Oil and gas company Nexen offered an apology Friday after a pipeline broke, leaking about five million litres of bitumen, water and sand in northeastern Alberta.

Ron Bailey, senior vice-president of Canadian operations told reporters Friday morning that the company was taking the leak very seriously.

"We are deeply concerned with this, and we sincerely apologize for the impact this has caused," he said. "We will take every step that we see as reasonable, and as the regulators help us decide what to do to respond to this."

The spill has affected about 16,000 square metres along the pipeline route near Nexen's Long Lake operations, Bailey said.

He said the spill, which was discovered Wednesday afternoon by a contractor, was shut down as soon as the company learned of it. The leak was contained to the pipeline right-of-way, except for in one area.

Bailey said vacuuming of the spill started Friday, and consultants are at the scene to determine the impact on the environment and wildlife. He stressed that there are no residential areas located close to the spill. However, there is a First Nation community located approximately 15 kilometres north of the spill, he said.

"There's no human impact here, immediately," Bailey said. "There's no residences near this, so there was no impact to that."

The double-walled Nexen pipeline is new, and only started operating late last year, he said. He said the company is concerned about the failure, and will be investigating to get to the root cause of the spill.

In particular, Bailey noted that the investigation will look at why the pipeline fail-safe systems did not alert technicians that a spill had occurred.

Greenpeace spokesperson Melina Laboucan-Massimo said that although Nexen is taking steps to be transparent and take responsibility for the spill, it doesn't change the magnitude of the disaster.

"It's think it's good that they're responding and taking responsibility for the spill, but that doesn't actually change the fact that we have one of the biggest spills in Canada's history on our hands," she told CTV News Channel Friday afternoon.

Laboucan-Massimo said the timing of the spill should be a warning sign to Canada's premiers, who reached a new energy deal Friday in Newfoundland, that they need to seriously consider environmental concerns before proceeding to build new pipelines.

"This is a clear indication that we still have a lot to address here in Alberta," she said.

Speaking in Newfoundland, Alberta Premier Rachel Notley recognized that the spill is "troubling." However she told CTV News Channel that it is important to wait for the results of the Nexen investigation so that steps can be taken to prevent spills from happening again.

With files from The Canadian Press