A federal judge ordered an environmental review of the controversial Dakota Access Pipeline on Wednesday. Photo: inhabitat.com

WASHINGTON: A federal judge ordered an environmental review of the controversial Dakota Access Pipeline on Wednesday in a dramatic twist that opens the possibility that the project could be halted.

US District Judge James Boasberg in Washington said the US Army Corps of Engineers did not fully consider the effects of a possible oil spill on the fishing and hunting rights of the Standing Rock Sioux tribe.

The decision is a partial victory for the tribe, which led high-profile protests against the $3.8-billion, 1,172-mile (1,886-kilometer) oil pipeline.

Although the Corps of Engineers "substantially complied" with federal environmental laws, "it did not adequately consider the impacts of an oil spill on fishing rights, hunting rights, or environmental justice, or the degree to which the pipeline´s effects are likely to be highly controversial," Boasberg wrote in a 91-page decision.

"To remedy those violations, the Corps will have to reconsider those sections of its environmental analysis upon remand by the court," he said.

The pipeline began pumping crude oil delivery from North Dakota to Illinois in May.

Although Boasberg did not suspend deliveries, overseen by pipeline operator Energy Transfer Partners, his order indicated that that could be considered at a later date.

The pipeline route under the Missouri River and man-made Lake Oahe in North Dakota was the subject of months of protests, as Native Americans and their supporters argued it ran the risk of potentially polluting the water.

Under former president Barack Obama, the Corps had called for further review and halted construction. But President Donald Trump issued an executive order directing officials to reconsider soon after taking office in January.

The Army Corps of Engineers cleared the way in February for the project to be finished, after which the tribe sued the Corps over its approval.

Standing Rock Sioux Chairman Dave Archambault hailed the latest decision.

"We applaud the courts for protecting our laws and regulations from undue political influence, and will ask the Court to shut down pipeline operations immediately," he said in a statement.

"The previous administration painstakingly considered the impacts of this pipeline and President Trump hastily dismissed these careful environmental considerations in favor of political and personal interests."

Judge Boasberg ordered both sides to appear before him next Wednesday to decide next legal steps.