The long-delayed Northern Access expansion project, which would move more natural gas out of Appalachia, cleared a major legal obstacle Tuesday when a federal appeals court found New York state regulators waived their authority to issue a crucial water quality certification (WQC) for the pipeline.

The U.S. Court of Appeals for the Second Circuit upheld an order issued by FERC in 2018 that found the New York Department of Environmental Conservation (DEC) waived its authority to issue the Section 401 WQC by failing to act within the one-year timeframe required by the U.S. Clean Water Act (CWA). 

National Fuel Gas Co. (NFG), which is developing the project, embraced the court’s decision, saying “the ruling certainly clears the most significant hurdle facing the continued...