Banbury-Don Mills Water Hardness & Quality Report (2026)

Banbury-Don Mills (a prosperous north Toronto neighbourhood centred on the Don Mills Road and Lawrence Avenue East intersection — encompassing the planned Don Mills community and the Banbury residential area with their characteristic mid-century modern architecture and ravine parks) receives its drinking water from the City of Toronto, drawing from Lake Ontario via the R.C. Harris Water Treatment Plant. Water is treated using ozonation, biofiltration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) standards. Hardness in this distribution zone is 234 mg/L (13.7 gpg) — classified as very hard by Health Canada, with TDS of 589 mg/L, consistent with Toronto's north-central distribution corridor.

Banbury-Don Mills receives R.C. Harris plant Lake Ontario supply through the north-central Toronto distribution network — part of the same fundamentally very hard Lake Ontario source that characterises all Toronto boroughs. The 234 mg/L is consistent with the neighbouring Parkwoods-Donalda (233 mg/L) and Mount Pleasant West (235.5 mg/L) sub-zones in the same northeast and north-central Toronto distribution corridor.

At 234 mg/L, Banbury-Don Mills homeowners experience persistent scale build-up — kettle and showerhead descaling every one to two weeks is typical. This established north Toronto community, known for its planned mid-century Don Mills neighbourhood (developed in the 1950s-60s as Canada's first planned suburban community), has a housing stock of the appropriate age to warrant review of the City of Toronto's lead service line replacement programme at toronto.ca/water. Annual hot water tank inspection and flushing are recommended throughout this characteristically very hard supply zone.