A proposed liquefied-natural-gas export project in Maryland has advanced with the Federal Energy Regulatory Commission's approval of Dominion Energy's estimated $3.4-billion to $3.8-billion plan to build the complex.

But Dominion's Cove Point project, located in Lusby, Md., on the western shore of Chesapeake Bay, may face a court challenge from environmental groups that strongly oppose the plan.

FERC's action, announced on Sept. 29, is its fourth LNG-export-facility approval. The other three are in the Gulf of Mexico; one was approved in 2012, and the other two were approved earlier this year. FERC says 14 other such proposals are pending.

A team of IHI E&C International Corp., Houston, a unit of Tokyo-based IHI Corp., and Kiewit Corp., Omaha, has the engineering-procurement-construction contract for the liquefaction facilities, which will be built at the site of Dominion's LNG terminal, which is 40 years old.

Dominion accepted FERC's ruling on Sept. 30, agreeing to its 79 environmental conditions. The company will file an implementation plan and seek a notice to proceed in coming weeks. Dominion would like to begin construction soon; the facility could go into service by March 2017.

Construction unions hailed FERC approval, saying the project will create more than 3,000 skilled-craft jobs during peak construction. The building trades and Dominion Energy have signed a project labor agreement for Cove Point.

But environmentalists blasted FERC's decision. Earthjustice is studying the ruling and planning its next step, said Jocelyn D'Ambrosio, associate attorney. She added in a statement, "If FERC has refused to revisit its inadequate environmental review, we will have no choice but to petition FERC to reconsider its decision and, ultimately, we may have to take the case to court."