Authorities have detected a contaminant in the St. Lawrence River in Montreal’s east end, less than two weeks after an oil spill in the same area.
The root cause of the oil spill near Pointe-aux-Trembles on July 25 is unknown, but authorities say they found the pipe that led the contaminant to the river.
The pollution comes days after the Canadian Coast Guard (CCG) finalized a cleanup operation on July 19 for a previous spill near Du Tricentenaire Boulevard. Some 19,000 litres of water and oil were recovered, according to the CCG.
A spokesperson for Quebec’s Environment Ministry said that a sample taken on July 25 shows the latest oil retrieved matches the profile of the motor oil spilled on July 11.
Given the contaminant is from a land source, a storm sewer, the Environment Ministry is now leading the investigation with support from the CCG, the ministry spokesperson confirmed Friday. It noted that additional samples are being taken to confirm the contaminant passed through the storm sewer pipe.
“Research continues in collaboration with the City of Montreal to find the origin of the spill in the network,” the statement reads.
Marina closed for cleanup
Thursday, the CGG, Urgence-Environnement Québec and Quebec’s Environment and Public Safety ministries were deployed to the Pointe-aux-Trembles marina. The CCG said it had sent a drone and a helicopter to assess the situation as well.
New mitigation measures are in effect to limit the spread of the contaminant, and recovery work is underway, according to the Environment Ministry.
“The marina will limit access to its facilities to boat owners only. They will only be able to leave the marina when their boats have been cleaned,” the Environment Ministry spokesperson said.
Thursday, the Coast Guard said the spill was coming from the river sewer located right next to the polluted area. The investigation is now focusing on how the oil slick ended up in the pipe.
A 2019 report by the Communauté métropolitaine de Montréal on vulnerabilities of the drinking water network in the event of oil spills mentioned two pipelines — Valero Energy’s Saint-Laurent and Portland-Montreal — which cross the river in the same sector.
Investigators have not connected the latest contamination with the two pipelines.