The board said the testing, which will check for pressure and weak points, is necessary to show the public that the pipeline will be safe.
Enbridge has been seeking permission to reverse a 639-kilometre stretch of Line 9B from from North Westover, Ont., to Montreal. The project will carry western oil, including Alberta diluted oilsands bitumen, to Eastern Canada.
Enbridge had hoped the pipeline would start moving oil east in November, but that was delayed when the NEB flagged concerns about the protection of water crossings along the route.
The NEB is calling for the following three sections of the pipeline to be tested:
- Between Kingston and Brockville in Ontario.
- Mirabel, Que.
A statement from the NEB said Line 9B passes through a heavily urbanized area with several waterways. It said any release would quickly end up in water systems and affect a large number of people.
Montreal Mayor Denis Coderre described the announcement as good news. Several mayors from the Montreal area had called for a number of conditions and asked for more strict testing before they gave their blessing for the pipeline to go ahead.