Organic waste — food scraps, yard trimmings, and food-soiled paper — represents a substantial portion of material sent to Canadian landfills. In response, most large Canadian municipalities have introduced organics collection programs that divert this material to composting or anaerobic digestion facilities. The scope, accepted materials, and processing methods vary significantly between cities and provinces.
Waste collection area in Toronto, Ontario, featuring green organic waste containers. Photo: Wikimedia Commons.
How green bin programs work
Residential organics collection programs typically provide households with a lidded outdoor container (often called a green bin or organics cart) and a smaller indoor counter caddy for accumulating daily scraps. Collection frequency ranges from weekly to bi-weekly depending on the municipality.
Collected organic material is transported to receiving facilities operated by municipalities or contracted processors. Facilities accept loads, screen for contaminants (plastic bags, non-compostable packaging), and then process the organic fraction through one of several treatment methods.
Processing methods
In-vessel composting
Many large Canadian facilities use enclosed in-vessel composting systems — large rotating drums or tunnels that combine feedstock with air and moisture under controlled conditions. Material passes through the active composting phase in the vessel over several days, then moves to outdoor windrow or aerated static pile systems for curing. The enclosed phase accelerates decomposition and reduces odour compared to open windrow processing.
Windrow composting
Outdoor windrow composting involves forming long, elongated piles (windrows) of mixed organic material, which are turned periodically by machinery. This approach requires significant land area and management to control odour, but is lower in capital cost than in-vessel systems. Many rural and smaller municipalities use windrow composting for yard waste and agricultural residues.
Anaerobic digestion
Some Canadian facilities process organic waste through anaerobic digestion — sealed tanks where microorganisms break down organics without oxygen, producing biogas (primarily methane) and a digestate residue. The biogas can be captured and used to generate heat or electricity. The digestate undergoes further composting or land application. Toronto's Dufferin Organics Processing Facility and facilities in Metro Vancouver use or have piloted anaerobic digestion components.
A typical residential collection bin used in municipal organic waste programs. Photo: Wikimedia Commons.
Accepted materials and contamination
Accepted materials lists vary between municipalities and can change as processing technology or policy changes. As of the most recently available guidance from major Canadian cities:
Commonly accepted in most urban green bin programs
- Raw and cooked fruit and vegetable scraps
- Meat, fish, and bones (accepted in many but not all programs)
- Dairy products (varies by program)
- Coffee grounds and paper filters; paper tea bags
- Eggshells and shells from seafood
- Soiled paper towels, napkins, and food-soiled cardboard (in many programs)
- Yard waste: grass clippings, leaves, small branches
Commonly excluded
- Plastic bags, even those labelled "compostable" (unless the program specifically accepts them)
- Styrofoam and food containers with plastic film
- Pet waste and litter (some programs accept, most do not)
- Diapers and personal hygiene products
- Large amounts of cooking oil and grease
Contamination — non-organic material mixed into organic collection bins — remains a persistent challenge for processors. High contamination rates increase processing costs, reduce compost quality, and can result in loads being diverted to landfill. Individual municipalities publish updated accepted materials lists on their waste management websites.
Where the compost goes
Finished compost from municipal organic waste programs typically has several end markets:
- Agricultural land application: bulk compost sold or provided to farmers for soil amendment
- Landfill cover and remediation: used as interim or final cover on closed landfill sites
- Municipal parks and greenways: applied to sports fields, park beds, and boulevard plantings
- Retail bagged products: some finished compost is screened and packaged for sale at garden centres
- Habitat restoration: used in revegetation and erosion control projects
Programs in Ontario operate under the Resource Recovery and Circular Economy Act, which establishes producer responsibility for packaging and organic waste. Provincial environment ministries publish data on diversion rates and program performance annually.
Provincial context
Organic waste diversion policies and the presence of residential collection programs are governed primarily at the provincial and municipal level in Canada. Several provincial contexts:
- Ontario: Major municipalities including Toronto, Ottawa, and Hamilton operate comprehensive organics collection programs. Ontario's waste diversion legislation has been updated through the Resource Recovery and Circular Economy Act.
- British Columbia: Metro Vancouver operates the Yard Trimmings and Food Scraps collection program across member municipalities. BC's Organic Matter Recycling Regulation governs composting facility operations.
- Quebec: The Politique québécoise de gestion des matières résiduelles (Quebec Residual Materials Management Policy) sets diversion targets that include organic materials. Several cities and the Communauté métropolitaine de Montréal operate organics collection.
- Alberta: Municipal programs vary widely; Calgary and Edmonton both operate green cart organics collection. Alberta's Municipal Government Act and Environment Act provide the regulatory framework.
- Nova Scotia: One of the earlier provinces to implement residential organics collection province-wide, with curbside programs operating in Halifax and many smaller municipalities.
Challenges in rural and northern communities
Curbside organics collection is primarily an urban program. Many rural, remote, and northern communities in Canada lack the population density and proximity to processing facilities that make curbside organics economically viable. In these contexts, backyard composting, community composting sites, and on-site management of organic waste are the more practical alternatives.
Some smaller municipalities operate seasonal yard waste drop-off depots and maintain community compost sites where residents can drop off organic material and, in some cases, collect finished compost.