The U.S. Supreme Court heard oral arguments this week in a case that could have far-reaching consequences in deciding the extent to which the National Environmental Policy Act (NEPA) applies to federal permitting when other laws also may apply, sources say.

The case — Department of the Air Force v. Prutehi Guåhan — could also “influence when and how the public can challenge federal agencies’ environmental decisions in court,” said Earthjustice, which is representing Guam-based environmental advocacy group Prutehi Guåhan in the case.

At issue is the U.S. Air Force’s May 2021 renewal application for a Resource Conservation and Recovery Act permit to continue its decades-long practice of detonating munitions at Tarague Beach in Guam. The Guam Environmental Protection Agency is still reviewing the permit application.…