Towards lower perfluorinated levels in water

Perfluorides are increasingly in the sights of public health organizations. New standards of 10 to 20 times lower are proposed in Canada, while a strict limit is imposed for the first time in drinking water in the United States. Eight cities in Quebec – Sainte-Pétronille, Longueuil, Waterloo, Val-d’Or, Saint-Donat, Sainte-Adèle, L’Épiphanie and Sainte-Cécile-de-Milton – have too much perfluorinated in their water, according to these standards .

Higher standards proposed in Canada

Since 2019, Health Canada has set targets governing the concentration of around ten perfluorinated substances in drinking water. The lowest targets are 200 nanograms per liter (ng/L). New stricter standards, which are the subject of public consultation until April, target around thirty perfluorinated substances. The sum of their concentration should not exceed 30 ng/L, which is much less.

Even more severe in the United States

In the United States, the Environmental Protection Agency (EPA) set in mid-March at 4 ng/L the limit for two perfluorides in drinking water.

Four other perfluorines are also targeted by the EPA, according to a complicated calculation with thresholds ranging from 9 to 2000 ng / L, according to Mr. Sauvé. EPA standards must be enforced by all states, which may even adopt more stringent standards.

Some states – for example, Michigan since 2020 – already monitor perfluorides in drinking water. “I think that in Canada, we should go towards lower limits, like in the United States”, estimates Scott Hopkins, chemist at the University of Waterloo, specialist in the measurement of perfluorides in drinking water and sewers. .

Too much perfluorinated in the water of eight cities in Quebec

Sébastien Sauvé applied the new EPA standards to his analysis of perfluorides in drinking water in Quebec, published in mid-February in the journal Water Research. The number of municipalities exceeding the thresholds is five according to the proposed Canadian standard of 30 ng/L, but rises to eight when the EPA standard is applied. Thus, the American standard would tip Sainte-Pétronille, Longueuil and Waterloo into the camp of cities where drinking water contains too many perfluorinated substances, in which Val-d’Or, Saint-Donat, Sainte-Adèle, L’ Epiphany and Sainte-Cécile-de-Milton according to the standard envisaged in Canada. It should be noted, however, that these measurements fluctuate: at L’Épiphanie, a subsequent measurement reported levels below the standard of 30 ng/L.

“The City is following this file closely through its participation in the Industrial Drinking Water Chair at Polytechnique Montréal, in collaboration with other municipal partners,” said Louis-Pascal Cyr, spokesperson for the City of Longueuil.

Voluntary Federal Standard

With the proposed new standards, Canada “is, in my opinion, more stringent than the American approach, which only covers a few perfluorinated compounds,” says Sébastien Sauvé.

The Canadian federal standard is not mandatory, but some provinces, notably Ontario and British Columbia, are more advanced in this area than Quebec – which does not limit the presence of perfluorides in drinking water.

Quebec is following the file

The National Directorate of Public Health of Quebec is following the file, according to the public relations specialist Robert Maranda of the Ministry of Health and Social Services, who underlines the “uncertainties concerning the probability and the importance of the effects on health” of perfluorides. At the end of February, the national director of public health, Luc Boileau, declared to Radio-Canada that the water of the Quebec distribution networks was “very drinkable”, despite the presence of perfluorides.

Almost eternal pollutants

Discovered in the 1940s, perfluorines are very resistant, which is positive for the industry, but it allows them to accumulate in the environment and living organisms without being degraded. They are notably used in stain repellents, anti-adhesives and high performance fire-fighting foams. An increased risk of certain cancers has been observed in populations living near highly contaminated sites, and more recently, immune problems at more widespread rates, driving the new norms.

The half-life (a technical measure of the elimination of half of a quantity of a product) of perfluorides sometimes approaches ten years. “We call them eternal pollutants, but that’s a bit of an overstatement, we’re not talking about hundreds or thousands of years,” says Mr. Sauvé. Good news: the concentrations in the American population of certain perfluorinated substances banned in 2004 by the Stockholm Convention on Persistent Organic Pollutants, which notably covers PCBs, have started to drop, according to the Centers for Disease Control (CDC) of the American government. . Theoretically, the regulations do not only include perfluorines, but also polyfluorines. The English acronym PFAS is also used to designate them, or in French “substances alkylées perfluorées ou polyfluorées”.

Analyze wastewater

The few private laboratories capable of analyzing the quantity of perfluorides in drinking water in Quebec probably have a detection limit of 4 ng/L, according to Mr. Sauvé. “With a little effort, they should be able to get down to 1 ng/L. That should be enough to meet the new Canadian standard. Mr. Sauvé’s laboratory has a detection limit of 0.05 to 0.1 ng/L, depending on the molecule, and covers 75 kinds of perfluorides.

At the University of Waterloo, Mr. Hopkins is working on a new technology for detecting perfluorides in wastewater. “Current techniques work with relatively clean waters,” says Hopkins. With sewage, it is more difficult. If we want to identify the sources of perfluorides to eliminate the problem at the source, we will need new technologies. »