Chambly basin - Water quality monitoring, phase 2
Bassin de Chambly: water monitoring for municipal autonomy
After carrying out an initial study to validate the bathing potential at the Centre Nautique Gervais-Désourdy and identify potential sources of pollution, Fondation Rivières once again collaborated with the City of Chambly in the summer of 2023 to monitor water quality at the Chambly Basin for a second consecutive year.
This time, the project focused on monitoring two regular sites, with an emphasis on validating the closure protocol proposed following the first study, and empowering city employees to carry out subsequent summer monitoring. This follow-up will also have ensured good water quality on July 2, 2023, when some twenty people diving in the Chambly basin for Grand Splash 2023.
Grand Splash in Chambly, photo: Alexya Morin
Services
- Validation of bathing potential
- Site vulnerability assessment - bacteriological water quality
- Continuous monitoring of water quality
- Providing tools and protocols to make the city self-sufficient
Partners and collaborators
- City of Chambly
Our methodology
The municipal team from the Gervais-Désourdy Nautical Centerwith technical support from Fondation Rivières, carried out regular water sampling at two sites, the Centre nautique and Municipal Wharf 56. The potential for bathing and water sports activities was assessed on the basis of bacteriological water quality, using counts ofEscherichia coli (E.coli). This regular monitoring yielded a total of 32 sampling days, with an average of 3 days per week, enabling us to determine water quality at the study sites and establish contamination trends.
Duration of the study
Sampling took place from June 14 to August 24, 2023 (11 weeks).
Findings
01.
Water at the Nautical Center meets Canadian swimming guidelines with flying colors (direct contact)
02.
The proposed closure protocol would prohibit access to as a preventive measure between 25% and 30% of time during a normal season
03.
The protocol would indicate preventive closures, whereas the bacteriological quality remains satisfactory for swimming about 4 times out of 10
The City of Chambly has access to good quality bathing water at the Bassin de Chambly and has everything it needs, including a well-equipped monitoring team and existing infrastructures that can easily be adapted, to allow swimming at the Centre nautique Gervais-Désourdy.
The main obstacle remains public perception
The studies produced by Fondation Rivières for 2022 and 2023 clearly demonstrate the swimming potential of the Centre nautique Gervais-Désourdy. Yet many people still resist the idea of taking a dip in the Richelieu River, which does not enjoy a very good reputation for water quality. Untreated wastewater discharges and numerous agricultural and industrial activities along the river have, in the pastThe river's water quality has been adversely affected by agricultural activities. Agriculture is still a major emitter of phosphorus, a by-product of fertilizers that promotes algal blooms and impairs fish oxygenation. On the other hand, management of municipal and industrial wastewater discharges has greatly improved over the past 30 years, with beneficial effects on the Richelieu River.
In fact, the Bacteriological and Physicochemical Quality Index (IQBP) measured at the Fryer dam station (located between the city of Saint-Jean-sur-Richelieu and the Chambly basin) since 2002 indicates that the water is generally of satisfactory quality at this location. This historical monitoring upstream of the Chambly basin, as well as the continuous monitoring of bacteriological water quality by the City of Chambly in the years to come, should hopefully reassure the most recalcitrant about the viability of access to swimming in the Chambly basin.
Do you make decisions within your municipality?
Consult the guide to opening an urban swimming site to find out how the Fondation Rivières can help you.
