Environmental groups say the state didn’t properly consider climate impacts of Laurel plant

The state’s approach to disclosing climate impacts in its regulatory decisions has entered Montana’s judicial arena once more.

On Sept. 29, Montana Environmental Information Center filed a lawsuit against the Montana Department of Environmental Quality, alleging that the state failed to properly consider and disclose the climate impacts and greenhouse gas emissions associated with Yellowstone County Generating Station, a gas plant NorthWestern Energy opened in Laurel in 2024 that was forecast to emit more than 23 million tons of atmosphere-warming greenhouse gases over a 30-year operational life. 

In its complaint, MEIC resurfaced a pair of rulings the Montana Supreme Court issued in the past year. The first is the Held v. Montana decision, where justices sided with 16 young Montanans who argued that Montana’s permissive approach to regulating fossil fuel plants jeopardized their constitutionally protected right to a “clean and healthful environment.” 

Two weeks after the state’s highest court released that order, justices examined a similar set of issues raised by environmentalists in the context of the permit for the 175-megawatt YCGS.

In the latter decision, the Supreme Court directed DEQ to “conduct an adequate analysis” of environmental impacts associated with the plant, including “evaluating [greenhouse gases] in its analysis of YCGS’ air quality permit.” But the court didn’t give the state much detail about how it should fulfill that task, and MEIC alleges that the analysis it generated doesn’t pass muster.

“DEQ failed to take a ‘hard look’ at the climate-related impacts of YCGS’s greenhouse gas emissions — including direct, secondary and cumulative impacts — and no-action alternatives or potential mitigation measures to avoid those impacts, as [the Montana Environmental Policy Act] requires,” according to the lawsuit.

MEIC and Northern Plains Resource Council have asked the district court to toss out the analysis DEQ did and order it to create a new one “that complies with MEPA, the Montana Constitution, and the Montana Supreme Court’s directive” in the January decision regarding the gas plant.