As of April 1, 2019, the ECO became part of the Office of the Auditor General of Ontario. This change occurred under the Restoring Trust, Transparency and Accountability Act, 2018.

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Shaking Ontario’s addiction to road salt

Ontario has some of the most abundant freshwater sources in the world. But excessive road salt is contaminating Ontario’s lakes, rivers, creeks and groundwater. Too much road salt in water does significant and lasting harm to aquatic ecosystems, and can make water undrinkable.

Road salt – used to maintain the safety of roads, driveways, stairs and sidewalks in winter – can enter waterbodies through runoff from roads, parking lots and walkways, losses at salt storage yards, and meltwater from snow disposal sites. In all of these cases, there are opportunities to reduce its use.

Road salt use in Ontario

De-icing truck on hgihwayIn 2009, Environment and Climate Change Canada reported that Ontario uses around 2.2 million tons of road salt each year. The amount varies from year to year depending on the weather.

The biggest single users of road salt in the province are the Ministry of Transportation (MTO) and large municipalities. The MTO and some municipalities have taken steps to apply road salt more effectively, thereby maintaining a high level of road safety while decreasing the total amount of salt applied. However, people who spread road salt on private parking lots, driveways and walkways may not understand how much salt is best, or when to use it to ensure safety. Research by the University of Waterloo showed the potential for the reduction of at least 25% in salt use.

Too much salt in water is harmful

Water with high amounts of salt is toxic to aquatic plants and animals, can impact soil health, and damages gardens, vegetation and trees. Freshwater fish, mussels, frogs and turtles cannot survive in water that is too salty. The sensitive paws of our pets and other animals can also be hurt if there is too much salt on the ground.

Drinking water sources contaminated by salt can be a human health risk. For example, levels of sodium (one component of road salt) in the town of Simcoe’s drinking water were so high in July 2017 that the Haldimand-Norfolk health officer issued a “do not consume” warning for people with high blood pressure and sodium-restricted diets.

Too much salt also causes damage to cars, sidewalks, buildings, bridges and other infrastructure. This results in higher repair and maintenance costs, and sometimes, dangerous conditions. Some reports note that the hidden costs of road salt on infrastructure and the environment range from $200 to $470 per ton of road salt applied. Corrosion from salt can cost car owners $850 per year and result in vehicle brake failures.

How can Ontarians use less road salt?

A lot of road salt on sidewalkThe fear of being sued from a slip-and-fall or car accident is a factor in excess salt use. Many people use much more salt on parking lots and private walkways than is needed for public safety.

Here are a few tips to help you make and keep the resolution to use less road salt:

  1. Before applying road salt, shovel snow off the ground, so the use of salt is more effective.
  2. Consider if sand is all you need.
  3. Follow the instructions and guidelines on road salt packages for how much is needed.
  4. Use road salt only when ice is on the ground or is about to form, like when freezing rain is falling or a storm is on the way.
  5. Do not use road salt in extreme cold. Below the freezing point, road salt becomes less effective the colder it gets. It is only moderately effective at -7 degrees Celsius, and by -18 degrees Celsius, it simply does not work.

Real world visuals of road salt - drawn image showing 58 g/m2 and photo showing 60 g/m2

This is what enough salt looks like. Source: Toronto and Region Conservation Authority

If hiring a contractor to maintain your property, ask if they use best practices (like the tips outlined above), and consider:

  • changing the terms of the contract if the contractor is paid based on how much salt they use – this encourages over-salting and wastes your money!
  • requiring them to train staff on the use of salt for winter safety and environmental protection such as the “Smart about Salt” training programs put on by the non-profit Smart About Salt Council.


Everyone should know the harm caused by excess road salt, and how to reduce its use. Safe roads and walkways are essential, but small changes can make a big difference. We can still stay safe without sacrificing environmental protection, polluting drinking water sources, and damaging vehicles and public infrastructure.

Learn more about road salt use in Ontario and its impacts in Chapter 2: Polluting our waters from Volume 2: Clean Water of our 2018 Environmental Protection Report, Back to Basics.

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