Montreal drinking water path

Source

St. Lawrence River Surface water · +2 sources

raw water

Intake

Raw water intake pump station

to plant

Treatment

Atwater (Sud-Ouest) UV · +5 more plants

finished

Mains

Distribution Service de l'eau produces and distributes drinking water island-wide through roughly 5,300 km of watermains. Six plants feed a common / interconnected distribution system serving Montréal boroughs and some neighbouring island municipalities via transmission mains and reservoirs (including Mont-Royal area storage).

drinking water

Tap

Household tap Montreal

Source & supply
St. Lawrence River
Lac Saint-Louis
Rivière des Prairies
Service de l'eau produces and distributes drinking water island-wide through roughly 5,300 km of watermains. Six plants feed a common / interconnected distribution system serving Montréal boroughs and some neighbouring island municipalities via transmission mains and reservoirs (including Mont-Royal area storage).
City describes a multi-barrier 9-step cycle from river/lake intakes through coagulation, filtration, ozonation, UV, and chlorination before distribution; participates in Québec’s Programme d’excellence en eau potable.
Treatment
Atwater (Sud-Ouest)
Major island plant drawing St. Lawrence / aqueduct system water; works in relay with Charles-J.-Des Baillets.
Charles-J.-Des Baillets (LaSalle)
Largest Montréal production plant; St. Lawrence intake; ozonation and UV among treatment steps.
Dorval
At the tap
Hardness 217 mg/L (Very hard)
Grade B (Good)
pH 7 · lead 0.1 μg/L
ECCC / municipal open data (seed)