The Minnesota Public Utilities Commission again on Tuesday stood by its decisions to permit Enbridge's contentious Line 3 oil pipeline in northern Minnesota.

In late June, the Public Utilities Commission unanimously voted in favor of granting the project a certificate of need, but requested Enbridge make additional compliance filings, or modifications, to its plan while also requiring the company to pledge $100 million for economic opportunities to tribal members and businesses.

Opponents of the project, including environmental groups and the Minnesota Department of Commerce, have filed petitions for reconsideration in the past, which were swiftly denied on both occasions.

And at a meeting in St. Paul Tuesday morning, the PUC again unanimously voted to deny the petitions to reconsider its approvals.

Acknowledging commissioners don't typically comment on reconsiderations, Commissioner Katie Sieben expressed frustration with the Department of Commerce, which has opposed the project and has filed appeals arguing the state doesn't need the pipeline under Govs. Mark Dayton and Tim Walz, both Democrats.

Sieben noted that the department advocated for some of the certificate of need modifications adopted by the PUC but is still questioning the need for a new pipeline.

"For the department to argue that the Commission should ignore the current condition of the very infrastructure that is to be replaced is nonsensical," Sieben said. "Further, the alternative was to have oil cross Minnesota in a corroded pipe, and in rail cars and on highways."

Although the Enbridge's proposed 340-mile long pipeline still needs numerous permits and faces court challenges, the company plans to have the pipeline completed in 2020.

The pipeline would replace Enbridge's existing 50-year-old Line 3 and carry 760,000 barrels of oil per day from Alberta to the Enbridge terminal in Superior.

Ahead of Tuesday's vote on Enbridge's $100 million economic package for tribal members and businesses, Commissioner John Tuma said the program would be carefully watched, adding that if Enbridge doesn't follow it, the company risks losing the certificate of need.

"That's what's at stake here," Tuma said

Enbridge attorney Christina Brusven said the company understood and would honor its commitment.

"We're invested in this program and making it work and enhancing those relationships with the communities and their members," Brusven said.