Enbridge expects its newly reversed Line 9 pipeline between southwestern Ontario and Montreal will come into service by the end of June now that it has addressed some of the National Energy Board's environmental concerns.

The Calgary-based company plans to ask the NEB for permission to open the pipeline within the next day or two, spokesman Graham White said Friday.

The pipeline was to have started up in November, but was delayed when the federal energy regulator flagged concerns about the protection of water crossings along the route.

The NEB approved the project in March 2014, but the green light was subject to several conditions.

The board said Enbridge had submitted "insufficient" information on how it decided where to place valves shutting off the flow of oil in relation to water crossings. In an October letter to the company, the NEB said it appeared only six of the 104 water crossings identified by Enbridge had valves installed within a kilometre of both sides.

On Friday, the NEB said Enbridge had demonstrated that its approach was appropriate, with a total of 62 valves along the pipeline's route. Of those, 17 were added as a result of the hearing process.

However, the NEB has imposed more obligations on Enbridge to make sure the pipeline will operate safely throughout its lifespan.

Over the next year, Enbridge must submit more information to the board, including an analysis on whether more valves are needed. A member of the board has also been assigned to review all future filings for the project.

"The board takes protection of people and the environment seriously and it expects the same of the companies it regulates," the NEB said in a release.

'NEB caved,' says critic

Adam Scott, with Environmental Defence, said Friday's announcement was "really disappointing."

"It basically looks like the NEB caved," he said.

He said he was encouraged by the October missive from the NEB to Enbridge taking the pipeline company to task.

"Enbridge basically wrote back and said 'We know what we're doing. Trust us.' And the board accepted that instead of actually enforcing their own regulation, which says that they have to have valves installed on all major water crossings within one kilometre," Scott said.

The additional obligations imposed upon the company are "meaningless" if Enbridge is allowed to start up the pipeline, he said.

"I would want to see all those engineering studies before they're allowed to actually turn the pipeline on. Either the NEB is concerned about these things or it isn't, but you don't ask them to do it after the fact."

Line 9 opponents have argued Enbridge's plan puts communities at risk, threatens water supplies and could endanger vulnerable species in ecologically sensitive areas.

Built in 1976, Line 9 originally shipped oil from Sarnia, Ont., to Montreal, but was reversed in the late '90s to pump imported crude westward. Enbridge wants to switch the direction back to feed Alberta crude to eastern refineries.

The company plans to move 300,000 barrels of crude oil per day through the line, up from the current 240,000 barrels, with no increase in pressure.

enbridge map

A map showing the route for the Line 9 proposal that will reverse and increase the flow of oil in the existing pipeline. (CBC)