BISMARCK, N.D. (AP) — An attorney for the Army Corps of Engineers is asking a judge to sign off on the Corps’ conclusion that the Dakota Access oil pipeline doesn’t harm American Indian tribes.

The Corps wants U.S. District Judge James Boasberg to rule in favor of its August 2018 finding that no more environmental study is needed on the $3.8 billion pipeline. The pipeline has been moving North Dakota oil through South Dakota and Iowa to Illinois for more than two years.

The Standing Rock Sioux want the pipeline shut down and more study done. The tribe fears an oil spill could contaminate the Missouri River.

A Justice Department attorney argues that the Corps “carefully and reasonably considered the environmental impacts” before it permitted the pipeline.

Pipeline developer Texas-based Energy Transfer says the line is safe.