PFAS in drinking water: 2024 regulatory milestones and the road ahead for U.S. water systems
2024 has been a pivotal year for efforts to address the pervasive challenge of per- and polyfluoroalkyl substances (PFAS) contamination in the water sector. The U.S. leads in its approach to confront this issue, including research into PFAS risks, regulatory actions and addressing the realities of remediation, setting an example for other nations grappling with similar challenges.
Regulatory developments
In 2024, the United States Environmental Protection Agency (EPA) introduced groundbreaking measures to address the presence of PFAS in water systems. Among the most significant regulatory achievements were the establishment of the first-ever national, legally enforceable drinking water standards for PFAS and the designation of two PFAS compounds as hazardous substances under federal law.
The EPA's drinking water standards set maximum contaminant levels (MCLs) for five individual PFAS — PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (commonly known as GenX Chemicals) — as well as limits for mixtures of certain PFAS compounds. This framework ensures that public water systems will monitor and mitigate those PFAS, marking a crucial milestone in federal regulation. Furthermore, the EPA designated PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund. This designation enables investigation and cleanup of PFAS releases, while recovering costs from those responsible.
In 2024, the U.S. Government introduced legally enforceable drinking water standards for PFAS and designated PFOA and PFOS as hazardous substances under federal law
Complementing these legally enforceable measures, the EPA also issued draft recommendations for health-based levels of PFAS in water bodies. While these recommendations are not binding, they provide essential guidance for state and Tribal regulators as they formulate policies to protect water quality. Moreover, last week the EPA announced the automatic addition of nine PFAS to the Toxics Release Inventory (TRI) for Reporting Year 2025. The addition of these PFAS stems from EPA finalizing toxicity values for the chemicals in 2024, bringing the total number of PFAS subject to TRI reporting to 205. The publicly available data enhances transparency and accountability, supporting informed decision-making by companies, government agencies, and communities.
The scale of PFAS contamination is not minor. Last May, the EPA reported that 89.3 million people in the U.S. have drinking water that tested positive for PFAS, according to nationwide testing under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5) from more than 10,000 water systems. The latest data, published in October, elevates that number to over 143 million. By 2026, all public water systems serving over 3,000 people will be required to test for 29 PFAS compounds, providing a clearer picture of the contamination crisis. This is the largest nationwide effort to understand the frequency that PFAS is found in drinking water, and at what levels.
These comprehensive actions reflect the U.S. government's commitment to addressing PFAS contamination and its wide-ranging implications for public health and environmental safety. The EPA’s third annual report on PFAS progress, released in November, highlights significant accomplishments achieved under its PFAS Strategic Roadmap.
Financial burden
While the regulatory advancements in 2024 represent a significant victory for environmental health, they come with a considerable financial burden for water systems. Addressing PFAS contamination requires substantial investments in monitoring, treatment technologies, and infrastructure upgrades, posing significant challenges for water utilities.
Drinking water systems failing to meet new PFAS standards face significant financial demands to remove these contaminants from local supplies
The new PFAS drinking water regulation gives water systems three years to conduct monitoring (by 2027), and two years more after that (by 2029) to comply with maximum contaminant levels (MCLs) for regulated PFAS, that is, to implement treatment systems if the contaminants are detected. Drinking water systems failing to meet new PFAS standards face significant financial demands to remove these contaminants from local supplies. Furthermore, wastewater treatment facilities, often considered "passive receivers" of PFAS contamination, are potentially liable for managing and disposing of these substances properly. This includes stricter regulations on the land application of biosolids containing PFAS, leading to additional costs and operational challenges.
Bluefield forecasts drinking water utilities will spend nearly $13.5 billion between 2023 and 2030 on PFAS retrofits - primarily dedicated to the installation of granular activated carbon (GAC) filtration, widely regarded as an effective solution for removing PFAS. Another analysis by Milliman, a global consulting firm, projected that the expected cost for remediating U.S. drinking water systems contaminated with PFAS could range between $120 billion and $175 billion.
The PFAS remediation landscape is further complicated by legal liabilities and ongoing litigation. PFAS litigation practice began more than seven years ago and led to the Aqueous Film-Forming Foam multi-district litigation (MDL), which consolidated hundreds of PFAS lawsuits. They included claims by water and wastewater service providers in addition to others affected by PFAS contamination. Notable settlements in recent years include those by DuPont for $1.18 billion and 3M for $12.5 billion.
Adding to the complexity of addressing PFAS pollution, many states have already taken their own steps to regulate PFAS, including drinking water limits. Moreover, as of December 11, 2024, thirty-one State Attorneys General had initiated PFAS litigation, to hold polluters accountable and secure resources to help clean up communities.
The PFAS remediation landscape is further complicated by legal liabilities and ongoing litigation
Balancing the need for environmental accountability with the economic realities of compliance – with litigation as a component of the cost recovery strategy – will be crucial as the U.S. water sector navigates this complex issue. The regulatory strides made in 2024 demonstrate the United States’ determination to tackle PFAS contamination, but they also illuminate the significant economic hurdles that must be overcome.
With billions of dollars needed to monitor and remediate PFAS, the financial burden on water systems is immense, necessitating innovative solutions and sustained investment. Looking head, the future of the EPA's regulatory strategy for PFAS is uncertain, as the incoming Trump administration emphasizes environmental deregulation, potentially targeting recent PFAS rules for rollback. Additionally, ongoing legal challenges to the EPA’s PFAS regulations, as well as to other actions at the state and federal level, with outcomes yet to be resolved, add further ambiguity.