Canada: in Montreal, the incompressible environmental cost of snow removal
Thousands of machines roam the streets of Montreal for several days after a snowstorm to clear the city.
© Leopold Picot/RFI
Text by: Léopold Picot Follow
Every winter, the city of Montreal, in Canada, receives nearly two meters of snow over the 250 km² of its territory.
To get rid of it, a veritable logistics machine is set up, with environmental costs that are difficult to reduce.
From our correspondent in Montreal,
From our correspondent in Montreal,
It's a spectacle that Montrealers end up not paying attention to.
After a snowstorm like that of last weekend, January 14, 2023, a tense flow of construction vehicles is set up to clear the roads and sidewalks.
We have a fleet of almost
2,200 devices in the field, small bombers, as they are called, to clear the sidewalks, diggers on the roads, sort of combine harvesters to collect the snow and throw it into the trucks. dumpsters
, ”explains, passionately, Philippe Sabourin, administrative spokesperson for the city of Montreal, driving his car a few days after the storm.
On one of the main arteries of the city, already cleared, we cross huge trucks filled with snow, we hear their back-up alarms, their vertical exhaust pipes emitting a discreet gray smoke.
A well-honed ballet
The numbers are dizzying.
3,000 employees are requisitioned for snow removal.
65 outings are organized on average each winter to spread salt and gravel to avoid falls or skids, to collect snow and make the city functional.
Each outing represents nearly 11,000 km of sidewalks and roads to cover, i.e. a return trip between Paris and Montreal in a few days.
One centimeter of snow on the territory of Montreal is one million Canadian dollars spent to make the routes safer: the city has a budget of nearly 200 million dollars for snow removal, and 190 centimeters of snow fall on average every year.
Once collected, 75% of the snow is stored to melt in sealed quarries in the city, before being discharged into the sewers.
The remaining quarter joins the pipes as is.
Until the 1990s, snow was dumped directly into the St. Lawrence, with all the waste and pollutants that entails.
The drain is a 180° turn that Montrealers are not necessarily aware of
,” says Philippe Sabourin as he crosses a construction site barrier on the banks of the majestic Canadian river.
The Fullum Snowfall is one of 16 sewer chute sites in the city.
We are a few hundred meters from the business center of Montreal, at the foot of the Jacques-Cartier bridge.
Large trucks come and dump their snow directly into holes two meters in diameter, to reach the pipes.
With a trained eye, the site foreman, Marcel Brisson, monitors the progress of operations: “
We have three holes that we use successively.
The more intense the water flow, the more snow can be evacuated at once.
Logically, when the snow blocks, it is the cold nights, when the water consumption decreases and it struggles to melt.
» Once dumped, the snow flows with the rest of the water to the
unique and gigantic wastewater treatment plant in Montreal.
The snow is cleared of cigarette butts, packaging, such as sewage.
The station is capable of treating 88 cubic meters of water per second, so it is never overloaded in winter
,” explains Philippe Sabourin.
Sewerage is a major step forward, but pollution linked to snow removal is still numerous.
Already, the engines of the city's 2,200 machines are running for hours, causing pollution that is difficult to quantify.
The spokesperson for the City tries to qualify: “
The first issue in reducing air pollution in Montreal is the use of wood stoves.
We optimize the routes of snow removal trucks, and citizens must also be vigilant: each car parked on our road despite warnings means 5 to 10 minutes wasted for operations, and as much additional pollution.
But the impact is not just atmospheric.
The noise and visual pollution is still substantial.
While waiting for the distant electrification of heavy goods vehicles, Montrealers who live not far from snow storage quarries intend to spend the night up to 300 trucks per hour.
The horns on our machines have recently been modified to be less strident, while still being audible.
We are well aware of the inconvenience this can cause, but the snow must be moved, otherwise everything is blocked
”, regrets the manager.
Reducing the environmental burden of snow removal in Montreal to zero seems impossible.
Nevertheless, the city claims to be working on alternatives.
Salt, for example, eats away at infrastructures, cars, pollutes the soil and increases the salinity of the water discharged into the St. Lawrence.
Its use was therefore limited in 2016. Between 150 and 300 grams are authorized per square meter, but contamination remains high: 150,000 tonnes of salt are dumped each year by the city.
We are still trying to replace it: we tried coffee grounds, it smelled good, but it was ineffective.
Beet juice was great for melting the ice, but it stuck and it was extremely messy for users
,” sighs Philippe Sabourin.
The issue of snow cover in Montreal highlights an original sin: fossil fuels have enabled millions of human beings to settle in climatically difficult areas.
At the time of the energy transition, the challenges for Montreal, winter city par excellence, are much more complex to meet than for cities located in temperate zones.
Receive all the international news directly in your mailbox
Follow all the international news by downloading the RFI application