• Waterdoc
    3 months ago

    Some facts:

    Background info.

    • PFAS is a class of chemical substances with varying properties, but in general act as surfactants.

    • PFAS are considered carcinogenic and impact birth weight.

    • PFAS contain a carbon-fluorine bond, which is a very strong bond that does not naturally degrade.

    • Some PFAS will naturally decrease concentration over time, but only to be transformed into other compounds that will not (often PFOS).


    • The US EPA has taken the approach of regulating a select few PFAS, generally based on their known toxicity. PFOA and PFOS will essentially be limited to a concentration of zero.

    • The US EPA has been working on this for years. Mr. Biden did not snap his fingers and make a regulation. These things move much slower than that, and the industry generally feels that this process moved too quickly because there is limited understanding of how much PFAS exists in drinking water.

    • Health Canada has proposed a guideline which limits PFAS to 30 ng/L (ppt) as a total sum of all compounds that can be accurately measured. Currently their guidelines limit PFOA to 200 ng/L and PFOS to 600 ng/L. Health Canada does not regulate your water provider through, that is up to your provincial/territorial government, which may have different guidelines than this.

    PFAS in the environment.

    • PFAS is ubiquitous in the environment due to its travel through the water cycle. It exists in Antarctic ice and on top of Mount Everest.

    • Usually the largest sources of PFAS in drinking water are firefighting training areas that used PFAS containing foams (airports and military bases), landfills, certain manufacturers (metal plating, paper, semiconductors), and municipal wastewater. There are many more sources than this though.

    • Landfills and municipal wastewater tend to be the highest mass loading of PFAS because of the ubiquity of PFAS in consumer products.


    • PFAS can be destroyed using electrochemical and thermal methods, but these are not feasible for drinking water treatment.

    • The current approach for drinking water treatment is adsorption to either granular activated carbon (GAC) or ion exchange resin.

    • Treating PFAS at the source is always the goal instead of treating it at a water treatment plant.

    Feel free to ask questions, I will do my best to answer them!