Drinking Water and Per- and Polyfluoroalkyl Substances (PFAS)

Lake Oswego currently meets or exceeds all federal and state requirements for water quality testing. PFAS is an emerging issue that all water providers and systems across the nation are experiencing. The City is closely tracking news about detections of PFAS in drinking water around the country, as well as the EPA’s newly proposed PFAS drinking water regulations. We are committed to protecting public health.

Fortunately, Lake Oswego and Tigard’s drinking water is at low risk for PFAS, and PFAS have not been detected in our drinking water from the Clackamas River.

What are PFAS?

Per- and Polyfluoroalkyl substances (PFAS) are a group of human-made chemicals found in a wide range of industry and consumer products. PFAS have been widely used by manufacturers since the 1940s and remain in the environment for a long time. These chemicals provide grease- and water-resistant properties in many everyday products. Some examples of products include:

  • Non-stick pans
  • Stain-resistant fabric
  • Firefighting foam
  • Some waxes
  • Waterproof rainwear
  • Paper food packaging

Why are PFAS a concern?

PFAS do not break down easily, which means they stay in the environment. Some of the chemicals are now known to be harmful to human health.

Are PFAS regulated for drinking water?

No, PFAS are currently not regulated at local, state or national levels. There currently are no federal (EPA) or state (OHA) drinking water standards for PFAS, and they have not been formally regulated by federal agencies that control hazardous pollutants in water, land or air.

PFAS drinking water results for Lake Oswego and Tigard

In 2013-2015, as part of EPA’s Unregulated Contaminant Monitoring Rule, all water systems in Oregon were required to test for PFAS. PFAS were not detected in any of the samples for Clackamas River water providers – Lake Oswego and Tigard are currently scheduled to start monitoring regularly for PFAS in the fall of 2023. In anticipation of this, the Lake Oswego-Tigard Water Partnership tested their drinking water source – the Clackamas River - in May 2023. PFAS were not detected.

What is being done about PFAS?

In April 2023, the EPA proposed a National Primary Drinking Water Regulation for six types of PFAS known to occur in drinking water. The proposed rule does not require any action until finalized, but if approved, it would set enforceable levels of PFAS in drinking water and require all public water systems to monitor for PFAS, notify the public of the levels, and reduce the levels of PFAS if they exceed the proposed standards.

How are Lake Oswego and Tigard protecting our drinking water from PFAS?

The best way to keep drinking water safe is to protect it at its source. In partnership with the Clackamas River Water Providers, a coalition of water providers that get their water from the Clackamas River, the cities of Lake Oswego and Tigard fund and participate in a source water protection and monitoring program.  Through this program, we are working proactively with our local partners on everything from spill response to pesticide collection events, and drinking watershed awareness to keep unwanted chemicals out of our water supply.


To learn more about PFAS, click on the helpful links included on the right hand side bar. 

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