Unscheduled Pipeline Maintenance – South Main Line east of Enterprise (Segment 430 – Enterprise) Update #1

As previously posted in Notice ID 712042, on May 30, 2026, Southern experienced an unscheduled pipeline maintenance event on the South Main Line that necessitates repairs and has required the isolation of a portion of the South Main Line. Southern continues working to investigate and make the necessary repairs. To date, there has been no customer impact due to this incident.

A Corrective Action Order (CAO) has been issued by the Pipeline and Hazardous Materials Safety Administration (PHMSA), Office of Pipeline Safety (OPS). Southern is now subject to a restriction of operating pressures on the 18-inch diameter South Main Line from the Enterprise Compressor Station in Enterprise, Mississippi to the Gallion Compressor Station in Gallion, Alabama. Under the restriction, the operating pressure along the affected pipeline segment may not exceed eighty percent (80%) of the actual operating pressure in effect at the failure location immediately prior to the failure on May 30, 2026. As a result, Segment 430 (Enterprise) capacity of 2,306,000 Dth/d will be updated to 2,166,000, reflecting an impact of 140,000 Dth/d effective Timely Cycle, gas day June 5, 2026.

Based on current system demand, Interruptible and Out of Path nominations may be restricted and should demand increase, there may be an impact to firm In-Path services.

Southern will provide updates as more information becomes available. If you have any questions, please contact your Scheduling Representative or Account Manager.