The contaminant(s) Per- and Polyfluoroalkyl Substances (PFAS) is on critical attention at the municipal drinking water treatment plants (MWTPs) or public water systems (PWSs), and water resource recovery facilities (MWRRFs). The 5th Unregulated Contaminant Monitoring Rule (UCMR) requires twenty-nine PFAS compounds to be monitored at the small to large PWSs. Following USEPA’s PFAS Strategic Roadmap with Research, Restrict, and Remediate integrated goal-approach, while potential PFAS-Source(s) have been under a critical review, a clean water action is also underway verifying on categorical industrial wastewater effluent dischargers via Effluent Guidelines Program Plan 15 (Plan 15); in addition, public input is initiated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) toward a feasible rulemaking on applicable PFAS. The Toxics Release Inventory (TRI) now requires applicable industrial facilities to report on certain PFAS, under the Emergency Planning and Community Right-to-Know Act (EPCRA). Given the ongoing regulatory review and USEPA proposing individual maximum contaminant level (MCL) of 4.0-ppt on perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and, a Hazard Index (HI) of 1.0 on another four PFAS, implications to the operation of PWSs and MWRRFs are significant as the treatment required in liquid processing train(s) and handling of solids for safe environmental removal of PFAS. Applicable PFAS-treatment processes and technologies for water treatment have been identified and, associated costs (as projected) would be significant for the municipal water utilities. Thus, this work includes a comprehensive evaluation on contaminant-PFAS, PFAS removal in municipal water processing, and potential cost effects to municipal water systems.