EPA Proposes Stringent Regulation of PFAS in Drinking Water

On March 14, 2023, the EPA proposed a National Primary Drinking Water Regulation under the Safe Drinking Water Act to establish Maximum Contaminant Levels (MCLs) for six per- and polyfluoroalkyl substances (PFAS):

  • Perfluorooctanoic acid (PFOA)
  • Perfluorooctane sulfonic acid (PFOS)
  • Perfluorononanoic acid (PFNA)
  • Hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX)
  • Perfluorohexane sulfonic acid (PFHxS)
  • Perfluorobutane sulfonic acid (PFBS).

The EPA anticipates finalizing the regulation by the end of 2023. Although the science around PFAS is still evolving, the EPA has touted the proposed rule as an essential measure that “will prevent thousands of deaths and reduce tens of thousands of serious PFAS-attributable illnesses.”

This statement evidences the EPA’s current position regarding the risks presented by PFAS. This said, it is notable that, for two of the PFAS, the MCLs are several orders of magnitude higher (i.e., less stringent) than the interim health advisory levels that the EPA published in June 2022. For example, whereas the interim levels for PFOA and PFOS were at the unprecedentedly low level of 4 parts per quadrillion (ppq) and 20 ppq, respectively, the proposed rule would establish an MCL of 4 parts per trillion (ppt) for each of these two chemicals. The proposed MCL is still a very stringent standard, an order of magnitude lower than the 70 ppt health advisory level, which various industry groups have criticized as unduly conservative and based on flawed science. In contrast to PFOA and PFOS, the acceptable limits for the other four PFAS will be determined using the EPA’s Hazard Index. This is a tool that the EPA uses to evaluate health risks resulting from exposure to mixtures of related chemicals simultaneously.

Safe Drinking Water Act (SDWA)
Finalization of the proposed rule also would bring with it the standard litany of obligations that the SDWA imposes upon “public water systems.” The SDWA defines public water systems broadly to include not just utilities but any water system that delivers potable water through 15 or more service connections or that regularly services at least 25 individuals for at least 60 days of the year. Exemptions apply to public water systems that obtain their potable water from a regulated source, neither sell nor treat water, and are not carriers engaged in interstate commerce (states may have their own criteria in addition to these federal ones). There are currently over 148,000 public water systems in the United States.

Among the principal obligations that non-exempt public water systems must perform are the following:

  • Monitoring: The EPA’s proposed rule would require regulated public water systems to monitor for the six PFAS. The frequency of the monitoring results will vary depending upon the results of the initial sampling (or in some cases, sampling performed before the rule goes into effect).
  • Public notification: The EPA requires public water systems to keep the public apprised of sampling results by publishing the latter in annual consumer confidence reports distributed to their customers. Additionally, exceedances of the MCLs would have to be reported to consumers no later than 30 days after discovery.
  • Treatment: If PFAS in drinking water exceed the regulatory standards, public water systems would be mandated to take actions to reduce the PFAS levels through (1) removal of the chemicals through treatment or (2) switching to another water supply that complies with the standard. The proposed rule seems to acknowledge that treating water supplies impacted by PFAS to attain the MCLs may be difficult with existing technologies and, therefore, references provisions in the Bipartisan Infrastructure Law that create funding mechanisms that could be applied to this end.

If enforced, the failure to comply with any of these measures would subject the owner or operator of a regulated public water system to statutory penalties, which may include monetary penalties, injunctive relief or other remedies. The maximum daily civil penalty under the SDWA is $25,000, subject to adjustment for inflation.

In addition to penalty exposure for statutory violations, the establishment of MCLs raises the potential of additional liability. As Pillsbury has noted in prior PFAS alerts, in the absence of directly applicable codified cleanup criteria, MCLs tend to serve as de facto remedial endpoints. Thus, assuming that the proposed rule is finalized, regulators overseeing sites impacted by these six PFAS may look to the MCLs for the standards that responsible parties must attain to obtain site closure. Accordingly, if finalized, the proposed rule could drive up cleanup costs and the duration of remediation at sites impacted by these six PFAS.

Similarly, numerous PFAS-related lawsuits involving allegedly contaminated water supplies are pending in state and federal court. It is reasonable to assume that the new MCLs will establish default limits that courts may point to for guidance in making determinations about whether harmful exposure has occurred.

Finally, in recent years, several states have issued their own PFAS standards based on the EPA’s 2016 health advisory level of 70 ppt for PFOA and PFOS. It is possible that these states may seek to align their standards with the final MCL.

Path Forward
Considering the potential impact of a final MCL for PFAS on regulated public water systems, such companies and others involved in remediating sites impacted by PFAS may wish to take advantage of the public notice and comment period for the proposed rule to influence its final outcome. The deadline for submitting public comments is 60 days after publication of the proposal in the Federal Register, which has not yet occurred.

At the same time, it is not too soon for potentially affected businesses to consider the merits of longer-term measures to evaluate their potential nexuses to PFAS and to identify strategies to mitigate or offset PFAS-related liabilities. The involvement of outside counsel in such initiatives increases the availability of legal privilege and confidentiality.

As for liability mitigation and offsetting strategies, the options vary depending on the nexus and nature of the business. For example, businesses with active environmental discharges or emissions may wish to consider the benefits of proactively installing control equipment to reduce the amounts of PFAS that they introduce into the environment. Public water systems may wish 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 and to take advantage of such exemptions to the extent that they qualify. Current or historic insurance also may be available to defray costs in certain circumstances and should be an early part of the internal investigation process.

Pillsbury attorneys have extensive experience dealing with all facets of PFAS-related environmental regulatory and remediation issues (including assisting companies in obtaining exemption from the National Primary Drinking Water Regulation), state and federal PFAS-related legislative issues, PFAS-related toxic tort and insurance recovery issues and PFAS-related corporate transactional issues.