[co-authors: Edward Mahaffey, Graham Ansell Ph.D., and Brett Winters, Ph.D.]
Section 7361 of the National Defense Authorization Act ("NDAA") for Fiscal Year 2020 requires the US Environmental Protection Agency (EPA) to "publish interim guidance on the destruction and disposal of perfluoroalkyl and polyfluoroalkyl substances and materials containing perfluoroalkyl and polyfluoroalkyl substances," reflecting increasing concern about the human health risks posed by these substances, commonly known as PFAS. On December 18, 2020, the EPA issued the interim guidance document, on which it will accept public comments until February 22, 2021. However, as discussed below, the guidance appears to be prematurely issued, given EPA’s uncertainty throughout in advising on the likely efficacy of various PFAS disposal and destruction methods.
Scope of Guidance
The stated intent of the guidance "is to identify and describe technologies that may control releases of PFAS waste to protect human health and the environment." However, it "is not a rule and it is not a statement of policy." Nor does it "establish what concentrations of PFAS in wastes, spent products, or other materials or media would necessitate destruction or disposal." Moreover, the guidance does not address PFAS-containing consumer products. Instead, it discusses the different types of PFAS-containing substances identified by the NDAA; potential technologies for destroying or disposing of them and the costs and benefits of these technologies, including uncertainties regarding their efficacy; some specific public health and environmental justice considerations regarding PFAS disposal; and planned research into PFAS disposal.
Overview of Recommendations
The interim guidance tentatively recommends four approaches to PFAS disposal "in the order of lower uncertainty to higher uncertainty," i.e., from most to least certain to prevent PFAS from entering the environment. The first of these technically is not a disposal method at all, but rather a catch-all approach, as follows: "interim storage… until research reduces the uncertainties associated with other options." The guidance document, however, does not discuss "interim storage" methods in any detail; it merely recommends "following manufacturers’ recommended best management practices as well as in accordance with any relevant industry, federal, state, or local requirements or guidelines."
The second approach is the use of underground injection wells, specifically the deep injection wells classified as "Class I" under the EPA’s underground injection control program. The interim guidance only recommends this approach for "liquid-phase waste streams," however.
The third approach uses permitted hazardous waste landfills regulated under Subtitle C of the Resource Conservation and Recovery Act (RCRA), which of all types of landfills "have the most stringent environmental controls in place and higher potential capacity to manage the migration of PFAS into the environment."
The final and thus most uncertain of the recommended approaches is the use of "[s]olid waste landfills (RCRA Subtitle D) that have composite liners and leachate collection and treatment systems." They "receive non-hazardous waste and tend to have environmental controls commensurate with the waste they receive," although such "controls can vary from state to state."
The interim guidance also discusses two other PFAS disposition possibilities that it deems subject to even greater uncertainty than the four recommended ones: "Hazardous waste combustors" and "[o]ther thermal treatment."
Vulnerability, PFAS, and Environmental Justice
The section of the interim guidance concerning "Considerations for Potentially Vulnerable Populations Living Near Likely Destruction or Disposal Sites" defines "vulnerability" as "differences in risk resulting from the combination of both intrinsic differences in susceptibility and extrinsic (or acquired) factors." The former "include age, gender, race/ethnicity, life stage (e.g., infancy, adolescence, adulthood, pregnancy/lactation), and genetic polymorphisms," while the latter "include socioeconomic status, disease status, nutrition status, geographic proximity to sources of exposure, and various lifestyle choices." Issues where intrinsic and extrinsic factors combine often "are related to environmental justice (EJ) concerns;" in other words, they involve "disproportionate impacts on minority populations, low-income populations, and/or indigenous peoples."
The interim guidance suggests that in the specific case of PFAS, decision-makers should consider the risks these compounds are likely to pose to children, fetuses, breastfed infants, people living and working near sources of PFAS, indigenous populations, and "[w]orkers involved in the manufacture, use, transport, transfer, handling, and storage of PFAS-containing waste." The guidance also provides links to EPA documents and statistical tools for risk assessment (including assessment of risks to children specifically), for analysis of environmental justice concerns, and for community engagement.
The interim guidance’s focus on environmental justice considerations likely will remain part of the EPA’s approach to addressing PFAS under the new administration. President-elect Biden already has identified environmental justice as a high priority item of concern for the new EPA Administrator.
Uncertainties and Planned Research
The interim guidance acknowledges throughout the uncertainties and risks associated with various methods of PFAS disposal, including EPA’s recommended ones. In the case of underground injection wells, the risks of PFAS migrating into the environment vary depending on the physical and chemical properties of each specific PFAS compound, the other substances with which it is potentially mixed, and the "geochemical properties of the injection zone," in ways that can make the safety of underground injection methods in a given situation uncertain. The interim guidance acknowledges even greater uncertainties regarding migration from landfills, including the unknown "potential for PFAS to migrate …without adequate controls" and the lack of "detailed information on the amounts and concentrations of PFAS and precursor compounds in wastes that are landfilled."
Thermal treatments also come with uncertain risks: the possibilities of both incomplete destruction of PFAS and release of non-PFAS pollution. Moreover, the guidance is unclear in referring to "products of incomplete destruction (PICs)." It does not identify which, if any, PFAS compounds actually are PICs. Nor does the guidance explain how such PICs are to be collected, sampled, or analyzed.
Further, there is a potential question of toxicity that the guidance does not address. Although PICs and aerial emissions are mentioned, without knowing which PFAS are PICs and possibly subject to aerial releases, it cannot be ascertained if a risk is presented, the nature of any such risk, what the potential exposure pathway could be, or the manner in which to analyze such PICs and aerial releases from a toxicity perspective.
EPA staff still is seeking to fill these many knowledge gaps in the guidance, in part from what it learns in instances where PFAS-containing materials are destroyed or disposed of using one of the recommended methods. Also, EPA intends to conduct targeted research to better understand the properties of different types of PFAS compounds, enhance ways to measure incineration and other thermal treatment outcomes, and discover new treatments to utilize prior to disposal.
Logistically, it is important to note that the EPA only has promulgated two analytical methods for the measurement of PFAS: 537.1 and 533. These methods only are for use with drinking water; they do not apply to sampling PFAS compounds in landfill leachate. EPA, as of January 13, 2021 released Method OTM-45, which is meant to be applied to PFAS "released into the air from stationary sources," which would encompass PFAS "emitted from vents and stacks." Importantly, the OTM-45 method is only intended to measure "a common list of PFAS compounds," and not compounds that potentially could be emitted as PICs. Sampling methods for these latter types of possible PFAS releases are missing from the guidance document, thus creating a considerable challenge that is further complicated by unknown factors such as exit velocities, particle size distribution, and temperature.
Furthermore, sampling for matrices like biosolids and landfill leachate is a complex process. In the absence of a promulgated method, as is the case here, sampling for such matrices usually is undertaken by performing a "modified" version of the drinking water method. However, such sampling modifications can result in inaccuracies due to, among other things, matrix interference difficulties.
Reasons for Caution in Following Recommendations
The uncertainty expressed throughout the guidance is very discomforting, given the potential environmental and legal risks inherent in following the EPA’s recommendations. Because the interim guidance "is not a rule and it is not a statement of policy," following the guidance’s recommendations is not a "get-out-of-jail-free" card; improper disposal or incomplete destruction of PFAS that may occur, even if following the guidance, does not protect a company from a government enforcement action or an action for damages under, for example, federal or state statutes, or common law. In fact, lawsuits have been filed against companies and government agencies under federal environmental laws for alleged incomplete incineration of PFAS-containing substances; improper disposal by other methods also may result in similar consequences.
While presently there are few federal laws that apply to PFAS, a number of states have PFAS-specific requirements; thus, care must be taken not to violate any standard in any such laws. For example, New York law forbids incineration of PFAS-containing firefighting foam in certain cities. Accordingly, it is recommended that entities seeking to dispose of PFAS-containing materials should confer with environmental professionals and legal counsel, in addition to consulting EPA’s interim guidance.
 "Interim Guidance on the Destruction and Disposal of Perfluoroalkyl and Polyfluoroalkyl Substances and Materials Containing Perfluoroalkyl and Polyfluoroalkyl Substances," https://downloads.regulations.gov/EPA-HQ-OLEM-2020-0527-0002/content.pdf, 3.
 Id. at i-iii.
 Id. at 4-5.
 Id. at 5.
 Id. at 3.
 Id. at 5 and 76.
 Id. at 5.
 Id. at 5-6.
 Id. at 84-85.
 Id. at 85.
 Id. at 85-86.
 Id. at 86-87.
 Id. at 87-89.
 Interim Guidance at 81-82.
 Id. at 68.
 Id. at 41-45.
 Id at 6.
 Id. at 93.
 Id. at 92-95.
 EPA Method Number 537.1, https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=537290&Lab=NERL; EPA Method Number 533, https://www.epa.gov/sites/production/files/2019-12/documents/method-533-815b19020.pdf.
 Id. at 3.
 Save Our County et al. v. United States Logistics Agency et al. (N.D. Calif., filed February 20, 2020); https://www.wamc.org/post/lawsuit-says-pfoa-and-pfos-have-been-secretly-incinerated-cohoes.