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Waste Time

Curbside composting feeds city gardens


Canadian cities have an expanding waste problem. And just as obesity has hidden risks, municipal waste can make the environment sick in ways not obvious to us.

Canadian cities have an expanding waste problem. And just as obesity has hidden risks, municipal waste can make the environment sick in ways not obvious to us. 

Organic materials decomposing in landfills emit methane—a greenhouse gas 20 times more potent than carbon dioxide. A Montreal study indicated that sharply reducing waste at the city landfills would be equal to taking 200,000 cars off the road. One key strategy to shrink a city’s waste size is to transform as much of the contents of garbage as possible from things that have to be dumped or incinerated into things people can use. Centralized composting programs do this by collecting green waste from households and taking it to central facilities, where it is turned into usable compost. Analysis of garbage in one city -— Vancouver -— found it was 16 percent food waste.

The United Nations Environment Programme reports that centralized composting is a core feature of the waste management programs in most northern European cities, and one that has been around since the early 1960s. In Canada we are only beginning to catch up.

Halifax bans organic waste

Halifax has been a leader among Canadian municipalities with its award-winning comprehensive waste management program. Through the Organics Green Cart Program initiated a decade ago, 41,000 tonnes of organic waste each year are diverted from landfills and turned into usable compost.

Halifax now actually bans a variety of materials, including organic waste, from being landfilled. Halifax provides households with mini-bins for their kitchens and carts for hauling accumulated organic waste to the curbside. A city survey found that 90 percent of Haligonians see the Organics Green Cart Program as an easy way to manage organic waste.

Toronto centralizes composting

Toronto started down the path to centralized composting in 2002 when the city of Etobicoke introduced a Green Bin program. The program has gone city-wide, so now all single-family households can participate. Green Bins collect not only vegetable peelings and grass clippings but a surprising range of other materials, including meat scraps, kitty litter, used Kleenex, and soiled diapers.

Toronto recognized that centralized composting was essential if it was to meet its waste reduction goals. A task force reported in 2001 that 30 percent of household waste was organic material. Since its introduction, the Green Bin program has diverted about 100,000 tonnes of waste from landfills. In return Toronto residents collect free finished compost each spring.

Edmonton offers convenience

In what is probably the most convenient composting program in operation, Edmonton requires no separation of organics from other household waste. Household waste — aside from recyclables — is collected, mixed with sewage, and turned into compost at Edmonton’s high-tech central composting facility.

And the rest?

So why don’t all Canadian cities centralize composting? Vancouver-region municipalities are still considering different options for handling organic waste. Ken Carrusca, a senior engineer with Metro Vancouver, points out that the decision has to be carefully weighed because some composting facilities have had to shut down due to odour problems. Port Coquitlam, though, is apparently not waiting for a regional solution and started its own green bin program in the summer of 2008.

David Cadman, a Vancouver city councillor and president of the international municipal organization, International Council for Local Environmental Initiatives (ICLEI) — Local Governments for Sustainability, sees a lack of sustained commitment as part of the problem.

Cadman observed, “Cities like San Francisco that are far closer to achieving their goals on waste reduction have achieved progress in a steady, incremental way. As a region, we achieved 52 percent recycling in a matter of five years. That was 10 years ago, and since then we’ve gone to sleep.”

Average citizens can make a difference by becoming committed waste watchers — participating in backyard, balcony, and office composting programs; recycling; and supporting zero-waste groups in our communities. We should also be at city hall demanding centralized composting programs. We need to put our garbage on a starvation diet.

Composting in your own backyard

You can reduce your household garbage by up to one third by composting at home.

Compostable garden items include:

  • Dry grass
  • Plants and weeds (without ripe seeds)
  • Soft plant stems
  • Chopped up leaves
  • Old potting soil

Compostable kitchen items include:

  • Fruit and vegetable scraps and parings
  • Crushed eggshells
  • Tea bags
  • Coffee grounds with filters
  • Shredded paper

For more composting information, go to the Composting Council of Canada website at



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Leah PayneLeah Payne