PFAS | Regulatory Insight

In July 2026, the U.S. Environmental Protection Agency (EPA) released proposed guidance for reducing potential risks from PFOA and PFOS in biosolids. If finalized, the guidance would provide voluntary recommendations to operators of wastewater treatment plants (WWTP), farmers, landowners, state and Tribal water agencies, and the public regarding potential ways to mitigate risks from PFOA and PFOS when managing sewage sludge and biosolids. The guidance is currently open for a 60-day public comment period, ending on September 4, 2026.

Sewage sludge and biosolids are created during the treatment of sewage at WWTP, which separates the liquid from solids. EPA defines “biosolids” as sewage sludge intended to be applied as a soil amendment or fertilizer and treated to meet applicable Clean Water Act (40 CFR Part 503) requirements.

In 2019, EPA announced plans to evaluate the potential human health and environmental risks associated with PFOA- and PFOS-contaminated sewage sludge. In January 2025, EPA released a Draft Risk Assessment addressing the potential human health risks associated with PFOA and PFOS in biosolids and sewage sludge.

In the new proposed guidance, EPA states that the 2025 Draft Risk Assessment contained several limitations that caused confusion among the public and regulatory community. EPA specifically points to the absence of a national sewage sludge survey conducted alongside the assessment; the focus on higher-exposure hypothetical scenarios that EPA now says do not represent the majority of U.S. land application; and confusion surrounding the use of 1 ppb as the modeled starting concentration for PFOA and PFOS.

Importantly, EPA has clarified that the 1-ppb concentration was used as a starting point to model potential risks under specific hypothetical exposure scenarios, not as a threshold for determining whether PFOA or PFOS concentrations in sewage sludge are safe or unsafe. This clarification also reflects an important distinction between assessing potential risks to individuals who may experience unusually high exposures at specific sites and evaluating potential impacts across the general U.S. population.

EPA emphasizes that current data do not indicate widespread national food-supply impacts from the use of biosolids containing PFOA and PFOS; sewage sludge is estimated to be land applied to less than 1% of U.S. farmland. At the same time, nearly 60% of sewage sludge is used in land applications in some form, underscoring the importance of land application as a management option for wastewater utilities and agricultural users.

How RHP Risk Management Can Help

Whether you’re responding to new regulations, evaluating potential liabilities, supporting product stewardship initiatives, or preparing for litigation, RHP’s Human Health Risk Sciences (HHRS) provides scientific expertise across the entire decision-making process.

Our scientists develop hazard summaries, evaluate toxicokinetic and dose-response considerations, assess epidemiological evidence for causality, and tailor PFAS risk communications for technical and nontechnical audiences.

To discuss a PFAS or biosolids risk question, contact RHP Risk Management or call (866) 481-8188.