FERC Staff Issues the Draft Environmental Impact Statement for the Mississippi Crossing and South System Expansion 4 Projects (Docket Nos. CP25-514-000 and CP25-517-000)

The staff of the Federal Energy Regulatory Commission (Commission or FERC) has prepared a draft environmental impact statement (EIS) for the Mississippi Crossing Project and South System Expansion 4 Project (or Projects).

MSX Project

Tennessee Gas Pipeline Company (TGP), proposes to: (1) construct approximately 199 miles of 36- and 42-inch-diameter pipeline from an interconnection with TGP's 100 Line in Washington County, Mississippi to a point in Choctaw County, Alabama (MSX Pipeline); (2) construct approximately seven miles of 36-inch-diameter pipeline lateral from Humphreys County, Mississippi to a point in Sunflower County, Mississippi (CGT Lateral); (3) construct approximately two miles of 30- and 36-inch-diameter pipeline laterals located in Attala and Lauderdale Counties, Mississippi and Choctaw County, Alabama; (4) construct three new gas-fired compressor stations located along the MSX Pipeline in Humphreys, Attala, and Lauderdale Counties, Mississippi and modify one existing compressor station in Washington County, Mississippi; (5) construct four new meter stations; and (6) construct three new overpressure protection facilities at interconnections with the existing TGP system in Washington, Humphreys, and Lauderdale Counties, Mississippi. The MSX Project is designed to provide 2.1 billion cubic feet per day (Bcf/d) of incremental firm transportation capacity to the southeast region to meet the growing demand for supply from multiple, diverse, and liquid supply basins to markets in the southeast region.

SSE4 Project

Southern Natural Gas Company, LLC and Elba Express Company, LLC (SNG and EEC, respectively) proposes to: (1) construct 22 new gas pipeline loops, organized into 14 segments totaling approximately 291 miles, primarily along its existing South Main Line in Mississippi, Alabama, and Georgia; (2) install new compression and/or perform horsepower expansions at 12 existing compressor stations across Mississippi, Alabama, and Georgia; (3) abandon nine existing compressor units at 4 compressor stations, replacing them with more efficient units at the same sites; (4) abandon approximately 2.2 miles of the 16-inch-diameter K Gen Lateral in-place and by removal in Clarke County, Mississippi; and (5) construct one new meter station in Clarke County, Mississippi, and one new meter station in Monroe County, Georgia, and modify nine existing meter stations in Alabama and Georgia. The SSE4 Project is designed to provide 1.323 Bcf/d of incremental firm transportation capacity to the southeast region. According to SNG/EEC, the Project purpose is to meet the increasing market demand of residential, commercial, and industrial customers and new electric generation fueled by natural gas in the southeast

The EIS has been prepared in compliance with the requirements of the National Environmental Policy Act (NEPA)and FERC regulations implementing NEPA (18 CFR 380).

The conclusions and recommendations presented in the EIS are those of the FERC environmental staff. Input from the three districts of the U.S. Army Corps of Engineers, the U.S. Environmental Protection Agency, the U.S. Fish and Wildlife Service, the National Park Service, the Alabama Department of Conservation and Natural Resources, and the Mississippi Department of Wildlife, Fisheries, and Parks participated as cooperating agencies in the preparation of the draft EIS was considered during the development of our conclusions and recommendations; however, these agencies could develop their own conclusions and recommendations and would adopt the final EIS per 40 CFR 1506.3 (where applicable) if, after an independent review of the document, they conclude that their permitting requirements have been satisfied.

The FERC staff concludes that construction and operation of the Projects would result in some adverse environmental impacts, but these impacts would be reduced to less-than-significant levels. This determination is based on a review of the information provided by TGP, SNG, and EEC (Companies) and further developed from data requests; field investigations; scoping; literature research; alternatives analyses; and contacts with the federal, state, and local agencies, Native American tribes, and other stakeholders. Although many factors were considered in this determination, the principal reasons are:

• The Companies would minimize effects on natural, cultural, and human resources through implementation of approved plans and procedures, including the project-specific Plans and Procedures; Erosion and Sediment Control Plans; Spill Prevention, Control, and Countermeasure Plans; Wetland and Waterbody Mitigation Plans; Blasting Plans; HDD Contingency Plans; Fugitive Dust Control Plans; Invasive Species Management Plans; Site-Specific Residential Construction Plans; and Visual Screening and Lighting Plans.

• The Companies would collocate new pipeline segments along existing utility and transportation corridors to the greatest extent practicable, thereby reducing new disturbance and long-term fragmentation of forested lands.

• FERC staff would complete consultation under section 7 of the Endangered Species Act and section 106 of the National Historic Preservation Act prior to construction, ensuring compliance with federal requirements for protected species and cultural resources.

• The Companies would comply with all applicable U.S. Department of Transportation safety standards for the design, construction, and operation of natural gas transmission facilities.

• The Companies would comply with all applicable federal and state air and noise quality regulations and would verify compliance through post-construction surveys and operational monitoring.

• An environmental inspection and monitoring program would be implemented to verify that the Companies and their contractors adhere to all required mitigation measures and environmental commitments throughout construction and operation.

In addition, we recommend adoption of the project-specific mitigation measures presented in section 5.2 of the draft EIS. These measures are necessary to further reduce or avoid environmental effects and to ensure that the Projects are constructed and operated in a manner that protects the surrounding natural and human environment. We conclude that with the successful implementation of these measures, MSX and SSE4 would not result in significant long-term adverse environmental effects.

The FERC Commissioners will take into consideration staff's recommendations when they make a decision on the Projects.

For those wishing to comment on the draft EIS, the public comment period closes March 23, 2026.