A federal appeals court ruled late Monday that the U.S. Environmental Protection Agency (EPA) must enforce proposed rules governing new sources of methane emissions from the oil and gas industry that were enacted during the Obama administration.

In a 9-2 ruling, the U.S. Court of Appeals for the District of Columbia ruled en banc that EPA Administrator Scott Pruitt exceeded his authority last May when he proposed a 90-day stay over the fugitive emissions, pneumatic pumps and professional engineer certification requirements outlined in updates to the New Source Performance Standards (NSPS).

By striking down the stay, the updated NSPS rules are now in effect. The ruling reaffirms the decision by a three-judge panel on July 3 to remove the stay.

“Today’s issuance of the mandate by the full D.C. Circuit protects families and communities across America under clean air safeguards that EPA Administrator Scott Pruitt sought to unlawfully tear down,” said lead attorney Peter Zalzal of the Environmental Defense Fund, one of six conservation groups that filed the lawsuit over Pruitt’s move in June.

However, despite the ruling, it is unclear how long the updated NSPS rules would remain in effect. The EPA is accepting public comments until next week (Aug. 9) over a proposed two-year stay of the rules. Environmental groups opposed to the two-year stay packed a public hearing on the proposal last month, while the American Petroleum Institute (API) testified in favor of the stay.

Although the EPA had not asked the court to rehear the case en banc, a long list of industry groups — led by API and including several representing the oil and gas industry — filed a petition for rehearing last Thursday.

“The panel should have deferred to EPA’s reasonable interpretation of an ambiguous provision,” the industry groups’ petition said. “Doing so would have avoided the perceived need to reach un-reviewable non-final agency action.

“Rehearing en banc is needed because the panel’s review of non-final agency action conflicts with Supreme Court and D.C. Circuit case law. The mandate should be withheld until the final disposition of this timely petition.”

The intervenors include API, the GPA Midstream Association (GPA), the Interstate Natural Gas Association of America (INGAA), the Independent Petroleum Association of America (IPAA) and Western Energy Alliance (WEA), as well as numerous state organizations representing producers. The states of North Dakota and Texas are amici curiae in the case, which is Clean Air Council et al. v. EPA [No. 17-1145].

The EPA took the unusual step last month of asking the court to recall its mandate, thereby giving the agency more time to weigh its options. Court records show API, GPA, INGAA, IPAA and WEA filed a motion in support of the EPA’s request.

EPA first unveiled the 2016 NSPS during the Obama administration. The rules were designed to reduce methane, volatile organic compounds and toxic air pollutants.

Last April, the EPA said it would reconsider the rules to comply with an executive order (EO) signed by President Trump on March 28. The EO included a directive for EPA to immediately review regulations on energy sources, and then to either suspend, revise or rescind them.