PFAS are a large group of manufactured chemicals, most of which never disappear from the environment. Studies have shown that some PFAS chemicals are toxic to humans and the environment, and PFAS have been found in some drinking water supplies in Washington.
In June 2022, we concluded PFAS are hazardous substances under the Model Toxics Cleanup Program, or MTCA (often pronounced "Motca"), Washington's environmental cleanup law. This means any PFAS releases need to be assessed for cleanup.
We now have preliminary soil and groundwater cleanup levels for six of the most common PFAS compounds. This draft guidance provides the cleanup levels and gives potentially liable persons, cleanup project managers, and consultants a practical approach for cleaning up PFAS contamination at Washington sites under MTCA.
This guidance is intended for people involved in cleaning up contaminated properties. It provides information and direction on:
- Known PFAS impacts across Washington.
- Preliminary soil and groundwater cleanup levels.
- Sampling options for PFAS compounds.
- Approaches to minimize cross-contamination.
- Protective concentrations for ecological receptors.
- Field-demonstrated treatment technologies.
This guidance will apply to both cleanups supervised or conducted by us and independent cleanup actions.