Gulf South’s 111-Mile Kosciusko Junction Pipeline Enters Federal Review
FERC has launched its environmental review of Gulf South’s 111-mile Kosciusko Junction Pipeline in Mississippi, marking a major step forward for the 1.2-billion-cubic-feet-per-day project approved by Boardwalk Pipelines last year.
By Mary Holcomb, Lead Digital Editor
(P&GJ) — Nearly a year after Boardwalk Pipelines approved the Kosciusko Junction Pipeline project, the U.S. Federal Energy Regulatory Commission (FERC) has formally initiated its environmental review for the 111-mile natural gas expansion proposed by Boardwalk subsidiaries Gulf South Pipeline Co. and Texas Gas Transmission.
FERC issued a Notice of Intent to Prepare an Environmental Impact Statement (EIS) on Nov. 14, 2025, under Docket No. CP25-547-000, confirming that the project has advanced from the corporate approval and commercial commitment stage to the federal regulatory phase.
The notice outlines pipeline specifications, route data, compressor horsepower, and a proposed review schedule extending through October 2026 — all details appearing for the first time in public filings.
Pipeline Route and Information
For an overview of this project and other related infrastructure developments, visit Global Energy Infrastructure.
The Kosciusko Junction project now includes approximately 111.5 miles of new 36-inch-diameter pipeline and nearly 93,500 horsepower of additional compression across multiple facilities in Mississippi.
According to the filings, Gulf South will construct and operate two new segments:
- Kosciusko Junction Pipeline: 103.4 miles of 36-inch mainline traversing Holmes, Attala, Leake, Newton, and Jasper counties;
- Columbia Gulf Lateral: 8.1 miles of 36-inch pipeline in Clarke County, providing interconnections with Columbia Gulf Transmission and other existing systems.
Three new compressor stations are proposed: a 51,554-hp Kosciusko Station, a 20,952-hp Holmes Station, and upgrades at the Isola Compressor Station adding two 20,993-hp units. The build-out will also include four new meter stations and mainline valve assemblies to support expanded operations.
Combined, the facilities would provide up to 1.175 billion cubic feet per day of incremental firm transportation capacity.
According to the filing, Texas Gas Transmission will abandon and transfer its 98-mile Greenville Lateral to Gulf South, which will construct two new segments totaling 111.5 miles of 36-inch pipeline and build three new compressor stations and four meter stations.
The design also creates tie-ins to Destin Pipeline, Southern Natural Gas (SONAT), and Columbia Gulf Transmission, improving flow flexibility to downstream markets in the Gulf Coast and Southeast.
Gulf South has described the expansion as a key link to meet growing natural gas demand from industrial users and power generation customers throughout the region.
The 111.5-mile route crosses portions of Washington, Sunflower, Humphreys, Holmes, Attala, Leake, Newton, Jasper, and Clarke counties. FERC’s environmental review schedule calls for a Draft EIS in April 2026 and a Final EIS in July 2026, with a decision deadline of Oct. 22 and a final order expected by Sept. 17, 2026.
Beyond the project’s physical scope, federal agencies have already signaled the expansion as a permitting priority.
In October 2025, the Kosciusko Junction Pipeline project was granted FAST-41 coverage by the Federal Permitting Improvement Steering Council, placing it under the federal program designed to streamline permitting timelines for large, complex infrastructure projects.
The designation makes the Kosciusko Junction project eligible for enhanced interagency coordination, increased transparency around permitting schedules, and centralized oversight through the Permitting Council, with the Federal Energy Regulatory Commission serving as the lead agency. FAST-41 status does not guarantee approval, but it is intended to reduce permitting uncertainty and help keep multi-agency reviews on track.
According to the Permitting Council, the project was selected for FAST-41 coverage due to its role in supporting rising electricity demand across the Southeast, including new and existing power generation and emerging large-load customers such as AI-driven data centers, by connecting supplies from the Haynesville, Utica/Marcellus and Fayetteville basins to regional markets.
The council said the designation reflects the project’s potential contribution to grid reliability and long-term energy security in the region, particularly as utilities and industrial users seek firm natural gas supply amid rising power demand.
Boardwalk first announced the Kosciusko Junction Pipeline in December 2024, approving it as a multi-million investment by subsidiary Gulf South Pipeline. That early approval outlined preliminary plans for a 36-inch line delivering 1.16 billion cubic feet per day — expandable to 1.58 billion cubic feet per day — and a 20-year anchor contract with a foundation shipper.
The latest filings confirm that the project has now moved from concept to detailed design and federal permitting, with engineering refinements that slightly expand the total length and formalize compressor configurations.
If approved, the project would mark one of Mississippi’s largest recent midstream undertakings, supporting increased supply reliability and new market access across the region.
SEE PREVIOUS SPOTLIGHT: Energy Transfer Unit Seeks Approval for Illinois–Missouri Pipeline Serving Big Hollow Gas Plant