Environmental Groups File Lawsuit Challenging U.S. Army Corps Permit for $1.5 Billion Transco Pipeline Expansion

U.S. Army Corps of Engineers for the Transco pipeline, known as the Southeast Supply Enhancement Project. The groups, represented by the Southern Environmental Law Center and the Appalachian Mountain Project, argue the permit allows construction methods that could harm aquatic ecosystems.

The plaintiffs include Wild Virginia, 7 Directions of Service, Haw River Assembly, Sierra Club and Appalachian Voices. 5 billion SSEP would run through five states, including North Carolina, where it would extend for 28 miles in Rockingham, Guilford, Forsyth and Davidson counties.

Inside Climate News reported that the project is one of the largest pipeline capacity expansions in the Southeast in decades.

It involves adding pipelines alongside existing ones to carry more gas between the Gulf and the Southeast. Transco states that the SSEP is necessary to meet regional demand for natural gas. U.S. The permit allows construction using a “dry-ditch, open-cut” crossing method.

The “dry-ditch, open-cut” method involves dewatering the construction site by diverting the river or stream flow while the ditch is dug and the pipe is laid, according to a 2021 study by Downstream Strategies of West Virginia, an economic and environmental consulting firm.

The goal of the method is to reduce the sediment releases from pipeline construction into the stream.

However, releases of sediment still occur, often when the diversion materials are being installed, the study states. “Rivers have the right to flow and thrive. Our communities and all species have the right to a healthy environment.

We continue to raise our voices against SSEP, and the dangerous policies that put corporate profit over community wellbeing,” said Crystal Cavalier-Keck, executive director of 7 Directions of Service, a North Carolina environmental nonprofit led by indigenous people.

U.S. Army Corps of Engineers did not respond to a request for comment. More than 90 environmental groups petitioned the Federal Energy Regulatory Commission in 2024 to require Transco to submit a comprehensive Environmental Impact Statement about the SSEP project.

In 2025, FERC allowed Transco to file an Environmental Assessment for the SSEP, which is less thorough and has a shorter public comment period than an Environmental Impact Statement.

Many local governments along the SSEP route in North Carolina passed resolutions of concern about the expansion. The SSEP expansion will require new, powerful compressor stations that push the gas down the pipeline. Compressor stations release harmful air pollutants, including carbon monoxide, volatile organic compounds, particulate matter and greenhouse gases.

The SSEP would intersect Enbridge’s T15 Reliability Project, which runs 45 miles between Person County and Rockingham County, near Eden. The SSEP would also intersect the MVP Southgate, which is an extension of the main Mountain Valley Pipeline near Eden. The main Mountain Valley Pipeline runs 300 miles through West Virginia and Virginia.

A consortium of energy companies owns the Mountain Valley Pipeline. The pipelines in North Carolina would supply Duke Energy’s natural gas projects, including two new power plants in Person County that are under construction. Duke Energy has proposed at least five more power plants, which will require approval by the state Utilities Commission.

Transco began construction on the SSEP on March 2. Contractors have begun to fell trees, install acoustic barriers and conduct test drilling in preparation for blasting for the SSEP. “SSEP would trench across streams and wetlands, damaging sensitive aquatic ecosystems,” said Caroline Hansley, campaign organizing strategist for the Sierra Club.

“Regulators have consistently ignored the overwhelming burden the SSEP project would place on the environment and the communities it would run through. Communities all along the proposed route have passionately spoken out against this unneeded project,” Hansley added.