Alberta's energy regulator says the pipeline spilled 40,000 liters (about 250 barrels) of crude oil into the stream.
The regulator said on its website that the incident happened on Thursday at the Bonterra Energy Corp. line 14 kilometers south of Droughton Valley, Alta.
It states that the line was closed and depressed and that retention blocks were installed.
AER says no impacts on wildlife have been reported.
Calgary-based Bontera said in a news release that he began investigating a problem with the pipeline at 8am on Thursday and 1pm. discovered a rupture that was leaking in Crete.
It is said to remove the oil with booms and gaps and to alleviate barrier-to-animal impacts as well as visual intimidation involving humans.
The crisis stream flows into the North Saskatchewan River, which is the source of Edmonton's water supply, and Bontera says it has set up an additional boom where the stream fills the river as an extra precaution.
The company said the cleanup and recovery is expected to continue in the next three weeks.