In a 2-1 vote, a US federal appeals court in Washington, DC ruled this week that the Environmental Protection Agency (EPA) may not suspend a rule planned by the administration of former President Barack Obama to restrict methane emissions from new oil and gas wells.

The decision is the first major legal setback for Scott Pruitt, the new EPA administrator appointed by President Donald Trump, who since taking office has worked to roll back dozens of Obama-era environmental regulations.

Shortly before the regulations requiring oil and gas companies to detect and repair leaks of methane and other air pollution at new and modified drilling wells were due to take effect on Jun. 3, the EPA proposed a two-year implementation delay.

The agency’s new leadership said that during the time it needed to “review” issues associated with the rule’s requirements to limit methane leaks and their potential negative impact on oil and gas drilling activities, companies would not have to comply with the requirements.

EPA contended also that oil and gas companies had not had a chance to comment on the new rules. However, in their Jul. 3 decision, the judges noted that some companies had commented, in writing, at the EPA's original request.

"Even a brief scan of the record demonstrates the inaccuracy of EPA's statements," the judges wrote, while commenting that a lengthy delay is "tantamount to amending or revoking a rule." The court said also that the agency’s decision was “unreasonable,” “arbitrary” and “capricious,” as it did not have the legal authority to block the rule.

While the Washington decision does not mean the methane restrictions cannot be reversed, to do so the EPA would have to write a new rule while in the meantime enforcing compliance with the Obama-era legislation.

Many of the environmental groups that have filed suit against other moves by the Pruitt EPA to overturn legislation said they expect other courts to decide similarly. David Doniger, director of the climate and clean air program at the Natural Resources Defense Council, told the newspaper New York Times he believes the administration “will be on the losing end of those battles.”