No need to salt our roads: Spring is approaching and salt poisons our water…

A geological study from the University of Toronto has found that road salt poses numerous threats to groundwater and water quality. Their research findings come from a study based on Pickering, ON. Pickering is a GTA community relatively close to the 401 highway and a community that has witnessed a lot of suburban growth. Both the 401 and suburban roads use copious amounts of road salt for highway and road safety and to minimize the likelihood of accidents. Alas, in the Pickering context, a lot of this salt has ended up in a nearby watershed called Frenchman’s Bay, a lagoon on the shores of Lake Ontario.

The geologists found that over 3,600 tonnes of road salt end up in Frenchman’s Bay every winter due to direct runoff in creeks and streams. It is no coincidence that the fish population in this lagoon has been declining due to increased levels of salinity. Putting the salinity levels in some context, it is estimated that the lagoon has levels of salt that closely resemble ocean water. Higher levels of salinity simply contaminate the waters and drive the younger fish population away. Younger fish, unlike older fish, do not have the capacity to cope with saline intrusions because they are not used to it.

The impacts of road salt on Pickering's ground and surface water imply a higher than average amount of road salt usage. In Canada, about five million tonnes, or approximately 150 kilograms per Canadian, is used on roads each year to make them safe for travel in winter. A lot of this road salt is applied to roads in Ontario and Quebec.

Where does government intervention fit into all of this? Well, Environment Canada has recognized the “adverse” impacts of salt on wildlife, plants, water, soil etc. In the past, they considered adding road salt to the nation’s list of toxic substances, but... that never happened. Six years ago, the government instituted a “voluntary code of practices” to "encourage municipalities and others to use the de-icer more sparingly", while maintaining highway safety.

It is the province though that is using road salt for the 401 highway, not the municipalities. Plus, communities like Pickering are growing rapidly placing more pressure on local government to salt their roads because it is the most economically sensible way of ensuring road safety.

Voluntary code of practices should not be applied in this particular case. The geological study provides convincing evidence that road salt has negative ramifications for the large Pickering watershed. While other options are currently being reviewed, I think that municipalities must establish regulations that govern the use of road salt to account for their environmental impacts. Quotas must be established until we come up with more sophisticated engineering solutions.

Key message: The use of road salt helps make our roads safer at the expense of contaminating water quality, declining fish populations and wildlife. In an era where we are trying to sensibly integrate public policy with science, we need to find more practical alternatives that benefit society and nature.