Parc-Extension Water Hardness & Quality Report (2026)

Service de l'eau de la Ville de Montréal supplies water to Parc-Extension, a densely populated neighbourhood in the Villeray–Saint-Michel–Parc-Amusement borough. The water originates from the St. Lawrence River, drawn through intakes that feed the Atwater and Charles-J.-Des Baillets treatment plants, both located on the island of Montreal. These facilities process raw river water for the island's 1.8 million inhabitants, distributing it via a vast underground network. No local groundwater sources are utilized; the system operates as a unified municipal supply. The St. Lawrence River watershed upstream of Montreal includes the Great Lakes-St. Lawrence basin, with significant tributaries such as the Ottawa and Richelieu rivers.

Beneath the surface, Ordovician limestone and dolomitic formations in southern Quebec readily dissolve, infusing the river water with a moderately mineralised character. Glacial deposits from the Pleistocene era lie atop fractured bedrock, promoting ion exchange that influences the water's chemistry, leading to a higher mineral content without extreme hardness. This geological makeup is key to the water's overall profile.

This moderately hard water can result in visible limescale buildup on fixtures like faucets and showerheads, as well as inside kettles. Appliances such as water heaters, dishwashers, and washing machines may experience reduced efficiency and a shortened lifespan due to scale accumulation, potentially increasing energy expenses. Some residents find their skin and hair feel drier after washing. Regular flushing of hot water systems and using vinegar for descaling can help manage buildup. For households experiencing persistent issues, installing a water softener is often recommended to prevent scale and extend appliance longevity. While Montreal's water is treated to a pH of 7.5–8.5 for corrosion control, recent reports indicated turbidity and lead level exceedances at some taps, attributed to aging infrastructure. PFAS 'forever chemicals' have been detected across Quebec, though below federal limits.