The Canadian pipeline company Enbridge Inc. is asking the U.S. for permission to dramatically increase the oil it pumps through northern Minnesota to a refinery in Superior, Wisconsin.
The change would increase the capacity of Enbridge's lines from just under 500,000 barrels a day to 880,000 by 2015.
The Milwaukee Journal Sentinel reports the expansion would involve upgrades to pumping stations, but no new pipelines. The lines carry oil from Canadian tar sands and from western North Dakota's oil patch to Superior.
Enbridge is seeking the expansion in two phases. The company presented plans for the first phase to Minnesota regulators last fall.
Enbridge has a breakdown of its recent U.S. pipeline expansions on its website.