The Wastewater PFAS Pathway
PFAS enter municipal wastewater systems from industrial discharge, stormwater runoff, and residential use of PFAS-containing products. Conventional wastewater treatment — biological treatment, sedimentation, and chlorination — does not effectively remove PFAS. As a result, PFAS pass through treatment plants and are discharged to receiving water bodies and spread in biosolids (treated sewage sludge) applied to agricultural land.
Industrial facilities that use PFAS — including semiconductor manufacturers, plating operations, textile finishers, and paper mills — discharge PFAS-containing wastewater directly or to municipal systems. Pre-treatment standards governing what industrial users can discharge to sewer systems are the primary tool for controlling industrial PFAS inputs.
EPA’s Effluent Limitation Guidelines Development
EPA is developing Effluent Limitation Guidelines (ELGs) for industrial sectors that discharge PFAS, beginning with the organic chemicals, plastics, and synthetic fibers sector and landfill leachate. ELGs set technology-based limits on pollutants that regulated facilities must meet, independent of receiving water quality.
The ELG development process involves extensive industry data collection, technology review, and economic feasibility analysis. EPA’s PFAS ELGs for key sectors are expected to be proposed in the mid-2020s, with compliance timelines that allow facilities to install appropriate treatment technologies.
Biosolids PFAS Contamination Crisis
The detection of high PFAS concentrations in biosolids has created a regulatory and agricultural crisis. Many states have restricted or banned PFAS-contaminated biosolids application to farmland, affecting millions of tons of material annually. Farmers who received contaminated biosolids are suing municipalities, biosolids generators, and PFAS manufacturers.
Biosolids disposal alternatives — landfilling, incineration, and pyrolysis — each have challenges for PFAS management. High-temperature incineration above 1100°C can destroy PFAS, but must be carefully controlled to prevent formation of toxic combustion products. The biosolids PFAS problem is driving innovation in thermal destruction technologies.