Road salt additive turning Montreal streets, sidewalks blue

Montreal streets are tintedblue these days thanks tosalt moistened with liquid magnesium chloride.

The mixture is said to be more effective than ordinary road salt because it stays on the road longer and sticks to icysurfacesbetter.

City of Montreal spokesman Philippe Sabourin said the city is studying how wellit works.

"We want to verify if optimizing the efficiency of de-icing products helps reduce the number of applications necessary and cuts down on the amount entering the environment," said Sabourin.

Sbastien Sauv, a professor of environmental chemistry at the Universit de Montral, saidliquid magnesium chlorideisn't very toxic and has been shown to reduce the amount of road salt used by 10 per cent to 30 per cent.

"That kind of reduction translates into [fewer]trips and lessgas consumed by trucksand that's significant," Sauvsaid.

Less degradation

Sylvain Ouellet, the spokesman on environmental issues for Projet Montral, said reducing the amount of salt used on the roads has the added benefit of slowing down the deterioration of roads and sewers.

"There's a Canadian study that shows every dollar of salt on our roads translates into the equivalent of five dollars worth of degradation to underground infrastructure," he said.

For the moment, the experimental mixture only represents a tiny percentageof the 130,000 tonnes of road salt and 34,000 tonnes of abrasives spread on Montreal's roads and sidewalks every winter.

Ouellet said the city needsto do more to reduce those amounts.

Then there's beets

He pointsto a Scandinavian innovation that can gaugehow slippery a surface isand adjust the amount of salt that's spread.

In December, Lavalintroduced a de-icing productderived froma sugar beet extracton its streets.

You might think that might mean that Laval streets would be tinted pink, but Laval officials said the city uses a white-beet source.