TEXAS GAS TRANSMISSION LLC

Incident Narrative

ON 04-24-2011, AT APPROXIMATELY 7:35 AM, GAS CONTROL NOTED THE PIPELINE PRESSURE WAS INCREASING IN THE NORTHERN PART OF THE MAINLINE SYSTEM NEAR JEFFERSONTOWN STATION. AT THE TIME, THE DISCHARGE PRESSURE AT THE SLAUGHTERS STATION WAS 784 PSIG AND THE STATION TURBINE WAS RUNNING IN A SLOWED BACK POSITION. IN ORDER TO INCREASE THE INJECTIONS INTO OUR HANSON STORAGE FIELD, THE GAS CONTROLLER INCREASED THE TURBINE SPEED TO INCREASE PRESSURES ON THE DISCHARGE OF SLAUGHTERS TOWARD THE HANSON STORAGE FIELD. (THE HANSON FIELD IS 8 MILES FROM THE STATION ON THE STORAGE LATERAL LINE.) THE GAS CONTROLLER WAS WATCHING THE DISCHARGE PRESSURE INCREASE AT SLAUGHTERS STATION, BUT NOT THE RELIEF VALVE AT GLENVILLE, KY WHICH IS LOCATED 18 MILES DOWNSTREAM OF THE SLAUGHTERS STATION ON THE MAINLINE SYSTEM. AT ABOUT 8:45 AM, THE GAS CONTROLLER RECEIVED A HIGH ALARM AT THE GLENVILLE RELIEF VALVE. AT THAT TIME, HE SENT A REMOTE CHANGE TO REDUCE THE SPEED ON THE TURBINE AT SLAUGHTERS STATION. AT 9:15 AM HE RECEIVED A PHONE CALL FROM A PROPERTY OWNER ABOUT THE GLENVILLE RELIEF VALVE BLOWING. AT 9:40 AM, THE GAS CONTROLLER INITIATED AN ENGINE SHUTDOWN AT SLAUGHTERS STATION TO REDUCE THE PRESSURE TOWARD THE GLENVILLE RELIEF VALVE ON THE MAINLINE SYSTEM. AT 9:42 AM, FIELD PERSONNEL SHUT OFF THE RELIEF VALVE. ADDED DATA TO PART E5.F AS REQUESTED BY PHMSA.