to affect public water supplies, and PWB has tested the deep well closest to the site, which was free of PFAS. Portland Water will continue working to understand the extent of the shallow groundwater contamination at these sites and take the necessary steps to ensure Portland’s water supply remains protected.

What is Portland doing to protect our drinking water from PFAS?

Portland Water is committed to protecting the health of the Portland community. Through its Groundwater Protection Program, Portland Water is taking active steps to protect Portland’s drinking water from PFAS contamination. These include:

  • Monitoring and testing groundwater aquifers and the drinking water served to Portlanders;
  • Working to identify potential PFAS sources in collaboration with the Oregon Department of Environmental Quality, who leads investigation and clean-up efforts of groundwater contamination sites; and
  • Regulating and providing technical assistance to facilities that manage hazardous materials within the Columbia South Shore Well Field in order to prevent releases to groundwater.

What are the results of Portland’s previous drinking water testing?

In 2014 and 2015, Portland Water tested for six types of PFAS in drinking water from the Bull Run Watershed and Columbia South Shore Well Field (CSSWF). The EPA required drinking water utilities around the country, including Portland Water, to test for PFAS as part the Unregulated Contaminant Monitoring Rule (UCMR 3)PFAS were not detected in any of the samples.

UCMR3 PFAS Results

Source Minimum Detection Limit CSSWF Groundwater Entry Point
Bull Run Surface Water Entry Point

Collection Date   7/8/2014 6/17/2015 3/19/2014 6/26/2014 9/11/2014 12/10/2014
Perfluorooctanesulfonic acid (PFOS) 2.3 ppt ND ND ND ND ND ND
Perfluorobutanesulfonic acid (PFBS) 1.8 ppt ND ND ND ND ND ND
Perfluorohexanesulfonic acid (PFHxS) 2.0 ppt ND ND ND ND ND ND
Perfluoroheptanoic acid (PFHpA) 3.1 ppt ND ND ND ND ND ND
Perfluorononanoic acid (PFNA) 2.2 ppt ND ND ND ND ND ND
Perfluorooctanoic acid (PFOA) 2.2 ppt ND ND ND ND ND ND


  • Minimum Detection Limit: the lowest amount the laboratory equipment can detect
  • ppt: parts per trillion
  • ND: not detected in the sample


Additionally, Portland Water tested groundwater from a deep drinking water well that is adjacent to the Portland Fire and Rescue training site in 2018. None of the 12 PFAS tested for were detected in the water sample.

What can customers do?

Portland Water encourages all of its customers to learn more about our water resources and what they can do to help protect Portland’s groundwater source. It is everyone’s responsibility to use chemicals responsibly and protect groundwater quality. Learn more on Portland’s How You Can Help Groundwater page, or attend one of Portland Water’s groundwater special events