As it launches a review—promised by the Trump administration—of Obama-era mandates, the U.S. Environmental Protection Agency on June 5 stayed for three months the 2016 requirements under the U.S. Clean Air Act New Source Performance Standards.

They regulate emissions of greenhouse gases and volatile organic compounds in oil-and-gas fracking facilities and other operations on which construction or modification began after Sept. 18, 2015.

The rules require a professional engineer to certify the design and capacity of closed-vent systems.

Industry executives claimed the mandates have no quantifiable environmental benefit. But six environmental groups on June 6 filed a U.S. appeals-court lawsuit to block the stay, claiming there was no public notice.