In the west sector, which includes land along the Bonaventure Expressway up to the approach of the Champlain Bridge across from Île des Sœurs, groundwater that drains to the river contains contaminants such as ammonia nitrogen, polycyclic aromatic hydrocarbons (PAHs) and dissolved metals.
To address this problem, the Corporation started work in June on a containment system consisting of a hydraulic barrier with 32 wells installed along the riverbank. Through active pumping, this barrier will intercept contaminated groundwater and carry it to an on-site treatment system.