Montreal’s first organic waste treatment centre finally opens


In the works since 2009, the St-Laurent facility will lock odours inside, slash travel time for grass clippings and apple cores, and process 20 Olympic swimming pools’ worth of waste per year.

Article content

Montreal’s first organic waste treatment centre, designed to transform the banana peels and grass clippings of the populace into brown gold, finally celebrated its official opening Monday.

Originally promised 15 years ago along with four other treatment centres, the $169-million facility located in an industrial sector of St-Laurent will be capable of processing 50,000 tonnes of waste per year — the equivalent of 20 Olympic swimming pools full — emanating from brown boxes and garden waste from the western boroughs and demerged suburbs of the island. At present, Montreal’s compost is trucked to facilities in Ontario and Joliette.

Advertisement 2

Story continues below

Article content

“Before, an apple core could travel on average 188 kilometres to be treated,” said Marie-Andrée Mauger, Verdun borough mayor and the city executive committee member responsible for the environment. “Today, thanks to this local infrastructure, the distance has been reduced to six kilometres,” significantly decreasing carbon dioxide emissions. The St-Laurent plant will treat the organic waste of 25 per cent of the Montreal population, she said.

The waste will be converted into 20,000 tonnes of Grade A compost that can be used by the city for its parks and other installations, or sold to farmers or citizens to spread on their fields, gardens and lawns.

Giant piles of compost are seen between concrete dividers in a waste treatment plant.
Giant piles of compost are divided at the St-Laurent organic waste treatment centre on Monday October 21, 2024. Photo by Dave Sidaway /Montreal Gazette

Roughly 80 per cent of Montreal’s homes have organic waste pickup. Among residences of eight units or less, about 60 per cent use the composting services, while in buildings with nine residences or more, compliance drops to 30 per cent. The city is aiming to encourage 60 per cent of all residents to use their brown bins by 2025.

Montreal’s second organic composting centre, a biomethanation plant in Montreal East, is slated to open next year.

Article content

Advertisement 3

Story continues below

Article content

A truck is seen outside a waste treatment plant, which features a long giant metal tube running horizontally.
The St-Laurent plant will treat the organic waste of 25 per cent of the Montreal population. Photo by Dave Sidaway /Montreal Gazette

Beyond creating compost, recycling organic matter has other positive environmental attributes, noted Karel Ménard, director of the environmental advocacy group Front commun québécois pour une gestion écologique des déchets. Half of a typical non-composting Montrealer’s garbage bag is filled with organic waste.

“When we bury organic matter, we create pollution by producing leachate and methane, which is a powerful greenhouse gas,” Ménard said. “When we compost it, we transform it into resources that our agricultural lands so badly need. All this while contributing to the longevity of our landfills.”

On a tour of the sprawling facility on Henri-Bourassa Blvd. W. near Highway 13, city officials explained how the waste is brought in via garbage trucks that are weighed before entering one of four bay doors. To prevent odours from escaping — a major concern among residents when the facility was first proposed — the plant is airtight and kept under negative pressure. All entrances have double doors where the interior one can’t open until the exterior one is closed, so air from the inside never travels directly to the outside. Air exiting the plant is chemically treated in large metal tubes before being exhausted to the outside.

Advertisement 4

Story continues below

Article content

An overhead view of the floor of a waste treatment plant, with a front-end loader parked in the foreground.
All entrances to the St-Laurent organic waste treatment centre have double doors, designed to stop odours from escaping the facility. Photo by Dave Sidaway /Montreal Gazette

The garbage trucks dump their loads of green waste onto concrete floors, where front-end loaders collect it to deposit into massive grinders, which take out any pieces wider than 80 millimetres (three inches). The masses are compacted to extract excess water. Plastic and other waste is filtered out later in the process. (City officials counsel using paper bags as opposed to plastic ones.)

The sifted debris is mixed with wood chip particles to aid with aeration and will sit for three weeks in concrete holding pens where humidity, oxygen and temperature levels are carefully regulated.

“It’s bacteria that is doing the work for us,” said Maxime Roberge, an engineer with the city’s environmental division. “We have to give it the time to do its work.”

Temperatures of the mixture hit about 55 C, killing off pathogens. This is followed by another four weeks in one of nine enclosed, aerated concrete storage units, each with a capacity of 380 tonnes, until the end product is reached: a peaty soil that is safe to the touch and the garden. The whole process takes about eight to nine weeks.

Advertisement 5

Story continues below

Article content

Quebec has 11 similar organic waste treatment centres in operation, with another five under construction.

A front-end loader is seen from the side in a composting plant.
Front-end loaders collect green waste from the floors of the St-Laurent facility and deposit it into massive grinders. Photo by Dave Sidaway /Montreal Gazette

The path to creating Montreal’s centres has been long, calamitous and costly, and is far from over.

Starting in 2009, successive city administrations planned five organic waste treatment centres for the east, west, south and north ends of the island. By 2016, the price to design, build and maintain the five installations had risen to $288 million from a 2013 projection of $237.5 million. The estimate for the five facilities rose again in 2017, to $344 million. In 2019, the combined estimate for the five facilities ballooned to $589 million. At that point, the Plante administration announced it was indefinitely postponing all but the St-Laurent composting facility and the Montreal East biomethanation plant.

The separate contracts for the St-Laurent and Montreal East facilities were awarded to Suez Canada Waste Services in 2019. French transnational Veolia Group acquired Suez in 2022 and now has the contracts.

A pair of hands clasp a handful of compost from a giant pile.
City of Montreal employee Camille Bégin holds compost at the St-Laurent organic waste treatment centre on Monday October 21, 2024. Photo by Dave Sidaway /Montreal Gazette

The pandemic delayed delivery of the St-Laurent plant to March 2022 and the Montreal East plant to August 2022. However, a financial dispute between Veolia and its main subcontractor, EBC, temporarily halted work on both facilities in July 2022. Veolia then demanded more money from the city to cover additional labour costs and material and equipment costs due to the combined impact of the pandemic, Russia’s war in Ukraine, factory shutdowns in China due to COVID-19, higher oil prices and a shortage of labour because of all the infrastructure projects in Quebec.

In April 2023, city council voted to approve an additional $32 million to Veolia — about $6 million more for the St-Laurent facility and about $26 million extra for the Montreal East biomethanation plant.

An interior view of an organic waste treatment centre.
Montreal’s first organic waste treatment centre officially opened Monday October 21, 2024 in St-Laurent. Photo by Dave Sidaway /Montreal Gazette

rbruemmer@postmedia.com

Recommended from Editorial

  1. The city of Montreal's waste composting plant in the St-Laurent borough in 2022.

    Montreal already spending on a third organic waste centre before first two open

  2. The city of Montreal's waste composting plant in the St-Laurent borough in March 2022.

    Cost of Montreal compost facilities balloons by another $32 million

  3. Brown food waste bins began rolling out in the Vaudreuil-Soulanges MRC last fall, and have been common place in most West Island cities for several years.

    The good, the bad and the smelly: learning to love your compost bin

Advertisement 6

Story continues below

Article content

Article content

Comments

Join the Conversation

Featured Local Savings

Source