On June 15, 2022, the U.S. Environmental Protection Agency (EPA) announced new drinking water Health Advisories Levels (HALs) for certain per- and polyfluoroalkyl substances (PFAS) as part of its PFAS Strategic Roadmap.

HALs provide information on a contaminant that may cause negative human health effects and is known or anticipated to occur in drinking water. HALs are EPA's recommendations for the concentrations of such drinking water contaminants at which adverse health effects are not anticipated to occur over specific exposure durations, such as one-day, 10 days or a lifetime. HALs are not legally enforceable standards.

The new HALs announced by EPA in June 2022 apply to perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), GenX, and perfluorobutanesulfonic acid (PFBS). The HALs are 0.004 parts per trillion (ppt) for PFOA, 0.02 ppt for PFOS, 10 ppt for GenX chemicals, and 2,000 ppt for PFBS. These HALs are significantly more stringent than the interim HAL EPA issued in 2016 for PFOA and PFOS at 70 ppt. The establishment of HALs at .004 ppt and .02 ppt for PFOA and PFOS indicates that EPA considers that nearly any detection of these contaminants in drinking water may potentially result in adverse health effects.


HALs are nonregulatory and non-enforceable. HALs are intended to provide technical information to drinking water system operators, as well as federal, state, Tribal, and local officials, on the health effects, analytical methods, and treatment technologies associated with drinking water contaminants. These entities may rely upon HALs as guidance or adopt HALs in establishing state and local drinking water standards. For example, five states adopted EPA's 2016 HALs of 70 ppt for PFOA and PFOS as de facto drinking water standards. Other states, such as New Jersey and Vermont, have adopted more stringent standards than EPA's HALs. Moreover, plaintiffs are expected to continue to leverage HALs in consumer-based litigation to pursue claims against chemical manufacturers and companies producing PFAS-containing products for alleged damage to drinking water sources and resulting adverse health effects.


EPA has not yet established Maximum Contaminant Levels (MCLs) for PFAS. An MCL is the maximum level of a particular contaminant permitted in public water systems under the Safe Drinking Water Act. EPA has indicated its intent to publish National Primary Drinking Water Regulations for PFOA and PFOS in 2022, with the rule anticipated to be finalized by the end of 2023. EPA has stated that the proposal will include both a non-enforceable Maximum Contaminant Level Goal (MCLG),1 an enforceable MCL, and a Treatment Technique.2 EPA's proposed rule may extend beyond providing Treatment Techniques exclusively for PFOA and PFOS to address PFAS in mixtures. This would allow EPA to regulate other types of PFAS under the Safe Drinking Water Act through an enforceable Treatment Technique. Additionally, EPA will release its PFAS Strategic Roadmap guidance regarding disposal and destruction of PFAS remediation wastes in December 2023. A number of industry challenges have already been brought against EPA's interim HALs, arguing that the agency's action was arbitrary and capricious because it deviated from its standard methods of assessment, overstated exposure assumptions, failed to submit the HALs for public notice and comment or consider the costs and benefits of the action, and exceeded its authority under the Safe Drinking Water Act. These legal challenges may delay further action by EPA.


EPA's issuance of the new, more restrictive HALs demonstrates that PFAS regulation continues to be a key focus area for EPA as it moves forward with the implementation of its PFAS Strategic Roadmap. EPA's push for more stringent regulation of PFAS in drinking water is joined by other local, state, and world health leaders. While there is currently no federal enforceable PFAS standards for drinking water, many states and localities have already established limitations or prohibitions on PFAS in drinking water. Other states are in the process of doing so. Moreover, in September 2022, the World Health Organization (WHO) issued a provisional guideline value (pGV)3 of 100 ppt individually for PFOA and PFOS, and a combined pGV of 500 ppt for total combined PFAS in drinking water. Some have criticized that this recommendation of a value for total PFAS lacks scientific evidence, arguing that regulations should be promulgated on a chemical-by-chemical basis. Meanwhile, environmental groups assert that WHO's recommendation does not do enough to protect public health. Despite these challenges, it remains clear that regulators at all levels, as well as consumers, continue to be focused on PFAS in drinking water.


1. MCLGs are the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.

2. A Treatment Technique is an enforceable procedure or level of technological performance that public water systems must follow to ensure control of a contaminant. Treatment Technique rules also list the best available technology for meeting the standard and compliance technologies available and affordable for smaller systems.

3. pGVs differ from HALs in that HALs are issued by EPA, whereas pGVs are issued by WHO. Both are derived with the objective of reducing human exposure and therefore risk.

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