In April 2024, the U.S. Environmental Protection Agency (EPA) finalized the first National Primary Drinking Water Regulation (NPDWR) for per- and polyfluoroalkyl substances (PFAS), establishing binding federal limits for these persistent constituents of emerging concern. For many utilities nationwide, this marks the beginning of a steep learning curve. Yet across the country, a number of systems have already spent years navigating PFAS treatment, designing, constructing, and operating full-scale facilities. Their experiences, both successful and challenging, offer valuable lessons for utilities preparing to comply with the 2031 deadline. With limited time to design, fund, and implement treatment, learning from what has already been tried and tested is essential. This presentation will distill key insights from years of PFAS treatment implementation and translate them into practical guidance for utilities across diverse regions. A central theme is that technology selection cannot be one-size-fits-all. Systems that selected treatment without tailoring it to their influent PFAS profile, site constraints, or operational capacity often faced underperformance or required expensive retrofits. In contrast, utilities that invested time in careful pilot testing and comparative evaluation of options, such as granular activated carbon, ion exchange resins, high-pressure membranes, or hybrid configurations—achieved reliable removal while keeping lifecycle costs manageable. Another critical lesson is the importance of designing with construction and operations in mind. Some utilities underestimated the demands of residuals management, pretreatment, and operator training. Others planned ahead by incorporating flexibility for future upgrades, reserving space for expansion, and balancing upfront capital costs with long-term operating expenses. These considerations are broadly relevant, as site-specific water quality conditions, climate, and system scale will ultimately shape project success. The session will also explore emerging PFAS technologies, including novel adsorbents and destructive treatment processes. While promising, these methods remain largely unproven at scale, and reliance on them under a compressed regulatory timeline presents risks. Proven approaches, paired with realistic cost forecasting and strong operational planning, remain the most reliable path forward. Finally, the presentation will address regulatory and financial aspects of implementation. The EPA’s final rule introduces rigorous monitoring, reporting, and compliance requirements that must be integrated into project planning from the outset. Utilities that coordinated these elements early minimized administrative delays, while those that overlooked them often encountered setbacks. In addition, funding strategies, leveraging state and federal programs, revolving loan funds, and grant opportunities, played a decisive role in helping systems achieve compliance while managing financial impacts