The Mississippi Hub is an underground natural-gas storage facility sited in a salt dome in central Mississippi, the US.
The facility is operated by namesake entity Mississippi Hub, an affiliate of Enstor Gas.
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Mississippi Hub stores and delivers large volumes of gas to Gulf Coast and southeastern US markets.
It began operations in 2010. Currently, it holds around 22.4 billion cubic feet (Bcf) of working gas.
Mississippi Hub Location
Mississippi Hub is located on the Bond Salt Dome in Simpson County, roughly 7.6 miles south-west of the small town of Magee, Mississippi.
The site’s inland location places it within reach of major interstate transmission systems and regional demand centres across the Gulf Coast and Southeast.
Ownership History
Mississippi Hub began operations in 2010, when Sempra Pipelines & Storage announced that its first cavern was placed in service.
In 2019, Sempra sold its non-utility US natural gas storage assets, including Mississippi Hub, to ArcLight Capital Partners’ affiliate Enstor Gas. The transaction closed in February 2019.
In May 2022, Enstor Gas was acquired by the Infrastructure Investments Fund (IIF), an investment vehicle advised by JP Morgan Investment Management. The terms of the transaction were not divulged.
As of April 2025, Enstor identify Emerald Storage Holdings as its parent company, under which Mississippi Hub operates.
Mississippi Hub Infrastructure
The existing Mississippi Hub comprises three operational caverns formed in the Bond salt dome with total working gas of about 22.4 Bcf.
It uses solution-mined salt caverns to store large volumes of natural gas. These are artificially created cavities made by dissolving salt in underground salt formations that have a high injection and withdrawal capacity.
It has multiple pipeline interconnections. This includes connections with Southern Natural Gas (SNG), Southeast Supply Header (SESH) and Transcontinental Gas Pipe Line (Transco/TGP).
Those interconnects give shippers access both to upstream Gulf-Coast and Appalachian supplies and to downstream markets and growing LNG export corridors.
The hub’s proximity to pipeline expansion projects makes it strategically placed to serve demand growth in the Southeast and Gulf Coast power and export markets.
Mississippi Hub currently has a certified Max Daily Withdrawal (MDW) rate of 1,200 MDth/day. Maximum daily injection capacity stands at 480MDth/day.
Mississippi Hub Expansion
In March 2024, Mississippi Hub submitted an application (docket number CP24-80) with the US Federal Energy Regulatory Commission (FERC) for the expansion of the gas storage facility.
It received permission to proceed with construction on the project in July 2025.
The expansion project will entail adding three additional storage caverns to the hub. Each of these caverns will have a working storage capacity of 10Bcf.
Additionally, the expansion will encompass the construction of compression station housing three gas-turbine centrifugal compressors, dehydration, saltwater disposal wells, and associated facilities.
Separately, the expansion is expected to include adding one meter skid and one filter separator each on the existing Southern Natural Gas Meter Site in Simpson County and Southeast Supply Header Meter Site in Covington County.
The existing Transcontinental Gas Pipeline Meter Site in Covington County will be fitted with two meter skids, two flow control skids, and one filter separator.
MS Hub expansion project is expected to enter service in 2028/2031, contingent on different factors.
Once complete, Mississippi Hub Expansion will increase working gas capacity by up to 33.5Bcf to around 56.3Bcf, around 2.5 times the facility’s present capacity. This includes a potential expansion of existing caverns.
The expansion will also add up to 0.7 million dekatherms per day (MMDth/day) of new injection capacity, while the injection capacity will increase to a total of 1.90 MMDth/day.
The withdrawal capacity will remain unchanged at 2.40 MMDth/day
Offtake agreements
Enstor’s public materials indicate there is commercial interest already committed to parts of the expansion.
The company says the first of the three newly authorised storage caverns has been fully subscribed under a long-term contract with a subsidiary of Kinder Morgan, covering storage services that will be accessible on Southern Natural Gas and Tennessee Gas Pipeline corridors.
Beyond that subscription, Enstor has stated its intent to offer market-based firm and interruptible storage, hub and wheeling services under the FERC authorisation.
