On June 6, 2014, the D.C. Circuit Court of Appeals issued an opinion holding that the Federal Energy Regulatory Commission acted improperly in separately analyzing the environmental impacts of several nominally separate interstate natural gas pipeline projects, rather than treating them as one interrelated project in its review under the National Environmental Policy Act (“NEPA”). Delaware Riverkeeper Network, et al. v. FERC, D.C. Cir. No. 13-1015 (June 6, 2014). The Court remanded the case to FERC with directions to conduct a further environmental review of four interdependent pipeline upgrade projects and their cumulative environmental impacts.

The D.C. Circuit’s opinion has significant implications for FERC’s environmental review of interstate natural gas pipeline project proposals under NEPA. The opinion suggests that proponents of multiple expansions of a pipeline, or FERC on its own initiative, may need to combine what might otherwise be considered separate projects for environmental review purposes. This could result in a more extensive review, and the need to evaluate the environmental impacts associated with multiple projects in turn can be expected to extend the time required for completion of FERC’s NEPA review process.