Chloride Overdose

Road Sal - Credit: Eddie Welker

Canadians are all too familiar with the perils of driving on icy roads. For decades, road salt has been used to keep our roads safe. It saves lives, prevents injuries, and keeps our cities moving. We apply it liberally to roadways, walkways, and driveways to melt snow and ice and expose the road surface below for greater traction. The American Highway Users Alliance found that road salt reduces collisions by up to 85 per cent.

Unfortunately, excess road salt is harming our local creeks and rivers. Every year, tens of thousands of tonnes of salt are applied to roads and parking lots in the Credit River Watershed. At the end of the winter, all of this salt doesn’t simply disappear. It dissolves in water and washes into the nearest lake, river or stream.

According to Environment and Climate Change Canada, road salts that contain chloride are a toxic substance due to their harmful impact on the environment. The negative impacts of road salt on water quality, wildlife and vegetation are well documented. Consistently applying salt year-after-year for decades means that some small urban creeks have a salt level much closer to the ocean than that of a freshwater creek. This is harmful to fish and other aquatic life.

CVC has been collecting chloride data since the 1960s. The research shows that chloride concentrations have been increasing across the watershed year-after-year. We used to get data from samples collected once monthly, but now we have 11 stations across the watershed that measure key water quality parameters in real-time. By taking measurements once every 15 minutes instead of once per month, we get a more detailed picture of chloride concentrations, which can help us find solutions.

Keeping roads safe is important, but there are less harmful ways to achieve this. Canadian municipalities, for example, are adopting the latest technology in salt-spreading equipment and trying innovative methods like applying brine (salt dissolved in water) before ice has a chance to form. These are all ways of making sure that we get the most out of the salt that we use, and aren’t putting down any more than necessary.

Municipalities in our watershed have even been getting creative with new products like pickle brine, potato juice, beet juice or even cheese brine as alternative solutions.

Learn more about water quality in local waterways by viewing monitoring results in real-time.

Cover photo by Eddie Welker

Comments (1)

  1. The Swiss have developed a much more eco sensitive alternative, well suited to Canada. An initial trial at a small municipality in Quebec was a success and will be expanded this year. A production site has been established in Ontario, however, facing difficulty to get Ontario based municipalities to consider a trial. I welcome a dialogue. Happy to provide info and studies.

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