PFAS (PFOS, PFOA, PFNA, PFBS, PFHxS, GenX)

Background

Hand holding water sample tubeCommonly found substances within the per- and polyfluoroalkyl substances (PFAS) family of compounds are PFOS, PFOA, PFNA, PFBS, PFHxS, and GenX. These are manmade compounds that have been used to make carpets, clothing, fabrics for furniture, paper packaging for food, and other materials (e.g., cookware) that are resistant to water, grease, or stains. They are also used in a number of industrial processes and in firefighting foam.

In March 2023, the U.S. Environmental Protection Agency (EPA) announced a proposed national primary drinking water regulation for these types of PFAS. The proposed regulation calls for a maximum contaminant level (MCL) for PFOS and PFOA of 4 parts per trillion (ppt) each. PFNA, PFHxS, PFBS, and GenX would have a combined hazard index limit of 1.0; the hazard index calculation would determine if the levels of these PFAS as a mixture pose a potential risk.

Previously, in June 2022, EPA announced reduced Health Advisory (HA) levels of 0.02 parts per trillion (ppt) for PFOS and 0.004 ppt for PFOA. The prior HA level was 70 ppt for PFOS/PFOA combined. EPA also established HAs for PFBS of 2,000 ppt and GenX of 10 ppt.

HAs are non-enforceable, non-regulatory guidelines under which there is no expected risk to health to all people, including sensitive populations, over a lifetime of exposure. The advisories, which offer a margin of protection, also take into account exposure through other sources beyond drinking water. However, they do not take into account technological and economic feasibility of testing and treatment.

Additionally, the State of Washington has an “action level” for five of the above PFAS substances and directed most water suppliers to begin testing between 2023-2025. An action level is the level at which a supplier should make operational changes to protect normal consumers over a lifetime of consumption or sensitive populations over a shorter period. Action levels for PFAS substances are: PFOA—10 ppt, PFOS, 15 ppt, PFNA—9 ppt, PFHxS—65 ppt, and PFBS—345 ppt.

How Washington Water is Protecting Our Customers

Technician preparing to test water sampleProtecting our customers’ health and safety is our highest priority, and Washington Water is committed to complying with all standards set by the public health experts. We are currently evaluating the impact of the proposed regulation on our systems and any treatment required should the regulation be adopted as proposed. We are also in the process of testing every active source in our systems now, so that we can better prepare to meet any eventual MCL set. In cases where detections are above the levels at which state public health experts have recommended water suppliers take action, we are taking the affected sources out of service until treatment is installed.

Studies indicate that long-term exposure to PFAS over certain levels could have adverse health effects, including developmental effects to fetuses during pregnancy or breastfed infants; cancer; or liver, immunity, thyroid, and other effects. Potential health impacts related to PFAS from all sources (which also include food wrappers, firefighting foam, and non-stick cookware, for example) are still being studied, and research is still evolving on this issue.

We believe a comprehensive approach is needed to properly address the situation. We support the EPA’s establishment of a consistent, science-based standard. We have also filed a lawsuit to hold the manufacturers of the compounds responsible and prevent our customers ultimately from having to bear the costs of treatment, to the extent possible, and are seeking grants to help further offset treatment costs.

This does shed light on the importance of protecting our water resources. While we are doing our part to treat the water and meet the standards the public health experts have set, it’s important that our population as a whole focuses on being good stewards of the environment and takes steps to prevent impacting the water supply.

More information on EPA’s proposed regulation is available in its March 14, 2023 press release.

Artondale system customers: Get details about information mailed to you in September 2023.
Classic Heights system customers: Get details regarding the letter sent to you in December 2023.

Common Names

  • PFOS: perfluoroctanesulfonic acid and perfluoroctylsulfonic acid
  • PFOA: perfluorocaprylic acid, perfluoroctanoic acid, and perfluoroheptanecarboxylic acid
  • PFNA: perfluorononanoic acid
  • PFBS: perfluorobutane sulfonic acid and potassium perfluorobutane sulfonate (together)
  • PFHxS: perfluorohexane sulfonic acid
  • GenX: hexafluoropropylene oxide dimer acid & its ammonium salt