FERC issued a final supplemental environmental impact statement (SEIS) for the Sabal Trail natural gas pipeline on Monday, but the project could be forced to shut down Wednesday (Feb. 7) unless the Commission takes additional action.

Last week, the U.S. Court of Appeals for the District of Columbia Circuit denied petitions from the Federal Energy Regulatory Commission and the pipeline’s backers for a rehearing over issues with the Southeast project. A formal mandate that would void Sabal Trail’s certificates with FERC is scheduled on Wednesday.

At issue is a ruling from last August, when a three-judge panel sided with a Sierra Club assertion that an environmental impact statement FERC conducted over the proposed Southeast Market Pipelines (SMP) project failed to adequately consider the impact of greenhouse gas (GHG) emissions. The court remanded the case to FERC and, in a twist, vacated all of the permits that had been issued for the pipelines.

Although FERC issued a 137-page final SEIS for Sabal Trail on Monday, additional action by the Commission is necessary to avoid a shutdown. FERC could either 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.

“The Sabal Trail Project would need the Commission’s order on remand to reinstate the soon-to-be vacated certificate of public convenience and necessity,” FERC spokeswoman Celeste Miller told NGI’s Shale Daily on Tuesday. “I do not have a timeline for FERC’s order, however.”

In a note to clients last week, analysts with ClearView Energy Partners LLC expressed skepticism that FERC would appeal to the Supreme Court.

Last Friday, the pipeline’s backers filed an emergency request with FERC, imploring the Commission to recertify the SMP Project, temporarily or otherwise, by Tuesday (Feb. 6) “to avoid irreparable harm to the public, the shippers on these certificated facilities, and the applicants from a shutdown.”

On Monday, the Sierra Club told FERC that while denial or modification of Sabal Trail’s certificates is, at a minimum, warranted, the environmental group argued that the Commission should not issue any new certificates for the project until 30 days after notice of the final SEIS has been published in the Federal Register.

“FERC should decline the applicants’ invitation to undermine the court’s order by disregarding its clear directive that the pipeline not be allowed operate before its environmental impacts have been fully considered and new certificates are denied or reissued on that basis,” attorneys for the Sierra Club said.

Last September, in an effort to address the court’s ruling one month earlier, FERC issued a draft version of an SEIS for Sabal Trail. Although the Commission said the document provided court-mandated GHG estimates, as well as details over its methodology, groups opposed to the pipeline argued the SEIS was insufficient.

SMP includes Sabal Trail, the Hillabee Expansion and the Florida Southeast Connection projects. 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. FERC issued a favorable final EIS for the projects in December 2015.

Sabal Trail is owned jointly by affiliates of Spectra Energy Partners LP (50%), NextEra Energy Inc. (42.5%) and Duke Energy Corp. (7.5%).