139 F.4th 903
D.C. Cir.2025Background
- Mountain Valley Pipeline, LLC (MVP) sought an extension of a construction deadline for its Southgate Project, an extension of the Mainline natural gas pipeline.
- The Southgate Project's original completion deadline (June 18, 2023) could not be met due to delays in Mainline permitting and litigation, which were prerequisites for Southgate construction.
- FERC (the Federal Energy Regulatory Commission) granted MVP a three-year extension for the Southgate Project, finding good cause due to circumstances beyond MVP’s control.
- Environmental groups challenged FERC’s decision, arguing the extension was not justified and that market need and environmental impact assessments were now outdated and should be revisited.
- The D.C. Circuit reviewed these petitions seeking to overturn FERC’s order, focusing only on the extension decision (not the merits of any proposed amendment to the project).
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether FERC properly found “good cause” for deadline extension | MVP did not actively pursue permits for Southgate and is abandoning the original project | Mainline permitting delays were beyond MVP's control, and extension is justified | FERC reasonably found good cause in light of Mainline delays |
| Whether FERC should revisit market need and environmental findings | Changed circumstances (e.g., market demand, new incentives) render past findings obsolete | No significant new evidence; previous findings remain valid absent major changes | FERC had discretion not to revisit prior findings; no major changes shown |
| Sufficiency of mitigation measures for erosion and sedimentation | Mainline had past failures; Southgate likely to suffer similar environmental harms | Southgate has improved measures and different circumstances; agency fully considered these issues | FERC’s review and mitigation measures met legal requirements |
| Whether extension required supplemental NEPA analysis | Extension plus project updates trigger NEPA analysis anew | No significant changes yet; future amendments will be reviewed under NEPA | FERC’s refusal to do supplemental NEPA review at extension stage was reasonable |
Key Cases Cited
- Sierra Club v. FERC, 97 F.4th 16 (D.C. Cir. 2024) (Commission may revisit need/environmental findings only if circumstances become significantly outdated)
- Baltimore Gas & Elec. Co. v. Nat. Res. Def. Council, 462 U.S. 87 (1983) (Agency judgments on technical matters receive considerable deference)
- Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29 (1983) (Agency must articulate rational connection between facts and decisions)
- Robertson v. Methow Valley Citizens Council, 490 U.S. 332 (1989) (NEPA is procedural; agencies must consider environmental impacts but not reach particular outcomes)
- Loper Bright Enters. v. Raimondo, 603 U.S. 369 (2024) (Review of agency authority and discretionary standards)
- PennEast Pipeline Co. v. New Jersey, 594 U.S. 482 (2021) (Background on NGA regulation of natural gas infrastructure)
- Citizens Against Burlington, Inc. v. Busey, 938 F.2d 190 (D.C. Cir. 1991) (Scope and limits of NEPA alternatives analysis)