Per- and Polyfluoroalkyl Substances (PFAS) and your Drinking Water

¹On March 14, 2023, EPA announced a proposed NPDWR for six PFAS (GenX chemicals, PFBS, PFOS, PFOA, PFHxS, and PFNA). After EPA has considered public comments and publishes a final PFAS NPDWR, EPA will update the reference concentrations for these six PFAS as appropriate

²ppt: Parts per Trillion, equivalent to two drops of water in an Olympic-sized swimming pool

³ Hazard Index: A unitless value that represents additive health risk from chemical mixtures

Per- and polyfluoroalkyl substances (PFAS) are human-made chemicals that have been used in various industry and consumer products since the 1940s, including: 

• Fire suppression foams 
• Electroplating 
• Non-stick cookware 
• Water-repellent clothing 
• Stain resistant fabrics and carpets 
• Products that resist grease, water, and oil 
• Cosmetics and personal care products.  

During production and use, PFAS can migrate into the soil, water, and air. Different PFAS are now found together and in combinations (or mixtures) in the environment. PFAS can enter water in many ways, including discharges to rivers, lakes, and groundwater from manufacturing and processing facilities, as well as during industrial and commercial use. Contamination can also occur in proximity to airports, military installations, and other sites where PFAS have been produced or heavily used. 

Though some types of PFAS have largely been phased out of use due to health and environmental concerns, PFAS can still be found in the environment as they break down at extremely slow rates, which is why they are often referred to as “forever chemicals.” Exposure to these chemicals occurs by using products made with PFAS, consuming PFAS-contaminated water or food, or breathing air containing PFAS. Scientific studies have shown that exposure to certain types of PFAS may be linked to harmful health effects in humans and animals. While more research is still needed, we now know that persistent exposure to PFAS may: 

• Lead to negative health effects on pregnant people and in developing babies 
• Weaken a body’s ability to fight disease 
• An increased risk for some cancers or liver damage 
• Elevated cholesterol levels (which can increase the risk for heart attack or stroke) 

TVWD’s drinking water sources are low risk for PFAS contamination based on data collected to-date. In general, ground water systems close to known or suspected PFAS usage areas (such as certain types of manufacturing, military, or aviation related fire suppression foams) are most at risk for PFAS. Water supplied to the TVWD distribution system is almost exclusively surface water with only seasonal usage of groundwater.  

• As part of UCMR3, TVWD tested for PFAS over a 12-month period beginning in 2014 and ending in 2015. No PFAS were detected in our drinking water sources, including seasonal groundwater.
• PFAS testing was also performed from 2013 to 2015 for TVWD’s future Willamette River source through the cities currently using this water source, the Cities of Wilsonville and Sherwood. No PFAS compounds were detected. 
• As part of UCMR5, TVWD completed an expanded 12-month monitoring period for PFAS, which began in July 2023 and concluded in April 2024. No PFAS were detected in our drinking water sources during this period, including seasonal groundwater.

All regional drinking water providers must complete their monitoring for this expanded list of PFAS by the end of 2025 under the UCMR5 program, including the Cities of Wilsonville and Sherwood currently using the Willamette River as their source. TVWD will share these results as they become available from our supply partners.  

On April 10, 2024, EPA announced the final National Primary Drinking Water Regulation (NPDWR) for six PFAS including PFOA, PFOS, PFNA, HFPO-DA (commonly known as GenX Chemicals), PFHxS, and PFBS. The regulation requires public water systems to:

• Monitor for the six regulated PFAS;
• Notify the public of the levels of these PFAS; and
• Reduce the levels of these PFAS in drinking water if they exceed the proposed standards.

A recent news article suggests that detectable amounts of PFAS may be present in at least 45% of the United States drinking water supplies, according to a recently released multi-year study by the US Geological Survey (USGS). The data from the study indicate PFAS concentrations and the frequency of the detections varied greatly by region, with a significant number of detections occurring in drinking water supplied by groundwater in regions where military sites and/or certain types of manufacturing facilities are in close proximity to a municipal water source.   

The USGS study included at least ten sites in Oregon, representing public and private water supplies sourced from both surface and groundwater sources. A single 1.76 parts-pe- trillion (ppt) detection of PFHxA (a PFAS mixture) was found among the sites sampled in Oregon. While PFHxA is not included in the EPA’s proposed Maximum Contaminant Level (MCL), the concentration of PFHxA detected in the Oregon sample is below the 4.0 ppt MCL for PFOA and PFOS as individual contaminants and below the hazard index for PFAS mixtures. 

The USGS study does not provide an exact location for the single Oregon detection other than indicating it was from a public water supply in the Portland area. While the presence of a detection is concerning, we are reassured by the fact that it was a single low-level detection relative to the rest of the dataset from the study.