Legal battle erupts over weakened US gas plant pollution rules under Trump

No new gas-powered plants have been built or started in the US since stricter Clean Air Act rules took effect in January 2020. Data up to March 2026 confirms this halt in construction. Meanwhile, environmental groups are now taking legal action against the latest updates to these regulations.

The dispute centres on the New Source Performance Standards, which limit smog-forming nitrogen oxides (NOx) from new gas plant turbines. Under the Biden administration, the EPA first proposed stricter draft rules. These were expected to cut annual NOx emissions by nearly 2,700 tons by 2032.

A half-dozen environmental organisations have filed a lawsuit to overturn the revised standards. Their challenge targets the final version released by the Trump administration, which significantly weakened the earlier draft. The updated rules now aim for reductions of only about 300 tons by 2032. The Trump-era policy also changed how the EPA assesses health benefits. The agency stopped converting predicted improvements—such as lower ozone or soot levels—into dollar values. This shift removes a key metric previously used to justify stricter regulations.

The lawsuit will determine whether the relaxed standards remain in place. If overturned, the EPA may reinstate tougher limits on NOx emissions from new gas plants. For now, no new facilities have been commissioned since the rules were first updated in 2020.