By Devika Krishna Kumar

NEW YORK (Reuters) – Native American Tribes including the Standing Rock Sioux Tribe on Wednesday told the U.S. Army Corps of Engineers that the environmental study on Dakota Access oil pipeline is biased and urged the Biden administration to bring in the U.S. Interior Department.

U.S. District Court for the District of Columbia issued an order for the study and revoked the key environmental permit for the North Dakota largest oil-basin pipeline last year.

On Wednesday, the Tribes stated that they think the current process was designed to allow for a new permit to be issued in the same area. They also claimed that the Corps’ draft study doesn’t take into consideration technical and cultural data that Tribes had provided to it.

In a letter to Jaime Pinkham (acting assistant secretary for Army Civil Works), the Tribes stated that their participation in EIS (Environmental Impact Statements) and review of the first draft revealed that the Corps fundamentally misunderstood courts’ directives and requirements.

The Administration should bring in the U.S. Department of the Interior to be a co-equal cooperating agent with the appropriate expertise in order for the Corps to center Tribal concerns and impacts.

The Dakota Access operators asked the U.S. Supreme Court earlier this week to reconsider whether the pipeline, which transports 570,000 barrels per day, requires further environmental review.

After months of resistance by environmentalists and Native American tribes as well their supporters, the pipeline was finally put into service in 2017. The pipeline was opposed by those who claimed it would destroy sacred artifacts, pose a risk to Lake Oahe and the larger Missouri River, as well as pose a danger to Lake Oahe and other critical drinking sources.

Energy Transfer (NYSE:), which operates the line, has said it is safe.