COLUMBIA GULF TRANSMISSION, LLC

Incident Narrative

ON JANUARY 20, 2016, COLUMBIA GULF TRANSMISSION, LLC (COLUMBIA) OPERATIONS PERSONNEL WERE PERFORMING ROUTINE PREVENTIVE MAINTENANCE TO A COLUMBIA PIPELINE FACILITY. UPON COMPLETING THE TASK AND DEPARTING THE AREA VIA BOAT, IT WAS NOTED THAT A FEW BUBBLES WERE EMANATING FROM THE BOTTOM OF THE MARSHLAND. NOTING THAT COLUMBIA HAS A PIPELINE FACILITY NEARBY, COLUMBIA PERSONNEL STOPPED AND STARTED INVESTIGATING. GAS SAMPLES WERE COLLECTED FROM THE IDENTIFIED BUBBLES LOCATION AND FROM THE CLOSEST MEASURING STATION. THE TWO SAMPLES WERE SENT TO THE LABORATORY FOR ANALYSIS TO DETERMINE IF THE DISCOVERED RELEASE WAS FROM A COLUMBIA PIPELINE OR OTHER OPERATORS IN THE AREA. MEANWHILE, COLUMBIA OPERATIONS PERSONNEL WERE DISPATCHED TO THE CLOSEST CRITICAL VALVES TO REDUCE THE PRESSURE FROM THE VALVES' OPERATING VALUE OF 800 PSIG DOWN TO APPROXIMATELY 200 PSIG. AFTER THE RESULTS WERE RECEIVED FROM THE LABORATORY, IT WAS CONFIRMED THAT THE VISIBLE BUBBLES WERE EMANATING FROM A COLUMBIA PIPELINE. ACCORDINGLY, A CONTRACTOR WAS ASSIGNED TO EXCAVATE AND COMPLETE THE NECESSARY REPAIR WHICH WAS IDENTIFIED TO BE FROM A PINHOLE LEAK IN A GIRTH WELD. A LEAK CLAMP WAS INSTALLED AND THE PIPELINE OPERATING PRESSURE WAS RAISED TO ITS NORMAL OPERATING PRESSURE ON FEBRUARY 15, 2016. KEY LESSONS LEARNED FROM THIS INCIDENT WERE THAT MAINTENANCE PIGGING ARE RECOMMENDED TO BE PERFORMED ON MORE ROUTINE SCHEDULED BASIS TO REMOVE TRAPPED LIQUIDS DUE TO LOW FLOW IN PIPELINE. ALSO TO PERFORM MAINTENANCE BATCH TREATMENT ON MORE ROUTINE SCHEDULED BASIS DUE TO LIQUID AND LOW FLOW CONDITIONS.