EPA’s Biosolids PFAS Risk Assessment
As the Environmental Protection Agency (EPA) continues to advance its understanding of the risk of “forever” chemicals on the drinking water, wastewater, solid waste and residuals front, it has released a first stage of its long-awaited risk assessment addressing PFAS in biosolids.
On January 14, 2025, the EPA released a draft risk assessment of the potential human health risks associated with the presence of toxic per- and polyfluoroalkyl substances (PFAS) chemicals in sewage sludge that is land applied as a soil conditioner or fertilizer (on agricultural, forested, and other lands), surface disposed, or incinerated (the Draft Sewage Sludge Risk Assessment for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS).
The draft risk assessment reflects the EPA’s latest scientific understanding of the potential risks to human health and the environment posed by the presence of PFAS chemicals in sewage sludge. The preliminary findings of the draft risk assessment indicate that there can be human health risks exceeding the EPA’s acceptable thresholds, sometimes by several orders of magnitude.
The EPA expects to publish a final risk assessment after reviewing public comments, and revising the draft risk assessment accordingly. Once finalized, the risk assessment will provide information on risk from use or disposal of sewage sludge and will inform the EPA’s potential future regulatory actions under the Clean Water Act (CWA).
If the final risk assessment indicates that there are risks above acceptable thresholds when using or disposing of sewage sludge, the EPA expects to propose a regulation under CWA section 405 to manage PFOA and/or PFOS in sewage sludge to protect public health and the environment. The results of the final risk assessment may be integrated with other considerations, such as economic costs and treatment feasibility, to reach decisions regarding the need for and practicability of implementing various risk reduction activities.
The EPA published a Fact Sheet on the Draft Risk Assessment for Wastewater Treatment Plants that can be found here, and public comments must be received by March 17, 2025.
This draft assessment is in line with the EPA’s PFAS Strategic Roadmap, under which the agency has already finalized the nation’s first drinking water standards for PFAS. Previously, as WGL has reported to our clients, in February 2024, the EPA added nine PFAS to the list of hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the Superfund law, and the EPA released its Maximum Contaminant Levels (MCLs) for drinking water by final rule published in April 2024.
WGL attorneys actively have been advising municipal clients on regulatory obligations and developing response strategies to address PFAS in permits, construction and regulatory enforcement since PFAS became a contaminant of emerging concern on the EPA’s drinking water landscape more than a decade ago. The presence of PFAS and how it impacts critical municipal functions will continue to present operational, fiscal and legal obligations for municipalities. WGL attorneys have led the way in providing educational programming for various national and regional industry associations as PFAS response becomes a growing obligation of government and their industry partners.
