top of page

Composting in a Growing City: What Calgary’s Numbers Really Show

How Calgary’s Green Cart program is delivering results and where our data falls short.

Rush-hour traffic, new highrises, and a booming population, Calgary’s growth is impossible to miss. But behind the bustle, the city’s waste habits are quietly changing. The residential Green Cart program is turning food and yard waste into environmental wins, but multi-family buildings remain harder to track: neither the city's commercial services or private haulers data is publicly available. 

 

Green cart volumes stabilized under 100k tonnes after pandemic peak

One of Calgary’s biggest recent shifts in waste management came with the launch of the Green Cart program in late 2017. Designed to handle food and yard waste, it quickly changed the city’s waste diversion picture: in its first full year, diversion rates (including both the green carts and the blue recycling carts) jumped by 23 percentage points. Green cart tonnage spiked during 2020 and 2021 when more people were home during the pandemic, but it has since leveled off to under 100,000 tonnes annually.

ree

 

Roughly half of waste generated is diverted from landfills

Since the introduction of the green cart, about half of all household waste (including recyclable materials) has been kept out of landfills each year.To keep waste diversion rates high, the City of Calgary continues to invest in education and monitoring. Campaigns like Right Bin for the Win encourage residents to compost food scraps instead of sending them to landfill. 

ree

 


756k tonnes of residential green cart waste collected

 The residential green cart program has collected about 756K tonnes of food and yard waste since its inception in the last half of 2017. By diverting this material from landfills, the program has helped cut methane emissions and conserve valuable landfill space. The finished compost is then returned to residents and community green spaces, enriching Calgary’s gardens, yards, and parks.

ree


About 4% of food waste improperly disposed in green cart study

 Food waste sealed in non-compostable bags or remaining in original packaging is improperly disposed of according to the composition study. In 2020, when the study was conducted, this 4% represented 4,560 tonnes of green cart waste going straight to landfill instead of heading to the composting facility. 

 

Periodic waste composition studies also provide a clearer picture of what’s ending up in the carts and how programs are performing. The residential communities sampled were selected to collectively represent housing types and demographics in Calgary.


Designed to help reduce contamination, the annual residential Cart Spot Check program expanded significantly in 2024, with a goal of 200,000 inspections. 

ree


383K tonnes of GHG emissions avoided

Diverting food and yard waste from landfill prevents methane generation—a powerful greenhouse gas. The City’s landfill gas management systems have kept annual GHG reductions steady at around 58,000–75,000 tonnes CO₂e, avoiding a total of 383,000 tonnes since 2019. That’s roughly the same as planting 2.9 million trees and letting them grow for six years.


The finished compost produced at the Calgary Composting Facility is sold to landscape soil blenders and compost baggers, which helps offset program costs and reduce green cart fees. Some is also distributed free to community gardens and to residents during annual giveaway days. Last year’s event drew over 10,500 people collecting compost for their yards and gardens.

ree

 

Rapid growth & Data gaps

According to the 2021 federal census, Calgary had about 357,000 houses eligible for green cart service. From 2022 to 2024, the Canada Mortgage and Housing Corporation recorded about 22,000 additional single, semi-detached, and row houses built in the city, plus around 23,000 new apartment units.


This is where the data problem emerges. The green cart figures only capture waste from eligible low-density housing. Calgary’s apartment buildings, which can be serviced by the city’s commercial waste division or by private haulers, are excluded from the publicly released data. The city’s commercial waste collection data is not shared publicly, nor is there transparency about the split between city-serviced multi-family buildings and those using private haulers. Without this information, it’s hard to tell whether stabilized green cart tonnage reflects actual waste reduction or simply the fact that more of the population now lives in high-density housing outside the program’s reporting scope.


The 239,000-person growth figure over the last three years also covers the entire Calgary CMA (Census Metropolitan Area), including nearby towns, villages and rural areas, all of which have their own waste systems and are not served by the City of Calgary.

ree

 

Call to Action

 

Calgary is expanding its composting facility, adding capacity and capturing biogas to turn waste into energy. But the picture isn’t complete: the city still doesn’t share public data on organic waste from multi-family buildings, leaving gaps in how we track progress and target improvements.


Since every multi-family building in Calgary must have an “Organics Only” green cart, just like single-family homes, residents play a key role in making the system work:


  • Do reduce food waste first. Plan meals, freeze leftovers, or dry excess herbs and fruit.

  • Do put in food scraps, coffee grounds, paper towels, and food-soiled pizza boxes (clean ones can go in recycling).

  • Don’t toss in plastic bags, even “biodegradable” ones, or regular trash.

  • Do scrape food out of containers before composting them.


With Calgary expanding its composting facility to process more organics and capture renewable energy, citizen efforts matter more than ever. Small actions keep the compost stream clean, cut waste at the source, and ensure the city’s investment pays off for a sustainable future.

 

Sources

  • City of Calgary Open Data Portal: 

    • Annual Waste Volumes

    • Waste and Recycling Services Performance Measures

    • Green Cart Waste Composition 2020




---

DataPost

 
 
 

Comments

bottom of page