Frequently asked questions about the work at the Le Royer facility

The plant serves the borough of Greenfield Park and the Le Moyne area in Longueuil, as well as the entire cities of Brossard and Saint-Lambert.

The valves are deteriorated and the City must inspect a main pipe at the plant's outlet. These interventions will improve the plant's reliability and secure the water supply in the Longueuil agglomeration, particularly in the areas served by the plant. The City will also replace a flow meter to meet the requirements of the Quebec government's Drinking Water Conservation Strategy, among other things.

It should be noted that this plant is the oldest in Quebec, built in 1925, and has undergone several phases of work over the years. The planned work is part of this ongoing process.

For more information about the work: Travaux à l'usine d'eau potable Le Royer | Ville de Longueuil

The work will begin on Saturday, September 27, at 8 p.m., and is scheduled to be completed on Monday, September 29, 2025. This is the first phase of the work. A second phase will be planned at a later date. The City will provide information about this in due course.

To find out about the impact on drinking water use and the instructions to follow during the work, click here.

The entire cities of Saint-Lambert and Brossard, as well as the borough of Greenfield Park and the Le Moyne sector in Longueuil, are affected.

No special preparation is required. If you wish, you can purchase bottled water in anticipation of the boil water advisory. Otherwise, you will need to boil your tap water for 1 minute before consuming it starting at 8 p.m. on Saturday, September 27.

If you live in a high-rise building (4th floor and above), it is advisable to stock up on water (for 1 to 2 days, approximately 2 to 3 liters per person) before the boil water advisory begins. These buildings are more likely to experience a drop in water pressure.

If you have not already done so, we invite you to sign up for our emergency alerts via the Saint-Lambert Citizen Portal. This is a preferred means of quickly reaching the population in the event of an emergency.

Contact the City at 450-672-4444 only if you no longer have water or if you notice a significant drop in pressure (very thin stream of water) in order to inform our teams.

We invite residents to obtain water from their neighbors, family, or friends, or to purchase bottled water.

The work is scheduled to be completed on Monday, September 29. Water pressure should return to normal during the course of that day.

Let the cold water run, preferably into the bathtub, until it becomes clear again. You can then boil it for 1 minute before consuming it.

Since the water supply will remain available throughout the duration of the work, there are no plans to distribute bottled water. Tap water remains available: simply boil it for at least one minute before consumption (drinking, cooking, preparing baby bottles, ice cubes, brushing teeth). This preventive measure is the safest way to continue using water during the advisory.

The City recommends postponing certain activities during the construction period at the Le Royer plant, for example: avoid doing laundry, avoid filling the bathtub completely if baths are necessary, limit the time spent in the shower, avoid filling the pool, avoid watering the garden and plants, avoid washing the car, etc.

Every little bit counts and can make a difference in avoiding overloading the drinking water system.

No. The City is required to maintain a minimum water pressure and water supply threshold during the work to mitigate such eventualities. There is therefore no risk in this regard.

• Drinking water | Ville de Longueuil (in French)
• Interview at the Le Royer drinking water plant in Saint-Lambert | L'épicerie