With much of southern Ontario still digging out of Wednesday’s snowstorm and more flurries in the forecast, a stringent snow management routine can make navigating the winter weather easier.
While waiting for the city plows, salting and shovelling your home or business can alleviate accessibility barriers, reduce damage to the environment, and help make the city easier to navigate for everyone.
Here some tips are to ease you through the winter weather.
How much salt do you actually need?
“You don’t need a ton,” said Larry Richards, with the Scarborough-based East-West Disposal Services. “Just enough to get you that traction.”
It may seem like copious amounts of salt are being used to de-ice sidewalks or parking lots across the city, but according to Richards, that’s a byproduct of repeated applications.
“When you go to the store, it looks like there’s an excessive amount of salt, and for the most part, there probably is, but you do kind of have to treat the asphalt throughout the winter,” he said.
Even on days that don’t see any snowfall, frost can accumulate and surfaces can quickly become slippery, ”so keeping salt on the ground in small amounts is probably best to prevent people slipping and falling,” he added.
How much salt is too much salt?
That said, you can still go overboard on salt.
About five million tonnes of road salts are used in Canada each year, according to the federal government. In Toronto, the city spends about uses between 130,000 and 150,000 tonnes of sodium chloride, about the same weight of the CN tower, each year.
Those salts will almost always find their way into local waterways, whether by direct runoff into surface water or through soil and groundwater, according to Environment and Climate Change Canada.
If waterways are contaminated, the salt can harm freshwater plants and fish. Even without entering bodies of water, road salts can damage roadside vegetation, soil, birds and other wildlife when vehicles pass by wet roads, splashing the salt over surrounding areas.
The risks persist beyond the winter months. In March 2021, the University of Toronto found that nearly 90 per cent of samples taken from rivers and creeks across the GTA during summer months had salt levels that exceeded federal guidelines, the Star previously reported. One third of the samples showed levels known to be lethal to freshwater wildlife.
“The environmental impact is a big concern,” said Richards. “You really need to just use what you need and not waste any of it.”
Environmental issues aside, road salts can corrode certain types of concretes and metals, stain yours shoes and clothing, and damage lawns during the spring melt.
What are the alternatives?
In addition to sodium chloride, magnesium, calcium, and potassium chloride have all been used as alternatives to de-ice surfaces. Each one comes at a significantly higher cost, however, and poses environmental and structural risks of its own.
“The reason some municipalities reach for those is they have much lower freezing points; rock salt typically is only good to -20 C or so, whereas magnesium and calcium chloride can get down to -50 C before it becomes ineffective,” said Doug Hooton, professor emeritus in civil and mineral engineering at the University of Toronto. “But, really, the thing with sodium chloride is it’s the cheapest (..) and we don’t have those kinds of low temperatures here.”
In an effort to move away from road salts altogether, municipalities worldwide have gotten creative with their de-icing techniques.
In Wisconsin, a local government started mixing cheese brine into its de-icing solution in 2014 to reduce salt usage. Cheese brine has a freezing point of -29 C, lower than regular salt, which can freeze around -21 C. As of last winter, the solution was still being employed in the municipality.
In frigid Minnesota, pickle juice has also been explored as an alternative. Similar to traditional rock salt, pickle brine can melt ice at temperatures as low as -21 C, while significantly reducing the amount of chloride released into the environment.
When temperatures drop below -20 C, Toronto and other GTA municipalities have be known to reach for beet juice in lieu of road salts. Beet juice freezes at a much lower temperature, around -30 C.
In these instances, the city doesn’t spray every road, as the solution is about four times more expensive than salt. Instead, they hit strategic parts of the city, such as hills and bridges, where ice is most likely to cause problems.
But beet juice comes with its own downsides.
“It does melt ice, but it’s also a bit slippery itself,” Hooton said. “With anything food-based, it’s going to bring wildlife out — they’ll be licking the pavements and then you’ve got another problem.”
What about liquid salt?
Around 2003, Toronto started applying liquid salt to roads ahead of expected snowfalls. The strategy is very effective in preventing falls but the liquid solution is often more concentrated, said Hooton. Moreover, pre-spraying is only effective when flurries can be reliably predicted, he said.
“Because if it’s longer than 24 hours since it’s been applied, the stuff basically runs off,” Hooton added. “It becomes ineffective on the pavement and of course, it’s liquid, so it’s going to run off and get into the groundwater.”
Could Toronto run out of road salts?
The short answer, like anywhere else, is yes. It just depends on how much is deployed. There have been a handful of shortages over the years, said Richards, usually during prolonged cold snaps or ice storms.
He said the city’s annual stockpiles are determined ahead of the winter season, so, in the event of a shortage, municipalities are often forced to look elsewhere for imports, in turn increasing costs.
“A few years back, we had to bring salt in from Egypt after an incident temporarily shut down the Goderich mine,” he said. “To import it in from the U.S. was just too expensive.”
In the event of the shortage, Richards said it’s not uncommon for private contactors to end up bearing the brunt of the spike in costs.
“If the poor snow plow guy is giving you a flat rate price, and then prices increase throughout the year, he’s got to absorb that.”
With files from Star staff and The Canadian Press
