Drinking Water and Water Quality
The city provides drinking water to nearly 67,000 people through the Régie intermunicipale d’aqueduc de la Vallée de Châteauguay (RIAVC), which serves the cities of Châteauguay, Mercier, Saint-Isidore, Sainte-Martine and Saint-Urbain-Premier.
The city has had filtered drinking water since the 1960s and more recently acquired an energy-efficient pump system. It economically produces mass quantities of high-quality water that is sourced 60% from groundwater and 40% from Lac Saint-Louis. To supply the entire population, four pumping stations are in operation: Jean-Louis Chèvrefils, Joseph-Chèvrefils, Marchand and Alonzo-Béliveau.
Under the Regulation respecting the quality of drinking water, to ensure that the water from the treatment plants is fit for consumption, the city must regularly test samples, based on specific criteria issued by the Ministère de l’Environnement et de la Lutte contre les changements climatiques, and transmit the results of the analyses to the government and the public.
Water is a finite resource, however, and a variety of circumstances may lead to abnormal colouration or shortages, such as overuse or an exceptionally hot, dry summer. It is therefore important to avoid daily waste by reducing consumption.
Every year, the city tables a report on the quality of the drinking water distributed in its territory, in keeping with the Regulation respecting the quality of drinking water.
The annual report for 2020 is now available. It provides a summary of the tests conducted during the year to verify the quality of our drinking water.
All the required analyses were carried out and all the standards were met. The drinking water distributed in the territory fully complies with all government health and hygiene requirements.
Some inspection work may cause a temporary drop in pressure, accompanied by a brownish or orange colour in the water. Fabric may be stained by this discoloured water. Situations that may affect water colour include:
- Work underway in the area
- A waterworks flushing operation
- The closure of one or more valves
- The use of a fire hydrant near your home
Even if the water is discoloured, it is fit for consumption. If the water is unfit for consumption, a boil-water advisory or do-not-drink order is immediately issued to the public.
To rectify the situation, just let the cold water run, preferably through the bathtub tap, for at least 20 minutes or until it runs clear, especially before doing laundry or washing the dishes.
If the problem is not resolved, you can report it to us in either of these ways:
Email us at:
To save water and help improve water quality, you can take simple actions.
In the kitchen
- Do not let the tap run while doing the dishes.
- Make sure your dishwasher is full before turning it on.
- Compost your food waste rather than using a garburator.
- Thaw your frozen foods in the refrigerator, rather than under running water.
- Clean fruits and vegetables using a brush in the sink, rather than letting the water run.
In the bathroom
- Turn off the tap when you are shaving or brushing your teeth.
- Take a shower rather than a bath, and keep it to five minutes.
- Flush only when necessary. Do not use the toilet as a trash can!
- Choose a low-flow toilet (6 litres or dual flush).
- Install a low-flow shower head.
- Set the water level in your washing machine based on the quantity of laundry to be washed.
Elsewhere in the house
- Reuse cooking water from vegetables and pasta, from the aquarium or from the dehumidifier to water your plants.
- Insulate your hot-water heater. By reducing heat loss, you will get hot water faster.
Around the house
- Mulch your trees and plants to help them retain water. Use light-coloured pots and planters to slow the drying of the soil.
- Water the roots of your plants in the morning or evening. In addition to avoiding evaporation, deep watering encourages root development.
- Direct the water from your roof gutters to your flower beds or lawn, rather than the deck or driveway.
- Collect rainwater in a barrel to water your plants and garden, wash the car or refill the aquarium.
- Use a broom or rain water to clean your driveway, rather than the watering hose.
For the pool
- Fill your pool to less than 20 cm from the brim, to reduce water loss through splashing.
- Use a pool cover to reduce evaporation.
For lawn maintenance
- Let your grass grow a little longer (6 cm); it will retain more moisture and look better.
- Water later in the evening to reduce evaporation.
- Don’t forget to turn off your automatic sprinklers if it rains.
- Follow the municipal watering by-law in effect.
For more information
Are you curious about your “blue print” – that is, your water consumption profile? The Ministère des Affaires municipales et de l’Habitation has developed an online interactive quiz to raise the public’s awareness about being “water-sponsible.”