MINNEAPOLIS -- The decision in a lawsuit against the U.S. State Department could hinge on whether or not an Enbridge pipeline project is considered a completely new pipeline.

Judge Michael Davis on Thursday heard arguments from both sides of a lawsuit filed in U.S. District Court by the White Earth Nation and environmental rights groups Honor The Earth, MN350, the Sierra Club and others against Secretary of State John Kerry and the State Department.

Ken Rumelt, lead attorney for the plaintiffs, argued Enbridge’s planned $2.3 billion Line 3 replacement project is not, in fact, a straight-up replacement of the aging pipeline that runs from Alberta, Canada, to Superior.

“It’s not a replacement,” he said. “It’s carrying more oil, it’s going to likely following a different route through Minnesota and it’s going to be larger.”

The current Line 3, built in the 1960s, is a 34-inch diameter pipeline that carries a thick type of crude oil known as tar sands oil across the Manitoba-North Dakota border, then along the U.S. Highway 2 corridor across Minnesota to Superior.

The proposed Line 3 replacement project, currently going through the regulatory process at the state level in Minnesota, will increase in diameter to 36 inches, increasing it to a daily capacity of up to 880,000 barrels.

Additionally, the new Line 3 is proposed to follow the route of another Enbridge pipeline, the Sandpiper, that is going through the approval process with the state’s Public Utilities Commission. Following the Sandpiper route would send the new Line 3 much further south, cutting across lands many environmentalists and Native American rights groups consider as highly sensitive.

A section of pipeline Enbridge wants to be part of the new pipeline already has been installed along the U.S.-Canada border. Enbridge deemed part of the current Line 3 to be in need of replacement, and the company made those repairs.

Rumelt said “this smart bit of trickery” by Enbridge was to avoid the presidential permitting process that has stalled the Keystone XL project, which has been in the national spotlight and mired in red tape for years. A presidential permit is required for pipelines crossing the U.S.-Canada border.

Enbridge representatives say there was no deception when the company made the repairs, then announced its Line 3 replacement project the next year.

“Enbridge is operating its pipelines consistent with the presidential permits and other permits that it holds for Lines 3 and 67, while meeting its responsibility and obligations to serve its shippers’ needs,” said Lorraine Little, spokeswoman for Enbridge. “We have responded fully to that lawsuit through our submissions to the court, which are a matter of public record. We believe that there is no merit to the claims of the Sierra Club and others.”

What Rumelt and others saw as deceptive leaves another opportunity for Enbridge to bypass environmental review and public input, he said.

“The reality is, the existing (Line 3) pipeline will remain in the ground, and it’s going to be maintained,” Rumelt said. “What you could end up with is this so-called replaced pipeline coming back into service.”

The industry standard in the United States to deactivate a pipeline is to fill it with inert gas that’s not dangerous if the pipeline leaks, said David Coburn, who represented Enbridge during Thursday’s proceedings. Canadian guidelines call for pipelines to be removed from the ground.

“There are further environmental factors to consider when you talk about removing a pipeline,” he said. “You might have to go dig up someone’s yard, that sort of thing.”

Coburn also said there are no plans to reuse the current Line 3 once the new pipeline is built.

Rumelt said it may be several months before there is a ruling in the case.