PCBs have been discovered in a Pointe-Claire storm drainage system near where an illegal stockpile of PCB-laden oil was discovered almost exactly one year ago.

The city of Pointe-Claire sent out a notice on Tuesday, warning the public that  two weeks ago municipal authorities discovered a leak of polychlorinated biphenyl in the storm drainage system on Hymus Boulevard, near the Reliance Power Equipment Ltd. storage site.

"When we disconnected the pipes, we found that PCBs were coming out of their pipes into our system," said Pointe Claire City Manager Robert Weemaes.

Weemaes said they still don't know how much of the toxic substance has leaked, or how long the storm drainage system has been contaminated.

The storm drains flow into Lac Saint-Louis.

Weemaes said the environment ministry will take over the operation.

Toxins discovered during repairs

The toxins were discovered during construction work on the underground infrastructure in the area, and they were traced back to the Reliance Power Equipment site.

Back in 2013, an investigation found Reliance Power had been illegally storing PCBs and that more than 1,000 litres of the chemical had leaked from the property.

PCBs were once used as coolants or insulating fluid. Their production and sale has been illegal in Canada since the1970s.

In a statement, city officials said the appropriate officials were immediately notified when the leak was discovered on Aug. 7 "to make sure that the leak in the storm drainage system would pose no risk to the environment and, in particular, to Lake Saint-Louis." 

The City of Pointe-Claire is now waiting on the provincial government to take action.

Pointe-Claire resident Joe Barrucco, who only learned about the toxins today, said people should have been informed right away.

"We need to understand what the repercussions would be when exposed to that level of toxicity ... How much of it leaked in to the sewer system? How much of it will reach us? How much could affect us?" said Barrucco, who lives in Pointe-Claire with his wife and three-year-old son.

"We'd like to be informed — we'd like to be informed as early as possible."

Pointe-Claire Mayor Morris Trudeau said they are measures in place to ensure there is no risk to people's health or the environment.