Environmental Monitoring & Protection

Fat, Oil and Grease, Information for Residents

How do fat, oil and grease cause sewer blockages?
When warm fats, oils, and grease are washed down the sink or toilet into the plumbing system they cool, harden and stick to the inside of sewer pipes (both in private sewer lines in your home and City sewers under the streets). Over time, the grease will build up and can block the entire pipe.


Where do fat, oil, and grease come from?
They often are a result of cooking, and can be found in meats, fats, lards, cooking oil, shortening, butter and margarine, food scraps, baking goods, sauces, salad dressings and dairy products.
What is the result of fat, oil, and grease build-up in the sanitary sewer systems?
You may think that once it’s gone down the drain, it simply washes away and is gone for good. But that’s not the case. Fat, oil and grease can build up in your pipes, causing blocked sewers which can lead to problems, such as:

  • Overflowing of raw sewage into your home, business, or neighbouring property, causing basement flooding – an expensive and unpleasant clean-up.
  • Contact with disease-causing organisms.
  • A raw sewage overflow into parks, yards, streets, creeks, rivers and the lake.
  • An increase in operation and maintenance costs to clean and repair damaged sewer pipes.


What can you do to help prevent sewer system blockages?

  • NEVER pour grease down sink drains or into toilets.
  • DO put basket/strainers into sink drains to catch food scraps and other solids. Empty the drain basket/strainer into the Green Bin for disposal.

What should you do with your fat, oil and grease?

  • Let the grease cool and harden, then scrape it and food scraps from trays, plates, pots and pans, utensils, grills, and cooking surfaces into your Green Bin.
  • Small volumes of liquid cooking oil can be placed into the Green Bin
    as long as the oil can be absorbed by the other organic materials or paper towels.
  • Larger amounts should be collected into a sealed container labelled “cooking oil” and can be dropped off at household hazardous waste (HHW) depots located at transfer stations and community environment days. You can also call the Toxics Taxi, which will pick up your liquid cooking oil along with any household hazardous waste you have (minimum quantity of 10 litres of combined cooking oil and household hazardous waste — but not mixed together).

For 24-hour reporting of water pollution based spills and complaints, please call 311.