Snowdon Water Hardness & Quality Report (2026)

Snowdon (a densely populated neighbourhood in the Côte-des-Neiges–Notre-Dame-de-Grâce borough of Ville de Montréal, centred on the Snowdon métro station area at Queen Mary Road and the Décarie Expressway) receives its drinking water through Ville de Montréal — Direction de l'eau potable, drawing from the St. Lawrence River via the Atwater and DesBaillets water treatment plants. Treatment includes ozonation, biofiltration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) standards. Hardness in Snowdon's distribution zone is 99 mg/L (5.8 gpg) — classified as moderately hard by Health Canada, at the upper end of the Côte-des-Neiges–NDG borough range.

Snowdon's slightly harder 99 mg/L (compared to the borough's typical 75–90 mg/L range) reflects its position in the CDN–NDG western distribution corridor near the Côte-Saint-Luc boundary, where the supply draw may proportionally favour harder St. Lawrence direct supply over the blended Rivière des Prairies–influenced water. The moderate 99 mg/L is consistent with the West Island corridor's 100–128 mg/L range, suggesting the western Snowdon sub-zone's distribution infrastructure draws water that trends harder toward the West Island supply characteristics.

At 99 mg/L, Snowdon residents experience moderate scale deposits in kettles and on tap aerators — descaling every two months is adequate. Hot water tanks operate reliably at this hardness. Snowdon's very dense, multicultural residential neighbourhood has a significant stock of pre-1960 apartment buildings; Montréal's Direction de l'eau potable follows Ministère de l'Environnement standards and provides Health Canada-compliant lead testing guidance critical for residents of the neighbourhood's aging housing stock.