Salaberry-de-Valleyfield Water Hardness & Quality Report (2026)

Salaberry-de-Valleyfield's drinking water is managed by Ville de Salaberry-de-Valleyfield, an industrial city at the southwest corner of the Island of Montréal corridor on the St. Lawrence River, drawing from Lake Saint-François — the broad St. Lawrence pool above the Beauharnois hydroelectric locks — via the municipal water treatment plant. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 104 mg/L (6.1 gpg) — classified as moderately hard by Health Canada, reflecting Lake Saint-François' mixed St. Lawrence chemistry from the Ontario–Quebec border reach.

Valleyfield's intake on Lake Saint-François draws St. Lawrence water that has flowed from Lake Ontario through the St. Lawrence Seaway channel. At this location — at the Ontario–Quebec border between the communities of Cornwall (Ontario) and Valleyfield (Quebec) — the river carries the accumulated calcium of the Ordovician and Silurian carbonate Great Lakes basin, moderately diluted by the large river volume. The 104 mg/L is softer than Cornwall (187 mg/L across the river) because different intake positions and different proportions of direct river vs. inshore limestone-zone water produce different local values.

At 104 mg/L, Salaberry-de-Valleyfield residents experience moderate scale deposits in kettles and on tap aerators — descaling every six to eight weeks is adequate. Hot water tanks operate reliably at this hardness. The city's industrial heritage includes significant chlor-alkali production (the Chemtrade Valleyfield facility), and residents follow Ministère de l'Environnement and Health Canada water quality guidance as published in annual reports by Ville de Salaberry-de-Valleyfield.