COLUMBIA GAS TRANSMISSION CORP

Incident Narrative

AT ABOUT 3:00 A.M. ON THE MORNING OF MAY 12, A SLOW PRESSURE DROP WAS NOTED ON LINE B NEAR COLUMBIA GAS TRANSMISSION'S WALBRIDGE COMPRESSOR STATION. THE CONTROLLER ON DUTY CONTACTED THE LOCAL TEAM LEADER, WHO THOUGHT THAT ONE OR MORE PRODUCERS IN THE AREA UPSTREAM OF THE PRESSURE DEVICE MIGHT BE MAKING AN OPERATIONAL CHANGE. A DECISION WAS MADE TO MONITOR THE PRESSURE FOR A SHORT WHILE. THE PRESSURE CONTINUED TO SLOWLY DROP. IT WAS DECIDED TO HAVE FIELD OPERATIONS START CHECKING THE LINE. BY SHORTLY AFTER 3:30 A.M., LOCAL FIELD EMPLOYEES WERE BEING CONTACTED. THEY BEGAN CHECKING LINE B AND OTHER UPSTREAM LINES THAT FEED INTO LINE B BETWEEN 4:30 AND 5:00 A.M. THE AREA TRAVERSED BY LINE B AND ITS UPSTREAM FEEDER LINES IS REMOTE AND RUGGED, OFTEN WITH MILES BETWEEN ROAD ACCESS POINTS. CHECKING THE SYSTEM WAS DIFFICULT AND SLOW. AT A FEW MINUTES AFTER 9:00, A CREW CHECKING UPSTREAM FEEDER LINE P CAME UPON A LANDSLIDE AREA. IT WAS DETERMINED THAT GAS WAS ESCAPING FROM THE COUPLED LINE IN THIS AREA. IT SHOULD BE NOTED THAT THIS PART OF EASTERN KENTUCKY HAD EXPERIENCED AN UNUSUALLY WET SPRING. THIS IS THOUGHT TO HAVE CONTRIBUTED TO THE LANDSLIDE. THE SITUATION WAS CALLED IN TO THE CONTROL ROOM. QUESTIONS WERE ASKED, INVESTIGATED, AND ANSWERED TO OBTAIN ACCURATE INFORMATION. AS SOON AS SUFFICIENT INFORMATION WAS OBTAINED TO DETERMINE THAT AN INCIDENT HAD OCCURED, A CALL WAS MADE TO THE NRC AND PHMSA'S SOUTHERN REGION OFFICE. MATERIALS AND EQUIPMENT WERE ASSEMBLED OVER THE NEXT DAY, AND RESTORATION WORK WAS BEGUN ON MAY 14. THE LINE WAS READIED FOR PLACEMENT IN SERVICE BY 9:00 MAY 20, AND WAS FULLY RESTORED TO SERVICE BY 12:05 A.M. ON MAY 21. NOTE THAT THE GAS LOSS CALCULATIONS REFLECT OUR BEST RECONSTRUCTION OF THE EVENTS AFTER DISCOVERY OF THE CONDITION. HOWEVER, IT IS POSSIBLE THAT GAS LOSS VOLUME MAY HAVE EXCEEDED 3,000 MCF THROUGH THE DURATION OF THE INCIDENT.