The Federal Energy Regulatory Commission (FERC) has prepared a final environmental impact statement for the Commonwealth LNG project, proposed by Commonwealth LNG LLC (Commonwealth). The project includes constructing and operating a natural gas liquefaction and export terminal and an integrated Natural Gas Act Section 3 natural gas pipeline in Cameron Parish, Louisiana.

The purpose of the Commonwealth LNG Project is to liquefy domestic natural gas for export to foreign markets as liquefied natural gas (LNG). The project will include one LNG plant comprised of six liquefaction trains, each with a designed production capacity of approximately 65.1 Bscf (1.8 × 109 m3) per year (equivalent to 1.4 million MTPA); six LNG storage tanks (each with a capacity of 1.4 MMscf [40,000 m3]); one marine loading berth (capable of loading LNG carriers with a capacity ranging from 353,147 scf to 7.6 MMscf [10,000 to 216,000 m3]); and a 3.04-mile (4.9-km), 30-in. (762-mm) pipeline. Under optimal operating conditions the project will have a peak capacity of up to 441.4 Bscf (12.5 × 109 m3) per year.

Facilities at the LNG station will include gas metering, pretreatment, liquefaction, LNG storage, marine facilities, and electric power. New gas metering facilities will include an onsite metering station; a liquid separation, filtration, and feed gas analyzer; and isolation and emergency shut-off systems. The pretreatment facility will house six pretreatment modules (one per liquefaction train) and six mercury guard bed, acid gas removal, and dehydration units (one per pretreatment module). There will be six liquefaction trains; with each train including: a 60-MW gas turbine with mechanical drive, a heavy hydrocarbon removal system, a feed gas booster compressor, liquefaction and separator modules, a refrigerant compressor package and air coolers, and a refrigerant make-up system and storage. The LNG storage will include six 1.4-MMscf (net capacity) full-containment LNG storage tanks, an earthen berm/dike providing tertiary containment for the tank farm, two submersible cryogenic send-out pumps per tank, and a radiant heat deluge system. Marine facilities feature a single berthing dock with the capacity to service vessels from 353,147 scf to 7.6 MMscf, four 16-in. (406-mm) marine loading arms — three LNG liquid and one vapor return, a gangway and mooring system, and a separate spill containment system. Electric power includes a 180-MW simple-cycle electric power generator for the LNG Facility auxiliary loads, an emergency power generator, and a backup battery system for uninterrupted power supply. Commonwealth LNG plans to have its new facility up and running by 2026.