The Hidden Dangers of Swimming in the Rivière du Nord: Limited Data on Water Quality Raises Concerns

With the hot weather, it can be tempting to take a dip in the Rivière du Nord to cool off, or simply to sail there to enjoy the good weather. But, will you get sick because the water is too polluted? In fact, very little data is available on the water quality of the Rivière du Nord. And any contact, even indirect, is at your own risk. Explanations.

Abrinord, the watershed organization of the Rivière du Nord, is the only one that monitors water quality on a recurring and long-term basis. It samples the watercourses with 48 stations, once a month from April to November, so eight times a year, explains Simon Poitras, project manager responsible for the watercourse quality monitoring program. But these data are not sufficient to establish whether swimming is safe or not.

A partial portrait

“Sampling is definitely a photo. It would take a lot more sampling to get a real picture of the river. Many things can happen in a month,” says Mr. Poitras.

These data are available online, thanks to l’application iEAU. They also show the thresholds above which direct (swimming) or indirect (navigation) contact with the waterway entails health risks. For the Rivière du Nord, we see that from Saint-Jérôme to approximately Prévost, even indirect contact is risky. From Piedmont to Sainte-Adèle, direct contact sometimes seems possible, but Mr. Poitras has a major caveat.

“The concentrations of contaminants vary greatly depending on the time of day, the weather and the section. […] There are a thousand factors to consider. That said, as a general rule, “the further upstream you are, the less contaminants there will be,” explains Poitras.

If on a hot summer day you decide to take the risk anyway, be aware that you are exposing yourself to pathogens, such as E. coli. These can cause diarrhea, indigestion, even hepatitis A and other more serious illnesses. You could also have swimmer’s itch, a skin irritation caused by the bites of parasites in the water. Certain behaviors increase risk, such as submerging the head and ingesting water.

To ensure safe swimming, “more regular monitoring would be needed, which would make it possible to have a better picture in real time”. “A river changes a lot. It’s easier in the lakes, where there is less flow,” suggests Mr. Poitras.

Reduce contamination

The objective of the Abrinord program is rather to have a global view of the rivers and their evolution, but above all to determine their sources of pollution and contamination.

On iEAU, we can see that the amount of contaminants varies considerably over time. It is therefore difficult to establish a trend, admits Mr. Poitras, but he believes that the quality of the water is tending to deteriorate. “In a context where the demography of the region is increasing, there is more human activity. Climate change also leads to an intensification of meteorological phenomena. Heavy rainfall, for example, carries more contaminants into the water. If we had the same conditions, with the efforts we are making, we might have seen an improvement. But strong development and climate change limit this positive impact. That’s why we must not let go of the piece: it will go on deteriorating. »

However, the program has already proven its usefulness. “There are sections where improvements have been made over the years. I can cite Saint-Jérôme, who had a problem with fecal coliforms. With the monitoring program, we were able to determine the source, and the City solved the problem,” says Mr. Poitras. Abrinord also carries out “small satellite projects”, for example on the impact of road salts or agricultural contamination.

The Rivières Foundation is currently a study on the North River, from Saint-Jérôme to Prévost, on its swimming potential, among other things. Its results should be made public towards the end of the summer.

2023-07-04 23:57:26
#Rivière #Nord #Swimming #risk #Log #Access