Dominion Energy Inc. has bumped up the estimated cost of its 604-mile natural gas pipeline from $6 to about $7 billion, adding that it also expects the project to be delayed until early 2021 following permitting issues.

Thomas Farrell, Chief Executive Office, said in a Feb. 1 press release that the company is “actively pursuing multiple paths to resolve all outstanding permit issues including judicial, legislative, and administrative avenues.” Dominion had originally hoped that the project would be operational by late 2019 and cost an estimated $5 billion, excluding financing. Numerous environmental challenges and lawsuits have caused delays and left the project in limbo. All construction has been halted since December due to a crossing permit in the Appalachian Trail. Now the company expects construction to resume later this year with a partial in-service in late 2020.

In the same announcement, the company also revised its cost and completion estimates for the 38-mile Supply Header project in West Virginia and Pennsylvania. The project will now enter service in late 2020 instead of 2019 and cost up to $700 million, $200 million more than the previous estimate.

EQT Midstream Partners LP’s $3-billion Mountain Valley project, which will serve Mid- and South-Atlantic regions, is also stalled and facing increasingly higher costs.

The Atlantic Coast pipeline, designed to extend from West Virginia to ship 1.5 billion cubic feet per day of natural gas into Virginia and North Carolina, is a joint proposal by Dominion Energy, Duke Energy, Piedmont Natural Gas, and Southern Company Gas.