Citing a failure to address the potential effects of an oil spill in the Lake Superior watershed, the Minnesota Court of Appeals on Monday reversed a state decision on the adequacy of the final environmental impact statement on a new Line 3 oil pipeline. The court ruled that the Public Utilities Commission erred in accepting the final environmental study for the Enbridge Energy line that cuts across the northeast corner of Carlton County on its way to terminals in Superior.

The statement will now need to go back to the PUC. Enbridge could also appeal the June 3 decision to the Minnesota Sup...