EPA’s preliminary regulatory determination is required by the Safe Drinking Water Act (SDWA). Under the SDWA, EPA must publish a list of contaminants, the Contaminant Candidate List (CCL), that are not subject to an MCL every five years.1 EPA must then decide whether to regulate at least five of the contaminants on the CCL.2 To make a determination to regulate (i.e., a positive determination), EPA must find that: (1) consumption of the contaminant may result in adverse health effects; (2) the contaminant has been found in public water systems with a frequency and at levels to raise public health concerns; and (3) regulation of the contaminant presents a meaningful opportunity to reduce associated health risks.3
The current CCL, the Fourth, was published in 2016. The Fourth CCL listed more than 100 contaminants, including PFOS and PFOA. On February 20, 2020, EPA announced its preliminary determinations for PFOS, PFOA, 1,1,-dichloroethane, acetochlor, methyl bromide, metolachlor, nitrobenzene and RDX. The preliminary determination is to regulate PFOS and PFOA, but not the other six contaminants. This means that EPA has found that consumption of PFOS or PFOA may result in adverse health effects, that they are in public water systems, and that regulating the contaminants presents a meaningful opportunity to reduce adverse health effects.4
Importantly, the announcement offers no guidance on the regulatory levels EPA anticipates setting for PFOS or PFOA. At this time, EPA is only seeking comment and further information on its decision to regulate PFOS and PFOA and not regulate the six other contaminants. The preliminary determinations have not yet been published in the Federal Register. Once they are published, EPA will accept comments for 60 days.
After considering the comments, EPA will publish a final determination on whether to regulate the eight contaminants. If EPA makes a positive determination for PFOS or PFOA, it must publish a proposed Maximum Contaminant Level Goal (MCLG) and MCL within 24 months.5 Within 18 months of that date, EPA must promulgate a final MCLG and MCL.6 These standards would be subject to a separate notice-and-comment period before adoption.
EPA’s PFAS Action Plan suggested that the Agency would determine whether or not to set drinking water standards for PFOS and PFOA by the end of 2019. EPA failed to meet that goal, and the preliminary determination suggests it will be some time before it does decide whether or not to set MCLs for PFOA and PFOS.