Water Systems PFAS Liability Protection Act This bill exempts specified water management entities from liability under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) for releases of certain perfluoroalkyl or polyfluoroalkyl substances, commonly referred to as PFAS. Specifically, the entities covered under the bill are public water systems, publicly or privately owned or operated treatment works, municipalities with a stormwater discharge permit, political subdivisions or special districts of a state that act as a wholesale water agency, and contractors performing the management or disposal activities for such entities. Under the bill, the exemption only applies if a specified entity transports, treats, disposes of, or arranges for the transport, treatment or disposal of PFAS consistent with applicable laws and during and following the conveyance or treatment of water under federal or state law, such as through the management or disposal of biosolids consistent with the Federal Water Pollution Control Act. Liability for damages or costs associated with the release of certain PFAS must not be precluded if an entity acted with gross negligence or willful misconduct.