Author: Kent Sorenson, Chief Technical Officer

Amid growing concerns and public awareness around the health risks posed by per- and polyfluoroalkyl substances (PFAS), the U.S. Environmental Protection Agency (EPA) has ramped up its regulatory efforts. The final PFAS National Primary Drinking Water Regulation was released in early April, which sets Maximum Contaminant Levels (MCLs) for six PFAS. The regulation mandates that public water systems monitor for PFAS within 3 years and implement solutions to reduce PFAS levels that exceed these MCLs within 5 years. 

PFAS have been linked to human health impacts including cancer, reduced fertility and lowered immune response. There are thousands of PFAS chemicals, which are found in industry and consumer products like nonstick cookware, firefighting foam and waterproof clothing. Once PFAS-containing products are thrown away, these “forever chemicals” are very slow to break down and often end up in the environment, including in groundwater and drinking water. In fact, a recent EPA study estimates that 60% of the U.S. population is exposed to PFAS in their drinking water.

Numerous open questions and uncertainties make it difficult for industry organizations, landfill operators and water treatment sites to take action based on this regulation and on another proposed rule that would designate nine PFAS as hazardous constituents. Here, I’ll address the most common questions we receive from customers and what actions the PFAS treatment industry should take in the wake of these initiatives.

What Is the Maximum Contaminant Level (MCL) for PFAS?

The EPA has issued a national drinking water regulation and an MCL for six PFAS:

  • perfluorooctanoic acid (PFOA)
  • perfluorooctanesulfonic acid (PFOS)
  • perfluorohexane sulfonic acid (PFHxS)
  • hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salt (also known as a GenX chemicals)
  • perfluorononanoic acid (PFNA)
  • perfluorobutane sulfonic acid (PFBS)

As expected, EPA has designated an MCL value of 4 nanograms per liter (parts per trillion) for PFOA and PFOS, and a hazard index (HI) of 1.0 as the MCL for mixtures of the other four compounds. The final rule did have one change from the draft, which was an MCL of 10 nanograms per liter for three of these compounds individually: PFHxS, PFNA, and HFPO-DA. To put that concentration in perspective with respect to the HI calculation, if any of these individual compounds were to exceed 10 nanograms per liter, it would cause the HI to exceed 1.0 as well. So, the individual MCLs for these are not a more onerous requirement than the HI, but probably make it easier to understand the limits.  

These nanogram per liter MCLs pose significant challenges for water treatment facilities. While the new MCL specifically applies only to public drinking water sources, it is often used as a default treatment goal for all types of treatment systems, including for in situ treatment of contaminated sites and discharges to publicly owned treatment works (POTWs). Ultimately, this will determine how the waste industry should design and install water treatment systems going forward.

Which Specific PFAS Will be Designated as Hazardous?

The EPA has announced a proposal to amend its regulation under the Resource Conservation and Recovery Act (RCRA) by adding nine specific PFAS to its list of hazardous constituents. This proposal is nearing the end of its 60-day period for public comment. The nine substances are:

  • perfluorooctanoic acid (PFOA)
  • perfluorooctanesulfonic acid (PFOS)
  • perfluorobutanesulfonic acid (PFBS)
  • hexafluoropropylene oxide-dimer acid (HFPO–DA or GenX)
  • perfluorononanoic acid (PFNA)
  • perfluorohexanesulfonic acid (PFHxS)
  • perfluorodecanoic acid (PFDA)
  • perfluorohexanoic acid (PFHxA)
  • perfluorobutanoic acid (PFBA)

That means these nine PFAS are suspected to have toxic, carcinogenic, mutagenic, or teratogenic effects. If the rule is finalized, facilities would be required to sample for these PFAS and, if necessary, clean up PFAS-containing waste in accordance with RCRA.

Despite uncertainty around when this proposal will be implemented and what changes will be made following the public comment period, the takeaway for the waste industry is clear: these nine PFAS will be regulated as hazardous waste in some capacity in the near future. Facilities that are generating or managing PFAS waste streams must start thinking now about how to effectively handle and dispose of waste containing these compounds.

How can Allonnia help?

Surface Active Foam Fractionation (SAFF®) technology is a proven and award-winning solution to permanently remove PFAS from contaminated water. It uses rising air bubbles to rapidly separate and concentrate PFAS for destruction in a sustainable and cost-effective method.

Allonnia commercially launched SAFF, which is manufactured by EPOC Enviro, to the North American market in 2022. The technology is effective across a full spectrum of applications, having been demonstrated to meet the MCLs in landfill leachate, groundwater, surface water, and reverse osmosis brine (reject). Allonnia’s booster for SAFF has also been shown to enhance removal of short-chain PFAS compounds, by increasing their aggregation and subsequent separation.

We have successfully deployed and operated SAFF units across more than a dozen sites from California to Massachusetts, helping facilities achieve regulatory compliance that meets or exceeds the most stringent state PFAS regulations.

For more information on the benefits of SAFF for PFAS removal at your site, contact us here or quantify the effectiveness of SAFF for your site conditions with our free calculator.