The Minnesota Public Utilities Commission meets Tuesday to consider a proposal for a new oil pipeline across northern Minnesota.
Enbridge Energy is seeking permits to build the pipeline from Alberta, Canada, to Superior, Wis.
The Minnesota Center for Environmental Advocacy opposes the project.
The group says the process of extracting the oil from Canadian tar sands is too energy-intensive and runs counter to Minnesota's energy efficiency goals.
Enbridge has said the project has already cleared an extensive environmental permitting process and the pipeline is the only matter before the Minnesota commission.
The PUC must sign off for the project to go forward.
The hearing starts at 9:30 a.m. on Tuesday at the PUC's St. Paul headquarters.