GIS MidStream > Our Services > Transmission


Our Transmission segment is comprised of interstate and intrastate pipelines that transport natural gas from interconnection points on other large pipelines to customers, such as local distribution companies, electric utilities, direct-served industrial complexes, or to interconnects on other pipelines. 

Certain of our pipelines are subject to regulation by FERC (Federal Energy Regulatory Commission) and by state regulators. In this segment, we often enter into firm transportation contracts with our shipper customers to transport natural gas sourced from large interstate or intrastate pipelines. Our Transmission segment assets are located in multiple parishes in Louisiana, including onshore and offshore producing regions around southeast Louisiana and multiple counties in Mississippi, Alabama, and Tennessee.


The Bamagas system is a Hinshaw intrastate natural-gas pipeline that travels west to east from an interconnection point with TGP in Colbert County, Alabama, to two power plants owned in Morgan County, Alabama. The Bamagas system consists of 52 miles of high-pressure, 30-inch pipeline with a design capacity of approximately 450 MMcf/d. Currently, 100% of the throughput on this system is contracted under long-term firm transportation agreements.


The AlaTenn system is an interstate natural-gas pipeline that interconnects with TGP and travels west to east delivering natural gas to industrial customers in northwestern Alabama, as well as to the city gates of Decatur and Huntsville, Alabama. Our AlaTenn system has a design capacity of approximately 200 MMcf/d and is comprised of approximately 295 miles of pipeline with diameters ranging from three to 16 inches, and includes two compressor stations with combined capacity of 3,665 horsepower. The AlaTenn system is connected to four receipt points and more than 25 active delivery points, including the Tetco Pipeline system.

Midla and MLGT

Our Midla system is a 1920’s vintage, interstate natural-gas pipeline with approximately 370 miles of pipeline linking the Monroe Natural Gas Field in northern Louisiana and interconnections with the Transco Pipeline system and Gulf South Pipeline system to customers near Baton Rouge, Louisiana.The mainline has a current capacity of approximately 198 MMcf/d and consists of approximately 170 miles of low-pressure, 22-inch-diameter pipeline with laterals ranging in diameter from two to 16 inches.

Our MLGT system is an intrastate natural-gas transmission system that sources natural gas from interconnects with the FGT Pipeline system, the Tetco Pipeline system, the Transco Pipeline system, and our Midla system to a Baton Rouge, Louisiana refinery owned and operated by ExxonMobil and several other industrial customers. Our MLGT system has a capacity of approximately 170 MMcf/d and is comprised of approximately 54 miles of pipeline with diameters ranging from three to fourteen inches. The MLGT system is connected to seven receipt and seventeen delivery points.

In December 2014, American Midstream Partners, LP, owner of the Midla pipeline reached an uncontested agreement with all interested parties regarding its Midla interstate pipeline. The parties involved reached an agreement to provide continued service to Midla’s customers while addressing safety concerns with the existing pipeline.

Midla and the parties agreed that Midla may retire the existing mainline and replace the existing natural-gas service with a new pipeline from Winnsboro, Louisiana, to Natchez, Mississippi (the “Midla-Natchez pipeline”) to serve existing residential, commercial, and industrial customers. Customers not served by the new Midla-Natchez pipeline would be connected to other interstate or intrastate pipelines or other gas-distribution systems, or they would be offered conversion to propane service. Further, portions of the northern and southern portions of the Midla system would be transferred to MLGT, which would continue to operate. The agreement is subject to final approval from the Federal Energy Regulatory Commission (FERC).

High Point

The High Point system consists of approximately 650 miles of natural gas and liquids pipeline assets located in southeast Louisiana and the shallow-water and deep-shelf Gulf of Mexico. The High Point system transports natural gas from both onshore and offshore producing regions around southeast Louisiana. The onshore footprint is located in southern Louisiana and the offshore footprint consists of the following federal Gulf of Mexico zones: Mississippi Canyon, Viosca Knoll, West Delta, Main Pass, South Pass, and Breton Sound. Natural gas is collected at more than 75 receipt points that connect to hundreds of wells targeting various geological zones in water depths up to 1,000 feet, with an emphasis on oil- and liquids-rich reservoirs.

The High Point System is comprised of FERC-regulated transmission assets and non-jurisdictional gathering assets, both of which accept natural gas from well production and interconnected pipeline systems. The High Point System delivers the natural gas to the Toca Gas Processing Plant, operated by Enterprise, where the products are processed and the residue gas is sent to an unaffiliated interstate system owned by Kinder Morgan.


Our other transmission systems include the Chalmette system, located in southern Louisiana, and the Trigas system, located in northwestern Alabama. The approximate design capacities for the Chalmette and Trigas systems are 125 MMcf/d and 60 MMcf/d, respectively. We also own a number of miscellaneous interconnects and small laterals that are collectively referred to as the SIGCO assets.