A water treatment system is disclosed. The water treatment system comprises a filtration module comprising one or more ultrafiltration membrane configured to remove one or more non-PFAS contaminant from a PFAS contaminated water stream to provide a partially purified water stream containing soluble PFAS contaminants. The water treatment system also comprises a sorption module comprising one or more sorption units comprising a sorbent material, the sorption module being in fluid communication with the filtration module and downstream therefrom and configured to remove substantially all PFAS contaminants from the partially purified water stream to provide purified water that is substantially free from PFAS contamination.