A coalition of environmental groups led by the Sierra Club urged a federal appellate court to reject calls by FERC and project sponsors to stay a mandate over a trio of Southeast natural gas pipelines, in effect shutting the projects down immediately.

Two weeks ago, the Federal Energy Regulatory Commission filed a motion asking the U.S. Court of Appeals for the District of Columbia Circuit to stay issuing a mandate for the proposed Southeast Market Pipelines (SMP) Project for 45 days. SMP includes the Sabal Trail, Hillabee Expansion and Florida Southeast Connection pipeline projects. Attorneys for the project's backers filed a similar motion the same day, asking for a 90-day stay.

Last Friday, which was the final day for comments regarding the requests, attorneys for the Sierra Club, the Chattahoochee Riverkeeper and the Flint Riverkeeper argued, in part, that the court should issue the mandate because FERC and the project sponsors failed to show good cause for a stay.

The environmental groups said a stay would undermine the court's ruling last August that the Commission had failed to adequately consider the impact of greenhouse gas emissions when it issued a favorable environmental impact statement for SMP in December 2015. They also claimed a final supplemental EIS (SEIS) issued by FERC on Feb. 5 was insufficient and did not justify a stay.

"Their goal is to push the mandate off until after FERC can issue a new certificate, rendering the vacatur moot and achieving the same result they sought with their petitions for rehearing," the environmental groups said. "But for the same reasons the court denied their petitions for rehearing, it should not permit them to skirt the vacatur through motions to stay issuance of the mandate."

Since the certificates originally issued by FERC were based on an "inadequate" analysis under the National Environmental Policy Act, the certificates are "defective and unlawful,” the groups argued.

The court was prevented from taking any action until last Friday, but it could rule on a stay at any time. FERC and Sabal Trails joint venture partners -- Enbridge Inc.'s Spectra Energy Partners LP, NextEra Energy Inc. and Duke Energy -- have until Friday (Feb. 23) to respond to the Sierra Club arguments in Sierra Club et al v. FERC, No. 16-1329.

FERC could choose to issue an order on remand reissuing certificates for the SMP Project; grant temporary certificates of public convenience and necessity for the project until it addresses the appellate court's directives on remand; or inform the appellate court that it intends to appeal its decision to the U.S. Supreme Court.

SMP would provide about 1.1 Bcf/d to markets in Florida and the Southeast. The project calls for building 685.5 miles of pipeline and six compressor stations, as well as modifying existing compressor stations in Alabama, Florida and Georgia.