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Help keep your sewer pipes in good working order, by not putting the wrong things down the drain.

In the kitchen

Don’t let fats, oils and grease go down your drain. Scrape them into your green bin instead.

Even small amounts add up over time.

When fats, oils and grease are poured down the drain and enters the sewer system, these materials cool, harden and stick to the inner walls of sewer pipes. Over time this material builds up, restricting flow, causing odours, and leading to messy, inconvenient and costly clogged pipes, basement flooding and sewer back-ups.

Clogged pipes lead to costly repairs for homeowners and The City

Cooking fats, oils and grease are the primary cause of wastewater blockages and back-ups. Every year, The City responds to over 8,000 sewer back-ups and spends approximately $3 million to repair damage caused by blockages. This doesn’t include the cost to individual homeowners to fix clogged pipes on their property.

What can’t be poured down the drain


Examples include:

  • Dairy products (yogurt, sour cream, milk, butter, ghee, cream, cheese, ice cream)
  • Margarine
  • Shortening
  • Gravy
  • Soups
  • Meat
  • Soups and broths


Examples include:

  • Cooking oils (e.g. olive, coconut, canola, vegetable, peanut, sesame)
  • Salad dressing
  • Condiments
  • Marinades
  • Mayonnaise


Examples include:

  • (includes animal fats left over from cooking meats) 
  • Bacon
  • Grease
  • Pan drippings

How to dispose of fats, oils and grease

Here are a few simple steps to follow to keep your drains healthy.

  • Wipe cooking equipment and scrape dishes before washing

    Tip: Use a spatula or reuse a paper towel and toss it in the green cart too.

  • Cool larger amounts of grease in a container or bowl until they solidify

    Scrape or wipe these materials into your green bin.

  • Scrape small amounts of expired dairy

    like sour cream and yogurt into your green bin.

  • Use a kitchen strainer

    to help prevent food residue from going down the drain.

How to dispose of large amounts of liquids

Only put in what can be absorbed by the contents of your kitchen compost pail (fuller kitchen pails can absorb more liquids than emptier ones).

For larger amounts of liquids, check out What Goes Where to find out what to do with the following:

Myth vs. fact

Myth: Flushing the drain with hot, soapy water when disposing of fats, oils and grease prevents them from hardening in my pipes.

Fact: Sewer pipes in the ground are fairly cold, so eventually fats, oils and grease will cool and harden on the walls of the pipe, even when hot water and soap are used. Eventually, it can build up enough to cause blockages.

Myth: If I use a garbage disposal unit, it’s okay to put fats, oils and grease down the drain.

Fact: Garbage disposal units cut food into smaller pieces, but the wastewater system is designed to manage the flow of wastewater exiting your home, not the scraps and shreds of food leftovers.

When these substances go down the drain, they will still cling to the pipe walls, which over time leads to clogged pipes and blocked sewers.

Myth: It’s okay to put small amounts of grease down the drain.

Fact: Even small amounts of grease add up and over time can turn into big clogs.

Calgary is a big, urban city. Imagine if every neighbour on your street cooking dinner poured a small amount of grease down their drain every evening.

Over time, massive blockages (called fatbergs) form in the wastewater pipe.

Myth: Flushing fats, oils and grease down the toilet is okay.

Fact: All the drains in your home, including the toilet, shower, kitchen sinks, laundry and bathtub are connected to the same sewer pipe so it’s important not to dispose of fats, oils and grease in any of these places.

Frequently asked questions

Should I still rinse my containers before recycling?

You should continue to rinse and dry your containers before recycling, however it’s important to remove as much food residue as possible before doing this. 

For smaller amounts of liquids, put what can be absorbed by the contents into your kitchen compost. Visit What Goes Where to find out how to dispose of larger amounts. 

For other material, use a spatula or reuse a paper towel to scrape and wipe any residue into your green bin. 

Won’t gravity keep this material flowing through the pipes?

Unlike wastewater, cooking fats, oils and grease harden when they enter cold pipes, causing some of this material to stick to the side of the pipes even when gravity is moving it along. 

Why is it a problem to flush foods down the toilet? The pipe connected to the toilet is larger in diameter than the one connected to the sink so it should be able to handle it.

All the pipes in your house, including from the toilet, connect to a single sewer pipe leading out of your house. Even if the material doesn’t block the toilet pipe it can still create blockages in other pipes in your home.

Isn’t the real problem non-flushable items like wipes?

Non-flushable items like wipes, menstrual products, floss and hair contribute to blockages in pipes but often it’s because they’ve combined with cooking fats, oils and grease. As these items move through your pipes they are snagged by the material stuck to the side of the pipes and create a blockage that is referred to as a fatberg. 

Why is flushing food down the toilet any worse than flushing poo or vomit?

When food is digested in your body, most of the fats, oils and grease are broken down and absorbed as food. While some fat, oil and grease will remain undigested, it’s a small amount and not enough to cause blockages. 

In the bathroom

The only things that are okay to flush down the toilet are pee, poo and toilet paper. Anything else can lead to sewer back-ups and blockages in the system.

Protect your home and our wastewater system from costly repairs by keeping these items out of your toilet, sinks and drains.

Keep these items out of your toilets, sink and drains

Wipes, paper towel and facial tissue

  • Wipes that claim to be flushable aren’t. Flushable wipes retain their shape and strength, and don’t break down in pipes.
  • Paper towel, facial tissue and serviettes also don’t break down like toilet paper and will block your pipes.
  • Bag wipes, paper towel and any items used as a toilet paper and put in your black cart. They do not belong in your green or blue bins.

Bathroom items

Dispose of these items in your garbage:

  • Sanitary pads, tampons and applicators
  • Diapers, wet wipes, rags, bandages
  • Dental floss
  • Cotton swabs, condoms, cosmetics


Compost hair in your green bin, or it can also go in your garbage.

Hair build-up in our treatment plants can result in equipment being shut down for manual cleaning.


Take unwanted medication to a pharmacy for disposal. Flushing pills and medication can be harmful to the environment.

Household hazardous waste

Cleaners, disinfectant, chemicals and paint thinners are considered household hazardous waste and should be taken to a household hazardous waste drop-off locations for safe disposal.

These include:

  • Bleach and ammonia
  • Clean solvents and spot removers
  • Disinfectants
  • Hot tub and swimming pool chemicals
  • Oven cleaners
  • Septic tank cleaners
  • Alkyd, latex and oil-based paints
  • Lacquers, stains and varnishes
  • Paint thinners, strippers and solvents
  • Petroleum-based products such as motor oil and gasoline

Need to find out how to properly dispose of an item? Visit

What we're doing

Prevention is better than cure, so we’re also carefully monitoring our vast network of wastewater pipes to identify where we can take proactive measures to prevent wastewater flooding into homes and businesses. We’re also improving the information we provide so more Calgarians are aware of what should and shouldn’t go down the drain.

  • We’re investing millions in preventative maintenance focusing on areas of the city where there have been frequent back-ups in the past.

  • Some of our wastewater pipes are on a regular flushing schedule to clean the pipes.

  • We’re retrofitting existing wastewater pipes that are vulnerable to sewage backups with new liners, which helps prevent fats, oils and grease from sticking.

  • Our staff are out working with Food Service Establishments to reduce blockages caused by fats, oils and grease.

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