FERC Clears Draft EIS for Nearly 500 Miles of New Southeast Gas Pipelines
FERC staff has issued a draft environmental impact statement for the Mississippi Crossing and South System Expansion 4 pipeline projects, which together would add more than 3.4 billion cubic feet per day of firm natural gas capacity to the Southeast.
(P&GJ) — The staff of the Federal Energy Regulatory Commission has issued a draft environmental impact statement (EIS) for the Mississippi Crossing Project and the South System Expansion 4 Project, two proposed natural gas pipeline expansions designed to increase firm transportation capacity into the U.S. Southeast.
The draft EIS, prepared in accordance with the National Environmental Policy Act (NEPA), evaluates the potential environmental effects associated with construction and operation of both projects under Docket Nos. CP25-514-000 and CP25-517-000.
Mississippi Crossing Project
Tennessee Gas Pipeline Company proposes to construct approximately 199 miles of 36- and 42-inch-diameter pipeline extending from an interconnection with its existing 100 Line in Washington County, Mississippi, to Choctaw County, Alabama. The project also includes about seven miles of 36-inch-diameter lateral pipeline in Humphreys and Sunflower counties, Mississippi, along with several shorter laterals in Mississippi and Alabama.
The project scope includes three new gas-fired compressor stations in Humphreys, Attala, and Lauderdale counties, Mississippi, modifications to an existing compressor station in Washington County, Mississippi, four new meter stations, and three new overpressure protection facilities. The Mississippi Crossing Project is designed to provide up to 2.1 billion cubic feet per day of incremental firm transportation capacity to meet growing demand across the Southeast.
South System Expansion 4 Project
Southern Natural Gas Company and Elba Express Company propose to construct 22 pipeline loops organized into 14 segments totaling approximately 291 miles along existing pipeline corridors in Mississippi, Alabama, and Georgia. The project also includes compression additions or horsepower upgrades at 12 existing compressor stations and the replacement of nine older compressor units with more efficient equipment.
Additional work includes abandoning about 2.2 miles of the 16-inch-diameter K Gen Lateral in Clarke County, Mississippi, construction of two new meter stations, and modifications to nine existing meter stations across Alabama and Georgia. The South System Expansion 4 Project is designed to add 1.323 billion cubic feet per day of incremental firm transportation capacity to serve residential, commercial, industrial, and power generation demand in the Southeast.
Environmental Review Findings
FERC staff concluded that construction and operation of the projects would result in some adverse environmental impacts, but that those impacts would be reduced to less-than-significant levels with implementation of proposed mitigation measures.
According to the draft EIS, the project sponsors would minimize impacts through the use of approved construction and environmental plans, including erosion and sediment controls, spill prevention measures, wetland and waterbody mitigation plans, invasive species management, and site-specific residential construction plans. New pipeline segments would be collocated with existing utility and transportation corridors to limit new land disturbance.
FERC staff also noted that consultation under the Endangered Species Act and the National Historic Preservation Act would be completed prior to construction, and that the companies would be required to comply with all applicable U.S. Department of Transportation safety standards and federal and state air and noise regulations.
The draft EIS recommends adoption of additional project-specific mitigation measures to further reduce environmental effects. With those measures in place, staff concluded the projects would not result in significant long-term adverse environmental impacts.
The FERC commissioners will consider staff’s findings and recommendations when making a final decision on the projects. The public comment period on the draft EIS closes March 23, 2026.