Energy giant Enbridge says it is working on the biggest project in the company’s history and is spending $7B to replace the Line 3 pipeline between Canada and the United States.

On Tuesday, the Calgary-based company announced that it would partner with its U.S. affiliate to replace the Line 3 pipeline between Hardisty, Alberta and Superior, Wisconsin.

Enbridge President and CEO, Al Monaco, says the project will act as a "buffer" that ensures the system remains reliable for customers and says the project won't need a Presidential Permit to proceed, reducing the probability of regulatory delays.

Monaco says replacing the whole 46-year-old line is more economical than other maintenance options.

Line 3 is one of the primary pipelines in Enbridge’s mainline crude oil system and crosses the Canada-U.S. border at Superior, Wisconsin.

The replacement project will replace 1,660 kilometres of pipeline when it is complete and is expected to be finished in the second half of 2017.

(With files from The Canadian Press)