The state of North Dakota could see 400,000 barrels a day (bbl/d) of crude oil production temporarily wiped out if the Dakota Access Pipeline (DAPL) is shut, a state official said on April 15.

Energy Transfer LP is in the middle of a years-long legal fight to keep open its 557,000-bbl/d pipeline, the largest out of the Bakken shale region of North Dakota and Montana, as U.S. officials conduct an environmental review of the line.

If the U.S. district court judge considering the case orders DAPL to cease flows, multiple wells in the second-biggest crude oil state would be shut, North Dakota Department of Mineral Resources Director Lynn Helms said at a monthly briefing.

“That would at least (lead) to some temporary shut-ins while people arranged alternate transportation,” Helms said.

North Dakota, which has seen its oil production plunge more than 30% to about 1.08 million bbl/d since its peak in November 2019, depends on DAPL to carry oil to the Midwest and then on to the U.S. Gulf Coast.

Roughly 40% of the state’s production is moved on the line, Helms has previously stated, and said it would take time for shippers on DAPL to find alternative routes for getting their oil to market.