About 680 barrels of an oil and water mixture spilled at the Nexen Long Lake site in northern Alberta on Thursday night.

The mixture was 80 per cent water and 20 per cent oil and was contained to the site, according to a spokesman from the Energy Resources Conservation Board.

The mixture was easy to remove because it had frozen in the cold weather, he said.

The Long Lake site is about 40 kilometres southeast of Fort McMurray.