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)
The Summer Hot Spot maps shows an increasing trend in summer-time data (Robert F. Bukaty, file/AP Photo)
Road salt is toxic to the environment
The toxicity of road salt depends on the amount used, explains Hendriks.
The more you put it, the more toxic it becomes. So what we see are levels close to ocean levels in freshwater systems.Elizabeth Hendriks, WWF Canada’s vice-president of freshwater
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.
We are creating freshwater systems that are inhabitable for freshwater ecosystems or freshwater species. And then, also, we’re seeing impacts to our drinking water and, for large urban centres and even smaller urban centres, impact on infrastructure.Elizabeth Hendriks, WWF Canada’s vice-president of freshwater
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 new Samuel de Champlain Bridge is seen on the right next to the old bridge in Montreal on Monday. Paul Chiasson/THE CANADIAN PRESS)
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.
They don’t know how the blue crab, which is an ocean crab, found its way to Cooksville Creek but it was thriving in a freshwater river, well supposedly freshwater river.Elizabeth Hendriks, WWF Canada’s vice-president of freshwater
WWF has also seen the phenomenon affect other fish or turtle species, becoming an aggravating factor for species at risk.
Elizabeth Henriks talks about the risk to the environment (Photo: WWF-Canada)EN_Interview_4-20190620-WIE40
“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 d...