Dakota Access pipeline: Supreme Court turns away challenge over tougher environmental review

WASHINGTON – The Supreme Court on Tuesday declined to hear a dispute between the company that operates the Dakota Access oil pipeline and several Native American tribes who say the project requires a more thorough environmental review.

By turning away the case, the justices without comment let stand a lower court ruling that required the more stringent review. The company that operates the pipeline has said the lower court's decision threatens to shut down its operations.    

At issue is a roughly 2-mile segment of the massive pipeline that carries some 200 million barrels of crude oil from North Dakota to Illinois every year. The short segment runs under Lake Oahe, a reservoir created in the 1950s on Sioux nation reservations. 

The U.S. Court of Appeals for the D.C. Circuit last year sided with the Standing Rock Sioux and other tribes who said the pipeline section should have been subjected to a more thorough environmental review by the U.S. Army Corps of Engineers. Several Native American tribes rely on the water for drinking, agriculture and religious practices. 

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In 2015, the Army Corps published a preliminary assessment that found construction of the pipeline would have no significant environmental impact. That determination meant that the pipeline's potential impact would not receive a far more rigorous examination by the government. The tribes argue the Army Corps ignored the danger of possible spills. 

"Tribes with management responsibilities over the affected waters identified major gaps in the analysis, especially about the risks of an oil spill and the devastating effects a spill would have on the Tribes," the tribes told the Supreme Court in December. 

Texas-based Energy Transfer, which operates the $3.8 billion, 1,172-mile pipeline, told the Supreme Court last year that the appeals court decision creates uncertainty and puts the pipeline "at a significant risk of being shut down, which would precipitate serious economic and environmental consequences."

Contributing: Associated Press