Biosolids. Biosolids are nutrient-rich organic materials resulting from processing domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth.

Under federal law, there are different rules for different classes of biosolids. Class A biosolids contain no detectable levels of pathogens. When used in bulk, Class A biosolids are subject to buffer requirements, but not to crop-harvesting restrictions.

The Department of Ecology (Ecology) implements the state's Biosolid Management Program. The rules for the program address how and when biosolids can be applied to land as a fertilizer. These rules also deal with matters such as total pollution concentration limits, pathogen reduction rates, and vector attraction reduction requirements.

Perfluoroalkyl and Polyfluoroalkyl Chemicals. Perfluoroalkyl and polyfluoroalkyl (PFAS) chemicals are characterized by their resistance to oil, stains, grease, and water, as well as their durability, heat resistance, and anti-corrosive properties. Ecology has identified PFAS chemicals as persistent, bioaccumulative, and toxic. They are added to carpets, cookware, food packaging, clothing, cosmetics, and other common consumer products. PFAS chemicals have many industrial applications and are used to make certain types of firefighting foams. 

Washington State has enacted laws and adopted regulations relating to PFAS levels in drinking water, firefighting foam and equipment, food packaging, and consumer products.

In 2021, the United States Environmental Protection Agency (EPA) announced the agency's PFAS Strategic Roadmap, laying out the agency's approach to addressing PFAS chemicals. The roadmap sets timelines by which EPA plans to take specific actions and commits to new policies to safeguard public health, protect the environment, and hold polluters accountable. As part of the roadmap work, EPA is conducting a biosolids risk assessment for two PFAS compounds, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), in biosolids. EPA plans to complete the risk assessment for PFOA and PFOS by December 2024.

Ecology must adopt rules to require written notice be provided to owners of properties adjacent to a land application site before land application of bulk biosolids may be approved.

"Bulk biosolids" means biosolids that are not sold or given away in a bag or other container holding less than one metric ton for application to land.

The state Biosolid Management Program must require a transporter of bulk biosolids to carry a manifest or similar document specifying that the transporter is transporting biosolids regulated under the state program.

By July 1, 2025, Ecology must establish pollutant limits for PFAS chemicals in biosolids, based on the results of EPA's risk assessment for PFAS chemicals in biosolids.

The state's Biosolid Management Program must ensure that biosolids are tested for PFAS chemicals for which a pollutant limit has been established by Ecology. The test results must be recorded and made available to the public.

Land application of biosolids that do not comply with a PFAS chemical pollutant limit is prohibited.

Ecology must publish and maintain a publicly accessible online map or list of the location of parcels where bulk biosolids have been approved for land application.