An environmental assessment (EA) was released by FERC staff Monday for proposed Columbia Gas Transmission LLC (TCO) Buckeye XPress Project in Ohio and West Virginia, which would add another 275 MMcf/d of natural gas capacity to the interstate pipeline system.

Staff concluded that approval of the project, with mitigating measures, "would not constitute a major federal action significantly affecting the quality of the human environment."

TransCanada Corp. affiliate TCO began gauging interest in Buckeye two years ago, though it envisioned a larger project at that time. TCO had requested Federal Energy Regulatory Commission approval in April to construct and operate the project.

Buckeye would include replacing 60.8 miles of aging 20- and 24-inch diameter pipeline with 66.2 miles of 36-inch pipeline in southern Ohio's Vinton, Jackson, Gallia and Lawrence counties, as well as in western West Virginia's Wayne County. The project, primarily designed to increase safety and reliability, would replace portions of TCO's R-system, which was constructed in the 1940s.

The R-system, which supports more than 1 Bcf/d of primary firm transportation, is critical to TCO's storage operations, according to the application. It provides the main path for gas to move into Ohio for summer storage injections and allows a way for gas to move southward from the Ohio storage fields in the winter.

Buckeye is expected to cost $709 million. In addition to replacing the old pipe, the project would add four mainline valves, four tie-in assemblies, installation of a regulation run at the existing Ceredo compressor station, and two sets of bidirectional launchers and receivers. The additions would help increase transportation capacity to its Leach, KY, interconnection with the Columbia Gulf Transmission system and the TCO pool market in the West Virginia region.

TCO previously set a target in-service date for Nov. 1, 2020.

FERC is accepting comments on the Buckeye XPress EA through June 19.