Residential lines

City of Leduc Public Services crews respond to about 120 residential sewer backup calls annually.

Please note: the city estimates the actual number of residential sewer backups is about 500 per year. Most residents call a plumber to unclog their pipes. In those situations, the city is typically not notified of the issue.

When city crews are called, they:

  • cnduct a mechanical cleaning of the line,
  • inspect the line by camera, and
  • apply a herbicide in the line to fight tree roots (when applicable).

These actions may be performed together or separately.

Flushing city mains

Each year, City of Leduc crews flush half of the city’s mains with high-pressure water or mechanical blades driven by high-pressure water to clear pipes and break up any material that may interrupt regular flow of waste through the system. Please note: No chemicals are used during this process.

Regularly flushing out the sanitary sewer (wastewater) collection system with hydrovac trucks helps keep the system operating efficiently. Flushing helps clean and remove foreign materials including:

  • FOG (fats, oils and grease),
  • wipes (even those labeled as flushable),
  • diapers,
  • rocks, dirt and tree roots, and
  • other non-flushables.

Areas in the city that are determined to be more susceptible to sanitary sewer problems may be inpsected and flushed more often than others. The goal of the sanitary sewer flushing program is to minimize service calls and sewer backups caused by sewer main blockages. Success of the program depends on the care and participation of Leduc residents.

It’s simple: Flush smarter. Flush only the 3Ps and dispose of everything else in your waste or organics cart.

Please note: Sewer main flushing can cause pressure fluctuations in your sewer pipes, potentially sucking out the water in p-traps. Simply fill your drains (including basement floor drains) with water, flush toilets and open a window to eliminate the smell. In addition, residents may notice their toilets, sinks or drains making noise, gurgling and splashing (especially in basements). Residents are asked to keep toilet lids closed and drains plugged while the work is being completed in the area. You can still utilize your toilets, sinks and appliances during the flushing process. 


What are sanitary sewer lines? 

Everything that goes down sinks and toilets ends up in the sanitary sewer system. This also includes any wastewater coming from dishwashers and clothes washers.  

Why are the sanitary sewer lines flushed? 

Flushing the lines helps remove any build up that has occurred helping keep the lines flowing preventing emergency repairs and enhances the longevity of the system.  

How will the flushing affect me and my home? 

During the flushing process residents can continue to use water and appliances. You may however experience noise, gurgling splashing and smell coming from drains. You are asked to run water down the drains, flush toilets and open a window to remove any odour. 

Are chemicals used to clean the lines? 

No chemicals are used to clean the sanitary lines. Crews utilize high-pressure water to clear the lines of debris.  

Inspecting city mains

Each main is inspected every five years by a camera lowered into the sewer main network. The camera check is an efficient way to determine whether the pipe is in good condition and help identify what is required to extend its lifespan. Options include repairing damage, replacing damaged sections or installing pipe liners.

Another service used to inspect city mains is smoke and dye testing. This testing is completed on sewer systems to identify if there is any inflow or infiltration occurring in the system. These issues may be a result of:  

  • Cracks in the sewer line 
  • Defective sewer connections 
  • Illicit cross-connections with storm drains 
  • Building connections that have improper traps or plumbing 

Infiltration and inflow in the sewer system is a problem because it can result in the following: 

  • It can result in rainwater entering the sewer system leading to overflows after heavy rains. 
  • Identify improper building connections like missing traps that can result in an unsafe build up of sewer gases inside buildings.  

Smoke and dye testing is a useful and inexpensive tools to identify these problems within the sewer lines. 

Without these city maintenance program, clay and concrete pipes could be expected to have a lifespan of about 50 years. The lifespan of plastic pipes is about 100 years. To extend the lifespan of the city system, crews often install liners in the mains.


Is the smoke harmful to people? 

No. The smoke is actually a non-toxic, odourless mist that has been utilized for this process for over 20 years.  

Is the smoke harmful to pets? 

During the process if you are away from your home it is recommended you leave a window open should smoke enter your home with your pet inside. If they have respiratory issues, having them removed from the premises during the testing in the off chance that smokes enters your home is the safest option.  

Is the smoke a fire hazard? Will it set off my fire alarm? 

As the ‘smoke’ is merely a mist, it is not a fire hazard. It can however set off your fire alarm if it enters your home. To clear the smoke, open your windows and doors. 

Removing tree roots

The city’s routine maintenance program includes the removal of tree roots in sanitary sewer mains. If left undisturbed, these tree roots will completely block the sewer causing sewer backup. Tree roots thrive in the warm, moist sanitary sewer mains that are full of nutrience trees need. As tree roots expand, they can cause breaks and large cracks in the sanitary sewer lines which significantly decreases the integrity of the pipe.