Per- and Polyfluoroalkyl Substances (PFAS)

Water drops on a Teflon coated pan

Milwaukie, like many communities in Oregon and across the nation, is addressing an emerging issue with per-and polyfluoroalkyl (PFAS) substances. In recognition of this, Milwaukie proactively began testing monitoring wells in 2023. In 2024, the city began a new program of testing and reporting for PFAS in drinking water. 

Overview

Since the 1940s, PFAS have been used around the world in industry and in consumer products such as food packaging, non-stick cookware, waterproof clothing, stain-resistant fabrics, and firefighting foam. These synthetic chemicals can enter the environment and water supplies from multiple sources and do not break down easily, which is why PFAS are sometimes called “forever chemicals.” There is evidence that continued exposure to PFAS can cause adverse health effects. More information can be found on the EPA's website

Detection

Below is a brief history of the city’s sampling efforts to better understand potential PFAS impacts. 

  • 2013 PFAS Sampling Non-Detectable:The city sampled for PFAS in all wells and hired an independent, certified lab to test for six different PFAS. All results showed PFAS were not present at detectable levels. The city performed this testing in compliance with EPA’s Unregulated Contaminant Monitoring Rule to collect data for substances that may be present in drinking water but are not yet regulated under the Safe Drinking Water Act. 
  • Summer 2023 PFAS Sampling Low Levels Detected:Although not required by federal or state standards, the city tested for PFAS in a monitoring well using a newer EPA method. Low levels of PFAS were detected and were below OHA’s Health Advisory Level at that time.  

In 2021, the State of Oregon established a combined health advisory limit (HAL) for PFOS, PFOA, PFNA, and PFHxS of 30 parts per trillion (ppt). In June of 2023, in response to new revelations about PFAS contamination in other parts of the country, Milwaukie sampled water from a monitoring well to determine if PFAS were present.  This sample indicated the presence of PFAS in the monitoring well, though none of the samples taken from the monitoring wells exceeded the Oregon Health Authority (OHA) health advisory level of 30 ppt.   

In January 2024, the city took additional samples and expanded the locations of sampling to additional monitoring wells.  These samples also detected the presence of PFAS. These wells were installed to monitor potential sources of contamination from previous industrial activities.    

The EPA’s fifth Unregulated Contaminant Monitoring Rule (UCMR, required monitoring for 29 PFAS compounds. Milwaukie proactively took samples for this in February 2024 and detected results in two of the samples that slightly exceeded the April 2024 adopted standard of 4.0 ppt.  Results from this February 2024 sampling are shown below.   

PFAS Sampling results for February 2024
Per- and Polyfluoroalkyl Substances (PFAS) February 2024
  Location Sampled
Substance Unit

Oregon Health
Advisory Level (HAL)

Adopted New
MCL*
Upper Treatment
Plant
Lower Treatment
Plant
Stanley 
Well 6
Perfluorooctanoic acid (PFOA) ppt** 30 ppt 4 ppt Not Detected Not Detected Not Detected
Perfluorooctanesulfonic acid (PFOA) ppt 30 ppt 4 ppt 4.5 6.3 Not Detected

*MCL = maximum contaminant level

**ppt = parts per trillion (1 ppt is equivalent to a single drop of water in 20 Olympic-sized swimming pools)