On June 30, 2020, the DC Circuit issued an opinion that will significantly alter how the Federal Energy Regulatory Commission (“FERC”) addresses challenges to its orders. In Allegheny Defense Project, et al. v. FERC, the court held that the Natural Gas Act does not allow FERC to issue “tolling orders” solely for preventing FERC’s 30-day deadline for acting on requests for rehearings from expiring. FERC has regularly issued such tolling orders in Natural Gas Act and Federal Power Act cases for the past 50 years; the court’s opinion effectively ends that practice. Notably, while the court invalidated FERC’s tolling order practice as effectively “deleting the thirty-day time period from the statute,” it indicated that more substantive orders on rehearing seeking additional information from the applicant or supplementing the record may meet the statutory requirements for extending the 30-day statutory deadline.