L'Île-Bizard–Sainte-Geneviève Water Hardness & Quality Report (2026)

L'Île-Bizard–Sainte-Geneviève's drinking water is managed by the Ville de Montréal north-island distribution network, drawing from both the St. Lawrence River and the Ottawa River corridor (Lac des Deux Montagnes) — a Montréal borough encompassing the rural-residential Île-Bizard island at the northwest tip of Montréal Island, connected by bridge to the Sainte-Geneviève sector. Water undergoes ozonation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 98 mg/L (5.7 gpg) — classified as moderately hard by Health Canada, consistent with the Atwater zone Montréal Island supply.

L'Île-Bizard sits at the confluence of the Rivière des Prairies and the Lac des Deux Montagnes — where the Ottawa River's water mixes with the St. Lawrence system at the northwest corner of Montréal Island. The 98 mg/L is consistent with the central Atwater zone Montréal Island supply (Atwater baseline ~98.5 mg/L from batch 15 Steveston context and Île-des-Soeurs 100 mg/L), reflecting the blended St. Lawrence and Ottawa River supply character at this northwest island location, where Ottawa River water from Lac des Deux Montagnes begins to influence the borough's moderately hard supply.

At 98 mg/L, L'Île-Bizard–Sainte-Geneviève residents experience moderate scale deposits — cleaning every six to eight weeks is adequate. Hot water tanks operate reliably at this hardness. Ville de Montréal publishes annual water quality reports following Ministère de l'Environnement standards. The borough's semi-rural Île-Bizard character, with many estate properties and private well users in the island's interior, means some residents use private ground water; those on private wells should test independently and contact the Ville de Montréal for guidance.