On April 10, 2024, the United States Environmental Protection Agency (EPA) issued a pre-publication version of its final rule establishing nationwide drinking water standards for some per- and polyfluoroalkyl substances (PFAS) under the federal Safe Drinking Water Act (SDWA).  The long-anticipated rule marks the first binding federal regulatory standard for PFAS, a group of thousands of man-made chemical compounds widely used since the mid-Twentieth Century in myriad products and processes that are now known to contribute to adverse health impacts and some cancers.  Public drinking water systems nationwide who will have to comply with the new rule over the next several years, and other entities that may face scrutiny as potential sources of PFAS contamination found in drinking water supplies, should take note of this important development in PFAS regulation.  The final rule will take effect 60 days after its publication in the Federal Register (it has not yet been published).  A pre-publication version of the final rule is available here. Given the scope of the rule, its anticipated costs and the emerging nature of the science of potential health impacts, legal challenges are certain to follow.

Federal Standards for PFAS in Drinking Water

EPA has studied PFAS for years but, until now, has left the imposition of regulatory standards to states.  Currently about half of states regulate PFAS in some manner.  Regulating PFAS nationwide via public drinking water standards has been a goal of EPA for many years and is a cornerstone of the Biden Administration’s PFAS Strategic Roadmap.  EPA announced its proposed rule in March of 2023 (for a summary of that proposal, see here).  After considering 120,000 comments on the proposed rule from stakeholders and engaging with the water sector and state regulators, a year later, EPA has issued a final rule.

The final rule will regulate PFOA and PFOS, the two most well-known and widely used PFAS, as individual contaminants, each with a regulatory limit called a Maximum Contaminant Level (MCL) of 4 parts per trillion (ppt) in public drinking water systems throughout the country.  The rule establishes a binding MCL of 10 ppt for three additional PFAS (PFNA, PFHxS, and HFPO-DA). HFPO-DA is commonly known as “GenX.”  Additionally, EPA will regulate mixtures of four PFAS (PFHxS, PFNA, HFPO-DA, and PFBS), which are prone to co-occur in drinking water, through a Hazard Index MCL.  EPA states that mixtures of different chemicals can elicit adverse health effects, even when individual chemicals are present at “safe” levels.  A Hazard Index MCL, which is calculated by adding the ratio of the water sample concentration to a Health-Based Water Concentration, is intended to address the adverse health effects associated with mixtures that include two or more of the four PFAS above.  Rule opponents claim EPA is over-estimating the risks posed by these compounds.

These standards are striking in their stringency.  To provide a sense of scale, 1 ppt is the equivalent of one drop of ink in twenty Olympic-sized swimming pools.  The low regulatory standards reflect EPA’s determination that some PFAS, like PFOA and PFOS, have detrimental health impacts at any measurable level, and that exposure to other PFAS are associated with a range of adverse health effects.  Indeed, as part of the final rule establishing MCLs, EPA is setting non-enforceable health-based goals called Maximum Contaminant Level Goals (MCLGs) of 0 ppt for PFOA and PFOS and 10 ppt for PFNA, PFHxS, and HFPO-DA.  EPA has indicated it would have preferred a lower MCL for PFOA and PFOS, but 4 ppt is the lowest concentration to which laboratories can reliably measure, and therefore, is the lowest regulatory standard feasible. 

Summary of Regulatory Levels in Final Rule

Implementation Timeline & Methods

Within three years of rule promulgation (i.e., 2024-2027), regulated public water systems must complete initial monitoring for regulated PFAS.  Three to five years following rule promulgation (i.e., 2027-2029), these public water systems must publish the results of their initial monitoring in a Consumer Confidence Report (CCR), also known as an Annual Water Quality Report, begin regular monitoring for compliance and publication of monitoring results, and provide public notice for monitoring and testing violations.  Starting five years after rule promulgation (i.e., beginning in 2029), public water systems must comply with all MCLs and provide public notification for any MCL violations. The rule provides mandatory exposure notification language that must be included in CCRs for MCL violations of each PFAS.

The final rule does not specify how water systems remediate water supplies that exceed the MCLs.  EPA designated four Best Achievable Technologies (BAT) that are technologically feasible for treating drinking water for the six PFAS: granular activated carbon (GAC), anion exchange resins (AIX), and high-pressure membranes (i.e., nanofiltration (NF) and reverse osmosis (RO)). This BAT designation is merely informational, and using BAT is not required.  Nonetheless, EPA indicated that the efficacies of these treatment technologies are supported by their histories of full-scale use as documented in the Best Achievable and Small System Compliance for Per- and Polyfluoroalkyl Substances (PFAS) in Drinking Water document (USEPA, 2024), information in the rule preamble, and public comments containing full-scale data and case studies, e.g., the 45 military installations that have treated PFAS.  Additionally, water systems may, in some cases, close contaminated wells or obtain new, uncontaminated sources.  Of course, both PFAS remediation and obtaining new water supplies can be costly undertakings.  Therefore, these providers will need to consider site-specific circumstances as well as technical, economic, and local regulatory considerations when choosing a compliance technology and approach.

Changes from the Proposed Rule

The MCL of 4 ppt for PFOA and PFOS and the approach for a hazard index for four other compounds (PFHxS, PFNA, HFPO-DA, and PFBS) did not materially change from the proposed rule to the final rule, but other aspects of EPA’s proposal did evolve.  The final rule now includes MCLs for PFHxS, PFNA, and HFPO-DA, which were not in the draft rule text.  In addition, EPA extended the compliance deadline for achieving MCLs to five years instead of the proposed three years, giving public water systems more time to plan, fund, and construct capital improvements necessary to meet the standards.  EPA also added flexibility on PFAS monitoring, allowing a decrease in monitoring frequency from quarterly to annually or triennial, if monitoring results support a reduction in frequency.

Impacts on Public Water Systems

The final rule requires public water systems nationwide to monitor for the regulated PFAS, notify the public if PFAS levels exceed their respective MCLs.  If the MCLs are exceeded, public water systems must reduce PFAS concentrations below the MCLs.  Thus, public drinking water systems nationwide will have to implement programs for monitoring, notification, and, if necessary, PFAS remediation.  EPA estimates that 6-10% of the 66,000 public drinking water systems in the country subject to the rule will have to take action to reduce PFAS because of the rule, and that the annual cost will be around $1.5 billion.  EPA estimates the benefits are in the order of $1.5 billion and that around 100 million Americans will have improved drinking water as a result of the rule, preventing 9,600 deaths and reducing cases of serious illness by approximately 30,000.  Critics of the rule claim the actual costs will be much higher and the benefits much lower. 

There is some funding and technical assistance available for public water systems, especially for small, disadvantaged, and rural communities.  The Bipartisan Infrastructure Law (BIL) dedicates $9 billion for investment in communities that have drinking water impacted by PFAS and other emerging contaminants.  Note that $1 billion of these funds can be allocated to private well owners that have adverse PFAS impacts.  The BIL also allocates $12 billion more generally for drinking water improvements.  EPA’s Water Technical Assistance team has resources to help communities identify water challenges, develop plans to address them, build technical, managerial, and financial capacity, and develop application materials to access water infrastructure funding.

Impacts on Other Entities

Entities, both private and public, that may be sources of PFAS contamination can expect that the new standards will increase both regulatory and public scrutiny and the likelihood of legal claims.  Such entities may include private manufacturers of PFAS, manufacturers of products that contain PFAS, and/or industries that have historically used PFAS in certain processes (i.e., textiles, petroleum refining, semiconductors, metal working).  Affected entities also include public entities that may not have been responsible for generating PFAS but may now have PFAS contamination on their property or within their control.  Municipalities, for instance, may have PFAS in their solid waste landfills due to leaching of PFAS from consumer products.  Water utilities or water purveyors may have PFAS accumulated in their water supplies due to releases from multiple sources.  Commercial services airports, which had long been required by the Federal Aviation Administration to use and discharge PFAS-containing fire-fighting foam, may find PFAS contamination on or emanating from their properties, even if they historically complied with all applicable laws and regulations.

Whether fairly or unfairly, PFAS sources, both public and private, will be in the crosshairs of regulators and the public alike if testing reveals PFAS in public drinking water supplies and communities work to identify where the PFAS originated.  The notice requirements triggered by this rule is likely bring even more attention these compounds, particularly given their ubiquitous nature.  This scrutiny, in turn, could result in greater regulatory enforcement and/or private party lawsuits, even in advance of other pending rulemakings discussed in more detail below.

Big Picture Take-Aways

After years of states leading the charge on PFAS regulation, EPA has stepped into the arena and established binding drinking water standards for some PFAS.  This rule may be just the tip of the iceberg for federal regulation of PFAS via the SDWA, as there are thousands of different PFAS compounds, and EPA is already in the process of testing water systems for more PFAS beyond those covered in this rule.  Further, regulation under the SDWA is just one of the ways EPA plans to address PFAS.

Simultaneous with issuing this rule, though separate from the establishment of drinking water standards, EPA is in the process of finalizing another significant PFAS rulemaking: its designation of PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund).  See KKR’s alert on that topic here.  That final rule, expected later this year, will expand EPA’s authority to investigate and remediate sites with PFAS contamination and create liability for various entities deemed responsible for PFAS releases.  EPA is also evaluating whether to regulate PFAS under the Resource Conservation and Recovery Act and considering guidance on PFAS enforcement.  

Just days ago, on April 9, 2024, EPA released a revised non-binding Interim Guidance on Destroying and Disposing of Certain PFAS and PFAS-Containing Materials That Are Not Consumer Products for public comment.  This interim guidance is an update over a prior non-binding interim guidance document the agency published in 2020.  It provides current information on options for PFAS destruction and disposal and encourages managers of PFAS and PFAS-containing waste to use destruction and disposal technologies that have a lower potential for releasing PFAS to the environment.  Recommended technologies are: underground injection in permitted Class I non-hazardous industrial or hazardous waste injection wells, landfilling at permitted hazardous waste landfills, and thermal treatment in permitted hazardous waste combustors.  The guidance provides an in-depth discussion of these and other destruction and disposal strategies, including emerging technologies.  The discussion may be helpful for managers trying to select a disposal strategy.  For instance, EPA provides advice on what type of landfill a manager should select for PFAS disposal depending on the state of the waste (solid, liquid, or gas) and its characteristics (i.e., whether the PFAS species in the waste are soluble, volatile, oxidizable, or biodegradable).  It identifies certain disposal technologies that might be most appropriate for certain products, such as liquid AFFF concentrate that many airports will be looking to dispose of as they switch to fluorine free fire-fighting foams (underground injection control or thermal treatment).  EPA notes throughout the guidance where uncertainties remain regarding effective PFAS treatment and disposal.  An update to this non-binding, interim guidance is expected within the next three years.  

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Kaplan Kirsch & Rockwell regularly counsels clients, both public and private, on regulatory compliance, emerging contaminants, and strategies to reduce environmental liability.  For more information about PFAS, the proposed rule, or how PFAS regulation or liability may impact your organization, please contact Thomas A. Bloomfield, Polly B. Jessen, Sara V. Mogharabi, or Timothy Roth.