NGWA: EPA’s Unprecedented Interim Drinking Water Health Advisories for PFOA and PFOS

February 20, 2023


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Council member Joe Cotruvo, along with co-authors Susan Goldhaber and Andrew Cohen, recently published a peer-reviewed article “EPA’s Unprecedented Interim Drinking Water Health Advisories (HAs) for PFOA and PFOS” in the National Groundwater Association Journal.

While the EPA health advisories are not enforceable regulations, they can have severe economic consequences as some states have already begun to adopt them as operating guidance or enforceable regulations and set standards for drinking water and site remediation. The co-authors argue that the “unmeasurable and scientifically questionable EPA HAs will increase public concern about the health effects of these chemicals and will result in major expenditures in many of the 150,000 public water systems in the U.S.”

Drinking water regulations should prioritize the most pressing drinking water health concerns in the U.S. which are decaying water distribution systems infrastructure, small systems, and legionellosis.


Per- and polyfluoroalkyl substances (PFAS) are persistent and widely distributed in the environment from commercial products and waste process residues, including in surface waters usually at low parts per trillion (ppt) levels. Groundwaters near contaminated locations can have higher parts per trillion or parts per billion (ppb) concentrations. Interim EPA Drinking Water Health Advisories (HAs) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) that were originally 70 ppt were recently reduced to 0.004 ppt and 0.020 ppt, respectively. Final HAs for perfluorobutane sulfonic acid and its potassium salt (PFBS) and hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (“GenX chemicals”) were established at 2000 ppt and 10 ppt, respectively. The minimum reporting levels (MRLs) for PFOA and PFOS are currently 4 ppt. The scientific basis for these very low and unmeasurable HA values for PFOA and PFOS is debatable and up to about five orders of magnitude below many other worldwide national recommendations (e.g., Australia, UK, Canada), which are in the range of 100 ppt and above.

Access the full text in NGWA’s online library here.

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