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The City of Portland, Oregon

Portland Water Bureau

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Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)

Perfluoroalkyl and polyfluoroalkyl substances (PFAS), sometimes also referred to as perfluorinated compounds (PFCs), are human-made chemicals that have a wide variety of uses. Some PFAS, such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are known to be harmful to human health. PFAS are not currently regulated in drinking water by the Environmental Protection Agency or the state of Oregon. PFAS have not been detected in Portland’s drinking water.

In 2016, the Environmental Protection Agency released a health advisory level for PFOA and PFOS. Health advisory levels are non-enforceable guidelines that are intended to protect human health. The health advisory level is 0.07 parts per billion (ppb) for PFOA and PFOS combined.

Historically, PFOA and PFOS were used in firefighting foams, fabric protectants, food packaging, and manufacturing processes. Between 2000 and 2015, manufacturers of PFOA and PFOS voluntarily phased them out of production in the United States. Regulations allow PFOS to be imported for specialty uses where alternative chemicals cannot be identified.

PFOA and PFOS are highly soluble and do not break down in the environment. Fire training facilities, especially those at airfields, have been sources of PFAS contamination because of their use of firefighting foam.  

Between 2014 and 2015, the Portland Water Bureau monitored for six PFAS, including PFOA and PFOS, in drinking water from the Bull Run Watershed and Columbia South Shore Well Field. These samples were collected as part of the third round of monitoring for the Unregulated Contaminant Monitoring Rule (UCMR 3), which required the Water Bureau to monitor for contaminants like PFAS. Two samples were collected at the Columbia South Shore Well Field groundwater entry point and four samples were collected at the Bull Run surface water entry point. PFAS were not detected in any of the samples.

Source Minimum Detection Limit Columbia South Shore Well Field Groundwater
Bull Run Surface Water

Collection Date   7/8/2014 6/17/2015 3/19/2014 6/26/2014 9/11/2014 12/10/2014
Perfluorooctanesulfonic acid (PFOS) 0.00230 ppb ND ND ND ND ND ND
Perfluoro-1-butanesulfonic acid (PFBS) 0.00180 ppb ND ND ND ND ND ND
Perfluoro-1-hexanesulfonic acid (PFHxS) 0.00200 ppb ND ND ND ND ND ND
Perfluoroheptanoic acid (PFHpA) 0.00310 ppb ND ND ND ND ND ND
Perfluoro-n-nonanoic acid (PFNA) 0.00220 ppb ND ND ND ND ND ND
Perfluorooctanoic acid (PFOA) 0.00220 ppb ND ND ND ND ND ND


Minimum Detection Limit: the lowest amount the laboratory equipment can detect

ppb: parts per billion

ND: not detected in the sample


For more information on PFAS:

EPA health advisory level for PFOS and PFOA

UCMR3 Information from the EPA