The City's Maintenance and Rehabilitation Program
We regularly inspect the sanitary sewer system and fix issues to make sure that the system:
- Has no blockages and is working properly
- Is not broken or collapsed at any location(s)
- Is reducing the risk of rainwater and groundwater entering the sanitary sewer system.
The City inspects and maintains the entire sanitary sewer system except for the service connection between your home or business and your property line, which is your responsibility to maintain.
Our inspection and maintenance work includes:
Video inspections – A camera takes a video as it travels through a sanitary sewer. City staff review the video and identify issues in the sewer, such as cracks, leaks, blockages, dips, roots, fats, oils and grease deposits, or breaks in the pipe. This allows the City to locate areas that need to be repaired or replaced. Video inspections are sometimes used to identify where service connections from each property join the sanitary sewer, if there are no records. New sanitary sewers are also video inspected to confirm that they have been built properly.
Smoke testing – A non-toxic vapor (that looks like smoke) is added to the sanitary sewer. If the smoke comes out of a roof downspout or cleanout on a house or building, then there is a possible cross connection (meaning rainwater or groundwater can enter the sanitary sewer system). Cross connections are a violation of the City’s Sanitary Sewer Bylaw No. 16611 and should be fixed by the property owner immediately. Smoke testing can also identify broken or missing lids or caps on inspection chambers and manholes.
Dye testing – A coloured, non-toxic liquid is added to a roof downspout or building foundation cleanout. City staff then inspects the storm sewer and the sanitary sewer downstream to see if the dye appears. If the dye appears in the sanitary sewer, then there is a cross connection. Similarly, if dye is added to a drain in a house or building and the dye appears in the storm sewer, this is also a cross connection. Cross connections must be fixed by the property owner immediately per the City’s Sanitary Sewer Bylaw No. 16611.
Pressure testing – A small section of the sanitary sewer is isolated using “bladders” and air is added to the isolated section to pressurize the pipe. A gauge then reads the air pressure in the isolated section over time. A drop in air pressure indicates that there is a leak or crack in the pipe that could allow groundwater to enter the pipe or sewer odours to be released to the environment. A gel-like substance (called grout) may be added to seal off the leak or crack in the pipe.
Flushing – Water is injected at high pressure into a sanitary sewer to move debris that is stuck in a sanitary sewer (similar to pressure washing your patio or deck). The debris is removed by a vacuum truck at a downstream manhole.
Root cutting – A circular rotating saw is sent through the sanitary sewer to cut tree and vegetation roots that have entered the sanitary sewer through cracks or joints in the pipe. While this work is necessary, sometimes cutting the roots actually makes the root system grow faster (pruning effect), so recent City campaigns are focusing on educating property owners about not planting trees, shrubs or other large plants over sanitary sewer pipes. See what a sanitary sewer full of roots looks like.
Emergency issues are repaired as soon as possible. Any remaining issues are added to the City’s upcoming projects list.