Charlesbourg Water Hardness & Quality Report (2026)

Charlesbourg (a northern borough of Ville de Québec) receives its drinking water through Ville de Québec, drawing from the St. Lawrence River via the Charlesbourg-Est water treatment plant — Québec City's primary treatment facility serving the northern and eastern boroughs. Water undergoes coagulation, sedimentation, ozonation, granular activated carbon filtration, and chlorination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness measures 79 mg/L (4.6 gpg) — classified as moderately hard by Health Canada, consistent with Québec City's moderate supply chemistry across most boroughs.

Charlesbourg sits on the plateau north of the Cap Diamant escarpment, above the St. Lawrence shoreline. Supply draws from the St. Lawrence River at a point influenced by both Precambrian Shield tributary inflows from the Laurentian Highlands (softening effect) and the Ordovician limestone plain geology of the St. Lawrence Lowlands (hardening effect). The blend produces the 79 mg/L characteristic of Québec City's northern boroughs — moderately harder than La Haute-Saint-Charles (50.5 mg/L) which draws from the soft upper Rivière Saint-Charles, but similar to the other city boroughs drawing from the main treatment network.

At 79 mg/L, Charlesbourg residents experience only modest scale deposits in kettles and on tap aerators — descaling every two to three months is typically adequate. Hot water tanks operate reliably at this hardness without dedicated treatment. For Charlesbourg's mid-century suburban housing stock, Ville de Québec follows Ministère de l'Environnement and Health Canada guidance on lead and provides lead service line management resources to residents in applicable areas.