An air quality advisory issued by the province on Feb. 3 due to “road dust” provoked some concerns around town about what chemicals might be in the air people are breathing.
Castlegar CAO Chris Barlow says all the products used on local roads contain only natural ingredients.
The sand the city puts down contains small pieces of gravel and five per cent rock salt. The liquid de-icer is a calcium chloride solution.
The de-icer is primarily used as a preventative measure when the temperature is below zero and falling and snow is forecast.
“On a typical snowfall, it is very helpful in getting us back to bare roads as soon as possible,” said Barlow.
He explained the de-icer creates a layer between the new snow and the road, forming a sort of barrier that allows for easier removal of the snow once it falls.
He says de-icer applied on ice and snow is less effective as it dilutes quickly once the ice starts to melt.
The city generally focuses sand application on hills and priority routes, but tries to avoid using it on flat roads except at intersections and stop signs.
Barlow says they keep in mind that come spring, all the winter sand must be cleaned up, so they try not to use more than necessary.
The city plans for typical winter conditions. But January’s double-the-average snowfall kept city crews working extra hard.
“All you can do is make the best with the staff and the equipment that you have,” sad Barlow.
The formulas used on local highways are very similar to those used in city limits.
Hayden Schmitz from local highway contractor YRB says they use a sand and salt mixture on the highways, but the sand concentration is three per cent.
For de-icing, YRB uses a sodium chloride mixture until the temperature falls below –6 degrees. At that point they switch to a calcium chloride formula.