The federal energy watchdog said in a letter this week it's "not persuaded" the Calgary-based pipeline giant (TSX:ENB) is meeting one of the conditions it attached to its approval of the project in March.
Condition 16 has to do with where valves are placed in relation to water crossings. The NEB says it appears only six of the 104 water crossings identified by Enbridge have valves installed within a kilometre of both sides. The valves would quickly shut off the flow of oil in the event of a pipeline rupture.
The board also said Enbridge's criteria for determining what constitutes a "major water crossing" are "not adequate."
"The board takes protection of people and the environment seriously and it expects the same of the companies it regulates," wrote board secretary Sheri Young.
Line 9 had been targeted to begin shipping western crude between southern Ontario and Montreal in early November, but it's looking like that will be pushed back by three months at a minimum.
The NEB's letter said Enbridge will need to address the board's concerns at least 90 days before it can apply for final permission to open the pipeline.
"We are confirming with the NEB what information they require from us," Enbridge spokesman Graham White said in an email, adding the company "will continue to work with the NEB to explain our rationale and address all of their concerns."
He said it's too early to say how long start-up will be delayed.
Adam Scott, climate and energy program manager with Environmental Defence, said he could see it "easily" taking more than a year for Enbridge to make sure it has the right equipment installed along the line.
"This is a major delay that they're looking at and it should give us a chance to reconsider the approval on this," he said.
Scott said he was struck by the tone of the NEB's missive.
"I've never seen a letter from the NEB with such strong language," he said.
Scott said it's a "basic safety measure" and a "no-brainer" to have valves near either side of a water crossing.
"It's something you absolutely have to do."
Scrutiny over Enbridge's pipeline safety practices intensified in 2010, when a pipeline in southern Michigan ruptured and leaked three million litres of crude, including some that flowed into the Kalamazoo River.
Line 9, between Sarnia, Ont. and Montreal, originally flowed in a west-to-east direction when it was built in the 1970s, but that was reversed in the late 1990s in response to changing market conditions.
Enbridge has completed most of the work required to restore Line 9 to its original configuration so that eastern refineries, like Suncor Energy Inc.'s (TSX:SU) 137,000 barrel-per-day plant in Montreal, can have access to more Alberta crude, supplanting pricier imports from abroad.