PFAS mitigation is a drinking-water system-design challenge: lessons from contrasting architectures

Per- and polyfluoroalkyl substances (PFAS) pose several challenges to drinking-water safety and regulatory compliance, yet debates over optimal PFAS treatment technologies often overlook how drinking-water system architecture dictates mitigation pathways. Here, we compare two distinct treatment configurations: localized adsorption processes retrofitted to groundwater-dominated systems and large-scale reverse osmosis integrated into desalination-based water supplies. Germany and Israel are used as representative cases. We demonstrate that effective PFAS management requires aligning interception, concentration, residual handling, and destruction strategies with the overall design of the drinking-water system, rather than evaluating technologies solely by individual plant-level effluent quality. Consequently, regulatory frameworks and technology assessments must adopt a system-level PFAS mass-balance perspective that accounts for redistributed PFAS across finished water, waste streams, and the environment.