Beaconsfield Water Hardness & Quality Report (2026)

Beaconsfield's drinking water is managed by Ville de Beaconsfield, drawing from the St. Lawrence River (Lake Saint-Louis section) on the west side of Montréal Island — an affluent West Island suburb on the Lake Saint-Louis shoreline, drawing from the south-shore Lake Saint-Louis intake via its water treatment facility. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 73 mg/L (4.3 gpg) — classified as moderately hard by Health Canada, reflecting the softer St. Lawrence (Lake Saint-Louis) supply characteristic of this West Island shoreline community.

Beaconsfield's 73 mg/L contrasts with the harder adjacent Kirkland (115.5 mg/L) which draws from the Ottawa River via Lac des Deux Montagnes to the north. Beaconsfield's position on the south shore of the West Island peninsula, with a direct Lake Saint-Louis St. Lawrence intake, produces a softer 73 mg/L supply compared to the Ottawa River–fed north shore communities. Lake Saint-Louis receives St. Lawrence water that has passed through the Great Lakes–St. Lawrence system at the same moderately hard level characteristic of the Lake Saint-Louis–Lake of Two Mountains section of the river.

At 73 mg/L, Beaconsfield residents experience minimal-to-light scale deposits — occasional kettle cleaning every two to three months is adequate. Hot water tanks operate well at this hardness level. Ville de Beaconsfield publishes annual water quality reports following Ministère de l'Environnement standards. Beaconsfield's established mid-20th-century residential character includes many pre-1970 properties where Health Canada lead precautionary guidance applies to older plumbing infrastructure in this well-established West Island community.