How to sort waste into categories (plastic, glass, organic)?

Waste separation in Calgary is a fundamental environmental and economic practice that ensures effective waste management through a three-color container system designed to maximize the diversion of materials from landfills. The City of Calgary has implemented a system of blue, green, and black bins that allows residents to properly sort materials according to their intended use and potential for recycling or composting. Proper sorting not only protects the health and safety of sorting plant workers, but also maximizes the efficiency of the entire waste management system, saving millions of dollars annually in costs associated with container contamination.

Fundamental principles of the waste sorting system

The three-bin philosophy

The Calgary waste management system is based on the principle of “too valuable to throw away,” which means maximizing resource use through proper sorting of materials. Each container has a specific purpose: blue for recyclable materials, green for organic waste, and black for residual waste that cannot be recycled or composted. This system has reduced the amount of household waste in black containers by 50 percent since the introduction of the blue and green container programs.

The importance of proper sorting

Contamination of containers with the wrong materials has serious consequences, including safety risks for workers, damage to equipment, and increased program costs for all Calgarians. One wrong item in a container can have far-reaching and long-lasting consequences. Batteries that end up at a recycling facility can cause fires in 100,000-square-foot buildings, resulting in staff evacuations and lost time.

Plastic Material Category

Acceptable plastic containers

Plastic materials for the blue container must be containers marked for recycling 1-7. The key criterion is that the item must be a container—a bottle, jar, jug, or other container—not an item made of plastic. Acceptable plastic containers include milk jugs, yogurt containers, soda bottles, food containers, laundry detergent containers, body lotion containers, beverage and juice bottles, antiseptic bottles, shampoo and conditioner bottles.

Understanding recycling symbols

Plastic recycling symbols in Alberta range from 1 to 7, and each type has specific characteristics.

  • Type 1 (PET or PETE): beverage, juice, and water bottles — the most common type of plastic for recycling.

  • Type 2 (HDPE): Milk jugs, detergent bottles, and some bags — one of the safest for recycling.

  • Types 3-7: Various containers ranging from food packaging to large containers.

Preparing plastic materials

All plastic containers must be empty, clean, and dry before being placed in the blue container. Lids and caps should be removed and placed separately in the container. Labels can be left on as they are removed during the recycling process. Containers should be rinsed of food residues and other substances, but do not need to be washed to a sterile clean.

Special category: tied elastic plastic bags

Stretch plastic bags should be collected in a single plastic bag and tied before recycling.

Test: if the bag stretches like a grocery bag, it can be recycled; if it crinkles or tears like a chip bag or cellophane, it cannot.

Acceptable bags: grocery bags, shopping bags, sandwich bags, zip-top bags, freezer bags, bread bags, dry cleaning bags, toilet paper film, bubble wrap.

Unacceptable plastic items

  • Styrofoam containers (cups, plates, meat trays, blocks, peanut packaging) — not accepted, even with a recycling symbol. From May 2024, they can be disposed of at three municipal landfills as part of a pilot program.

  • Plastic items that are not containers: plates, cutlery, drink lids, straws, stirrers, bread tags, protective seals, ties, rubber bands.

Glass materials category

Acceptable glass containers

Glass materials for recycling include only clean food jars and bottles. Jars for pasta sauces, jams, pickles, salsa, and other products are accepted, as well as bottles of all colors for beverages. The color of the glass does not matter — clear, green, brown, and blue containers are accepted.

Preparation of glass materials

Glass containers must be free of food residues and other substances. Lids and caps should be removed and placed separately in a container, as different materials have different recycling processes. Labels can be left on jars and bottles, as they are removed during the industrial recycling process.

Unacceptable glass items

Ceramics, mirrors, coffee cups, tempered glass, drinking glasses, or window glass cannot be recycled through the blue bin program. These materials have different melting temperatures and chemical compositions, making them incompatible with the standard glass recycling process for containers.

Broken glass requires special handling—it should be placed in a box labeled “broken glass” and disposed of in the black container. This ensures the safety of waste collection and sorting workers.

Organic materials category

All food waste

The green container is for all food waste, regardless of its condition—raw, cooked, spoiled, or moldy. Acceptable food waste includes leftovers from plates, fruit and vegetables including pits (fruit stickers should be thrown in the trash), meat, poultry and bones, fish, seafood, shellfish and shells, bread, grains, pasta, rice and porridge, baked goods, cookies, cakes and muffins, eggs and eggshells, milk, cheese, sour cream and dairy products, condiments, sauces, gravies and jams, nuts, seeds, chips, popcorn and candy.

Contaminated food paper

Contaminated food paper also belongs to organic waste. This category includes used paper towels and napkins, wet or contaminated cardboard and paper products such as pizza boxes, even with grease stains, wooden chopsticks, coffee filters, and tea bags.

Garden waste

Garden waste makes up a significant portion of organic materials and includes grass clippings, small tree branches, pine cones, twigs, weeds, turf, and leaves. Cold ashes from barbecues or fireplaces can also be composted, but they should be in a bag for safety. Untreated wood includes untreated lumber, wood chips, popsicle sticks, toothpicks, and chopsticks.

Pet waste

Pet waste includes dog waste, cat litter, animal bedding, animal feed, and fur or feathers. Critical: For collector safety, pet waste, cat litter, animal bedding, sawdust, and wood shavings must be bagged.

Preparation of organic materials

Materials can be placed directly in the green container or in certified compostable bags, paper bags, or newspaper lining. Plastic bags are strictly prohibited for organic waste. To prevent food waste from freezing to the walls of the container in winter, it is recommended to use compostable bags or place crumpled newspaper at the bottom of the container.

Technical aspects of proper sorting

Preparation of materials for recycling

General rules for preparing items for the blue container include cleaning items of food and other residues and placing all recyclable materials loosely in the container without sorting them by type. Labels can be left on metal cans, glass bottles, and plastic containers, as they are removed during industrial processing. Lids and caps should be removed and placed separately in the container.

Metal containers include lids from metal food cans, which can be placed inside the can or left attached. Aluminum foil should be crumpled into a ball before recycling for better sorting at the plant.

Reminder and tool systems

Waste Wizard is an online tool provided by the City of Calgary that allows you to quickly find the correct container for any item. Users can enter the name of the item, and the system will show which container it should be placed in. This tool is especially useful for complex items or those that are unclear.

The Calgary Garbage Day app provides reminders of collection days, displays the collection schedule on the go, and sends notifications of schedule changes. The app has a rating of 4.8 out of 5 and is used by over 100,000 residents.

Logistics and container placement

Container placement rules

Containers must be out by 7:00 a.m. on collection day. Place containers on a level surface, not on a raised platform. For front-of-house collection: Place the wheels of the container against the curb. For collection in alleys: place containers with sufficient space for passage between the container and the rear fence, garage, or fence.

Distance requirements

  • 0.5 meters (2 feet) between containers and 0.5 meters (2 feet) of space behind containers.

  • At least 1 meter (3 feet) from obstacles on the sides, such as parked cars and utility poles.

  • At least 3 meters (10 feet) of space above the containers - away from basketball hoops, tree branches, gutters, and electrical wires.

The automated arm on the collection truck can extend 2.5 meters wide and rise 3 meters high. Proper placement of containers ensures safe collection for all neighbors.

Storage and winter tips

Containers must be removed from the street by 7:00 p.m. on collection day. In winter, snow should be cleared from the lids of blue containers to protect the materials from getting wet. Containers should be stored in a protected area and brought out on collection day so that they do not freeze to the ground. The area around the containers should be kept clear of snow and ice.

Pollution control program

Spot check system

The spot check program runs year-round and plans to visit 45,000 addresses annually to check that sorting is being done correctly. The team, mostly made up of college students, travels to several hundred homes ahead of the trucks on collection day. They open the lids to check the contents of the bins, using sorting sticks to get a better view.

The inspection procedure includes looking for obviously dangerous or unacceptable materials, such as propane tanks in recycling or plastic bags in compost. If an incorrect item is found, a tag is left on the container with a message about the incorrect item. The container may also be left uncollected so that the resident can correct the problem.

Gold recognition tags

Gold tags are awarded to containers that are flawless—everything is sorted and prepared correctly. These tags recognize the efforts of citizens who go the extra mile to sort materials correctly. Residents who receive gold tags express pride in the recognition of their voluntary efforts to sort correctly.

Consequences of contamination

The financial consequences of contamination include fines imposed by the city on parties who sort the material. In 2024, fines for container contamination are expected to cost the city nearly $1 million. Safety incidents, such as fires at businesses that require the Calgary Fire Department, also have associated costs.

Contamination rates for 2024 showed that 4% of green containers for organic waste and 29% of blue containers for recycling were contaminated. When Tetra Tech, the company that took over the program, revisited the offenders, contamination decreased by 17%.

Additional recycling opportunities

Community recycling centers

Community recycling drop-off locations are located throughout Calgary and are available 24/7 for additional recycling materials. These locations are especially useful for materials that do not fit in household blue bins. There are 17 community recycling drop-off locations with 147 city-owned bins.

Eco-Centres

Eco-centres at three city landfills accept a wide range of materials, including garden waste for composting, blue bin recyclables, scrap metal, household items, drywall, wood, hazardous waste, bicycles, Styrofoam packaging, and electronics.

System development and improvement

Technological innovations

Apps and digital tools continue to evolve to improve waste sorting. The city of Calgary even has a game to teach proper waste sorting, which helps educate citizens about the correct use of containers. The game aims to reduce the complexity of sorting and the number of contaminants.

Future plans

Extended producer responsibility (EPR) for single-use products, packaging, and printed paper began in Alberta in April 2025. The switch to EPR will reduce blue bin fees for Calgary households from $9.34 per month to $2.17 per month, representing a savings of $7.17 per month or approximately $86 per year.

Proper waste separation in Calgary is a critical practice that ensures the efficiency of the entire waste management system and protects the environment for future generations. By properly using blue bins for plastic, glass, and metal, green bins for organic waste, and black bins for residual waste, Calgary residents have saved generations of landfill space and saved over a million trees annually. Understanding the specific requirements of each material category, preparing items correctly, and complying with container placement logistics requirements ensure the smooth operation of this successful waste management system.