June 29, 2018
Heat waveThe City of Dollard-des-Ormeaux is offering several services to help keep you cool during periods of extreme heat. Cooling centres... Lire la suite Read more
June 8, 2018
The new Facebook page of the City of Dollard-des-Ormeaux is now online. This page will allow the City to better communicate with its citizens.... Lire la suite Read more
May 18, 2018
Dollard-des-Ormeaux, May 17, 2018 – The City of Dollard-des-Ormeaux today inaugurated the expansion of the Community Centre. This expansion will... Lire la suite Read more
May 16, 2018
1. GENERAL INFORMATION In its fight against the spread of the emerald ash borer, the City has set up three financial assistance programs to help... Lire la suite Read more
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Descriptions of sewer systems

The City of Dollard-des-Ormeaux has two sewer systems; one for sanitary waste water and the other for storm water. Waste water from residential and commercial users empties into the City of Montréal’s underground sewer main, which runs across the City to the east end of the Island of Montréal. This waste water is treated and returned to the St. Lawrence River (for more information, please consult the City of Montréal’s waste water treatment website at

Runoff flows into the sewer system through catch basins located along street gutters. Some of the water collected in this way is temporarily held in the Centennial Lake (retention pond), before being discharged into the Rivière des Prairies.


Since storm water is not treated before being discharged, it is strictly prohibited to empty toxic or dangerous products into the storm water system through the grates located along the streets. These products require a special collection.

Prevention and obligations

All sanitary waste water systems have rats. The City’s system is no exception. While the City hires a company to put rat poison each year in sewer manholes to reduce the rodent population and limit its spread, rats cannot be eradicated completely.

  • Residents must seal any opening that could allow rats to enter the home.
  • The National Plumbing Code of Canada stipulates that all homes must have a back water valve on the horizontal line in basements and cellars.

In addition to preventing rats from entering the home, this back water valve prevents sewer backups.

Possible situations and interventions

Foul odours

  • Outdoors
    A foul odour can originate from many sources; for example, dead leaves or other debris in the catch basin can cause a noxious smell in the sewer. Call the Public Works Department, give your address and describe the problem. An inspector will be dispatched to the premises to analyze the problem and suggest appropriate action (siphoning or cleaning).
  • Indoors
    A dry drain can emit a foul odour inside a home. Allow water to flow into the basement or garage drain. If the odour persists, call the Public Works Department, give your address and describe the problem.

Sewer backup

The City has a maintenance program to prevent sewer backups. The Public Works Department uses a high-pressure jet and sewer vacuum mounted on a trailer to remove accumulated solids in the entry hole. The work is done regularly, except during the coldest winter months.

  • Home: If the sewer pipe becomes blocked and causes a backup, the resident should call a plumber.The plumber will look inside the pipe with a video camera to assess the problem. If after these measures have been taken, the problem is found to be on public property, the Public Works crew will do the necessary work. The resident can then forward a claim to the City within two weeks of the incident.
  • Roots: A sewer in good condition is watertight. Tree roots infiltrate water drains through existing cracks, an open joint or other opening. Call a plumber and/or a contractor.
  • Ramp drain: If a resident notices that the drain on his driveway is blocked, he should clean it out.

Concerned department

Public Works, 514 684-1034