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.  While both classes are treated, class A biosolids contain no detectable levels of pathogens, but class B biosolids may.  When used in bulk, class A biosolids are subject to buffer requirements but not to crop-harvesting restrictions.  In general, class B biosolids are subject to buffer requirements, public access requirements, and crop harvesting restrictions.

Biosolids Management Program.  The Department of Ecology (Ecology) administers a biosolids management program (program).  Rules for the program address how and when biosolids can be applied to land as a fertilizer.  These rules include other requirements of biosolids, including total pollution concentration limits, pathogen reduction rates, and vector attraction reduction requirements.

Perfluoroalkyl and Polyfluoroalkyl Chemicals.  Perfluoroalkyl and Polyfluoroalkyl (PFAS) chemicals, sometimes called forever chemicals, are a class of fluorinated organic chemicals that contain at least one fully-fluorinated carbon atom.  PFAS chemicals are characterized by their resistance to oil, stains, grease, and water, in addition to their durability, heat resistance, and anti-corrosive properties.  They are added to carpets, cookware, food packaging, clothing, cosmetics, and other common consumer products.  PFAS chemicals are also included in certain types of firefighting foams.

State Developments.  Ecology identifies PFAS chemicals as persistent, bioaccumulative, and toxic.  In November 2024, Ecology and the Washington State Department of Health released a statewide funding strategy for future projects addressing PFAS chemicals in drinking water, environmental contamination, and waste.   In recent years, Washington State has enacted laws and adopted regulations relating to PFAS chemicals levels in drinking water, firefighting foam and equipment, food packaging, and many consumer products.

Federal Developments.  In 2021, the United States Environmental Protection Agency (EPA) first announced its PFAS Strategic Roadmap, laying out the agency's approach to addressing PFAS chemicals.  On January 14, 2025, EPA released a draft risk assessment for two PFAS compounds:  perfluorooctanoic acid (PFOA) and perfluoroctane sulfonic acid (PFOS).  EPA stated the result of the assessment indicates there are potential risks to human health to those living on or near impacted properties or primarily relying on their products from land application and surface disposal of sewage sludge containing PFOA and PFOS, depending on chemical concentration, chemical management practice, and local and geological conditions.

EPA also designated PFOA and PFOS as hazardous substances and set maximum contamination limits for these PFAS chemicals in drinking water.

National Pollutant Discharge Elimination System.  Ecology has delegated authority from EPA to administer the Clean Water Act in Washington.  Ecology issues National Pollutant Discharge Elimination System (NPDES) wastewater discharge permits to facilities in the state, except to federally-owned facilities and facilities on tribal lands, which are issued by EPA.  NPDES permits regulate discharges to surface water from commercial industry and publicly-owned treatment works, also referred to as municipal wastewater treatment facilities.  NPDES permits limit the quantity and concentration of contaminants that may be discharged.  Permits may also require wastewater treatment or impose operating or other conditions, including monitoring, reporting, and spill prevention planning.

Ecology must convene an advisory committee with representatives from the farming community, toxicologists, utilities that produce soil amendments, experts, interested parties, and other similar stakeholders (advisory committee).

By July 1, 2027, after consulting with the advisory committee, Ecology must establish PFAS chemicals sampling or testing requirements for biosolids regulated under the program.  By July 1, 2028, Ecology must complete an analysis of the levels of PFAS chemicals in biosolids produced in Washington.

By December 1, 2028, Ecology must submit a report to the Legislature and the public with a summary of the analysis and recommendations on how to proceed based on the analysis.

For the purposes of Ecology establishing PFAS chemicals sampling or testing requirements and reporting recommendations, biosolids do not include septic tank sludge, also known as septage.

Nothing in the act affects requirements imposed on a discharger by a NPDES permit or restricts a local government from addressing the contamination of biosolids by PFAS chemicals.