PFAS at cleanup sites
PFAS (Per- and polyfluoroalkyl substances) are a family of manufactured chemicals, most of which never disappear from the environment. They're used to make products resistant to oil and water, or to reduce friction. PFAS are a common ingredient in consumer products.
Studies have shown that some PFAS chemicals are toxic to humans and the environment. In Washington, PFAS have contaminated some drinking water supplies. To date, most of this contamination has been linked to the use of PFAS in firefighting foam. PFAS have also been detected in surface waters, groundwater, wastewater treatment plant effluent, compost, freshwater and marine sediments, freshwater fish tissue, and osprey eggs in Washington.
Current and past releases of PFAS compounds must be reported to Ecology and contaminated sites must be cleaned up.
Regulating PFAS
Ecology has concluded that Per- and polyfluoroalkyl substances (PFAS) fall under the Model Toxics Control Act (MTCA). This conclusion is based on an evaluation of existing regulatory authority which says that compounds considered hazardous substances under the Dangerous Waste regulations or the Hazardous Waste statutes are also hazardous substances under MTCA.
In April 2024 the EPA released maximum contaminant levels (MCLs) for the following PFAS chemicals:
- Perfluorooctanoic acid (PFOA)
- Perfluorooctane sulfonic acid (PFOS)
- Perfluorononanoic acid (PFNA)
- Perfluorohexane sulfonic acid (PFHxS)
- Hexafluoropropylene oxide—dimer acid (HFPO-DA, GenX)
- Perfluorbutane sulfonic acid (PFBS)*
*(The EPA didn't establish an individual MCL for PFBS. They did establish a MCL that requires calculating a hazard index for mixtures of PFNA, PFHxS, HFPO-DA and PFBS. All but PFBS also have individual MCLs.)
Investigating & Remediating PFAS Contamination in Washington State
Ecology is applying the maximum contaminant levels as federal requirements along with our risk-based levels, which are calculated to protect people's drinking water. We added the maximum contaminant levels to our Cleanup Levels and Risk Calculation (CLARC) resource, which also has the most up-to-date PFAS cleanup levels for other media. CLARC is a collection of technical information about chemicals useful for calculating cleanup levels under Washington's cleanup rule.
In June 2023, we published Guidance for Investigating and Remediating PFAS Contamination in Washington State. This guidance provides information and direction on:
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Known PFAS impacts across Washington
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Sampling options for PFAS compounds
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Approaches to minimize cross-contamination
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Protective concentrations for ecological receptors, and
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Field demonstrated treatment technologies.
NOTE: Some of the soil and groundwater cleanup levels in the guidance are out of date. Please see the current version of CLARC for up-to-date cleanup levels.
We accepted public comments on the draft guidance from Dec. 15, 2022 to March 3, 2023. The final guidance contains the comments we received, as well as our responses. It also explains how we determined the appropriate cleanup levels and how they apply to individual sites.
A long-term problem
Although Washington has made progress in dealing with PFAS, this is a long-term problem. Efforts to reduce the use of PFAS and to prevent additional releases into the environment will continue to require resources into the future. We are working with other agencies, the public, and stakeholders to figure out the best way to clean up source areas and reduce exposures.
PFAS releases into the environment
If PFAS compounds are released to the environment and might pose a threat to human health or the environment, they must be reported to Ecology within 90 days of discovery. As with releases of other hazardous substances, the next step will often be an assessment of whether further action is necessary. If so, follow-up is usually a site investigation and, if needed, a cleanup.
Related links
Contact information
Bonnie Brooks
Toxicologist
bonnie.brooks@ecy.wa.gov
360-584-8856