State utility regulators Thursday stood by their decision approving a route for Enbridge's controversial new pipeline across northern Minnesota.

The decision by the Minnesota Public Utilities Commission (PUC) was expected, as the PUC rarely rescinds its earlier judgments. The PUC already had voted last month against reconsidering the certificate of need for the $2.6 billion project.

The denials were necessary for pipeline opponents to file planned appeals of the decisions on the pipeline, a replacement for Enbridge's deteriorating Line 3. Environmental groups and some American Indian bands are expected to appeal the certificate of need decision to the Minnesota Court of Appeals next week.

The PUC decided in late June to grant Calgary, Alberta-based Enbridge both the certificate of need and route permit, with some conditions on both approvals.

While the new pipeline's 330-mile route follows the current one from the border to Clearbrook, Minn., it then juts south to Park Rapids before it heads east to Superior, Wis.

As has been the case in many Line 3 matters, the PUC's downtown St. Paul hearing room was packed on Thursday, as was an overflow room nearby.

Pipeline supporters outnumbered opponents at this hearing, though several pipeline protesters chanted "Line 3 climate disaster" and other slogans immediately after the meeting ended. Seven St. Paul police officers stood before them. There were no incidents.

While the PUC is the prime regulatory authority over Line 3, Enbridge still needs several permits from the Minnesota Pollution Control Agency and the state Department of Natural Resources. It also must receive water crossing permits from the U.S. Army Corps of Engineers.

The new pipeline would replace the current Line 3, which is aging, corroding and operating at only 51 percent capacity due to safety reasons.

Pipeline opponents said the route for the new Line 3 opens a new region of Minnesota's lakes and rivers to environmental degradation due to possible oil leaks. They also believe the project would exacerbate climate change.

In June, the PUC approved Enbridge's route permit by a vote of 3-2. Thursday's vote to reaffirm the approval was unanimous, as were the votes on the certificate of need.

The two commissioners who previously voted "no," Katie Sieben and Dan Lipschultz, said that changes made since June have allayed their concerns. In September, the Fond du Lac Band of Lake Superior Chippewa agreed to let Enbridge build a stretch of the new pipeline on its reservation, allowing the new pipeline's route to avoid Big Sandy Lake.

All six of Enbridge's current cross-state pipelines traverse the reservations of the Fond du Lac band and the Leech Lake Band of Ojibwe. In Enbridge's original route plan, the Line 3 replacement would have crossed neither reservation. However, as approved by the PUC, the new pipeline would closely skirt the Fond du Lac band's reservation.

The band had opposed any new pipeline. But after the PUC's June approval, the band decided it would get more benefit from a new Line 3 on the reservation than adjacent to it. Fond du Lac also renegotiated leases for the six existing Enbridge pipelines. Financial details weren't disclosed.

The Leech Lake band adamantly objected to any new pipeline on its land, and wants the current Line 3 to be removed from its reservation once it's decommissioned. Enbridge and the Leech Lake band reached an agreement on the scope and process of the removal, according to a document filed Thursday with the PUC.