The race to zero: EPA announces new PFAS drinking water health advisories

The U.S. Environmental Protection Agency (EPA) released new lifetime drinking water health advisories for certain per- and polyfluoroalkyl substances (PFAS) on June 15, 2022. These interim advisories for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) replace the health advisory levels (HAL) the EPA issued in 2016. The interim HALs for PFOA of 0.004 parts per trillion (ppt) (4 parts per quadrillion or ppq) and PFOS of 0.02 ppt (20 ppq) are the lowest levels issued by the EPA to date.

The EPA also issued final health advisories for two PFOA and PFOS replacement chemicals for the first time. The final HALs were announced to be 2,000 ppt for perfluorobutane sulfonate (PFBS) and 10 ppt for hexafluoropropylene oxide (HFPO) dimer acid, more commonly known as “GenX.”

News of these advisories issued by the EPA has garnered a lot of attention from those who follow PFAS developments. Here are our top takeaways and how they may affect you moving forward:

  1. PFOA and PFOS advisory levels are much lower than previous values: The EPA’s 2016 health advisory level of 70 ppt (individually or combined for PFOA and PFOS) has been used as a benchmark for many states in developing their guidance levels for drinking water sources. These new HALs are orders of magnitude lower than the previous advisory levels.
  2. There are new criteria for two prominent replacement chemicals—PFBS and GenX: While the focus from EPA and the states has been on PFOA and PFOS, this action gives further indication that PFBS and GenX will be among the PFAS constituents receiving greater scrutiny. In the near term, this opens the door for water systems to assess the level of PFBS and GenX in their systems and in turn likely require upstream sources to assess their contributions if elevated levels are detected. If elevated levels of PFBS and GenX are found in public or industrial systems, these new HALs provide a treatment threshold that will need to be achieved to reduce these compounds in drinking water.
  3. States will review this for implementation, and it is part of the EPA MCL process: While HALs are not enforceable and currently only serve as advisory levels, this announcement is part of the process to establish a maximum contamination level (MCL) for PFAS substances, which is enforceable. The process to establish an MCL is ongoing, and according to the EPA’s PFAS Strategic Roadmap, the target date for the release of enforceable draft levels is fall 2022, with targeted establishment of a final rule in 2023. This does not change how states develop their standards for PFAS. States may adopt these new advisory limits or establish their own guidelines.
  4. Measurements at parts per quadrillion cannot be determined with current methods: Current laboratory technology and the established EPA drinking water test methods 533 and 537.1 are only capable of accurately reporting PFAS substances at the single-digit ppt level. Technology to detect PFOA and PFOS at the ppq level is simply not available, and the EPA acknowledges this. In addition, in 2023, public water systems will begin to test for 29 PFAS substances, including PFOA, PFOS, PFBS, and GenX, through the Fifth Unregulated Contaminant Monitoring Rule (UCMR-5), in which the current detection limit is 4 ppt. Of greatest note for drinking water systems and industrial sources is that if the health advisories are any indication, one can expect the final limits to be extremely low.

The issued health advisory has raised questions as to how these levels were determined and concerns over the available ability to detect sources accordingly. In a statement dated June 15, The American Water Works Association says, “The PFOA and PFOS advisory levels are extremely low and do not reflect the draft recommendations of EPA’s own expert Science Advisory Board review. The health advisory levels at parts per quadrillion, undetectable by modern laboratory methods.”

The EPA also has the authority and intent to set a maximum contamination level goal (MCLG) that “is the maximum level of contaminant in drinking water at which no known or anticipated adverse effect on health of person would occur.” While an MCLG is not enforceable, MCLs are set as close to the MCLG as feasible, using the best available technologies. Based on our teams’ extensive PFAS knowledge, our experts predict the EPA are likely to set enforceable limits through the MCL process at or near the single-digit ppt level.

Public and private industries that are actively addressing PFAS or are reviewing their potential contributions are encouraged to understand how these new levels may impact future regulatory requirements.

Barr’s PFAS team of experts continues to leverage our more than 20 years of experience working on PFAS projects with public and private clients. Our team can address questions raised by these new levels, including understanding laboratory screening, establishing sampling protocols, chemistry evaluation, and treatment technologies. All these aspects of our experience are critical in understanding a PFAS profile and increasingly more important at these low-level thresholds.

We continue to monitor PFAS developments across the United States and around the world.  

Have questions or need help? Please contact

Theme picker

Let's Chat!

We actively participate in conferences, career fairs, campus events, and more. Check our events page to see where we’ll be next, we’d love to connect with you.