Transco Declares Force Majeure at Station 517, Limits Mainline Gas Flows

Transco has declared a force majeure at Compressor Station 517 after an unplanned outage, restricting west-to-east gas flows and cutting primary firm capacity by up to 40% through late December.

(P&GJ) — Transcontinental Gas Pipe Line Company (Transco) has declared a force majeure following an unplanned outage at Compressor Station 517, limiting natural gas transportation capacity on its mainline system, according to a system notice posted Dec. 14.

The force majeure stems from equipment failure on Main Unit 5 at Station 517, located at mainline milepost 127.96, prompting Transco to begin unplanned maintenance and restrict scheduled quantities for shipments moving west to east through the affected segment.

Transco said primary firm transportation services will be limited beginning with the Dec. 14 ID2 cycle, with west-to-east flows subject to cuts of approximately 30% to 40%, based on historical utilization. Transactions moving east to west will not be impacted, the company said.

Under the operating conditions, Transco will manage capacity using a receipt-based Throughput Section Boundary (TSB) at Station 517. During the outage, the total primary firm transportation capacity available through the location is estimated at 2,375 Mdth/d, according to the notice.

The company said it has increased system capacity compared with earlier estimates following an updated review, effective Dec. 14, but full service restoration is not expected until between Dec. 24 and Jan. 1, 2026. Transco said additional updates will be provided as more information becomes available.

The force majeure was issued pursuant to Section 11 of Transco’s FERC Gas Tariff and supersedes a prior notice related to the outage. Transco indicated that impacted shippers may be required to take immediate operational actions as conditions evolve.