Sewer cleaning

Why does the City clean the sewer system?

The City of Ottawa conducts routine cleaning of sewers to ensure that wastewater from homes and businesses is efficiently transported to the Robert O. Pickard Environmental Centre (ROPEC), the City’s treatment facility.

What is a sewer blow-back?

During the cleaning process, the use of high pressure water creates air pockets inside the sewer pipe that generally escape with no impact to a property’s internal plumbing.

In some cases, this air pressure can only escape through the sewer connection between the house and the City’s sewer system, via the internal plumbing vent. If this passage is blocked, air pressure may escape through a toilet or drain. This can result in the release of odours, or on rare occasions sewage contaminated water, into a home or business – known as a "blow-back."

What can I do to prepare for sewer cleaning activity?

To determine if there is upcoming routine sewer cleaning in your area, please call 3-1-1.

Keeping lids on toilets during cleaning can minimize impacts in the unlikely event of a blow-back.

What if I experience a blow-back?

Please immediately contact the City at 3-1-1. City staff will contact the homeowner by phone to determine the scope of the problem. If required, staff may be dispatched to your home.

Please note:

  • Properties identified as having experienced a blow-back in the past are placed on an advanced notification list and receive a hand delivered notice 24-48 hours in advance of cleaning activity.
  • During subsequent sewer cleanings, the pressure at which cleaning is carried out is at lowered at sites that have experienced a blow-back to help reduce the possibility of a repeat event.
  • If you have a second incident, consider checking your plumbing to ensure that service connection and vent pipes are clear of debris and are functioning properly.

Where can I get help with the cleanup?

Typically, recovery from a blow-back event is simply a matter of removing any debris and the cleaning of toilets, sinks, baths and showers that have come into contact with the contaminated water. You may then continue normal use.

Please note:

  • The City does not provide a cleaning service. Your options are to proceed with the cleanup yourself or hire an outside cleaner. If you hire a company to complete the cleaning, please submit these costs as a claim and the City will reimburse all reasonable costs that are properly documented.
  • If there are damages beyond cleaning, consider contacting your insurance company. Damages should be brought to the attention of City staff during the initial inspection process.

Do I need to worry about my health?

Blow-back events that involve only the discharge of sewage contaminated water to walls or surfaces do not result in an immediate health risk. However, it is important that all sewage contaminated water and debris be removed and that surfaces that have come in contact with this water be cleaned. This will require the cleaning of surfaces with a soap solution and disinfection with a diluted household bleach/water solution. Regular household cleaning products are all that is needed and rubber gloves are recommended.


  • Never mix ammonia and chlorine products such as household bleach. If sewage contaminated water has come in contact with a person in your home or has possibly been ingested and you are concerned about your health, please seek medical attention.

Making a claim

  1. Prior to submitting a claim, contact 3-1-1 to:
    1. Initiate an inspection by the City’s First Response team
    2. Receive a customer service request number for future reference.
  2. Initiate a claim with the City by letter or sending an e-mail to You will need to reference the event, date, and actions taken.
  3. The Claims Unit will ensure claims are acknowledged, investigated, tracked, evaluated and resolved.

If you have any questions, please contact our general claims line at 613-580-2655 or email at