The Federal Energy Regulatory Commission on May 6 released an environmental assessment (EA) for the North Main Lines Relocation Project proposed by Southern Natural Gas Co. LLC (SNG) as a way to work around longwall mine subsidence coming up due to the 2016 mining plans by Cliffs Natural Resources at its Oak Grove coal mine in Jefferson County, Alabama.
The FERC staff concludes that approval of the proposed project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment. Comment on the EA is being taken until June 5.
The proposed project includes the abandonment of about 9.0 miles of 20-, 22-, and 24- inch-diameter natural gas pipelines to be replaced with 10.9 miles of 20- and 24-inch-diameter natural gas pipelines. The project, located northwest of Rock Creek, Alabama, would relocate three parallel pipelines within the same corridor (North Main Line, North Main Loop Line, and 2nd North Main Line) and the Calera Branch Line in a separate corridor. The purpose of the project is to relocate the pipelines to avoid ground subsidence related to planned longwall coal mining operations.
Mining operations are planned to begin as early as April 2016 and would take place underneath the current location of the existing pipelines. SNG would relocate the three existing North Main Lines north of the mining operations and the Calera Branch Line east of the mining operations. Longwall subsidence occurs when the roof above a mined-out area collapses into the newly-created mine void, causing fractures up through the overlying rock.
SNG anticipates that construction of the relocation project would begin in August 2015 and it is expected to take approximately eight months to complete. The forecasted in-service date for the project is April 2016.