Contamination in the carts

Contamination in carts

The consequences of putting the wrong items in the bins

What exactly is “contamination”?

Contamination is when the wrong items are put in the wrong bins.

Each of your blue, green and black cart programs has specific materials that are ok to go in these bins. Anything other than the listed materials or properly prepared materials could be considered a contaminant. Sorting your waste into the right bins is necessary so that material ends up at the right facility to be turned into new products or to go for final disposal.

A single piece of contamination in the bin can have far-reaching, long lasting impacts. The consequences of contamination create real challenges that impact the health and safety of workers, the waste facilities and increase program costs for Calgarians.

Contamination is when the wrong items are put in the wrong bins.

Green cart filled with household materials

Blue cart filled with non-recyclable materials.

Contamination concern #1

Safety Hazards

One of the biggest impacts of incorrect sorting are major safety hazards that could harm your collector and the staff that work at the composting facility, recycling sorting facility and at the landfill.

When these safety incidents occur, it often results in work stoppages to deal with the hazard immediately to prevent it from getting it worse. In some instances 911, EMS and the Calgary Fire Department have to get involved using up emergency services. Many of these incidents can be prevented by making sure that items are disposed of properly. 

Click on the images below for more information on several safety hazards.

Problem item: Batteries

Why: Batteries can get compacted in the collection truck or other facility equipment. If the casing breaks open, the battery chemicals then react with the air, generating high heat and potential fires hazards.


Multiple fires at the City landfills and at the recycling facility has resulted in evacuations and temporary work stoppages.

Problem item: Bear spray canisters

Why: Even if empty, bear spray canisters will still hold residue chemicals that can be very harmful for people. These pressurized tanks can easily get punctured open by the sorting equipment releasing bear spray into the air.

Impact: Multiple bear spray releases have occurred at the recycling facility. Staff get exposed to the chemicals and require medical attention. EMS and Fire assistance are often needed to help clear the facility.

Problem item: Needles and syringes

Why: Needles, diabetic lancets, and syringes are medical devices that need to be safely disposed of. They need to be properly packaged into a puncture-proof container to go safely into the garbage.

Impact: Collectors and other facility staff have been pricked by improperly packaged needles and needles that end up in the wrong bin. The employee will need to be monitored through blood tests for up to 2 years as well as any further treatment if exposed to disease through the needle.

Contamination consequences for Calgarians

Putting the wrong items into your blue, green and black carts can lead to consequences for you at home including:

  • Your bin(s) may be left uncollected until the contamination issue is fixed
  • Repeat contamination offenses can lead to bylaw enforcement and fines
  • Increased program fees on your ENMAX bill that impact all Calgarians that use the cart programs

Contamination concern #2

Damage to equipment

Contamination can also result in major damage to the equipment on the collection trucks and at the facilities. Not only is replacing and repairing damaged equipment costly, but this type of damage also leads to lost production time with work delays, stoppages and even losing access to the necessary technology to manage our waste.

Problem item: Hoses, cord and other danglers

Why: Dangly items like garden hoses, electrical cords and stringy items cause a major mess at the recycling facility. They get tangled up around the good recyclables creating a giant ‘hairball’.

Impact: Recycling hairballs stop the sorting process entirely and clog up the sorting line. They create costly delays and unnecessary hazards for workers to deal with. 

Problem item: Scrap metal like frying pans, pipes and household items

Why: Large pieces of metal are too unwieldy and dangerous to be sorted at the recycling facility. They often jam up equipment, rip apart the conveyor belts and damage other technology.

Impact: Damaged equipment results in major delays as repairs take place. A damaged conveyor belt can cost upwards of $25,000 to fix.

Did you know?

Contamination applies to all three of your bins. There are some items that don’t belong in any cart like electronics, chemicals, propane tanks, batteries and more.

Green cart filled with household materials.

Contamination concern #3

Lower quality of materials to become new items

For recycling and composting programs to be effective they must be able to provide quality materials to the end manufacturers. That means the compost shouldn’t have plastic bits in it and the recyclables need to be empty and clean.

When the wrong items end up in the wrong bins, it can add up to some costly mistakes. Sometimes, that even means having to landfilling materials if there’s just too much of the wrong items instead of the right ones.

Problem item: Food still in the packaging

Why: While food scraps are compostable, the packaging your food comes in is often not. It is important to separate food out from packaging before putting food scraps into the green bin.

Result: Food still left in the packaging doesn’t get composted or recycled. The entire package ends up in the landfill.

Problem item: Loose bags in the recycling

Why: Bags must be bundled into a single bag and securely tied close before going into the blue cart. This ensure they can be properly sorted at the recycling facility.

Result: Loose bags get mixed up in the good recyclables and jam up the sorting equipment causing delays. They do not get recycled and end up going to landfill.

Problem item: Plastic bags in the compost

Why: Plastic is the #1 problem in the green cart. They are not a compostable item as they do not breakdown and end up leaving plastic bits in the finished compost.

Result:  Expensive processing is needed to remove plastic and other materials from the compost in order to have a quality finished product.

The more contamination, the more it costs all of us

For example, the recycling facility charges The City and blue cart homeowners with extra fees to cover the costs of dealing with contamination. In 2021, the Blue Cart program paid out almost $2,000,000 in penalties, transportation and disposal of contaminated materials.

Preventing contamination in the bins

Help keep our blue, green and black cart programs safe for everyone by keeping these contamination items out!

The City picks up waste from 330,000 households each week. That’s a lot of bins that get emptied and material that needs to be taken away. Putting the right items into the bins will allow for your collectors to safely pick up your bins and stay on schedule for you and your neighbors.

It will allow staff and equipment at the recycling, composting and landfill facilities to handle our waste responsibly and safely.

Keep these items out of all your carts

  • No batteries
  • No chemicals and propane tanks

Keep these items out of your blue and green carts

  • No garbage – black garbage bags
  • No household items (e.g. furniture, hoses, toys etc.)
  • No scrap metal – pots and pans, pipes, car parts

What can and can’t go in the carts

Black cart

Blue cart

Green cart