The Energy Resources Conservation Board issued its final approval to Plains Midstream Canada to restart operations on the Rainbow pipeline, though no official restart date was set.
Operators closed the Rainbow oil pipeline in April after a spill was discovered in northern Alberta. Canada's RCB said about 28,000 barrels of oil spilled from the pipeline, making it one of the largest spills since the 1970s.
An assessment of the April incident found stress on a crack in a weld on the pipeline contributed to its failure. Plains committed to pulling and inspecting all sections of the pipeline containing the type of welds in question, the ERCB added.
The ERCB said the interim maximum operating pressure of the pipeline was limited to 75 percent of its maximum operating pressure.
Plains All American Pipeline, the parent company of Rainbow operator Plains Midstream Canada, was scrutinized in 2006 for a 7,500-barrel leak at a section of the same pipeline in Edmonton. Investigators blamed stress and corrosion for the 2006 leak. The pipeline was built in 1966.