Beauharnois Water Hardness & Quality Report (2026)

Beauharnois's drinking water is managed by the Ville de Beauharnois, drawing from the St. Lawrence River or the Beauharnois Canal — Beauharnois is a city in the Beauharnois-Salaberry regional county on the south shore of the St. Lawrence in Montérégie, home to the spectacular Centrale de Beauharnois (Beauharnois Power Station), one of Hydro-Québec's largest hydroelectric generating stations (installed capacity 1,903 MW), a facility that channelled the St. Lawrence River flow through the Beauharnois Canal when constructed in the 1930s, creating one of Quebec's most significant industrial power heritage sites on the St. Lawrence River. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 96.5 mg/L (5.6 gpg) — classified as moderately hard by Health Canada, consistent with the Montérégie south shore St. Lawrence supply range.

Beauharnois's 96.5 mg/L is consistent with the St. Lawrence River supply character on the Montérégie south shore corridor (session reference: Montérégie south shore 69.5–128 mg/L; Richelieu Valley 97–102 mg/L). The St. Lawrence at Beauharnois carries dissolved Ordovician and Devonian carbonate minerals from the upstream Great Lakes basin and the St. Lawrence Lowlands, producing moderately hard supply in the Beauharnois–Salaberry-de-Valleyfield corridor. Water quality reports are published following Ministère de l'Environnement standards.

At 96.5 mg/L, Beauharnois homes experience light to moderate scale deposits — cleaning every two months is adequate. Hot water tanks have a reliable operational lifespan. Health Canada lead precautionary guidance applies to pre-1975 properties in the historic Beauharnois industrial-era worker housing and the established residential streets near the Beauharnois Canal and power station.