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Saint-Laurent Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

river

pH Level

7.7

neutral = 7.0

Lead

0.003 mg/L

✓ Below action level

TDS

229.3 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: Health Canada Water Quality · Updated 2026

hard~120–179 mg/LHard · est.

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 Saint-Laurent, your appliances are currently losing 20% efficiency due to mineral buildup.

ApplianceIn Saint-LaurentSoft Water CityEfficiency Loss
Kettle
6.8 yrs
8.5 yrs-20%
Washing Machine
9.6 yrs
12 yrs-20%
Water Heater
12 yrs
15 yrs-20%

Regional Water Comparison

How Saint-Laurent compares to its nearest neighbours

CityHardnessMineralizationRisk
Saint-Laurent, Quebec≈ 120–179 mg/LHigh🟠 Hard
Mont-Royal, Quebec≈ 60–120 mg/LMedium🟡 Moderately Hard
Côte-Saint-Luc, Quebec119.5 mg/LMedium🟡 Moderately Hard
Snowdon, Quebec≈ 60–120 mg/LMedium🟡 Moderately Hard
Parc-Extension, Quebec≈ 60–120 mg/LMedium🟡 Moderately Hard

National Benchmark

How Saint-Laurent compares to the Canada average

BenchmarkHardnessAppliance Risk
Saint-Laurent≈ 120–179 mg/L🟠 Moderate
Canada National Avg140 mg/L🟠 Moderate
Vancouver Top Rated3 mg/L🟢 None

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What Makes Saint-Laurent's Water Unique?

Local geology and source profile

Source: RiverTDS: 229.3 mg/LpH: 7.7

Ville de Montréal provides drinking water to Saint-Laurent, a borough of the city. The supply originates from the St. Lawrence River, with water drawn through two primary intakes. The Atwater treatment plant handles the western sector, including Saint-Laurent, while the Charles-J.-Des Baillets plant serves a wider area. These advanced facilities employ coagulation, flocculation, sedimentation, and filtration to treat the river water. Their extensive distribution networks, monitored annually, deliver safe drinking water to over a million residents across Montreal Island. The St. Lawrence River watershed itself collects drainage from upstream tributaries and the Laurentian Plateau.

Geologically, the region is characterized by Ordovician limestone and dolomite formations belonging to the St. Lawrence Platform. These underlying carbonate rocks are the primary reason for the water's mineral content. As water flows over and through these bedrock layers, it dissolves minerals like calcium and magnesium. Glacial till and marine sediments also cover these formations, further influencing the water's composition. This geology results in a water supply that is notably hard, reflecting the dissolution of minerals from the carbonate bedrock.

Homeowners will likely notice the effects of this hard water on their appliances and plumbing. Expect scale buildup in pipes, water heaters, dishwashers, and washing machines, which can decrease efficiency and shorten their lifespan. Soap may not lather as effectively, leading to soap scum in showers, and laundry might appear less bright. Heating elements and fixtures are particularly susceptible to damage from mineral deposits. Regular maintenance, such as flushing and deliming, is a good idea. To significantly reduce these issues and protect your home's systems, installing a water softener is highly recommended. Ville de Montréal's annual reports confirm that the water meets Health Canada guidelines, with a pH typically between 7.5 and 8.0 for corrosion control.

Geology & Source: St. Lawrence River watershed; Ordovician limestones and dolomites from the St. Lawrence Platform create hard water.

Other Quebec Water Reports

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Frequently Asked Questions

Is Saint-Laurent's water safe to drink?
Yes. Saint-Laurent's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Saint-Laurent?
At ≈ 120–179 mg/L (Hard), Saint-Laurent's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.
How does Saint-Laurent compare to the Canada average?
The Canada national average is 140 mg/L. Saint-Laurent (≈ 120–179 mg/L) is 10 mg/L above the national average. The softest major city is Vancouver at just 3 mg/L.