Montréal Water Hardness & Quality Report (2026)
Water Hardness
Source
river
pH Level
7.5
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
180 mg/L
Est. Daily Cost
$0.31
energy & soap waste
Source: Health Canada Water Quality · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Montréal, your appliances are currently losing 15% efficiency due to mineral buildup.
| Appliance | In Montréal | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.8 yrs | 8.5 yrs | -32% |
| Washing Machine | 9.3 yrs | 12 yrs | -22% |
| Water Heater | 11 yrs | 15 yrs | -27% |
Regional Water Comparison
How Montréal compares to its nearest neighbours
| City | Hardness | Mineralization | Risk |
|---|---|---|---|
| ▶ Montréal, Quebec | 116 mg/L | Medium | 🟡 Moderately Hard |
| Laval, Quebec | 118 mg/L | Medium | 🟡 Moderately Hard |
| Ottawa, Ontario | 88 mg/L | Medium | 🟡 Moderately Hard |
| Gatineau, Quebec | 90 mg/L | Medium | 🟡 Moderately Hard |
| Québec, Quebec | 81 mg/L | Medium | 🟡 Moderately Hard |
National Benchmark
How Montréal compares to the Canada average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Montréal | 116 mg/L | 🟡 Low |
| Canada National Avg | 104 mg/L | 🟡 Low |
| Vancouver Top Rated | 3 mg/L | 🟢 None |
Bring Vancouver-quality water to your Montréal home
Shop water softeners on Amazon.com →
What Makes Montréal's Water Unique?
Local geology and source profile
Montréal's drinking water is managed by Ville de Montréal — Direction de l'eau potable, drawing from the St. Lawrence River at the Atwater and DesBaillets water treatment plants, as well as the Rivière des Prairies via the Charles-J. Des Baillets facility. These plants treat approximately 1.1 billion litres per day using coagulation, ozone treatment, activated carbon filtration, and UV disinfection — among the most advanced municipal treatment processes in Canada, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) standards. Hardness is measured at 116 mg/L (6.8 gpg).
Montréal sits within the St. Lawrence Lowlands, where Ordovician limestone and dolostone bedrock underlies the river corridor. As water flows through this sedimentary basin, it dissolves carbonate minerals at moderate concentrations. The hardness level of 116 mg/L reflects this limestone geology, balanced by dilution from upstream Precambrian Shield tributaries that carry very soft water.
Residents in Montréal experience moderate limescale accumulation in kettles and around tap outlets, requiring descaling every six to eight weeks. Hot water tank anode rods benefit from annual inspection, as scale deposits can accelerate corrosion. A simple jug filter or kettle descaling tablet handles most limescale concerns at this moderate hardness level.
Geology & Source: Supplied by Ville de Montréal — Direction de l'eau potable from the St. Lawrence River and the Rivière des Prairies — water traversing Ordovician limestone and St. Lawrence Lowlands sedimentary formations picks up moderate calcium, producing water at 116 mg/L (6.8 gpg).