Sainte-Foy Water Hardness & Quality Report (2026)

Sainte-Foy (a borough of Ville de Québec) receives its drinking water through Ville de Québec, drawing from the St. Lawrence River via the Sainte-Foy Water Treatment Plant — one of Québec City's primary treatment facilities, located along the south cliff of Cap Diamant. Water is treated with coagulation, sedimentation, ozonation, granular activated carbon filtration, and chlorination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness measures 81.5 mg/L (4.8 gpg) — classified as moderately hard by Health Canada, consistent with Québec City's characteristically moderate supply chemistry.

Sainte-Foy receives supply from the St. Lawrence River at a point where significant Precambrian Shield tributary inflow from the Laurentian Highlands — primarily the Rivière Saint-Charles and upstream Ottawa/Saint-Maurice rivers — dilutes the harder Ordovician limestone-influenced baseline. This Shield dilution effect is prominent at Québec City, producing water noticeably softer than the same river at Montréal or downstream at Trois-Rivières, where limestone influence is proportionally greater.

At 81.5 mg/L, Sainte-Foy residents experience only moderate scale deposits in kettles and around tap aerators — descaling two to three times a year is typically sufficient. Hot water tanks operate well at this hardness without dedicated scale treatment. For households in Sainte-Foy's substantial stock of mid-20th-century apartment buildings and university district housing, Ville de Québec advises compliance with Health Canada lead guidelines and encourages residents to request water quality testing if original lead service pipes are suspected.