Brown bins have become a fixture in NDG, and thanks to residential support, we are now able to divert tons of organic waste away from landfills. While we know that composting is good for the environment, it’s not always exactly clear what happens to your kitchen scraps once your brown bin has been picked up.

Montreal’s food waste collection system is currently in a transition period. Collected waste is normally transported off-island to fields to decompose naturally and become fertilizer for farms.

However, a new composting facility in St Laurent, slated to be finished in 2021, will allow us to compost most of our waste on-island. This will reduce our greenhouse gas emissions because it will lessen the number of kilometers travelled by the compost trucks. Even more exciting, however, is the construction of a biomethanation plant in Montreal East.

Essentially, biomethanation is a composting method that harvests the energy produced by decomposing materials. When organic matter breaks down, it either occurs aerobically (in the presence of oxygenrich environments) or anaerobically (in oxygen-poor environments).

Typically, open-air composting is mostly aerobic,however, biomethanation itself uses anaerobic decomposition. By keeping compost in controlled facilities and reducing oxygen levels, matter can break down within 2-6 weeks. This type of decomposition process releases methane and carbon dioxide.

These natural gases can then be collected and purified (instead of being released into the atmosphere), and used as fuel! As we transition away from fossil fuels, biomethane produced from natural composting can be an important fuel source for vehicles that are hard to electrify, such as transport trucks. It can also be used for central heating.

Another benefit of biomethanation, then, is that we can generate revenue from our composting by collecting the biogas and selling it to energy companies!

Lastly, these two composting facilities will be supplemented by three more in the future, one of which will also be a biomethanation plant in Lasalle. This is great news for businesses and citizens living in apartment buildings with more than eight units, because the expanded composting capacity will allow the city to start collecting compost from them! They are likely to be invited to join the food waste collection program by 2021. And if you can participate in the composting program now, there’s never been a better time to start.

– Allison Lalla (summer student)