PFAS, pretreatment, and biosolids: The growing challenge for water permitting
Per and polyfluoroalkyl substances (PFAS) pose one of the most urgent and complex challenges for wastewater systems in the United States. As federal agencies reconsider their regulatory strategies and states impose their own standards, publicly owned treatment works (POTWs) and the industries that discharge to them face increasing pressure to control PFAS at the source. These pressures affect pretreatment permits, industrial dischargers, and biosolids management, forming a rapidly evolving compliance landscape. Recent federal assessments and state actions show that PFAS in wastewater and biosolids is no longer a distant regulatory issue. It is a primary driver shaping future POTW permitting.
PFAS in POTW systems: A problem that starts upstream
PFAS enter POTWs through a mix of industrial wastewater, landfill leachate, household products, and consumer goods. Because PFAS are persistent and resistant to conventional treatment, they pass through biological processes largely unchanged. This means industrial contributors sending PFAS to a POTW can cause downstream compliance problems, even at low concentrations. EPA has emphasized that the best way to manage PFAS in wastewater is to prevent the chemicals from entering treatment systems in the first place, placing new attention on upstream industrial sources.
EPA’s 2025 trajectory indicates broader PFAS rulemaking is coming under several environmental statutes, including the Clean Water Act (CWA), Resource Conservation and Recovery Act, and Safe Drinking Water Act, although the federal landscape remains in flux. Still, agencies agree on one point: pretreatment programs will be an essential component of PFAS control.
Pretreatment permits: The first line of defense
Pretreatment permits regulate indirect dischargers, meaning industrial facilities that send wastewater to POTWs instead of directly to surface waters. These permits already manage pollutants that interfere with treatment or pass through into receiving waters. Now, PFAS has become a central focus.
States and POTWs are increasingly requiring:
- PFAS monitoring in industrial wastewater,
- Source identification surveys,
- Product substitution or process changes,
- Best management practices to reduce PFAS at the facility, and
- Local limits or prohibitions on PFAS discharges
EPA’s PFAS strategy specifically encourages states and POTWs to deploy all available pretreatment authorities to control PFAS at the source. This approach aligns with statements from EPA representatives asserting that upstream controls are one of the most effective tools for preventing PFAS from entering wastewater systems.
Biosolids under scrutiny: The impact of PFAS
The PFAS problem does not end with liquid effluent. It extends into biosolids, the treated sewage sludge generated by POTWs. In 2025, EPA released a Draft Sewage Sludge Risk Assessment evaluating risks associated with PFOS and PFOA in biosolids applied to land. The assessment found potential human health risks under certain scenarios when biosolid concentrations exceeded 1 part per billion. Although EPA emphasized the assessment is not a regulatory standard, many states immediately treated the value as a de facto limit for biosolid land application.
This rapid adoption has created a challenging environment for POTWs. Unless PFAS inputs from industrial sources are reduced, biosolid PFAS levels remain high, limiting disposal options such as:
- Agricultural land application,
- Composting,
- Surface disposal,
- Landfilling, and
- Incineration
Some states have already implemented bans or strict standards on biosolid land application due to PFAS concerns.
Regulatory uncertainty adds pressure
EPA’s PFAS regulatory posture has shifted several times. In 2025, EPA announced its intent to rescind certain PFAS drinking water designations while maintaining standards for PFOS and PFOA, signaling continued reassessment of its overall PFAS approach. These actions underscore the unsettled nature of federal rulemaking.
Meanwhile, the 2021 PFAS Strategic Roadmap and its subsequent progress updates outline multiple forthcoming actions under the CWA, including potential effluent limitation guidelines (ELGs) for PFAS manufacturers and metal finishers. These ELGs, if finalized, would apply to industrial direct and indirect dischargers and shape pretreatment standards nationwide. Yet, as of early 2026, EPA has not finalized technology based effluent limits for PFAS nor established national PFAS biosolids requirements, leaving states to fill the regulatory void.
What POTWs and industrial users should do now
Despite uncertainty, actions today can reduce long term liability:
- Conduct PFAS source identification at industrial users,
- Require PFAS monitoring in pretreatment permits,
- Develop local limits where state guidance is emerging,
- Engage with industrial facilities early on substitution and pollution prevention,
- Evaluate biosolids PFAS levels to assess disposal risks, and
- Participate in state rulemaking to anticipate new limits
POTWs should also coordinate with state environmental agencies, which continue to implement PFAS restrictions independent of federal action.
Pretreatment programs and biosolids management are becoming central to U.S. PFAS compliance. POTWs sit at the intersection of regulatory expectations, industrial discharges, and community concerns. While federal PFAS rules remain in development, state actions and EPA’s strategic direction make one fact clear: controlling PFAS at the source is essential.
Key to remember: For both industrial users and POTWs, proactive PFAS management is no longer optional. It is a core element of future permitting, planning, and risk reduction.






















































