The commissioning follows an approval by the US Federal Energy Regulatory Commission (FERC) for the full in-service of the Mountaineer Xpress pipeline, which has a capacity of transporting 2.7 billion cubic feet of natural gas per day. The 36inch natural gas pipeline, which is supported by long-term contracts with customers, will serve the TCO Pool and Leach markets on the Columbia Gas Transmission System.

Built between Marshall County and Wayne County, the pipeline project also features three new compressor stations, and modifications to three existing compressor stations.

TransCanada also reported that its $600m Gulf XPress (GXP) project, which is a network of seven new compressor stations built in Kentucky, Tennessee and Mississippi, has been placed into partial service. Out of the seven compressor stations, four of them located in Kentucky, Tennessee and Mississippi, have been placed into service.

According to TransCanada, the facilities put together will deliver additional capacity of 530,000 million cubic feet of natural gas per day on the Columbia Gulf Transmission System, which is equivalent to nearly 60% of the project’s total capacity.

The Gulf Xpress, which is also supported by long-term contracts with customers, is slated to be brought into full service in the next few weeks.

TransCanada said that the Mountaineer XPress and Gulf XPress projects are an important link between Appalachian natural gas supplies and emerging markets in the US and beyond.

Both the midstream projects secured FERC environmental approvals in July 2017.

TransCanada president and CEO Russ Girling said: “Mountaineer XPress and Gulf XPress are extremely important to TransCanada as they provide much-needed takeaway capacity for our customers, while also growing our extensive footprint in the Appalachian Basin.

“Both projects will also deliver attractive long-term returns and stable cash flow for our shareholders.”

Earlier this month, a US federal judge in Montana turned down TransCanada’s request to carry out certain pre-construction field activities for its proposed $8bn Keystone XL pipeline project. The Keystone XL pipeline project is designed to transport more than 800,000 barrels per day of heavy crude from Canadian oil sands into the US.