Environmental groups scored a legal victory Tuesday when a federal court reportedly ruled that the Tennessee Valley Authority violated the National Environmental Policy Act regarding its controversial new gas-fired power plant at the Kingston Fossil Plant site.

The Southern Environmental Law Center, Appalachian Voices, the Sierra Club, and the Center for Biological Diversity originally filed the lawsuit in 2024, challenging TVA’s plan to replace retiring coal units with natural gas generation. According to court documents, the ruling vacates TVA’s Environmental Impact Statement and Record of Decision.

While the formal court decision remains under seal, TVA has already announced plans to appeal and filed a motion to stay the judgment. The utility argues that halting construction will cause irreparable harm, including high risks of rolling blackouts due to unmet load demands and significant financial setbacks for the 2,000 to 2,100 craft laborers currently working on the site.

Construction on the facility began in 2025. Although TVA’s board voted earlier this year to keep its existing coal plants operating past previous deadlines, construction on the gas plant continued. Plaintiffs praised the decision as a necessary check on corporate transparency, while the utility prepares to fight the ruling in higher courts. The Kingston site previously made national headlines as the location of the 2008 coal ash spill, the largest industrial spill in U.S. history.