Varennes Water Hardness & Quality Report (2026)

Varennes' drinking water is managed by Ville de Varennes, a growing Montérégie suburb on the south shore of the St. Lawrence River approximately 20 km east of Montréal — an industrial and residential community known for the Varennes cogeneration plant and the Hydro-Québec LNG facility, drawing from the St. Lawrence River via the municipal treatment plant. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 112 mg/L (6.5 gpg) — classified as moderately hard by Health Canada, consistent with the Montérégie south shore harder corridor (Boisbriand 112.5 mg/L from batch 14, Saint-Bruno 119 mg/L from batch 16).

Variennes' 112 mg/L reflects the characteristic south shore Montérégie supply — somewhat harder than the typical central Montréal Island boroughs (70–105 mg/L) due to the Ordovician limestone Lowlands bedrock of the St. Lawrence south shore plain contributing dissolved calcium to the river supply intake. Varennes sits on the St. Lawrence south bank east of the Boucherville islands, at a point where the river's south shore Lowlands plain is well developed and the groundwater contribution from carbonate-rich bedrock adds to the supply hardness.

At 112 mg/L, Varennes residents experience moderate scale deposits on kettle elements and tap aerators — descaling every six to eight weeks is adequate. Hot water tanks operate reliably at this hardness. Ville de Varennes publishes annual water quality reports following Ministère de l'Environnement standards. Health Canada lead precautionary guidance applies to residents in the community's older pre-1970 industrial-era residential areas near the historic Varennes village and waterfront.