Legal battle erupts over weakened Clean Air Act rules for gas plants

Environmental groups have launched a legal challenge against updated Clean Air Act rules for new gas-fired power plants. The lawsuit targets the Trump administration's weakened standards, which replaced stricter draft proposals from President Biden's EPA. At stake are significant cuts in smog-forming nitrogen oxides (NOx) that experts say could have been far greater under the original plan.

The dispute centres on the New Source Performance Standards for nitrogen oxide emissions from new plant turbines. Under Biden's EPA, draft rules projected a reduction of nearly 2,700 tons of NOx annually by 2032. The Trump administration's final version, however, slashed that target to just 300 tons—less than a tenth of the original estimate.

A key change in the Trump-era policy was the removal of dollar-value calculations for health benefits tied to cleaner air. The EPA no longer quantifies the financial gains from reducing ozone or fine particle pollution under new regulations. This shift has drawn criticism from campaigners, who argue it downplays the real-world impact on public health. The lawsuit, filed by six environmental organisations, claims the weakened rules fail to protect communities from harmful smog. Notably, no new natural gas power plants have been built in the US since January 2020. While the legal battle unfolds, the focus remains on whether stricter limits will be reinstated—or if the current standards will remain in place.

The outcome of the lawsuit could reshape emissions rules for future gas plants. If the courts side with the environmental groups, stricter NOx limits may return, aligning closer with Biden's original proposal. For now, the Trump administration's relaxed standards remain the legal benchmark, with no new gas plants commissioned since their introduction.