On October 15th, the Department of Defense (DoD) issued an internal guidance document regarding CERCLA cleanup actions involving per- and polyfluoroalkyl substances (PFAS). The DoD guidance sets screening levels for three PFAS compounds that some have criticized as being inconsistent with draft screening levels that are in the process of being finalized by U.S. EPA.
DoD’s October 15th guidance document adopts U.S. EPA’s proposed screening level (in groundwater) of 40 parts per trillion (ppt) for sites containing both perfluorooctane sulfonate (PFOS) and perfluorooctanioic acid (PFOA). However, the DoD guidance adopts a higher screening level for sites containing only one of the three targeted PFAS compounds. For sites containing only PFOA or PFOS, the DoD screening level jumps to 400 ppt. The guidance also sets a screening level for perfluorobutanesulfonic acid (PFBS) (a shorter chain PFAS compound) at 40,000 ppt.
The DoD guidance is silent with respect to other PFAS compounds. The guidance also doesn’t specify a particular clean-up level if the above-referenced screening levels are exceeded. Instead, the guidance notes that a site-specific risk assessment will be conducted to determine if remedial measures are necessary.
Notwithstanding the DoD guidance document, there is no indication that U.S. EPA will not continue to rely on its 40 ppt level screening (both for single- and combined-PFAS compound sites) and 70 ppt preliminary cleanup goal proposed in its draft interim guidelines for remediating PFAS-impacted groundwater at DoD sites.