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Per - and Polyfluoroalkyl Substances (PFAS)

Per- and Polyfluoroalkyl Substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) are a group of thousands of different chemicals that have been manufactured and used in a variety of commercial products since the 1940s – from everyday household items to food packaging – due to their heat, moisture, stain resistance, and non-stick qualities.  PFOS and PFOA have been the most extensively produced and studied of these chemicals, followed by PFHxS and PFNA.  These chemicals do not break down in the environment or human body and can accumulate over time.  There is evidence that exposure to certain PFAS can lead to adverse human health effects.  For more information on exposure routes and health effects, see the OHA Environmental Public Health PFAS webpage

Final PFAS Drinking Water Regulation
EPA released the final National Primary drinking water regulation for six PFAS on April 10, 2024. The rule establishes individual maximum contaminant levels (MCLs) for five PFAS and a hazard index MCL for a mixture of four PFAS. For more information on the new PFAS drinking water rule, see EPA's Final PFAS National Primary Drinking Water Regulation web page. For more information on adoption of the new PFAS rule in Oregon, see the OHA-DWS PFAS Rule web page

PFAS Monitoring by Public Water Systems in Oregon

Third Unregulated Contaminant Monitoring Rule (UCMR3)

Six PFAS compounds (PFOS, PFOA, PFNA, PFHxS, PFHpA, and PFBS ) were among the list of contaminants that public water systems were required to monitor for under the third Unregulated Contaminant Monitoring Rule (UCMR3). All public water systems nationwide serving more than 10,000 people and 800 representative systems serving 10,000 or fewer people monitored for these and other unregulated contaminants during a 12-month period from January 2013 through December 2015. In Oregon, 65 public water systems monitored for these PFAS contaminants and there were no detections reported.


Fifth Unregulated Contaminant Monitoring Rule (UCMR5)

EPA’s Fifth Unregulated Contaminant Monitoring Rule (UCMR5) requires sample collection and analysis for 29 PFAS compounds and lithium between 2023 and 2025. In Oregon, a total of 127 public water systems will be monitoring under UCMR5. OHA follows up with public water systems that have UCMR5 PFAS detections by providing information on how the results compare to state/federal health advisory levels and proposed regulations, reporting requirements to customers, and information on available funding to address the contaminant. More information about UCMR5 can be found on EPA’s Fifth Unregulated Contaminant Monitoring Rule web page

OHA PFAS Sampling Project

OHA conducted a PFAS drinking water monitoring project in 2021 through 2023 at public water systems in Oregon identified as at risk due to their proximity to a known or suspected PFAS use or contamination site. The purpose of this sampling project was to make sure customers are not being exposed to potentially harmful PFAS chemicals in their drinking water. The analysis was paid for through an EPA grant and was done at no cost to the water system. The Oregon Department of Environmental Quality lab analyzed 195 drinking water samples from 143 public water systems for 24 PFAS compounds using EPA Method 533. A list of the PFAS compounds included in Method 533 can be found here under the “Method 533” column.   


Labs for PFAS Analysis in Drinking Water

Public water systems that are interested in testing for PFAS in their drinking water should use a lab that is accredited by the Oregon Environmental Laboratory Accreditation Program (ORELAP) and analyze the sample using EPA method 533 or 537.1. See below for a list of ORELAP-accredited labs for the analysis of PFAS in drinking water:


For more information: