Baie-Comeau Water Hardness & Quality Report (2026)

Baie-Comeau's drinking water is managed by Ville de Baie-Comeau, an industrial port city on Quebec's Côte-Nord (North Shore) at the mouth of the Manicouagan River — home to the Aluminerie Baie-Comeau (Rio Tinto) aluminum smelter and a major newsprint and forest products industry, drawing from local watershed reservoir supply sourced from the Côte-Nord Precambrian Shield uplands. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 63.5 mg/L (3.7 gpg) — classified as moderately hard by Health Canada, slightly above the soft/moderately hard boundary of 60 mg/L, reflecting the very low-mineral character of the northern Quebec Shield watershed.

Baie-Comeau's watershed drains the Grenville Province of the Canadian Shield on the North Shore — ancient Precambrian gneiss, marble, and anorthosite of the Manicouagan Reservoir region, one of the world's largest impact craters (Manicouagan reservoir). These ancient metamorphic and crystalline rocks dissolve very slowly, producing the near-soft 63.5 mg/L supply. The very low TDS of 143 mg/L confirms minimal overall dissolved mineral content, consistent with the characteristically soft supplies of all Côte-Nord and Saguenay–Lac-Saint-Jean communities on the Quebec Shield.

At 63.5 mg/L, Baie-Comeau residents experience minimal scale — occasional kettle cleaning every two to three months is adequate. Hot water tanks have an excellent operational lifespan. Ville de Baie-Comeau publishes annual water quality reports following Ministère de l'Environnement standards. Health Canada lead precautionary guidance applies to residents in the community's older industrial-era housing stock built during the post-war aluminum smelter and paper mill development era.