Court rules against Signal Peak's US coal mine expansion

The 9th Circuit Court of Appeals ruled that the U.S. Department of the Interior's Office of Surface Mining violated the National Environmental Policy Act, or NEPA, when it approved Signal Peak Energy LLC's expansion of the underground Bull Mountains coal mine in Montana in 2018.

The 2-1 decision said the 2018 environmental assessment "hid the ball and frustrated NEPA's purpose."

In the ruling, Circuit Judge Morgan Christen said the Interior Department failed to provide a "convincing statement of reasons to explain why the project's impacts are insignificant."

Christen added that the "Interior did not account for the emissions generated by coal combustion, obscuring and grossly understating the magnitude of the mine expansion's emissions relative to other domestic sources of greenhouse gas emissions."

The proposed expansion project at Bull Mountains would emit an estimated 240.1 million tons of greenhouse gases over the 11.5 years of its operations, according to the court document.

Meanwhile, in a dissent, Circuit Judge Ryan Nelson said "the courts are ill-equipped to step into highly politicized scientific debates like this, particularly with so little direction from either the legislative or executive branch." Nelson is an appointee of former U.S. President Donald Trump.

The ruling is a victory for environmental plaintiffs 350 Montana, Montana Environmental Information Center, Sierra Club and WildEarth Guardians, Sierra Club said in a statement.