Pierrefonds-Roxboro Water Hardness & Quality Report (2026)

The drinking water for Pierrefonds-Roxboro, a borough of Montreal, Quebec, is supplied by the Pierrefonds-Roxboro water filtration plant and supplemented by the Pointe-Claire filtration plant. These facilities treat raw water primarily sourced from the St. Lawrence River, serving the residential and commercial areas of the borough. The utility operates under the City of Montreal's water services division, ensuring distribution through municipal mains. Dollard-des-Ormeaux also relies on these plants, indicating a shared regional supply network focused on river-sourced potable water.

The St. Lawrence River watershed encompasses over 1,000 km from Lake Ontario to the Atlantic. Paleozoic carbonate platforms, including Ordovician limestones and dolostones, dominate the sub-basin, leaching multivalent cations into the river flow. Glacial deposits from the Pleistocene Wisconsinan glaciation add minor buffering, resulting in moderately mineralised water rather than very soft glacial melt profiles seen elsewhere. This geological setting yields a supply with operational mineral content.

Moderately hard water in Pierrefonds-Roxboro leads to moderate limescale buildup in pipes, water heaters, and dishwashers, reducing efficiency over time and spotting glassware. Kettles and showerheads may require occasional descaling, while laundry and soap lathering feel slightly less efficient. Maintenance involves annual flushing of hot water systems and vinegar soaks for fixtures; a water softener is often recommended for households with aesthetic concerns or older plumbing to prevent cumulative deposits and extend appliance life. Water quality testing by Montreal shows general compliance, though 2022 reports noted exceedances in turbidity and lead levels, likely from distribution system issues rather than source water.