On April 10, 2024, EPA issued the first-ever national, legally enforceable drinking water standard for five individual per-and polyfluoroalkyl substances (PFAS): PFOA, PFOS, PFNA, PFHxS, HFPO-DA (so-called, “GenX chemicals.”) EPA’s action will require all public water systems to complete initial work to monitor for these chemicals within three years.

In its press release announcing this action, EPA indicated it “will be working closely with state co-regulators in supporting water systems and local officials” in implementing the rule. These systems must implement solutions to reduce PFAS below regulatory levels in their drinking water within five years. EPA estimates that between 6 to 10% of the country’s 66,000 public drinking water systems may have to take action to meet the new standards.

The New Federal Standards

  • For PFOA and PFOS, EPA has set a Maximum Contaminant Level (MCL) Goal (a non-enforceable health-based goal) at zero.
  • The MCL (an enforceable limit) for PFOA and PFOS, individually, is being set at 4.0 parts per trillion (ppt).
  • For PFNA, PFHxS, and “GenX Chemicals,” the MCLGs and MCLs are being set at 10 ppt.
  • EPA’s rule also sets a limit for any mixtures of two or more of the following PFAS: PFNA, PFHxS, PFBS, and “GenX chemicals.”
CompoundFinal MCLGFinal MCL (enforceable levels)
PFOAZero4.0 parts per trillion (ppt) (also expressed as ng/L)
PFOSZero4.0 ppt
PFHxS10 ppt10 ppt
PFNA10 ppt10 ppt
HFPO-DA (commonly known as GenX Chemicals)10 ppt10 ppt
Mixtures containing two or more of PFHxS, PFNA, HFPO-DA and PFBS 1 (unitless)
Hazard Index
1 (unitless)
Hazard Index

EPA has previously proposed to designate two PFAS (PFOA and PFOS), including their salts and structural isomers, as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), more commonly known as Superfund. This rule was initially proposed in September 2022, and is expected to be finalized imminently.

New York’s PFAS Standards

With EPA’s promulgation of federal drinking water standards for these PFAS that are stricter than New York’s current MCLs, the New York State Department of Environmental Conservation (DEC) is likely to take action to align its standards with EPA’s. New York is one of 10 states with its own PFAS rules, having adopted a rule in 2020 setting the MCL for drinking water for PFOA and PFOS at 10 ppt. With more stringent federal limits taking effect, we should expect to see an announcement from DEC, possibly expanding upon the federal limits. Given there are thousands of PFAS chemicals in use, with only five being the subject of EPA’s regulatory action, the scope of regulation could easily be expanded.


In addition to penalty exposure for statutory violations, the establishment of MCLs raises the potential of additional liability, which will not be limited to only public water systems. While public water systems will certainly bear the initial brunt of actions required to comply with the rule, it is likely the impact will ripple across multiple sectors of the economy. EPA’s announcement hints at the rule’s costly impact, indicating EPA will make “an unprecedented” $21 billion available to strengthen the country’s drinking water systems. Of that, $9 billion is earmarked specifically for addressing PFAS and emerging contaminants. The regulation will undoubtedly drive up cleanup costs during remediation at sites impacted by these five PFAS. PFAS-related lawsuits involving allegedly contaminated water supplies are pending in state and federal court nationwide. It is reasonable to assume the new MCLs will establish default limits that courts may point to for guidance in making determinations about whether harmful exposure has occurred.

Furthermore, designating PFAS as CERCLA hazardous substances will have wide-ranging impacts on manufacturers and secondary users whose products are allegedly tied to environmental contamination. In the form proposed, there would be no exclusions from liability for water utilities and wastewater treatment plants, landfills, agricultural biosolid operations, and airports, to name but a few of the sectors at risk. While EPA indicated it was considering contribution protection and enforcement discretion policies to shield these potentially responsible parties as a matter of agency policy, they would still be vulnerable to third-party claims in litigation.

CERCLA liability also creates significant risk for passive receivers who do not manufacture CERCLA-regulated hazardous substances, but who merely incorporate materials and substances containing PFAS into their products, with or without knowledge of the existence of PFAS. EPA has also proposed regulations that would classify nine PFAS as “hazardous constituents” under the federal Resource Conservation and Recovery Act (RCRA) and expand oversight of waste facilities to include PFAS and other substances.

Next Steps

Companies should be consulting with qualified attorneys and technical consultants in developing a compliance and risk mitigation strategy as they brace for potential increased litigation in the wake of the new regulations. It is expected there may be an uptick of toxic tort actions filed by people alleging injuries (including cancer and other health issues) as the result of failure to meet these new regulations, despite the weak science. In the absence of codified groundwater cleanup standards, the conservative MCLs stand to serve as de facto remediation goals as well as standards that plaintiff’s counsel may seek to have courts apply in toxic tort cases. It is critical to prepare a plan for conducting the necessary diligence to determine what PFAS-related information is known or reasonably ascertainable, and then collect and analyze it.

The retention of technical experts skilled in PFAS testing, remediation, and offsetting strategies is crucial. For example, businesses with active environmental discharges or emissions may wish to consider the benefits of prophylactically installing control equipment to reduce the amount of PFAS emerging from processes. Public water systems will want to assess the applicability of the codified exemptions from the National Primary Drinking Water Regulation under the Safe Drinking Water Act and its state analogues to take advantage of such exemptions if they qualify. Companies will also want to examine current or historic insurance policies to offset costs, which should be part of an early internal investigation process. Once completed, the extent of required reporting can be determined, particularly since some portion of collected information may qualify as confidential information unsuitable for public disclosure.

If you have any questions about the matters in this Legal Alert, please contact:
Gene Kelly at 518-701-2740/gkelly@harrisbeach.com, Kelly Jones Howell at 212-912-3652/ khowell@harrisbeach.com, or the Harris Beach attorney with whom you usually work.

This alert does not purport to be a substitute for advice of counsel on specific matters.

Harris Beach has offices throughout New York state, including Albany, Buffalo, Ithaca, Long Island, New York City, Rochester, Saratoga Springs, Syracuse and White Plains, as well as Washington D.C., New Haven, Connecticut and Newark, New Jersey.