Dominion Energy Inc. asked U.S. energy regulators for two more years to complete the long-delayed $8 billion Atlantic Coast natural gas pipeline from West Virginia to North Carolina, which the company now expects to enter service in early 2022.

“Due to unforeseen delays in permitting, additional time is required in order to complete the construction,” Dominion said in a filing late on June 16.

The U.S. Federal Energy Regulatory Commission (FERC) approved Dominion’s request to build Atlantic Coast in October 2017, authorizing the company to complete the project by October 2020.

Atlantic Coast, the nation’s most expensive gas pipe, is one of several projects delayed in recent years by state opposition and local and environmental legal and regulatory battles.

The company still needs to renew permits from the U.S. Forest Service and U.S. Fish and Wildlife Service (FWS) that were knocked out by decisions in the U.S. Court of Appeals for the Fourth Circuit, and a state air permit for a compressor in Virginia.

Dominion said it expects to receive the necessary approvals by the end of the year.

The company already received one ruling in its favor this week when the U.S. Supreme Court reversed a Fourth Circuit decision and ruled that the Forest Service has legal authority to permit the pipe to cross under the Appalachian Trail.

Dominion suspended construction of the 600-mile project in December 2018 after the Fourth Circuit stayed a biological opinion from the FWS that allowed construction in areas inhabited by endangered species.

Atlantic Coast is owned by units of Dominion and Duke Energy Corp.

When Dominion started work on the 1.5 Bcf/d pipe in the spring of 2018, the company estimated it would cost $6.0–$6.5 billion and be completed in late 2019.