The United States Environmental Protection Agency (EPA) is making advancements on its per- and polyfluoroalkyl substances (PFAS) Action Plan and PFAS Strategic Roadmap. In April, the EPA introduced enforceable limits (Maximum Contaminant Levels or MCLs) for six specific PFAS compounds in drinking water. They also classified two PFAS compounds as hazardous substances under CERCLA. These new regulations are set to increase the demand for PFAS treatment across various industries and could potentially lead to the generation of PFAS-impacted waste streams.
While the new PFAS drinking water standards (MCLs) and hazardous substance designation (CERCLA) for PFAS have received much attention, there's another important development from the EPA. On April 8, 2024, the EPA updated its Interim PFAS Destruction and Disposal Guidance. This update, a significant step in the ongoing efforts to manage PFAS, follows the EPA’s original Interim Guidance on the Destruction and Disposal of PFAS released in December 2020.
The EPA's 2024 update to the Interim Guidance on PFAS Destruction and Disposal (2024 Guidance) is a comprehensive document. It incorporates recent data on treatment efficacy, addresses public comments received, and outlines persisting data gaps. Additionally, the 2024 Guidance prioritizes key data gaps and uncertainties that ongoing research aims to tackle to achieve efficient PFAS destruction and minimize environmental release.
What are the updates to the Interim PFAS Destruction and Disposal Guidance?
Despite over three years of additional experience and data collection, a definitive solution for PFAS waste management remains elusive. There is no silver bullet, and each option has its limitations. The 2024 Guidance evaluates three existing PFAS destruction and disposal technologies: incineration, landfilling, and deep-well injection. It retains the suggestion that site-specific considerations may warrant interim storage of PFAS-impacted wastes with controls.
Furthermore, the 2024 Guidance introduces information on emerging PFAS-destructive technologies, as evaluated by the EPA’s PFAS Innovative Treatment Team (PITT). EPA specifically highlights four emerging PFAS-destructive technologies (mechanochemical degradation, electrochemical oxidation, gasification and pyrolysis, and supercritical water oxidation), which have shown theoretical promise but remain limited in commercial availability and existing data characterizing treatment efficacies/outputs.
Importantly, the 2024 Guidance neither prohibits nor endorses any specific approach to PFAS waste destruction and disposal. Instead, the EPA provides a framework for evaluating existing and emerging technologies to determine the most suitable technology on a case-by-case basis. The evaluation framework offers a transparent and consistent approach for evaluating technology selection, considering disposal/destruction efficacy, available analytical methods, field screening, and impacts on vulnerable communities. An overarching theme in EPA’s evaluation framework is the selection of technologies that minimize risk to human health and the environment. Notably, the 2024 Guidance distinguishes between the potential for a PFAS release and a direct or unacceptable risk to human receptors, thus acknowledging the nuanced balancing act inherent in the complexities of PFAS waste management while prioritizing safeguarding human health and the environment. Embedded within the 2024 Guidance is a noteworthy observation; the EPA anticipates that deep-well injection of liquid PFAS wastes may offer the lowest potential for environmental release compared to other disposal and destruction methods.
How does this Guidance Fit with EPA’s New PFAS MCLs and Hazardous Substance Designations?
Considering the implications of the 2024 Guidance in conjunction with the new PFAS MCLs and hazardous substance designations, it’s important to examine how these regulatory measures intersect and impact PFAS management. The recent PFAS MCL ruling requires that public drinking water systems put processes in place to prevent six specific PFAS compounds from occurring in drinking water at levels higher than the MCLs by 2029. The impacts of the recent CERCLA hazardous substance designations are still somewhat uncertain, but they provide the EPA with enforcement authority to clean up hazardous waste sites. Both pieces of legislation are anticipated to result in an increase of PFAS-impacted waste that must be treated.
In response to these regulatory shifts, the EPA evaluated Best Available Technologies (BAT) to comply with the new MCLs and identified granular activated carbon (GAC), ion exchange (IX), and high-pressure membrane separation via reverse osmosis or nanofiltration (RO/NF) for drinking water treatment. Many of these technologies are appropriate with other matrices, such as groundwater and landfill leachate, though complex chemistries complicate their efficacies. The EPAs BAT evaluation concludes that while these technologies are generally effective for removing newly regulated PFAS compounds from drinking water streams, they lead to PFAS-concentrated residuals that require disposal or destruction.
Of particular concern is the fate of PFAS during destructive treatments like incineration. The EPA notes that additional research and understanding of the fate of PFAS during various thermal treatments is needed to better understand and manage PFAS air emissions from incineration facilities. A major limitation in understanding the efficacies of full PFAS destruction via incineration practices is the lack of analytical methods.
Addressing these uncertainties, the 2024 Guidance underscores the imperative to further characterize air emissions resulting from incineration practices to facilitate more informed decision-making. EPA identifies current data gaps in thermal treatments, including products of incomplete combustion/destruction (PICs/PIDs) and the fate of precursors not identified in targeted analytical methods that only report concentrations of a limited number of PFAS compounds. Toward this end, EPA has released a draft analytical method, OTM-50, for PFAS in air from stationary sources, allowing better characterization of uncertainties around PICs.
While the 2024 Guidance may not offer a straightforward solution to disposing of PFAS-impacted wastes, it does present a systematic approach for evaluating disposal and destruction options. Furthermore, by highlighting critical data gaps, the EPA sets the stage for future research efforts, which will be crucial given the anticipated quantities of PFAS-impacted waste requiring management.
What’s Next?
The 2020 National Defense Authorization Act (NDAA) required the EPA to address PFAS destruction/disposal and provide updates at least every three years; the 2024 Guidance represents the first of these three-year updates. Public comments can be submitted but may not be incorporated in EPA-issued guidance until the next version is released, potentially not until 2027 (per the three-year requirement).
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During this active period at the EPA, additional PFAS regulations and updates are anticipated. Please be on the lookout for additional articles on this topic. Meanwhile, if you have PFAS-related questions, concerns, or challenges, drop your information into our contact form, and we’ll schedule a time to discuss how you can prepare for and manage PFAS-related regulations.