By Keller O’Leary

The Water Quality Research Foundation (WQRF) recently hosted their first In-the-Know Webinar of 2024 about one of this year’s leading conversations: PFAS.

How To Classify PFAS

Jamie DeWitt, PhD., professor of environmental and molecular toxicology at Oregon State University and a previous external reviewer for PFAS research materials, began the session.

She led attendees through a higher-level definition of PFAS, which can be categorized as either polymers or nonpolymers. In these categorizations, nonpolymers can be catalogued in the perfluoroalkyl and polyfluoroalkyl substance categories. These can be further subdivided into categories based on their carbon chains:

  • Long-Chain Acids (PFOA, PFOS)
  • Short-Chain Acids (GenX, PFBS)

DeWitt pointed out the fact that there are an estimated 14,000 different PFAS that could currently exist in our environment, the majority of which still require further research to classify.

As for general exposure, DeWitt outlined the various methods in which an individual may be exposed to PFAS. While workers in factories with PFAS will primarily become exposed to PFAS through the air in the facility, common households have other potential to become exposed.

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The pathways stem from industrial sources, and PFAS will then be encountered primarily through diet and consumer goods, exposure from drinking water contaminated with PFAS, or other environmental sources.

DeWitt outlined the myriad of health outcomes that have been linked, or are being further studied, between PFAS and its presence in the human body. There are studies that link PFAS bioaccumulation to:

  • Cancers
  • Liver problems.
  • Immune deficiencies that result in a suppressed immune responses.

No exposure to these chemicals is considered safe, but the EPA has issued Maximum Contaminant Levels (MCLs) to help regulate the amount of the chemicals allowed in public drinking water before health outcomes are expected.

How the Water Treatment Industry is Responding to Emerging Contaminants

Steven Woltornist, Ph.D., senior manager of product development at Marmon Water Residential Filtration, outlined the three major pathways for water treatment against PFAS:

  • Municipal (surface, groundwater treatment facilities)
  • Point of Entry (incoming house water filtration systems)
  • Point of Use (direct usage filtration)

For each of these, there are also three prevailing methods for ridding water of contamination:

  • Activated carbon filtration
  • Ion exchange resin
  • Membrane filtration

These systems of treatment are sometimes utilized in tangent with one another, particularly in larger municipal treatment facilities.

Woltornist went on to outline the major changes coming to the industry in the upcoming year, in the form of further regulations and guidelines for the amount of these contaminants allowed in water samples, as well as an increase in the number of labs being constructed to test for these contaminants.

The previous certification of 70 parts per trillion (ppt) for PFOA and PFAS are expected to be replaced by a new maximum of 20 ppt outlined by joint guidelines between the National Science Foundation (NSF) and the American National Standards Institute (ANSI). While larger facilities could easily tackle these new requirements, there is a concern for the smaller facilities that would struggle to maintain cost-effectiveness to adhere to these stricter regulations.

As NSF/ANSI certifications and guidelines continue to limit the amount of PFAS allowed in drinking water systems, Woltornist optimistically speculates on the creativity and innovation from industry professionals to adhere to these increasingly stringent guidelines, as well as the industry’s advancements in educating consumers in these important topics.

For a video of the full presentation, follow the link below.


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