Val-des-Arbres Water Hardness & Quality Report (2026)

Val-des-Arbres (a residential sector of Ville de Laval in the north-central part of the island city) receives its drinking water from Ville de Laval, drawing from the Rivière des Prairies — the north channel of the Ottawa River between Laval island and the mainland — via the Laval Water Treatment Plant. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness in this distribution zone is 101 mg/L (5.9 gpg) — classified as moderately hard by Health Canada, reflecting the Rivière des Prairies' blended supply from the Ottawa River corridor.

The Rivière des Prairies receives water from the Ottawa River system through Lac des Deux Montagnes — a broad lake collecting flows from both the Precambrian Shield Laurentian highlands to the north (contributing soft water) and the Ordovician limestone Lowlands plain of the Ottawa–Montréal corridor (contributing harder water). The balance between soft Shield tributary inflow and harder Lowlands carbonate dissolution in the Ottawa–Montréal reach produces the moderate 101 mg/L measured in Val-des-Arbres' distribution sub-zone — slightly harder than other Laval sectors like Duvernay (65.5 mg/L) that receive a higher proportion of softer Shield-diluted water.

At 101 mg/L, Val-des-Arbres residents experience moderate scale deposits in kettles and on tap aerators — descaling every six to eight weeks is adequate. Hot water tanks operate reliably at this hardness. Ville de Laval publishes annual water quality reports following Ministère de l'Environnement standards. Residents in older pre-1975 homes should follow Health Canada lead precautionary guidance, as Laval's older housing stock may include original plumbing with higher lead risk.