On December 18, 2020, U.S. EPA issued its long awaited draft interim guidance on disposal and destruction methods for per- and polyfluoroalkyl substances (PFAS). The guidance, which U.S. EPA was required to issue pursuant to the National Defense Authorization Act for Fiscal Year 2020, discusses three disposal/destruction technologies—thermal treatment, landfilling and underground injection.
In discussing these technologies, the guidance acknowledges that it does not address what concentrations of PFAS in wastes, spent products, or other materials or media would necessitate destruction or disposal, noting that other regulatory mechanisms or risk based guidance are more appropriate for establishing such concentrations. Instead, the guidance is intended to provide information and suggested considerations to assist in evaluating destruction and disposal options for PFAS waste.
The guidance does not endorse any single technology—rather, the guidance generally discusses the following technologies in order of lower to higher uncertainty in terms of the ability to control the migration of PFAS into the environment during the disposal/destruction process.
- Interim Storage. Acknowledging that this is not a destruction or disposal method, the guidance notes that interim storage may be an option if the immediate destruction of the PFAS materials is not necessary. Interim storage (from two to five years) could be relied upon while research continues to minimize uncertainties associated with the other options.
Permitted Deep Well Injection (Class I). Underground injection would be limited to liquid-phase waste streams. However, the guidance notes that there are a limited number of wells and logistical issues could limit the practicability of this option.
- Permitted Hazardous Waste Landfills (RCRA Subtitle C). The guidance notes that RCRA Subtitle C landfills have the most stringent environmental controls in place and therefore have a higher potential to prevent the migration of PFAS into the environment.
Solid Waste Landfills (RCRA Subtitle D) with Composite Liners and Leachate Collection. These landfills can only receive non-hazardous wastes and therefore have less stringent environmental controls that vary from state to state.
Hazardous Waste Combustors. These consist of commercial incinerators and cement/aggregate kilns that can achieve temperatures and residence times sufficient to break apart the PFAS. However, the guidance notes that emissions from these combustion sources haven’t been adequately characterized to confirm that the PFAS compounds are in fact destroyed.
- Other Thermal Treatment. These consist of carbon reactivation units, sewage sludge incinerators, municipal waste combustors, and thermal oxidizers. However, the same uncertainties that were referenced in the previous bullet would also apply to these technologies.
The appropriate methodology for dealing with PFAS waste has been subject to controversy with environmental groups such as Sierra Club suing the Department of Defense (DoD) in an effort to prevent DoD from incinerating its stockpile of PFAS-based firefighting foams. Although U.S. EPA set a 60-day comment period on the interim guidance, U.S EPA could certainly elect to delay issuance of any final guidance to give the new Biden Administration an opportunity to put its imprint on the guidance )especially considering the emphasis that the new administration has placed on PFAS).