(Adds comment from Portland-Montreal pipeline company, paragraph 14)
By Richard Valdmanis
BOSTON, March 7 (Reuters) - A decision by Canadian regulators to let pipeline company Enbridge pump oil sands into Quebec has environmental activists and politicians worried the oil could eventually spill into the neighboring New England region of the United States.
Canada's National Energy Board on Thursday approved a plan by the country's No.1 pipeline company Enbridge to reverse and expand its Line 9 from southern Ontario to Quebec on condition that it undertake additional work on consultation and safety.
The project would feed refineries around Montreal and Quebec City, but would also place oil sands at the northern terminus of the Portland-Montreal pipeline, which runs through Vermont, New Hampshire and Maine. Canada's approval had been expected because the plan uses existing infrastructure, requires no new pipeline and much of the work will take place on Enbridge property or right-of-ways.
The Portland-Montreal pipeline moves oil north, but the company has said it is interested in possibly reversing its flow to provide Canadian producers a way to get their tar sands to the global market through the Portland Harbor in Maine.
Dylan Voorhees, a director at the Natural Resources Council of Maine, said the environmental advocacy group is opposed to the idea because he believes Canadian tar sands are more polluting than conventional oil when it spills.
"We saw during spills in Kalamazoo and Mayflower that an oil sands spill releases more toxic chemicals, basically the dilutants, into the air," Voorhees said, citing pipeline ruptures in Michigan and Arkansas, respectively.
"It also has a propensity to sink into water in a way that makes it nearly impossible to clean up," he said.
The Portland-Montreal pipeline crosses several Maine waterways, including Sebago Lake, which is the source of water for one in seven Maine residents.
Maine's Democratic Senator Chellie Pingree and Independent Senator Angus King urged Washington to require a Presidential Permit for a reversal of the Portland-Montreal pipeline.
"My constituents have consistently expressed concern at the lack of any environmental review of a project of this nature, given that there appears to be no substantive state review process that would be triggered," King wrote in a letter to U.S. Secretary of State John Kerry on Thursday.
Federal approval has delayed for years other oil sands pipeline proposals in the United States, notably Keystone XL, which would carry crude to Nebraska from Alberta, Canada. A decision is pending from the U.S. Secretary of State.
Last year, the city council of South Portland, where the Portland-Montreal pipeline originates, adopted a six-month moratorium on any tar sands project in the city in order to provide time for drafting a new ordinance governing industrial development on the waterfront.
Several towns in Vermont have also voted to oppose efforts to pump Canadian oil sands across the state.
The Portland-Montreal pipeline company said in a statement that it had not filed a proposal to reverse the flow of its pipeline. A spokesman declined to comment further.
Any reversal of Enbridge's line 9, the project Canada approved Thursday, on its own may not be enough to trigger a Portland-Montreal reversal, however, because the project's 300,000 barrel per day capacity would meet only part of the demand from eastern Canadian refineries.
The project is just one of several major pipeline investments proposed for North America, fueled by the rapid growth of Canada's oil industry. TransCanada Corp, for example, has proposed a 1.1 million bpd pipeline to eastern Canada, with a target startup date of 2018. (Editing by Grant McCool)