PFAS in biosolids legislation
Senate Bill 5033 was signed into law on May 17, 2025. This new law introduces sampling and analysis requirements for Per- and Polyfluoroalkyl Substances (PFAS) for facilities regulated under the Biosolids General Permit. Ecology must develop guidance to clarify the sampling requirements.
Legislation summary
Once this law is implemented, facilities must sample their biosolids for a period of time and have them analyzed by an accredited laboratory using EPA method 1633A. Ecology is required to develop PFAS biosolids sampling guidance to clarify requirements, including frequency of sampling.
We must then analyze the data received from facilities and compile a summary report of the levels of PFAS found in biosolids generated and/or land-applied in Washington state. While drafting the report, we must use the analysis and consult with an advisory committee to develop recommended next steps. This report will be made available to the legislature and public.
Timeline
| July 1, 2025 – June 30, 2026 | Ecology seeks input on sampling guidance requirements. |
| July 1, 2026 | Ecology publishes guidance clarifying sampling requirements. |
| Jan. 1, 2027 – June 30, 2028 | Facilities must sample certain biosolids for PFAS chemicals using EPA method 1633A, starting no later than Jan. 1, 2027 and ending June 30, 2028. |
| Sept. 30, 2028 | Facilities must provide all sampling results to Ecology. |
| Oct. 1, 2028 – March 31, 2029 | Ecology analyzes the levels of PFAS chemicals in biosolids produced in and/or land applied in Washington, establishes and consults with an advisory committee to develop recommended next steps based on the analysis, and drafts the legislative report. |
| July 1, 2029 |
Ecology submits the report to the legislature and the public. |
Contact information
Biosolids team
biosolids@ecy.wa.gov