Dozens of supporters and opponents of a plan to replace a deteriorating 60-year old line that carries crude oil across northern Minnesota turned out Tuesday for the first public meetings on the proposal.

Enbridge Energy's Line 3 is one of five pipelines that carry about 2.5 million barrels of oil a day from Alberta, Canada, across Minnesota, to the company's hub in Superior, Wis. But it's getting old. To keep it safe, the company has had to reduce the amount of oil it pumps through it. And lately it's had to increase the amount of maintenance it does on the pipe.

"In the past five years we've been doing integrity digs, which take care of any imperfections in the pipe, we put sleeves on it, weld it up, make sure no leaks ever happen," said Derek Pederson, a pipeliner from Esko.

But "everything has a shelf life I believe, and it's up for Line 3," he said.

Pederson was one of about 150 people at the public hearing in Grand Rapids. That meeting and another in Bagley earlier in the day were the first of 22 the Minnesota Department of Commerce has scheduled on the proposal over the next three weeks.

A new pipeline would cost $2 billion in Minnesota alone, and would create about 1,500 construction jobs. It also would allow Enbridge to nearly double the line's capacity from 390,000 barrels a day to 760,000.

But the proposal has sparked intense opposition from environmental and tribal groups.

"Don't tell me it's because we need the oil because we all drive around, I got that. I've lived in the fossil fuel era my whole life. But what I want is a graceful transition out of it. I don't want to choke on it," said Winona LaDuke from the White Earth reservation and the group Honor the Earth.

The oil comes from Alberta's tar sands region. It requires more energy to extract and process. A federal report found it emits about 17 percent more greenhouse gasses than conventional oil.

"So it really is, it's like putting gas into your car, and then having a little bit extra pollution on top of that, to be using this tar sands oil," said Andy Pearson of the environmental group Minnesota 350.

Derek Pederson speaks at a news conference Tuesday before the public meeting. Dan Kraker | MPR News

Pearson and others want the state to deny Enbridge permits to replace Line 3.

But Todd Rothe of Duluth, who owns a construction company that has worked on Enbridge projects for the past 20 years, says that wouldn't have any impact on the environment.

"Stopping a pipeline like this does nothing, because Canada is going to produce it. They're going to sell it to some other country if we don't take it," he said.

The oil Enbridge pipes from Canada provides about 80 percent of the petroleum that Minnesota refineries use, and about 75 percent of the oil for Midwestern refineries. They've been operating for more than half a century. But it's only in the past few years where they've sparked such intense scrutiny.

That's largely for two reasons. Concerns over climate change, which led the Obama administration to kill the Keystone XL project.

Secondly, several of these pipelines cross Indian reservations or ceded treaty territory. The threat of a spill in the Missouri River led to massive protests last year over the Dakota Access pipeline.

"Everybody wants to know what is happening now, after Standing Rock. This is the next big thing," LaDuke said.

State regulators are expected to make their final decision next spring. It won't be an easy call.

"I would say there's no clear winner out of any of these alternatives," said Bill Grant, assistant commissioner of energy at the Minnesota Department of Commerce. "They all have their warts."