Leaf River Expansion Wins FERC Green Light for Mississippi Gas Storage Growth

Leaf River Energy Center has secured FERC approval to expand its Mississippi natural gas storage facility, adding 19.18 Bcf of working gas capacity through new cavern development and facility upgrades.

Mary Holcomb, Lead Digital Editor

(P&GJ) — The Federal Energy Regulatory Commission has approved the Leaf River Expansion Project, authorizing Leaf River Energy Center LLC to expand its Mississippi natural gas storage system by 19.18 Bcf of working gas capacity through the construction of a new storage cavern, expansion of two existing caverns and installation of additional compression.

The order also reaffirms the company's market-based rate authority for existing storage, hub and interruptible wheeling services while approving market-based rates for a new firm wheeling service.

The project will expand the company's existing New Home Salt Dome Storage Facility in Smith, Jasper and Clarke counties, Mississippi. FERC approved construction of a new storage cavern, designated Cavern 5, additional solution mining of Caverns 2 and 4, three new gas-powered compressor units and associated pipeline and water facilities. The expansion will increase the facility's total working gas capacity from 36.0 Bcf to 55.18 Bcf.

Specifically, the project includes:

• Expansion of Caverns 2 and 4 through solution mining, increasing each cavern to 15.07 Bcf of working gas and 4.52 Bcf of cushion gas.
• Construction of Cavern 5 with 12.52 Bcf of working gas capacity and 3.75 Bcf of cushion gas.
• Approximately 4,010 feet of new 16-inch and 24-inch gas header pipeline.
• Installation of one 15,900-hp and one 11,110-hp gas-powered centrifugal compressor at the existing compressor station.
• Installation of one 6,130-hp gas-powered centrifugal compressor at the existing booster station.

The Commission found that Leaf River demonstrated sufficient market demand for the expansion through open seasons conducted in 2025 and a binding precedent agreement with EQT Energy covering 5.46 Bcf, or roughly 31% of the project's new capacity. Commissioners also noted the company expects to execute additional long-term agreements for the remaining capacity.

"The Leaf River Expansion will increase Leaf River's ability to provide a variety of storage services to natural gas market participants in the region," the Commission wrote.

"Leaf River states that its storage services are needed to provide incremental storage capacity for natural gas-driven electric generation during extreme weather, and that local storage provides needed backstop supplies during periods of peak demand and to support the electric grid's increased uptake of intermittent energy resources."

FERC concluded the expansion satisfies the Commission's Certificate Policy Statement, finding the project will provide additional storage capacity without adverse impacts to existing customers, competing storage providers or surrounding communities.

"Accordingly, we find that Leaf River has demonstrated a need for the project," the Commission wrote. "Further, the project will not have adverse impacts on existing customers, existing pipelines, or other storage providers and their existing customers."

The Commission also approved Leaf River's request to continue charging market-based rates for its existing firm and interruptible storage, storage derivative hub and interruptible wheeling services, while granting new market-based rate authority for a proposed firm wheeling service. FERC determined the company lacks market power in the relevant Gulf Coast market, citing its relatively small market share and the availability of competing storage facilities and local production.

According to the order, the expanded facility will have a total storage capacity of 71.68 Bcf, including 55.18 Bcf of working gas and 16.50 Bcf of base gas. FERC also approved Leaf River's request to restate the certificated capacity of its existing caverns based on revised subsurface temperature assumptions, increasing the facility's certificated working gas capacity before expansion by 1.56 Bcf.

Commission staff concluded the proposed facilities are appropriately designed to support injection rates of up to 250 million cubic feet per day and withdrawal rates of up to 500 million cubic feet per day for each cavern. Overall, the storage facility will support a maximum injection rate of 1.0 billion cubic feet per day and a maximum withdrawal rate of 2.0 billion cubic feet per day once the expansion is complete.

The environmental review found the project would temporarily affect approximately 31.8 acres, with 17.9 acres remaining permanently affected after construction. FERC concluded the impacts would be mitigated through required environmental conditions and would not significantly affect the quality of the human environment.

"Based on the analysis in the EA... we conclude that if the project is constructed in accordance with Leaf River's application and... the environmental conditions... our approval of this proposal would not constitute a major federal action significantly affecting the quality of the human environment."

Leaf River formally accepted the certificate on July 17, one day after the Commission issued the order. In its filing, the company accepted the certificate, market-based rate authorizations and regulatory waivers while reserving the right to revisit its acceptance should the order change as a result of rehearing requests or judicial review.