Since the Confederation Line of the LRT opened in mid-September, commuters have been complaining about a rancid smell in the downtown tunnel. The City now believes it has identified the source of that smell.

In an email to Newstalk 580 CFRA, Troy Charter, Director of Transit Operations, says that a sump pump wasn't working in an escalator pit, causing a buildup of moisture.

"Repairs have been made to the sump pump, the escalator pits have been cleaned, and steps have been taken to eliminate the accumulation of moisture," he says, but there was a sealant material used to prevent future leaks. It's that sealant that the City says is causing the smell. It can continue while the product continues to dry, a process that can take weeks.

Charter says a deodorizer is being used to help minimize the smell. City staff will continue to monitor the situation.