Ontario's concerns about the potential environmental impact of the pipeline narrowed considerably Wednesday following a meeting between Premier Kathleen Wynne and Alberta counterpart Jim Prentice.
Ontario and Quebec had set out seven principles for the project, which would carry western crude to refineries in Eastern Canada.
Premier Brad Wall says his biggest source of concern had been the possibility of applying a greenhouse gas measure to oil in the pipeline.
But after meeting Prentice in her office, Wynne said her concerns were limited to greenhouse gas emissions from the pipeline project itself — not from so-called upstream emissions related to getting the crude out of the ground, refining and burning it.
"On this project, we're talking about the reality that greenhouse gas emissions as they pertain to the project in Ontario, they need to be taken into account," she told reporters. "That's what the principle says."
Wynne said her stance was not a change in position, but she couldn't say exactly what potential greenhouse gas emissions would be generated by the pipeline project that have her concerned.
"That's for the discussion," she said. "We haven't outlined that."
TransCanada Corp. (TSX:TRP) has applied to use a repurposed natural gas pipeline to carry crude two-thirds of the way across the country, and to build a pipeline extension that would connect it to Saint John, N.B.
Wall said that he credits the Ontario and Quebec premiers for clarifying the terms.
"Whether it's a clarification or a change, it doesn't really matter," said Wall, who added that a greenhouse gas measure related to the construction of the pipeline won't pose a problem.
"Save for a very small, small part of the pipeline through Ontario, it's already in the ground," he said. "Should this be approved, there will be that same pipeline under the feet of Ontarians carrying a hydrocarbon, but oil, and largely conventional oil."
He said he was troubled by the initial proposal for a measure on greenhouse gas emissions. Wall had said that Ontario and Quebec leaders were creating "unnecessary barriers" for the project.
The Saskatchewan legislature passed a motion last week calling on the two provinces to recognize the National Energy Board as the appropriate body to review the pipeline proposal.
On Thursday, Wall said he believes joint pressure from Alberta and Saskatchewan, which included private discussions and public debate, helped to move the discussion forward.
"Both had an impact. Maybe that's a formula Premier Prentice and I can work on," he said.
"Those behind-the-door meetings are very important," he said. "But Canadians need to know the facts too. I think Canadians in Ontario and Quebec are more likely to reconsider maybe an opposition they have to the pipeline when they know that this is replacing foreign oil."