EPA Releases Draft Health-Based Levels for PFAS in Drinking Water

As part of its PFAS Strategic Roadmap, EPA committed to developing a proposed drinking water standard for PFOS and PFOA by Fall 2022 and a final standard by Fall 2023.  As part of this process, EPA must first set a health-based maximum contaminant level goal (MCLG).   The Safe Drinking Water Act (SDWA) requires EPA to consider cost and technical feasibility when setting maximum contaminant levels (MCLs) as the enforceable drinking water standard.

EPA recently released draft risk values for PFOS and PFOA that are orders of magnitude lower than EPA calculated in 2016, raising potential new challenges for drinking water utilities.  EPA is proposing a reference dose (RfD) (or greatest amount an adult can ingest daily over the course of a lifetime without health risks) of 1.5 x 10^-9 milligrams/kilograms (mg/kg)-day for PFOA and an RfD of 7.9 x 10^-9 mg/kg-day for PFOS.

This is significantly more stringent than the RfD values of 2 x 10^-5 mg/kg-day for both chemicals that EPA used in setting its 2016 lifetime health advisories of 70 ppt for the chemicals. Using the same formula EPA used in developing the 2016 health advisories, and adjusting it to be protective of children, would result in a range of 6 to 7 parts per quadrillion (ppq), or 0.006 to 0.007 ppt, for PFOA and 30 to 37 ppq, or 0.030 to 0.037 ppt, for PFOS -- levels that are below most laboratories’ detection limits. 

Furthermore, if EPA finalizes its proposed health-based conclusion that PFOA is a likely carcinogen, then the MCLG would be zero.  However, any final enforceable drinking water standard would most likely be some number above zero because economic and technical feasibility considerations for setting the MCLs.  Many environmental organizations have advocated for an MCL of 1 ppt for all PFAS.

In addition to any MCLG, EPA is also likely to issue revised non-enforceable health advisories before setting MCLs.  Even though the health advisories are non-binding, for drinking water utilities they are in practice, e de facto MCLs due to public pressure.  With more stringent PFOA and PFOS health advisories, as well as an upcoming first-time health advisory for additional PFAS, utilities will be forced to make decisions about whether to take contaminated wells offline or to buy wholesale water from other suppliers. 

On November 16, 2021, EPA released a press release indicating that it had submitted the draft risk values for PFOS and PFOA to the Science Advisory Board (SAB).  While the agency has not set a target date for revised PFOA and PFOS advisories, EPA has indicated that it “will move as quickly as possible to issue updated health advisories for PFOA and PFOS that reflect” the new science and input from the agency’s Science Advisory Board, which is scheduled to review the PFOS and PFOA documents in December 2021 and January 2022.

While EPA has a lot of work to do before it can issue a proposed drinking water standard for PFOS and PFOA next year, it appears that the MCLG and likely health advisories for PFOS and PFOA in drinking water could be very stringent (and possibly below detection limits).  NASF will continue to work with EPA officials and provide critical updates on this rulemaking to NASF members.  If you have any questions or would like more information regarding the draft health-based levels that will be used to set drinking water standards for PFOS and PFOA, please contact Jeff Hannapel or Christian Richter with NASF at jhannapel@thepolicygroup.com or crichter@thepolicygroup.com.   

This update is courtesy of the National Association for Surface Finishing (NASF). For more information or to become a member, visit nasf.org.