Photo: Guillaume Levasseur Duty
On paved roads, the sodium chloride loses its properties déglaçantes to approximately -15° Celsius in addition to build up in the soil and wells of drinking water during the snowmelt.
Aware of the negative environmental impact of road salt, used to salt roads in winter, quebec municipalities are turning increasingly to alternative methods to make the sidewalks and roads without damaging the wildlife, the flora and the aquatic environment.
After the beet juice, the corn syrup or the sand, several quebec municipalities will spread on their roads this winter wood chips soaked in chloride of magnesium. An alternative to de-icing salt, which is considered a “toxic substance” by the canadian law on the protection of the environment.
The product made in the last two months by the company’s Technologies EMC3, located in Joliette, is inspired by an initiative from Switzerland, which uses the past eight years the wood chips on its sidewalks, cycle tracks and roads such as non-skid.
“It is a product that is 100 % biodegradable that has a neutral pH, thus with less risk of polluting water courses. And it’s not as if we could miss wood chips in Québec, ” says the president of the company, André Prévost.
This winter, the product will be tested in several cities across the province. Orders are about to be delivered to Rosemere and Lanoraie, near Montreal, or even in Granby, Montérégie. Individuals have also placed the order, and Mr. Prevost intends to approach hardware stores for the adoption of its product by a greater number of people.
This technique will also be tested in the coming weeks on the bike path of the Jacques-Cartier bridge, which connects Montreal to its south shore. Closed in the winter, because it was too dangerous for the users, the trail will be the subject of a pilot project this year to test different methods for the removal of snow and ice.
“Currently, it has retained at least four products to try, including the heating mat and the wood chips, but it still has other types of de-icing liquid or granular, which contain less sodium chloride which are in the study “, explains Cathy Beauséjour, communication consultant for the company The Jacques Cartier and Champlain Bridges Incorporated.
Photo: Jacques Nadeau Le Devoir
The wood chips would cover up to four times more surface area than the salts and would last longer.
The sodium chloride that is found in the de-icing salt has the tendency to damage the steel structure of the bridge. Even on the traditional routes, it is observed that the salt loses its properties déglaçantes to approximately -15° Celsius in addition to build up in the soil and wells of drinking water during the snowmelt.
“The salt has a severe impact on the flora. We see nothing around the highway, where the vegetation is really not in a good state because of the melters or abrasives on the roads “, said Marc Olivier, a chemist specializing in environmental design at the Université de Sherbrooke.
Unlike the salt, the wood chips do not reach the groundwater table, and they do not damage neither the concrete nor the steel of the bridges, says André Prévost.
With a length of 5 to 20 millimeters, the small pieces of wood embed themselves in the snow and can hold for 6 days, and up to a temperature of -30° Celsius, thanks to the magnesium chloride in which they are soaked, to assure Dr. Prevost.
In Switzerland, after the past winter, the wood chips are recovered as compost, which is used to heat homes in the winter following.
If he recognizes that his product is more expensive than salt, M. Prévost believes that, for the same quantity sold, the wood chips will cover up to four times more surface area than the road salt and will last longer.
“Not to mention the savings that one could get in déneigeant least the sidewalks, for example, since it is used without problem on packed snow, as an abrasive rather than as a flux,” explains Mr. Prévost.
On his side, Melanie Deslongchamps, director of the Association for the protection of the environment of lac Saint-Charles et des Marais du Nord (APEL), questions about the effectiveness of wood chips. “As other abrasives such as gravel and small rocks, it is often found on the edges of the roads [after the passage of the cars]. “
The organization is increasingly concerned by the impact of the methods of the ib in force in the province. In the region of Quebec, APEL has found rates of salinity are important in the water of lakes and rivers, including lake Saint-Charles is the main source of drinking water to the inhabitants of Quebec. In addition, many aquatic species cannot survive in salt water and are therefore threatened.
Last December, the organization has provided for the first time, an awareness-raising training to nearly thirty entrepreneurs in the field of snow removal. “But they are just fulfilling their mandate. It is from municipalities, politicians, line ministries, it is directly necessary to take action, ” believes Ms. Deslongchamps.
And écoroutes ?
In his eyes, the replacement methods used across the province have not made miracle “. “Most of the products contain a minimum of salt, the beet juice also in addition to the sugar, which will also have an impact on the quality of the water,” notes Ms. Deslongchamps.
The solution is based rather on a change in the behaviour of citizens. It gives for example the écoroutes winter, which are essentially common abrasives rather than de-icers that contain salt. There are a dozen in the province. However, they are mainly located in rural areas where the speed limit is 90 km/h and less, since this type of abrasive request that motorists take a driving considerably slower. “It can’t work on the highways,” says Ms. Deslongchamps.
The chemist Marc Olivier is also in favour of these ” white roads “. “In the time of horse-drawn carriages, we beat off the snow instead of removing it. This is when we decided that we were a modern society with cars that had been asking for more space for parking that we decided to do away with the snow and spread the salt everywhere. “
Many attempts, few results
In recent years, the City of Montreal has tested several methods of de-icing on its streets and sidewalks in order to find an alternative solution that is more eco-friendly road salt. Of beet juice and corn syrup mixed with salt, for example, have already been tried in some districts of the metropolis. As of de-icers such as magnesium chloride, which gave a blue tint to the streets, or salts, pre-moistened, who adhere more quickly to the ground. According to the City, the results were never quite conclusive to abandon the salt and traditional gravel. The administration thus prefers to work for the time being to better manage the dosage of salt as well as the spreading on the roadways.
The ib, in a few figures
Budgets associated with the purchase of deicing road in 2016-2017 :
$ 13 million to a total of 152 000 tonnes of deicing
$ 0.6 million for 35 000 tonnes of abrasive
This is about 15 % more than for a winter average, whereas only 11 to 12 million dollars are disbursed in fluxes. The City of Montreal reminds us that the past winter had been marked by several episodes of milder temperatures followed by a drop of mercury. This had led to the risk of ice and the need for a greater use of de-icers.
Source : City of Montreal