Bad winter weather can create an icy havoc for people using highways, roads, sidewalks, and even your own front porch. Road salt, also called rock salt, is an affordable way to lower the freezing temperature of water to prevent ice from forming or to help melt existing ice. Southern Ontarians are all too familiar with being stuck behind a salt truck or scrubbing salt stains off their shoes. However, many people are unfamiliar with the impact of using high quantities of road salt.
First, let's break down what road salt is. Road salt is a natural mined mineral form of NaCl (sodium chloride) or table salt. Unlike table salt, road salt is not purified and can contain mineral impurities such as iron, aluminium, and phosphorus.
According to the Government of Canada, Canada uses about five million tonnes of road salt every year to make road conditions safer. This does not include the amount of road salt used for personal use in driveways and sidewalks. About 35% of Canadians live in Southern Ontario and just over 90% of Ontarians live in Southern Ontario. With this dense concentrations of people, you can assume that we use large amounts of road salt each year.
So, what happens to all of this road salt? Road salt goes into our water systems through direct runoff or by infiltrating the soil and into groundwater. High concentrations of road salt can create negative environmental impacts for water ecosystems and roadside vegetation.
Large quantities of chloride ions from road salt in water systems can affect the distribution of oxygen and nutrients in the lower levels of water bodies. This impacts the life cycle and reproduction rate of various invertebrates, fish, and amphibians. It also affects the growth and survival of aquatic plants. Impurities in road salt can also cause damage to water systems. Large amounts of phosphorus in water can shift the collection of plants growing to include less desirable species or invasive species.
Road salt can also impact soil quality, which causes degradation of roadside vegetation. The decrease of these plants can create an opportunity for salt-resistant plants, which includes several invasive species, to thrive. Road salt can also cause animals like deer and moose to come closer to the side of the road to lick the salt. This can increase collision and danger on roadways.
Currently, road salt is the best option to increase road safety in the winter. However, there are several different ways to reduce your use of road salt and decrease its environmental impact. First, you can shovel the snow in your driveway and pathways before they are walked on to prevent the formation of ice. Another thing you can do would be to use road salt alternatives to reduce the amount of road salt needed. For example, some alternatives to road salt include agricultural by-products such as beet juice, cheese brine, pickle brine, and potato juice. Lastly, you can call your municipality to encourage them to use optimal road salt application. Please see the 'Five-year Review of Progress: Code of Practice for the Environmental Management of Road Salts' produced by Environment Canada for more information on these options (link below).
BARC and our partners strive to educate and involve our community in restoring the ecology of our Harbour and watershed.
The Bay Area Restoration Council is a registered charitable non-profit organization. Formed in 1991, BARC represents the public interest in the restoration of Hamilton Harbour and its watershed. BARC is responsible for community engagement and educational activities in the implementation of the Hamilton Harbour Remedial Action Plan. BARC encourages public understanding and citizen action through school programs, volunteer participation, public workshops, evaluative reporting on current issues and opportunities for digital communications.