PFAS in biosolids: Insights into current and future challenges

Biosolids, valued as nutrient-rich soil amendments, are now approached cautiously by farmers due to growing public concern, and increasingly stringent and varying per- and poly-fluoroalkyl substances (PFAS) regulatory standards across jurisdictions. PFAS concentrations in biosolids vary widely between countries and wastewater treatment plants. Inconsistent monitoring and testing protocols hinder accurate assessment and comparison across sites. The fragmented regulatory landscape, with diverse thresholds and evolving requirements, complicates compliance and long-term planning for water utilities, challenging infrastructure investment. A key issue is lack of proven, scalable PFAS treatment technologies for municipal wastewater plants. Current solutions often lack performance, cost-effectiveness, and practicality at scale. Utilities face financial burdens for monitoring and remediation while balancing other priorities, like managing emerging contaminants and reducing greenhouse gas emissions from energy-intensive processes. Effective source control to limit PFAS entry into wastewater systems is critical and cost-effective. Integrated strategies targeting multiple pollutants can optimize investments. Clear, science-based regulatory standards for PFAS in biosolids are urgently needed to guide compliance. Collaboration among utilities, academia, technology providers, and stakeholders, supported by transparent engagement, is essential for practical PFAS management solutions and rebuilding public trust. Sustainable biosolids management depends on evidence-based, interdisciplinary efforts integrating technological innovation, regulatory clarity, and socioecological resilience.