Drinking water

Last updated June 27, 2022
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What should you do if you notice a change in your tap water? What types of advisories inform residents of the steps to take in the event of contamination or a service interruption? Learn everything you need to know about drinking water in Montréal.

In order to provide quality drinking water, the city carries out regular tests at its six water treatment plants:

  • Atwater (Sud-Ouest)
  • Charles-J.-Des Baillets (LaSalle)
  • Dorval
  • Lachine
  • Pierrefonds
  • Pointe-Claire 

In spite of the precautions that are taken, changes in drinking water are occasionally observed. Maintenance work on the water supply system can also require service interruptions and affect the water’s appearance.

Colour

Tap water can sometimes appear white, grey, yellow, brown or orange in colour. Several potential causes can come into play. Ton find out what to do, read our article.

Decrease in water pressure

Various factors can contribute to a decrease in water pressure. They include work operations in progress and the presence of rust in water mains. Residents can contact 311 to report a problem. Corrective measures will be applied as required.

Water service interruptions

The drinking water supply is sometimes interrupted during work operations on the supply system. These interruptions are usually of short duration. In the event of a more prolonged water service interruption, residents will be notified about measures taken to provide them with drinking water.

Notices to residents

The city is sometimes required to issue warnings concerning drinking water consumption in the event of work operations, a breakage, defective equipment or water contamination. Lawn watering bans may be issued. The instructions to follow are outlined in advisories distributed to residents.

The city issues five types of advisories:

  • Boil-water advisory 
  • Water service interruption advisory
  • Drinking water advisory
  • Water use advisory
  • Notice of watering ban

 

A notice is issued when regular services are restored, and new guidelines for drinking or using tap water are provided.

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