The National Energy Board has begun their review process of the controversial Energy East pipeline project, a procedure which will take 21 months to complete.

The NEB says that the review will include public consultation "unlike any other".

First, a panel of three will work to determine if Energy East is in the public interest and then the agency will look to the public for their input.

So far, there has been a lot of feedback for Energy East and the NEB wants to hear from as many people as they can both in writing and in person.

During the review periods, officials will visit hundreds of communities along the 4,500 km route so the NEB can gather all the information they can.

Environmental impact is also very important, NEB officials said, and it will look at greenhouse gas emissions as well as any negative impact during construction and operation of the pipeline.

"This is an exercise that involves balancing the economic, the social and the environmental considerations related to the pipeline," said Jean-Denis Charlebois with the NEB. "Those considerations need to be directly tied to the pipeline to form part of the hearing panel assessment."

TransCanada, the company behind Energy East, called the review an 'important and welcomed milestone'.

In a statement, TransCanada says it is looking forward to the community sessions, which are expected to begin this fall.

Thursday's announcement came as another group came out in opposition to the plan and as Saskatchewan Premier Brad Wall, a longtime proponent, is in eastern Canada to support it.

He says the pipeline will generate $55B in economic benefit for Canada and create over 3,300 operational jobs across the country.

Wall met with New Brunswick Premier Brian Gallant on Wednesday, who is on board, but Wall will have a tougher time making his case in Quebec.

Politicians and critics in that province have pushed back against Energy East since it was announced, questioning if the environmental risk outweighs the economic reward.

Wall says he acknowledges Quebec’s concerns, but says it’s important to build the pipeline in a safe way and give people answers to their questions.

Also on Wednesday, the Assembly of First Nations in Quebec and Labrador both submitted formal opposition against the pipeline and pledged they would make their views heard both inside and outside of the province.

The final decision on the Energy East pipeline isn’t expected for another two years.

If approved, the pipeline would ship 1.1M barrels of oil per day from Alberta and Saskatchewan to the east coast.