Toronto’s Growing Snow Mountains: A Toxic Environmental Hazard

Toronto is facing a growing environmental challenge as record snowfall creates massive snow storage piles, dubbed “snow mountains,” that pose a threat to local waterways and ecosystems. These mountains, reaching up to 100 feet in height, are not simply frozen water. they contain a toxic mix of road salt, antifreeze, oil, and other pollutants.

Record Snowfall and the Rise of Snow Mountains

In late January 2026, Toronto experienced one of the heaviest single days of snowfall in its history, with nearly 23 inches falling in some areas. The city had already removed 264,000 tonnes of snow from 1,100 km (680 miles) of roads, sidewalks, and bike lanes by mid-February . Similar heavy snowfall impacted New York City at the end of February, with over 25 inches accumulating in some regions.

To maintain public safety, the city trucks snow to six storage facilities located on the urban outskirts. One prominent site, visible from the highway, currently holds 144,000 cubic metres of snow across two acres . These sites operate around the clock during major storms, utilizing industrial melters to reduce the snow’s volume.

The Environmental Impact of Road Salt

Although essential for road safety, the extensive use of road salt presents a significant environmental problem. Salt doesn’t disappear with the snow; it washes into Ontario’s creeks, lakes, and rivers, potentially contaminating drinking water and harming wildlife .

Chloride, a key component of road salt (sodium chloride), is particularly damaging to freshwater ecosystems. Recent testing by researchers at the University of Toronto found chloride levels high enough to be lethal to most aquatic species at 30% of tested sites, exceeding federal guidelines at virtually all locations . Sodium levels in groundwater also increase over time, impacting water quality.

Balancing Safety and Environmental Concerns

City officials acknowledge the need to balance public safety with environmental protection. Toronto’s Salt Management Plan aims to minimize salt usage while maintaining safe roads and sidewalks . However, Donald Jackson, a professor of ecology at the University of Toronto, notes that the amount of salt used on private properties – driveways and parking lots – may equal or exceed that used by the city itself .

The risk of legal liability also encourages overuse of salt by private operators .

Salt Shortages and Future Challenges

Despite the environmental concerns, Toronto is currently experiencing a shortage of road salt, even though the world’s largest salt mine is located less than 150 miles west of the city . Many stores across the Greater Toronto Area are reporting empty shelves .

Experts warn that climate change is likely to bring more frequent and intense storms, increasing the demand for road salt and exacerbating the environmental challenges . Even if salt application were to cease immediately, it would take years, or even decades, to flush out of soils and groundwater .