Water is leaking into Ottawa's new light-rail tunnel, and the president of the Ottawa and District Labour Council is concerned it poses a safety risk to construction workers.

Sean McKenney was sent a photo that shows a flooded portion of the tunnel at the west portal, near Lebreton Flats.

"It's murky, it's dark, you can't see what's underneath it, so when you're walking through it certainly there are hazards there and that is a concern of ours," McKenney said.

In the past, workers have expressed several other concerns about working conditions and incidents inside the tunnel.

The allegations include poor housekeeping, tripping hazards, poor air quality, improper traffic control, people working while impaired and worries about a potential structural collapse.

Flooding a 'unique situation'

The photo in question was taken after a record rainfall on July 25, 2018, according to Steven Cripps, the city's director of rail implementation.

Temporary pumps couldn't handle the excessive amount of water, which caused the flooding, he said. But Cripps added that the Rideau Transit Group, which is building the LRT system, took appropriate steps to protect workers.

You've got to remember this is still a construction site. We're still in temporary conditions. - Steven Cripps, Ottawa's director of rail implementation

And when the project is complete, permanent pumps and drainage systems will handle any inflow of water, he added.

"You've got to remember this is still a construction site. We're still in temporary conditions," Cripps said, calling the flooding a "unique situation" that was dealt with in a matter of days.

Other minor leaks are common because much of the LRT system sits below the water table.

"The tunnel has a waterproof layer around it but water will always find its way in, so that's why they'll address it on an individual, case-by-case basis," Cripps said.

Repairs on schedule, RTG says

In a written statement, RTG said Ottawa Light Rail Transit Constructors injects grout and other compounds to address and repair the leaks.

The injected material, once solidified, is impenetrable.

The group said the number of leaks in the Confederation Line tunnel are not unusual compared to other tunnels, but did not provide examples.

It said leak repair is on schedule and nearing completion.