Hull Water Hardness & Quality Report (2026)

Hull (the historic core of Ville de Gatineau, directly across the Ottawa River from Parliament Hill) receives its drinking water from Ville de Gatineau, drawing from the Ottawa River via the Hull Water Treatment Plant on the Gatineau riverfront. Water is treated using conventional coagulation, sedimentation, filtration, UV disinfection, and chloramination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness in Hull's distribution zone is 122.5 mg/L (7.2 gpg) — classified as hard by Health Canada, reflecting a higher proportion of Ordovician limestone Lowlands influence in the Ottawa River chemistry at the Hull intake.

The Ottawa River at Gatineau–Hull drains a watershed spanning both the Precambrian Shield of the Laurentian and Gatineau highlands (contributing soft water) and the Ordovician limestone plain of the Ottawa–St. Lawrence Lowlands (contributing harder water). Hull's distribution zone, served from the Hull treatment plant at the river's narrows near the Chaudière Falls, draws from a section of the Ottawa River where the harder Ordovician Trenton and Black River Group limestone geology of the Ottawa Embayment contributes proportionally more dissolved calcium than the softer upstream Shield-dominated reaches — producing the elevated 122.5 mg/L measured in Hull's taps.

At 122.5 mg/L, Hull residents experience noticeable scale deposits in kettles and on tap aerators — descaling every six to eight weeks is advisable. Hot water tanks benefit from annual inspection and flushing. For Hull's mix of government-district commercial buildings and older residential neighbourhoods, Ville de Gatineau follows Ministère de l'Environnement and Health Canada guidance — particularly regarding lead in the older housing stock of this historic riverside community.