Toronto's Giant Snow Piles Are Making a Salty, Toxic Mess

Toronto's newest "peak" isn't on any hiking map—and what's inside it is raising alarms. Leyland Cecco reports in the Guardian about the city's six mammoth snow dumps, where plowed snow mixed with road salt, oil, antifreeze, and street trash is stacked into artificial mountains that can reach the height of a 10-story building. One facility alone can hold 144,000 cubic meters of snow, with industrial melters running around the clock after major storms to slowly shrink the piles.

The problem, ecologists say, is what happens as those heaps melt. Salt is the biggest concern: University of Toronto researchers recently found chloride levels high enough to kill many freshwater species at nearly a third of sites tested, with almost all locations above federal guidelines—and some saltier than seawater. The Toronto City News reported in January that such was the salt usage that snow contractors had already run into shortages. With climate change expected to bring fewer winter days but more intense storms, cities may lean even harder on salt, while scientists warn the buildup will linger for years. "Even if we stopped applying salt right now, it would take years to (a) decade to flush out of all of our soils and the groundwater," says University of Toronto ecologist Donald Jackson. For the full picture, read Cecco's report in the Guardian.