Improper disposal of fats, oils, and grease by residents can build up in the sewer system and cause blockages. This can result in sewer backup, property damages, and cost to residents as well as to the City.

Each year, out of approximately 4,500 calls, Utility Services responds to over 220 calls from homeowners who are having sewer troubles that are directly related to blockages resulting from FOG buildup. 

In addition, crews respond to approximately 200 mainline blockages each year. Historically over 50% of these blockages are due to fats, oils, and grease problems.

Grease can be seen on the cleaning equipment during routine cleaning of the sewer lines. Grease buildup can be confirmed by running a small camera through the line to determine what is causing the blockage.

Lines are cleared by special equipment that uses water under high pressure to remove the grease from the walls of the pipe and a vacuum process to remove the dislodged grease from the manhole.

In 2015, the City cleaned approximately 1,200 kilometres of sewers at a cost of $2 million. In addition, Utility Services televised 123 kilometres of mainline at a cost of $1.6 million. It is estimated that grease is present in 25% to 50% of these lines.

There are approximately 3000 km of pipe in the sanitary and combined (sewers used for both sanitary and stormwater) sewer systems. On a yearly basis we can televise about 150 kilometres. Based on these numbers, it would take 20 years to televise the entire city. Therefore, it is not possible to monitor all the sewer lines for grease buildup on a regular basis.

The City has a little over 5,000 km of sewer pipe in total consisting of:

• 2,000 km of sanitary pipe that handles the wastewater from residences.
• 2,100 km of storm pipe that handles the runoff from rain and snow melt.
• 937 km of combined sewer pipe that handles both wastewater and stormwater.

Hot water and soap may remove grease from the dishes but not from the walls of sewer pipes. Sewer pipes in the ground are fairly cold so any liquid grease in the wastewater solidifies on the walls of the pipe. Eventually, it can build up enough to cause blockages.

No. Wastewater from every toilet, shower, kitchen sink, dishwasher, or bathtub is connected to a single sewer pipe from your residence.   Therefore all grease laden wastewater ends up in the same sewer pipe.

Cooking oil does not solidify so when garbage collectors pick it up, there is a chance the container can break and oil will be spilled causing a safety hazard.

Used cooking oil should be placed in a capped, plastic jug, labeled, and set out for garbage collection. Amounts larger than 1 litre should be taken to an Eco station for disposal.

Yes. Everyone should dispose of cooking fats, oils, and grease in the proper way rather than pouring them down the drain.