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Deux-Montagnes Water Hardness & Quality Report (2026)

Water Hardness

moderately hard

~60–119 mg/L

Moderately Hard

estimated · not lab-verified

Source

river

pH Level

7.5

neutral = 7.0

Lead

0.004 mg/L

✓ Below action level

TDS

177.6 mg/L

Est. Daily Cost

$0.24

energy & soap waste

Source: Health Canada Water Quality · Updated 2026

moderately hard~60–119 mg/LModerately Hard · 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 Deux-Montagnes, your appliances are currently losing 12% efficiency due to mineral buildup.

ApplianceIn Deux-MontagnesSoft Water CityEfficiency Loss
Kettle
7.5 yrs
8.5 yrs-12%
Washing Machine
10.6 yrs
12 yrs-12%
Water Heater
13.2 yrs
15 yrs-12%

Regional Water Comparison

How Deux-Montagnes compares to its nearest neighbours

CityHardnessMineralizationRisk
Deux-Montagnes, Quebec≈ 60–119 mg/LMedium🟡 Moderately Hard
Saint-Eustache, Quebec22 mg/LLow🟢 Soft
Sainte-Marthe-sur-le-Lac, Quebec≈ 120–179 mg/LMedium🟠 Hard
L'Île-Bizard–Sainte-Geneviève, Quebec≈ 60–120 mg/LMedium🟡 Moderately Hard
Pierrefonds-Roxboro, Quebec≈ 60–120 mg/LMedium🟡 Moderately Hard

National Benchmark

How Deux-Montagnes compares to the Canada average

BenchmarkHardnessAppliance Risk
Deux-Montagnes≈ 60–119 mg/L🟡 Low
Canada National Avg140 mg/L🟠 Moderate
Vancouver Top Rated3 mg/L🟢 None

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What Makes Deux-Montagnes's Water Unique?

Local geology and source profile

Source: RiverTDS: 177.6 mg/LpH: 7.5

The municipal water for Deux-Montagnes, Quebec, is supplied by the Ville de Deux-Montagnes, serving about 18,000 people in the Laurentides region. The source is the Lake of Two Mountains, a section of the Ottawa River. Water is drawn from the lake and treated at the local water treatment plant. There, it undergoes standard processes like filtration and disinfection before entering the municipal distribution system. This system delivers water to the city's core and nearby areas within the Deux-Montagnes MRC.

The Lake of Two Mountains is part of the Ottawa River watershed, sitting at the edge of the Canadian Shield and the St. Lawrence Platform. The bedrock here consists of Ordovician limestone and dolomite from the Beekmantown Group, with some influence from older Precambrian granite further upstream. Layers of glacial deposits and clay from ancient seas cover the surface, affecting how water moves through the area. As water flows over these rocks, it picks up minerals like calcium and magnesium, a common characteristic of rivers in areas with limestone.

This moderately hard water can lead to limescale buildup in appliances such as kettles, water heaters, and dishwashers, which can lower their efficiency and increase energy bills. You might notice soap scum in showers, leaving skin and hair feeling dry, and laundry may require extra detergent. Regularly descaling fixtures with vinegar can help, but installing a water softener is often recommended to prolong the life of your appliances and improve cleaning. The treated water typically has a pH between 7.5 and 8.5, which is alkaline.

Geology & Source: Ordovician limestones and dolomites; carbonate-rich bedrock dissolves calcium and magnesium, producing moderate hardness

Other Quebec Water Reports

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Frequently Asked Questions

Is Deux-Montagnes's water safe to drink?
Yes. Deux-Montagnes's water meets all federal safety standards. The hardness is ≈ 60–119 mg/L (Moderately Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Deux-Montagnes?
Deux-Montagnes's water is moderately hard at ≈ 60–119 mg/L. A water softener is generally not necessary, though a carbon filter can improve taste and remove any remaining chlorine.
How does Deux-Montagnes compare to the Canada average?
The Canada national average is 140 mg/L. Deux-Montagnes (≈ 60–119 mg/L) is 50 mg/L below the national average. The softest major city is Vancouver at just 3 mg/L.