Drinking water shortage or contamination 

Several factors can lead to drinking water contamination or shortages. When extreme heat or flooding affects the region, extra caution is required! 

When should you boil water before drinking it? 

It is recommended to boil water for at least 1 minute if : 

• It has an unusual odor. 
• It has a suspicious taste. 
• It is discolored. 

If you suspect chemical contamination, do not consume tap water and contact 311.

How the City of Laval informs its citizens 

When drinking water is affected by a water main break, a chemical spill in a reservoir, a flood, or a drought, the City of Laval may issue three types of notices : 

• A boil water advisory 
• A do-not-consume advisory 
• A temporary water supply interruption notice 

If a water supply interruption is planned, the City will leave a door hanger at your residence to notify you. 

For more information on these advisories or to receive alerts about important notices or emergency situations, visit the Drinking Water Notices page.

There are three key recommendations to follow for your health and safety : 

• Follow issued advisories. 
• Adhere to the 72-hour self-sufficiency plan by keeping bottled drinking water at home. 
• If your water comes from a private well, artesian well, or surface well, remain cautious—regularly test your water and disinfect your well when necessary. 

In case of extreme heat 

When temperatures rise, it is essential that Laval residents have access to a large supply of drinking water for hydration and cooling. That’s why the City may issue watering restrictions to preserve water reserves for residents. 

These restrictions are put in place during drought periods and are communicated via this page or by signing up for City of Laval alerts.

In case of flooding 

During a flood, the municipal water supply may become contaminated. Before consuming tap water, check the City of Laval’s drinking water advisories.

Water supply wells  

Water supply wells may be submerged during a flood, contaminating drinking water. Residents must wait until floodwaters recede, the well is cleaned and disinfected, and a water quality test confirms it is safe to drink. 

If a supply well is contaminated, wait for the City of Laval’s clearance before consuming the water. 

Septic systems 

Flooding can overload septic systems, leading to significant pressure drops and even making sanitary facilities unusable. 

Until your septic system is fully functional again, follow these steps: 

• Reduce or completely stop using appliances that discharge water into the septic system (toilets, showers, washing machines, etc.). 
• Avoid contact with wastewater from septic systems. 
• Do not pump out the septic tank. 
• Do not consume water if you suspect chemical contamination.

Private wells

After a flood, it is safer to assume that your well water is non-potable, even if it appears clear and odor-free. Until you can disinfect your well and have your water tested by a certified laboratory, you should: 

• Drink bottled water. 
• Consume water that has been boiled for at least one minute.