TEXAS GAS TRANSMISSION, LLC

Incident Narrative

A POTENTIAL LEAK ON TEXAS GAS'S WLJ 14"" LINE WAS REPORTED BY A LOCAL FARMER. OPERATIONS PERSONNEL CONFIRMED THE LEAK. THE LINE WAS ISOLATED AND REPAIRED AND RETURNED TO SERVICE. CAUSE REMAINS UNDER INVESTIGATION. 3-5-2018 *GAS CONTROL CENTER, THROUGH SCADA, IDENTIFIED A POTENTIAL SYSTEM UPSET AND CONTACTED FIELD OPERATIONS TO INVESTIGATE. CONCERN WAS POTENTIAL LOSS OF GAS. WHILE FIELD OPERATIONS WERE PERFORMING THEIR INVESTIGATION, A LAND OWNER NOTIFIED CONTROL CENTER THAT OUR PIPELINE WAS LEAKING. BASED ON THE FACT THAT OUR SCADA INDICATED A LOSS OF GAS AND WAS CONFIRMED BY A LAND OWNER, TEXAS GAS DECLARED DISCOVERY OF AN INCIDENT ON OUR SYSTEM WHICH WAS ON 12-11-17 AT 16:42. *FIELD PERSONNEL ARRIVED ONSITE ON 12-11-17 AT 17:03 AND RECONFIRMED PIPELINE LEAK WAS OURS. *NRC WAS CALLED ON 12-11-17 AT 17:15. *A DECISION WAS MADE TO BLOCK THE PIPELINE AND ALLOW THE GAS PRESSURE TO DISSIPATE THROUGH THE LEAK LOCATION. 5-9-18 REVISED TO UPDATE VARIOUS DETAILS INCLUDING A4 CALCULATION USING METHODOLOGY RECENTLY PROVIDED BY PHMSA. UPDATED COSTS. REPAIR WAS MADE BY REPLACING A PUP OF PIPE. IN REGARD TO PART G, THE METALLURGICAL REPORT INDICATED THAT THE FAILURE SURFACE WAS ASSOCIATED WITH FATIGUE. TEXAS GAS ENLISTED THE SERVICES OF STRESS ENGINEERING SERVICES, INC. TO EVALUATE EQUIPMENT LOADING, PRESSURE CYCLING, TEMPERATURE, AND OTHER SOURCES OF FATIGUE ON THE PIPELINE. WE ASSUME THAT THE POTENTIAL FOR FATIGUE OCCURRED DUE TO THE CONSTRUCTION METHODS USED AT THE TIME SINCE THIS LOCATION IS ASSOCIATED WITH A WRINKLE BEND. BASED ON OUR ANALYSIS, WE BELIEVE THIS IS A UNIQUE SITUATION AND IS NOT A SYSTEMIC ISSUE.