In several of our past blogs, we discussed the developing attention by regulators to the environmental contaminants known as per- and polyfluoroalkyl substances (PFAS). You may recall the April 2021 announcement by Health Canada: “Notice of intent to address the broad class of PFAS.”
In accordance with that April 2021 notice of intent, Health Canada announced on February 10, 2023, the “Draft objective for per- and polyfluoroalkyl substances in Canadian drinking water.”
Previously Established Maximum Acceptable Concentrations for PFAS
Previously (in 2018 and 2019), Health Canada established drinking water maximum acceptable concentrations (MAC) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in drinking water. As well, they had established screening levels for nine other PFAS.
The two established MACs in drinking water are:
- PFOA 200 ng/l (nanograms/litre)
- PFOS 600 ng/l
Health Canada states that once this current Objective is complete, it will replace these MACs and screening levels. NOTE: ng/l = parts per trillion.
Health Canada also states that total PFAS should include all PFAS listed in the EPA method and detected above the Method Detection Limit.
(Image by Jason Gillman from Pixabay)
PFAS Regulation Elsewhere
It is worth noting that Michigan, which has been in the national news for PFAS contamination for some time, established maximum contaminant levels (MCLs) that are much more stringent: 8 ng/l (PFOA) and 16 ng/l (PFOS). The federal government in the United States has yet to establish MCLs for specific PFAS in drinking water; only maximum contaminant level goals have been established.
Additionally, as a point of reference, in September 2022, the World Health Organization proposed drinking water values of 100 ng/l for both PFOA and PFOS and 500 ng/l for total PFAS.
Objective for Canadian Drinking Water Quality for PFAS
The document from Health Canada was developed with the intent to “provide regulatory authorities and decision-makers with an objective for per- and polyfluoroalkyl substances in Canadian drinking water supplies.”
As stated in the document, an objective of 30 ng/L is proposed for the sum of total PFAS detected in drinking water. In defining the total PFAS, Health Canada states that PFAS should be calculated using the full list of substances in either the United States Environmental Protection Agency (EPA) Method 533 or EPA Method 537.1, or both.
EPA Methods for PFAS Analysis
Here is some background on the referenced EPA methods. The EPA’s Method 533 focuses on “short chain PFAS (i.e., those with carbon chain lengths of 4 to 12). Method 533 complements EPA Method 537.1 and can be used to test for 11 additional PFAS. Using both methods, a total of 29 unique PFAS can be effectively measured in drinking water.
Later in the document, Health Canada states that EPA Method 533 provides better coverage of the PFAS that have been observed in PFAS data gathered in Canada.
Health Canada also states that total PFAS should include all PFAS listed in the EPA method and detected above the Method Detection Limit.
According to the document, utilities should strive to analyze as many PFAS as possible to gain a better understanding of the PFAS present in the drinking water. This will help in deciding the best treatment option to reduce exposure.
Importantly, if both of the EPA Methods are used in the analysis and there are duplicative PFAS reported, the highest duplicative result should be used in summing the total PFAS.
Treating PFAS in Drinking Water
Health Canada provides information on water treatment technologies (e.g., granular activated carbon, reverse osmosis, and anion exchange). Treatment technologies do pose additional complications such as disposal of spent media containing PFAS removed from the water. The goal in treating the drinking water is as low as reasonably achievable or ALARA.
You can find the complete document from Health Canada here: “Objective for Canadian Drinking Water Quality Per- and Polyfluoroalkyl Substances.”
As PFAS are found virtually everywhere and are a global concern, expect more testing and regulations in the near future.
More Information on PFAS
If you are looking for more information on PFAS, we have a fair bit of information on our PFAS Resources Page.
If you need technical assistance with a PFAS issue, we can help. We have been involved in a number of PFAS projects concerning sampling, groundwater remediation, litigation support, and providing technical advice.
You can contact our office at 519-948-7300 or send an email to us at info@dragun.com.
This blog was drafted by Alan Hahn. Alan has an undergraduate degree in Environmental Studies and completed a graduate program in Environmental Management. He has worked in environmental management for 45 years. He has written hundreds of blogs and articles. His published work includes HazMat Magazine, BizX Magazine, Michigan Lawyers Weekly, GreenStone Partners, Manure Manager Magazine, and Progressive Dairy.
This blog was reviewed by Christopher Paré, P.Geo. Chris is a senior geoscientist and manager of Dragun’s Windsor, Ontario, office. Chris has more than 30 years of experience on projects ranging from environmental site assessments (Phase One/Two ESA), remedial investigations, soil and groundwater remediation, Permits to Take Water, Records of Site Conditions, excess soil management, vapour intrusion, and site decommissioning. Chris is a frequent speaker, author, and expert witness. See Chris’ bio.
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