Barry Robinson, a staff lawyer for advocacy group Ecojustice, said in a statement Thursday the project put the pristine western coastline at risk.
"The Northern Gateway pipeline is an unsafe, unsustainable and unnecessary project, and it does not serve the national interest of this country," he said.
Canadian pipeline company Enbridge received support from the energy board to build a pipeline designed to send 525,000 barrels of oil per day to ports in British Columbia.
The Canadian Association of Petroleum Producers said that, with nearly all of the Canadian oil exports now headed to the United States building Northern Gateway to western Canadian ports was good for energy diversity.
"Oil pipeline access to the West Coast will strengthen Canada's ability to receive maximum value for its natural resources by connecting responsible, secure oil suppliers and energy consumers," the group said Thursday.
Alberta Energy Minister Diana McQueen said the decision by the National Energy Board to support the pipeline means Canada could get paid more for its natural resources, which could translate to economic stimulus at home.
The NEB, in a decision released Thursday, subjected the pipeline to more than 200 conditions but said the Canadian economy would be well-served by the project.
With the NEB's consent, Enbridge needs to petition the federal government for approval.