Aware of the negative environmental impact of road salts, used to de-ice roads in winter, Quebec municipalities are increasingly turning to alternative methods to make sidewalks and roads safe without damaging the flora and fauna. and the aquatic environment.
After beet juice, corn syrup or even sand, several Quebec municipalities will be spreading wood chips soaked in magnesium chloride on their roads this winter. An alternative to de-icing salt, considered a "toxic substance" under Canadian Environmental Protection Act.
The product, manufactured for two months by the company Technologies EMC3, based in Joliette, is inspired by an initiative of Switzerland, which for eight years already uses wood chips on its sidewalks, cycle paths and roads as non-slip.
“It is a 100% biodegradable product which has a neutral pH therefore with less risk of polluting waterways. And it's not as if we could run out of wood chips in Quebec ”, assures 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 Rosemère, near Montreal, or to Granby, in Montérégie. Individuals have also placed orders, and Mr. Prévost intends to approach hardware stores to have his product adopted by a greater number of people.
This technique will also be tested in the coming weeks on the Jacques-Cartier Bridge bike path, which links Montreal to its south shore. Closed in winter because it is considered too dangerous for users, the track will be the subject of a pilot project this year to test various snow and ice removal methods.
“Currently, we have identified at least four products to try, including heating mats and wood chips, but we still have other types of de-icers in liquid or granular form that contain less sodium chloride that are in the market. study, ”explains Cathy Beauséjour, communications advisor for Les Ponts Jacques Cartier and Champlain Incorporée.
Photo: Jacques Nadeau Le Devoir Wood chips would cover up to four times more surface than road salts and last longer. The sodium chloride found in de-icing salt tends to damage the steel structure of the bridge. Even on traditional roads, we see that salt loses its de-icing properties at around -15 ° Celsius in addition to accumulating in soils and drinking water wells when the snow melts. “Salt has a severe impact on the flora. You can only see it around highways, where the vegetation is really not in good condition because of the fluxes or abrasives applied on the roads ”, notes Marc Olivier, chemist specializing in environment at the University of Sherbrooke. Unlike salt, wood chips do not reach the water table and they do not damage the concrete or the steel of bridges, underlines André Prévost. With a length of 5 to 20 millimeters, the small pieces of wood become embedded in the snow and can last for 6 days, and up to a temperature of -30 ° Celsius, thanks to the magnesium chloride in which they are soaked, assures Mr. Prévost. In Switzerland, once the winter has passed, the wood chips are collected as compost, used to heat homes the following winter. While he recognizes that his product is more expensive than salt, Mr. Prévost estimates that, for the same quantity sold, wood chips will cover up to four times the surface area of road salts and will last. Longer. "Not to mention the savings that could be made by removing snow from sidewalks less, for example, since it can be used without problem on packed snow, as an abrasive rather than as a flux", specifies Mr. Prévost. For her part, Mélanie Deslongchamps, director of the Association for the Protection of the Environment of Lake Saint-Charles and the North Marshes (APEL), wonders about the effectiveness of wood chips. “Like other abrasives such as gravel and small rocks, it's often found on roadsides [after passing cars]. " The organization is increasingly concerned about the impact of the icebreaking methods in effect in the province. In the Quebec City region, APEL observed significant levels of salinity in the water of lakes and rivers, including Lake Saint-Charles, which is the main source of drinking water for the inhabitants of Quebec. In addition, many aquatic species cannot survive in salt water and are therefore endangered. Last December, the organization gave awareness training for the first time to nearly thirty contractors in the snow removal industry. “But they just do fulfill their mandate. It is with municipalities, politicians and ministries that we must act directly, ”believes Ms. Deslongchamps. And the ecoroutes? In his view, the alternative methods used across the province have "not worked miracles." “Most products contain a minimum of salt, beet juice also in addition to sugar which will also have an impact on the quality of the water,” notes Ms. Deslongchamps. Rather, the solution is to change the behavior of citizens. She gives as an example the winter ecoroutes, on which abrasives are mainly spread rather than fluxes which may contain salt. There are about fifteen in the province. However, they are mostly located in rural areas where the speed is limited to 90 km / h or less, since this type of abrasive requires motorists to drive considerably slower. “It can't work on highways,” regrets Ms. Deslongchamps. The chemist Marc Olivier is also favorable to these “white roads”. “In the days of horse-drawn carriages, we crushed the snow instead of removing it. It was when we decided that we were a modern society with cars that needed more parking space that we decided to clear the snow and spread salt everywhere. "