Large-scale interstate pipeline projects typically go through the federal review process incrementally, rather than as a single approval. Entry into the FAST-41 permitting framework, however, is one of the most significant steps in that process. Upon entry into the framework, a project enters into a coordinated and time-lined review process. Southern Natural Gas Company’s South System Expansion 4 Project has now entered into the FAST-41 permitting framework, a major step forward for the project.
Entering FAST-41: What does this project entail?
On November 25, 2025, the Federal Permitting Improvement Steering Council (FPISC) added Southern Natural Gas Company’s South System Expansion 4 (SSE4) Project to the FAST-41 Federal Permitting Dashboard.
When a project is included on the FAST-41 dashboard, the FPISC indicates that the project is subject to the regulations and provisions of Title 41 of the Fixing America’s Surface Transportation Act (FAST ACT), which was enacted to provide increased transparency and better coordination of the federal review process for large infrastructure projects.
Although the FAST-41 designation does not guarantee approval, it does establish a time-limited permitting schedule and clearly defines the roles of all participating federal agencies. In SSE4, the Federal Energy Regulatory Commission (FERC) is designated as the lead federal agency and will oversee other federal agencies, including the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service.
An overview of the Southern Natural Gas expansion
The South System Expansion 4 Project is being developed by Southern Natural Gas Company and Elba Express Company, both wholly owned subsidiaries of Kinder Morgan. The project is intended to increase the capacity of Southern Natural Gas’ South Main Line by an estimated 1.3 billion cubic feet per day to serve customers located in Mississippi, Alabama, Georgia, and South Carolina.
Unlike many similar large-scale pipeline projects that require large amounts of new “greenfield” construction, SSE4 is largely a “brownfield” expansion. Rather than building entirely new pipelines and related infrastructure, SSE4 will add new pipeline looping and compression capabilities to approximately 291 miles of existing Southern Natural Gas infrastructure, and modify existing compressor and meter stations.
By limiting new land disturbance and adding more capacity to the existing system, this approach supports efficient and effective growth in the region.
Why does FAST-41 Matter for Project Timing?
With the addition of SSE4 to the FAST-41 permitting framework, there will be an established public timeline for environmental review and permitting decisions. As reported in the federal permitting dashboard, the environmental review and permitting processes for SSE4 are currently underway. Subject to completing the necessary reviews, the Federal Energy Regulatory Commission (FERC) expects to issue a final certificate order by July 31, 2026.
While the actual approval of a large-scale multi-state pipeline project may be critical to advancing the project, establishing a predictable and transparent timeline for these approvals can be equally important. The ability of project sponsors, customers, and regulators to align their expectations regarding the project timing, while also ensuring procedural integrity, is supported by the predictability and structure provided by the FAST-41 framework.
The demand drivers behind the project
The need for additional capacity reflected in SSE4 is part of a larger trend in the Southeastern United States. Increasing natural gas consumption from power generators, industrial plants, and local distribution companies has created growing pressures on existing pipeline capacity. SSE4 is intended to alleviate those pressures by providing greater reliability and flexibility to the Southern Natural Gas system. Project sponsors believe that the additional coordination provided by the FAST-41 framework is especially beneficial due to the large scale and complexity of the expansion and the numerous federal approvals that are required for the project.
