Road salt levels have hit new record levels in Canada’s Great Lakes region, making some waterways as salty as the ocean according to new chloride maps revealed by environmental advocates.
WWF-Canada’s Great Lakes Chloride Summer Hot Spot Map reveals that levels in many rural and urban southern Ontario waterways are increasing dangerously.
“Since 2007, we’ve seen an increase in chloride’s impact of chloride levels in the summer months. So the map is showing a spatial impact of chloride contamination,” said Elizabeth Hendriks, WWF Canada’s vice-president of freshwater.
The study focuses only on the Great Lakes region but the organisation has seen trends increasing in large urban centres anywhere where significant development is happening over time as well.
Road salt, which is a mix of sodium chloride, calcium chloride and magnesium chloride is widely used in Canada during icy winter to keep public areas safe.
Public Road agencies use 7 million tonnes of road salt every year in Canada according to WWF. Road salt use by the private sector and small towns is not currently tracked or controlled in the province.
The problem of road salt affecting the environment is not new since many reports have been published over the years on the negative impact of this product.
- Winter road salt slowly killing a lake (April 12, 2018)
- Winter road salt and environment: revision needed (April 9, 2015)
Road salt is toxic to the environment
The toxicity of road salt depends on the amount used, explains Hendriks.
According to the map, the levels recorded are between 1000 and 1200 mg/l in some places.
In comparison, “a healthy salt level for freshwater ecosystems like as mussels, fish and turtles is 120 mg/l”, says the environmental advocate.
Anything above this limit as a significant impact on biodiversity but also on communities and drinking water.
For example, salt erosion affects infrastructure such as the Gardiner Expressway, a municipal highway along the shore of Lake Ontario in Toronto, or the major bridge in Montreal, the Champlain Bridge. The latter is in such poor conditions that the city has had to build another one to replace it, which will be officially inaugurated on June 24.
The organisation already had concerns about drinking water in some areas as well.
In terms of wildlife, the presence of blue crabs in Cooksville Creek in Mississauga, Ontario, is a consequence of high chloride levels.
WWF has also seen the phenomenon affect other fish or turtle species, becoming an aggravating factor for species at risk.
“It’s the new normal”
One of the main results of this map is that the trend throughout the years (from 2007 to 2017) sees an increasing trend in summer-time data. We usually don’t expect to see such high salt levels in summer, making the results quite alarming explains Hendriks.
Usually, salt will run off in the Spring with rain and everything clearing but if we look at the data, it stays.
Alternatives to Salt
WWF Canada’s vice-president of freshwater recognises that they are alternatives to salt road but it depends on the scale of the community. Each one has to assess what’s most appropriate.
Some communities in Canada use beet juice or sand for example which have an effective use. Some Quebec towns mix beet juice with regular road salt and reduce the salt’s environmental impact but also save money, for example.
Other municipalities like Williams Lake in northern B.C. have been using Beet 55, a mixture of saline, sugar and beets.
Beet 55 is sprayed on roads before the snow arrives. It lowers the temperature required for rock salt to melt ice, and can last for two to five days—meaning it can last through multiple snowstorms.
WWF aims to raise public awareness of the risks associated with road salt
These mixtures can be essential in some parts of the country because salt has its limits.
New measures to change this trend
The World Wide Fund for Nature works in collaboration with the private sector explains Hendriks.
At national level, the government is aware of the problem and has put in place a “A Risk Management Strategy for Road Salts” to solve it.
The environmental advocate emphasized the fact that her organization is working towards solutions in partnership with many people who are at the table and willing to change things.
WWF-Canada’s maps will help inform policy recommendations to the Ontario government.
In a press release, the organization details its recommendations.