CENTERPOINT ENERGY GAS TRANSMISSION

Incident Narrative

ON AUGUST 16, 2011 AT 20:45 A CEGT WESTERN REGION EMPLOYEE REPORTED TO CEGT SYSTEM CONTROL THAT A THIRD PARTY CONTACTED HIM ABOUT BLOWING GAS AT AMBER STATION. CEGT SYSTEM CONTROL CONTACTED AMBER FIELD PERSONNEL TO GO TO THE AMBER STATION AND CHECK OUT THE REPORT. AT 21:19 AN AMBER TEAM EMPLOYEE ADVISED CEGT SYSTEM CONTROL THAT THEY DO HAVE GAS BLOWING AT AMBER STATION AND THAT HE IS CURRENTLY UNSURE WHAT THE CAUSE IS. AMBER EMPLOYEES ADVISED THAT EMERGENCY PERSONNEL (FIRE AND POLICE) ARE ON SCENE. AT 21:30 AMBER EMPLOYEES CONTACTED THE CEGT SYSTEM CONTROL MANAGER AND INFORMED HIM OF THE SITUATION AT AMBER AND REQUESTED ASSISTANCE ON REPORTING THE INCIDENT. AT 21:40 AN AMBER EMPLOYEE CONTACTED SYSTEM CONTROL AND ADVISED THAT WHEN HE ARRIVED AT 21:15 GAS WAS STILL BLOWING. HE INFORMED SYSTEM CONTROL THAT HE MANIPULATED VALVES TO STOP THE RELEASE AT 21:29. HE ADVISED FIRE AND POLICE HAVE CLOSED THE ROAD OUTSIDE OF THE STATION. AT 22:41 CEGT SYSTEM CONTROL MANAGER CONTACTED PERSONNEL ON LOCATION AND CONFIRMED THAT THE ROAD CLOSURE WAS COUNTY ROAD 1280. THE ROAD WAS REOPENED WHEN THE STATION WAS SECURED AND FIRE AND POLICE WERE RELEASED. AMBER EMPLOYEES, ON THE SCENE, REPORTED THAT THE STATION ESD'ED AND WAS BLOWING GAS FROM THE SUCTION AND DISCHARGE LINES. EMPLOYEES OPERATED THE MAINLINE VALVE TO GET THE STATION BACK UNDER CONTROL. EMPLOYEES BEGAN GOING THROUGH THE YARD CHECKING THE SYSTEMS. THEY REPORTED THAT POWER AND COMMUNICATIONS WILL BE RESTORED WHEN THE STATION IS TAKEN OUT OF ESD MODE. A LIGHTENING STORM CAUSED AN ELECTRICAL SUPPLY PROBLEM THAT IN TURN CAUSED THE STATION TO ESD. THE STATION BACKUP GENERATOR DID NOT START. A POWER GAS VALVE FAILED AND DID NOT ISOLATE THE SUCTION AND DISCHARGE LINES, RESULTING IN GAS CONTINUING TO BLOW FROM THE MAINLINE TO THE STATION BLOW DOWN. ON AUGUST 17, 2011 AT 01:45 AMBER TEAM EMPLOYEES HAD THE REPAIRS MADE, RESUMED NORMAL OPERATIONS AT THE STATION AND LEFT THE LOCATION.