Clean Water Act Authorities Relevant to PFAS
The Clean Water Act (CWA) regulates water pollution through multiple programs relevant to PFAS: the NPDES program governing point source discharges to surface water; Effluent Limitation Guidelines (ELGs) setting technology-based discharge limits by industry sector; Water Quality Standards establishing acceptable PFAS concentrations in receiving waters; and the Section 319 Nonpoint Source program for diffuse PFAS sources.
EPA’s designation of PFOA and PFOS as hazardous substances under CERCLA does not directly affect CWA regulation, which has its own framework. However, the Superfund designation strengthens EPA’s authority to require cleanup of PFAS-contaminated surface water bodies and to pursue responsible parties for remediation costs.
Effluent Limitation Guidelines Development
EPA is developing ELGs for the top PFAS-discharging industrial sectors, beginning with organic chemicals, plastics, and synthetic fibers; airports; landfills; and metal finishing. ELGs will require specific treatment technologies for PFAS removal in industrial wastewater before discharge to receiving waters or municipal treatment systems.
The ELG development process involves extensive data collection on PFAS discharges, treatment technology performance and cost, and economic impact analysis. Draft ELGs for the first sectors are expected in the mid-2020s. Once finalized, ELGs become enforceable through NPDES permits for affected facilities.
Water Quality Criteria Development
EPA is developing human health and aquatic life water quality criteria for PFAS — the concentration guidelines for surface water that states use to develop water quality standards. Without federal criteria, states have inconsistent approaches to evaluating whether PFAS discharges impair designated water uses.
Aquatic life criteria for PFAS are particularly challenging because aquatic organisms bioconcentrate PFAS to high levels, and fish consumption is a significant human PFAS exposure pathway. Human health criteria must account for both direct water ingestion and fish consumption pathways to fully protect against PFAS exposure through surface water contacts.