TORONTO -- Toronto uses so much salt on its roads that some city creeks are becoming saltier than the ocean, year round — a surprising conclusion in a new study that is among the reasons city council is debating ways to cut down on salt.

Coating city roads in at least 130,000 tonnes of rock salt costs the city upwards of $11 million a year, but the true costs could be much higher than that when damage to shoes, bikes, cars and the environment is factored in, says Councillor Mike Layton.

“This is a toxic substance,” Layton said in an interview. “I would hazard to guess we are being quite wasteful and haphazard in our application of salt.”

“It needs to be applied with greater care to ensure that we’re putting the absolute right amount of salt on our roads,” he said.

Layton’s motion, to be discussed Friday, requests to use the lowest amount of salt possible to do the job, explore using a mix of salt and water instead called brine, which sticks to roads better, and even just pre-wetting the rock salt with water so that it helps stick the salt to the pavement.

He’s pushing for an audit of actual rates of salt application, which would include the cost of damage to city infrastructure, and asking the city to consider new standards on private property owners, which the motion says are responsible for 40 per cent of salt use across the city.

A University of Toronto study published in March found that nearly 90 per cent of the 214 samples taken across rivers and creeks in the summer in the GTA had salt levels that exceeded federal guidelines. In one third of the samples, the level was high enough to be lethal to freshwater wildlife.

“In the winter it gets much worse,” said one author of the paper, Donald Jackson. “Depending on melting conditions and applications, we can have some of these streams and rivers that exceed sea level concentrations. We can have urban streams that are saltier than the ocean might be.”

Transitioning to using brine instead of salt would cut the salt use by around 30 to 40 per cent, which would save the city millions each year, he said.

Toronto was one of the first cities to implement a salt management plan. The city already substitutes beet juice for salt, but only if it’s below -20 C, when the salt and water mixture would itself freeze.

Other jurisdictions are trying other alternatives, such as mozzarella cheese brine in Wisconsin, and sugarcane molasses in Minnesota.

CTV News Toronto reached out to three major private owners of malls in the GTA to ask about their salt strategies, but none returned calls.

Michelle Woodhouse of Environmental Defence said that response is not a sign that the private landowners don’t care — just a sign they need more guidance.

“We need more from the city level so that we can make sure we can apply better standards across the city,” she said. 

“There are solutions that our experts have shown us that we can implement to do this. It’s about empowering ourselves with knowledge and acting on that knowledge,” she said.