The City of Châteauguay has been producing fluoridated drinking water since the 1960's. More recently, the City has been using a system with energy efficient high yield pumps to produce quality water more economically and in sufficient quantity. To ensure natural recharging, the water is drawn from ground-water (60 %) and Lake Saint-Louis (40%).
Châteauguay provides drinking water not only for its residents. The pumping stations Jean-Louis Chèvrefils, Joseph-Chèvrefils, Marchand and Alonzo-Béliveau also service the Régie intermunicipale d'aqueduc de la vallée de Châteauguay, which includes the municipalities of Mercier, Sainte-Martine, and sections of Léry, Saint-Isidore and Saint-Urbain.
The water is routinely tested before it goes into the public system. Samples are taken up to three times a week at the different stations. A total of 42 samples are sent each month to independent laboratories accredited by the ministère de l'Environnement for analysis. According to experts, the toxicology level is below the recommended regulatory standards.
The bacterial analysis of the drinking water is also followed in a very cautious sampling process at the source, from the tap, the lake and the river or the wells with or without a pump.
The container is supplied to the City by the laboratory. It is a sterilized bottle that contains a preserving agent. The city must use this bottle as is, and above all, not rinse it. It's identification is also rigorous: name, date and location of sample taking, on the bottle as well as on the corresponding form. To avoid any risk of contamination, the rim cannot be touched, nor the inside of the lid. The bottle must be filled up to one centimetre from the rim, not full.
At the tap, the filter at the end must be removed, the water must run for 5 minutes and the bottle filled according to the above procedure. From the lake or river, the bottle must be held by its bottom and plunged into the water, facing the current, opened and closed under water, if possible. From a well with a pump, 10 pounds must be pumped before the sample is taken and it must be removed during the pumping. Finally, for a well without a pump, the bottle must be attached to a new or very clean string with a weight.