Transco’s 1.6-bcfd SSE expansion receives FERC approval

Transcontinental Gas Pipe Line Co. (Transco), a subsidiary of Williams Cos., has received US Federal Energy Regulatory Commission approval for its 1.6-bcfd its Southeast Supply Enhancement (SSE) project, which will include work in Virginia, North Carolina, South Carolina, and Alabama. Transco’s 20-bcfd mainline runs from Texas to New York.

The SSE expansion will enable Transco to transport natural gas from its existing Compressor Station (CS) 165 Zone 5 Pooling Point and the Cherrystone Interconnect with Mountain Valley Pipeline LLC (MVP) in Pittsylvania County, Va., to natural gas markets in the southeast US. Transco states that the project will allow it to remove pipeline capacity constraints in its Zones 4 and 5 and to meet growing demand for gas-fired power generation, as well as for commercial, residential, and industrial use. 

SSE work includes:

• Building 31.2 miles of 42-in. OD pipeline in Pittsylvania County, and Rockingham County, NC (Eden Loop).
• Builiding 24.1 miles of 42-in. pipeline in Guilford, Forsyth, and Davidson Counties, NC (Salem Loop)
• Installing two new 33,000-hp electric motor-driven compressor units at CS 165. Work at CS 165 will be limited to a total incremental horsepower of 45,000, thereby increasing the total certificated station horsepower to 96,930 from 51,930.
• Installing a new 23,465-hp Solar Titan 130 gas-fired turbine-driven and two new 31,871-hp Solar Titan 250 gas-fired turbine-driven compressor units at Transco’s existing CS 155 in Davidson County, NC.  

Work on the $1.53-billion project is expected to begin fourth-quarter 2026 to meet a fourth-quarter 2027 in-service target.

Environmental concerns

However, some lawmakers, nonprofit leaders and neighbors have publicly argued that the pipeline expansion threatens air and water quality.

“With this authorization, [SSE] now has the right to take private property to build a pipeline that no one wants,” Caroline Hansley, campaign organizing strategist for the Sierra Club, said in a statement. “We cannot allow our communities to be threatened and our streams and rivers to be polluted in the pursuit of pipeline profits.”

FERC commissioners acknowledge in the order that SSE will impact the environment and individuals living near the project’s facilities. However, they go on to say in their order that “the project impacts, as mitigated, would not be significant.”

“FERC’s approval of the SSE project marks a major step forward in strengthening energy reliability across the Southeast, targeting an in-service date in 4Q 2027,” Cherice Corley, a Williams spokesperson, said in a statement Monday. 

Mountain Valley Pipeline growth approved

Another pipeline project in the region also received federal approval recently. On Dec. 18, 2025, FERC approved an amended application for the Mountain Valley Pipeline Southgate project, an expansion that runs a similar path from Pittsylvania County through Rockingham County, North Carolina.

A dozen Democratic state lawmakers sent a letter dated Nov. 25, 2025, to FERC and the Virginia Department of Environmental Quality opposing both pipeline projects.

“Our concerns about both projects are similar, as they pose significant risks to Virginia’s water resources within the Dan River Basin Watershed, to sensitive aquatic and plant species along the route, and to the communities faced with additional, massive methane-emitting gas transmission lines which pollute local air and water,” the letter stated.

In addition to looking at environmental ramifications of both projects, FERC members had to decide whether they served a need.

The FERC order for the Southgate expansion noted that Transco had commented that the Southeast Supply Enhancement Project could “handle all of the Southgate Amendment Project capacity with only minor alterations within its currently proposed footprint.”

Appalachian Voices, a nonprofit environmental organization, agreed with Transco on their position, an exception to the rule. FERC commissioners, however, took an opposite view.

“Allegations that the project is not needed because Transco’s proposed Southeast Supply Enhancement Project could handle the … volumes are not persuasive,” they wrote in the Dec. 18, 2025, order.

There may be more pipeline projects involving Pittsylvania County to come. In the first quarter of 2025, Williams hinted at another future expansion of its Transcontinental Gas Pipe Line, this one designed to meet Virginia’s voracious appetite for power related to data center growth.

The potential project, known as Transco’s Power Express pipeline, would carry an additional 950 million cu ft of natural gas daily to markets north of Station 165 in Pittsylvania County.

“This project will provide the same kind of return as our Southeast Supply Enhancement project, and the demand for this capacity has been robust,” former Williams president chief executive officer Alan Armstrong said during an earnings call.