As Toronto deals with fluctuating winter weather, environmental advocates say excessive road salt is harming Ontario wildlife — and they're urging people to use less.

Salt used to melt icy roads and sidewalks can end up flowing into rivers, lakes and soil, creating dangerously salty environments for some freshwater plants and animals.

In certain areas during winter, "some of our rivers will have salt as high as oceans," said Elizabeth Hendriks, vice-president of freshwater with the World Wildlife Fund Canada.

Some frog and salamander species can't breed in ponds with high salt volumes, said Environment Canada scientist Patricia Gillis, while rivers can become salty enough to kill young freshwater mussels.

"Impacts to even a few species can effect the whole ecosystem," said Gillis in an email.

Many people tend to use too much salt, said Hendriks, who previously said a small pill bottle worth of road salt is all you need to melt a city sidewalk slab.

Road salt doesn't disappear when the ice melts, says Environment Canada, and can run into freshwater river and lakes. (Taylor Simmons/CBC)

"People tend to lather road salt on the ice," said Angela Murphy, manager with Ryerson Urban Water.

"It's really not necessary."

The WWF is working with Ryerson University to use less salt on campus

In a pilot program last year, Murphy says they used six fewer tonnes of salt by spraying a mixture of salt and water called brine in four test locations prior to snow and freezing rain.

Angela Murphy, with Ryerson Urban Waters, says their salt reduction pilot saved six tonnes of salt last winter. (CBC)

"It was just as effective," said Murphy, who says Ryerson made the brine in-house and it did not hurt public safety.

"There was no increase in liability, no increase in complaints ... there's really no need for people to apply so much road salt."

Their team is scaling up the project this winter, Murphy said, and studying the impact of using brine in place of road salt in certain city areas.

City uses 130,000 tonnes of road salt

The city of Toronto uses more than 130,000 tonnes of road salt each winter, as well as brine and some salt alternatives.

However, City of Toronto spokesperson Eric Holmes said salt is the most cost effective and efficient way to clear ice from roadways.

The city has to balance negative environmental impacts, he said, but their focus is on public safety.

The city implemented a salt management plan in 2002 to reduce salt use, Holmes said, which reduce salt usage 15 per cent in its the first 15 years.

Lake Ontario is a "gem," says Liz Hendriks, but everything we do on land impacts the rivers and waterways. (CBC)

They also put down salt brine before a storm, he said, and city trucks use automated equipment to determine where to spread salt based on road temperature.

Last year they also used beet juice a few times, Holmes said. But while it works in colder temperatures than road salt, he said, beet juice is harder to get and more expensive.

Although safety is critical, Hendriks said both public roadways and private properties contribute to over-salting in Ontario's lakes and rivers.

She points to information programs like "Smart About Salt," where contractors and property owners can learn ways to reduce their salt usage.

"Everything we do on the land feeds into our river system and into [Lake Ontario]," Hendriks said.

"What we do on the land and on our roads matters."