British Columbia

More than a pinch: 4,000 tonnes of road salt ready for south Vancouver Island

A contractor explains the preparation and chemistry it takes to make icy roads safe for drivers.

Contractors are preparing to help holiday commuters safely get where they need to go

Rock salt imported from Mexico is used to de-ice roads on southern Vancouver Island. (David Horemans/CBC)

Laying off the salt at Christmas dinner might be a good idea, but Rick Gill is prepared to use tonnes if it means getting you to that dinner party safely.

Gill manages Mainroad South Island Contracting, which clears the roads on south Vancouver Island and the Gulf Islands. He spoke with On The Island host Gregor Craigie about salt and the challenges of keeping icy roads driveable.

4,000 tonnes at the ready

Gill uses salt imported from Mexico that is ideal for B.C.'s wet winters, where temperatures generally range between -2 C and 2 C. 

About 4,000 tonnes of salt is hauled up the coast by barge each year for use as both road salt and brine.

Brine is made by diluting the salt with water. When necessary, a Mainroad staff member will spend his or her entire day mixing the solution,

Mind the ratio

"The ratio is very important. We mix a 23-per-cent salt solution," said Gill. Sea water, by comparison, is around 11 per cent salt.

Rock salt on the road needs to be crushed before it is effective, therefore brine is a quicker way to de-ice roads.

"Basically, you are moving the salt process further. Salt doesn't become a de-icer until it is a liquid," said Gill.

"In the old days, we would just put rock salt on the roads and the first semi truck would just blow it into the ditch."

There is a strong possibility of a white Christmas this year, but Gill for one isn't too excited about the prospect of snow.

"I love a green Christmas," he said.


With files from On The Island.