Even though it has been monitoring a site in Mascouche containing more than 160,000 cubic meters of highly contaminated soil for nearly 30 years, the Quebec government has still not found a solution to manage these toxic materials while respecting environmental rules, learned The duty. Cells that contain hydrocarbons and PCBs were meant to be a temporary solution.
The history of this potentially very costly environmental liability for Quebec taxpayers dates back to the 1960s. At that time, the Montreal company Le Vidangeur was authorized to bury on site “residues” from refineries in the east of the city. . But after less than five years of operation marked by various spills, the site was abandoned.
Following tailings pond overflows that posed risks to public health and the environment, contaminated soils and hazardous materials from the site were finally stored in four cells set up in 1993 and 1994.
Since then, nothing has been done to ensure that the contents of these cells, described as “temporary” by the Quebec government, are managed according to current environmental rules. Result: nearly 30 years later, the site under the responsibility of the Quebec government, but located on the land of a private company, still contains 160,000 cubic meters of contaminated soil and hazardous materials. This is equivalent to the storage capacity of more than 40 Olympic swimming pools.
Toxic products
These cells located north of Highway 640, however, do not contain water suitable for swimming, but rather various contaminants inherited from an industrial era where environmental regulations were lax to say the least. This “file” is also listed in the “Directory of soil and industrial residue deposits”, but the Government of Quebec’s website does not provide information on the nature of the contaminants present on the site under its responsibility.
However, the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP) has a list. “The main contaminants in soil cells are mineral oils and greases, monocyclic and polycyclic aromatic hydrocarbons, total halogenated hydrocarbons, polychlorinated biphenyls (PCBs), sulfur and metals,” it says by email. “Hazardous residual materials cells are mainly made up of sludge and hydrocarbon plates,” adds the ministry.
However, the authorities are unable to specify the quantities for each of these types of highly toxic residues. “The contamination found in the cells is of a mixed type, ie it contains several or all of the contaminants listed above. It is therefore not possible for the ministry to isolate the volumes affected for the various contaminants present,” argues the MELCCFP.
In a report by the Bureau d’audiences publiques sur l’environnement (BAPE) published in March 2010 for another project to bury contaminated soil on the Mascouche site, the commissioners insisted on the fact that “soil confined in the cells are heavily contaminated with PCBs and heavy metals”.
In the same breath, the BAPE invited the government, 13 years ago, “to manage these soils as soon as possible before the containment cells put in place in the 1990s can no longer adequately secure their content”.
Even though we asked the MELCCFP twice if the cells had leaked in the past three decades, they never answered our question. Nevertheless, in 1997 the ministry installed a total of 13 “observation wells” around the cells, and “work to plug the leaks would have been done in 2001”, writes the BAPE in its report published in 2010. The same report mentions a call for tenders which was to be launched “soon” in order to begin taking charge of the 160,000 cubic meters of soil.
Lack of transparency
When will contaminated soils and hazardous materials be treated or safely buried? “Characterization work on the contents of the cells is planned in the short term and additional characterization work on the site will have to take place with the aim of starting the rehabilitation work as soon as possible, in accordance with government contractual rules. applicable”, simply indicates the MELCCFP.
“Considering the complexity of the mandate and the sensitivity of the actions to come, given that the cells under the responsibility of the ministry are found in particular on private property, the ministry will not issue any additional comments on this file”, adds one. . The private company in question declined to comment on the case.
Daniel Green, from the Society for Defeating Pollution, had already visited the Mascouche site before the cells were set up, since it was part of a “toxic” tour he had organized to show journalists the worst contaminated sites. He criticizes today the “lack of transparency” of the ministry in this file. He wonders in particular if the cells are still watertight, 30 years after their implantation.
One thing is certain, adds Mr. Green, the management of the soils of this “orphan” site risks being costly for the Quebec State. “Old contaminated sites always come back to haunt us. And since little monitoring is done, there are always risks of more widespread contamination, including for groundwater. And it could cost us dearly. »