Oil company Canadian Natural Resources Ltd. was ordered to stop injecting high-pressure steam into its Primrose South operation following a series of spills.
The company reported a spill volume of 175 barrels initially, though the Toronto Star, which originally highlighted the incident, reported last week it obtained documents indicating about 26,000 barrels of bitumen, or tar sands, mixed with surface water have been removed since cleanup began in May.
Alberta Energy Regulator spokeswoman Cara Tobin said updated estimates of the amount of oil spilled were expected Saturday, though no information from the regulator or the energy company was available by Monday.
Tobin said the contaminated area was limited and isolated from populated areas.
"The incident is ongoing, there are a number of sites that have bitumen coming to the surface and that bitumen continues to come to the surface," she said Friday. "It's a slow release but it's a release nonetheless."