The 182-kilometre line would connect Edmonton to Hardisty, Alta., to the southeast, the starting point of U.S.-bound oil conduits such as Enbridge's Alberta Clipper and TransCanada Corp.'s Keystone lines.
The NEB says First Nations communities, landowners and others took place in a public hearing into the Edmonton-to-Hardisty line.
The energy watchdog attached some conditions to its approval, such as requiring Enbridge to hand over safety programs and manuals and traditional land use investigations.
The company also must provide the board with an updated weed and clubroot management plan and a post-construction management report.
In announcing the project in late 2012, Enbridge pegged its cost at $1.8 billion. It also said it would have an initial capacity of 570,000 barrels of oil per day.
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