By Henry Flanagan

Last winter, more than 60 centimeters of snow blanketed Vancouver between December and March. The heavy snowfalls and sustained cold temperatures caused chaos throughout the city: vehicles slid and crashed on icy streets; transit was rerouted and delayed; and residents struggled to keep their driveways and sidewalks cleared.

Last year’s winter weather was highly unusual for the Lower Mainland, and cities and residents struggled to cope. Part of Vancouver’s response was to spread large quantities of salt over roads in the city. The city purchased an unprecedented volume of salt, more than 9,000 tons, for de-icing, spending more than a million dollars in the process. In contrast, the city purchased less than 1,000 tons of salt in 2015-2016.

Salt (sodium chloride) has a unique property of lowering the freezing point of snow and ice. This causes ice to melt at lower temperatures than it would normally, which is why salt is commonly spread on roads and sidewalks.

On the surface, the practice of salting appears to be a safe and responsible way of dealing with snowy and icy surfaces. Why else would the city of Vancouver have used so much of it last winter?

However, researchers have identified significant environmental damages that are caused by road salting. Stuart Findlay and Victoria Kelly of the Cary Institute of Ecosystem Studies have studied how salt from roads runs off into nearby bodies of water such as streams and lakes, or seeps into groundwater. Their studies show that this can lead to lethal concentrations of salt for various types of fish, insects, and trees.

Even in nonlethal amounts, salt runoff can cause harm by affecting the life cycles of aquatic organisms and increasing dispersion of heavy metals in soils. There are also concerns for human health: salt runoff can potentially contaminate aquifers that are used for drinking water.

So, what alternatives exist to salting roads? Sand is already heavily used by the city, with thousands of tons used in the last few months of 2016 alone. Sand does little to melt snow and ice but increases traction and makes walking and driving safer. Additionally, other deicing salts, such as calcium chloride, have higher costs but may have a reduced environmental impact.

Some cities are even exploring organic deicers like molasses and cheese brine, which can help melt ice with fewer potentially harmful chemicals. Although many options exist, some degree of road-salting is necessary to increase safety in extreme winter events, and alternatives are intended to reduce the quantity of salt needed rather than fully replacing it.

The City of Vancouver should further explore ways in which it can limit the amount of salt used on roads during winter in order to minimize the damages that it causes. Vancouver prides itself on being a "green" and sustainable city, and these values shouldn’t be thrown out during winter storms—even if they happen infrequently.

Rather than having a reactionary response to snowfall like last winter’s, the city needs to have a plan in place for exceptional snow and ice events so that it is not forced to spend huge sums on emergency shipments of ecologically harmful salt. This could include better study and utilization of salt alternatives for deicing, more planning to increase the efficiency of salt that is used, and improved snow tires and chains for public transit.

By researching and investing in road-salt reduction now and better preparing for future heavy snowfalls, the City of Vancouver could help the environment and save taxpayer money. And with Environment Canada forecasting another colder-than-average winter, this should happen sooner rather than later.