The Region of Waterloo uses 140,000 tonnes of rock salt each winter, but wants to cut down

The Region of Waterloo uses an estimated 140,000 tonnes of rock salt on local roads each year but it's trying to cut down, says Eric Hodgings, manager of hydrogeology and water programs.

The annual salt dump on the region's streets, sidewalks and parking lots affects soil quality, fish habitats, and drinking water, Hodgings said, and as the region's population increases, the amount of salt used increases too as more roads are built.

"We've been implementing a pilot project on two of our parking lots — region-owned parking lots — to look at the contractor who services those and changes that they can make to reduce the amount of salt going down," Hodgings told CBC Kitchener-Waterloo.

The project, which is going into its third year, has the contractor measure the ground temperature to figure out exactly how much rock salt is needed. An excess of salt could potentially be used if contractors are relying on air temperature alone, Hodgins said. 

"Hopefully [this will] be the year that we'll be able to see how the changes are affecting how much salt goes on."

The region has also been experimenting with a de-icing method at the Region of Waterloo International Airport, using rock crystals that are diluted in water with an additive. Surfaces are coated with the liquid as a greener alternative. 

"We spray in advance so that basically the snow and ice doesn't actually stick to the surface," said Dion Sararus of Dundee Nursery and Landscaping, the contractor the region has hired at the airport. 

"We create a layer of brine that the snow and ice float on, and then we can melt it away or we can plow it away and the surface remains clear." 

Sararus said that they "use 70 per cent less salt to deal with the same conditions."

"[Liquids] can significantly reduce the amount of salt actually entering the environment," said Hodgings. "The liquid tends to stay better on the ground."

A liquid brine is harder to use, said Hodgings, and "it's a big learning curve," since it's a new way of doing things with new equipment — there's a sprayer instead of a salter, for example — but it can be effective.

"We see the environmental benefits through other pilots that have been run across North America over the last couple of years," said Hodgings.

"They're all saying that if we can get a broader change to liquids then that's going to be a way that we may be able to help reduce the impact on the environment and our drinking water."