COLUMBIA GAS TRANSMISSION, LLC

Incident Narrative

ON MARCH 26, 2020 AT 08:45 EASTERN DAYLIGHT TIME (EDT), COLUMBIA GAS TRANSMISSION, LLC (COLUMBIA) MONITORING CENTER RECEIVED A CALL FROM A PASSER-BY REGARDING THE OBSERVATION OF GAS BUBBLING IN TUSCARAWAS RIVER. COLUMBIA OPERATIONS PERSONNEL WERE ON SITE AT 09:58 EDT AND CONFIRMED THAT THE UNINTENDED NATURAL GAS (MATERIAL) RELEASE WAS FROM LINE O-1460. THE INVOLVED SECTION OF LINE O-1460 IN THIS EVENT CROSSED AT THE BOTTOM A RIVER. LINE O-1460 IS CARBON STEEL TRANSMISSION PIPELINE WITH 6 INCH IN DIAMETER AND MAXIMUM ALLOWABLE OPERATING PRESSURE OF 280 PSIG OPERATED AND MAINTAINED BY COLUMBIA. ON MARCH 28, 2020 AT APPROXIMATELY 18:55 EDT, THE AFFECTED SECTION OF LINE O-1460 WAS ISOLATED AND EMERGENCY BLOWDOWN OF THE AFFECTED SECTION WAS INITIATED. THE BLOWDOWN WAS COMPLETED AT 19:28 EDT. THE LEAK WAS ISOLATED AND THE AFFECTED SECTION OF THE LINE O-1460 WAS ISOLATED AND REMOVED FROM SERVICE. A COMPRESSED NATURAL GAS TANKER WAS CONNECTED AND STARTED FEEDING THE DOWNSTREAM CUSTOMERS WHOSE SERVICE IS PROVIDED BY THE LOCAL DISTRIBUTION OPERATOR. THE RIVER-CROSSING SECTION OF LINE O-1460 WAS CUT AND CAPPED ON BOTH ENDS. THE INITIAL NATIONAL RESPONSE CENTER REPORT NO.1278263 AND THE NRC 48-HOUR REPORT NO. 1274397 HAVE BEEN CALLED-IN ON MARCH 26TH AND MARCH 28TH RESPECTIVELY. THE INVOLVED SEGMENTS OF LINE O-1460 IN THIS INCIDENT WERE SENT TO A METALLURGICAL FAILURE ANALYSIS LABORATORY TO ESTABLISH THE ROOT CAUSE BEHIND THIS RIVER-CROSSING PIPELINE FAILURE. THE METALLURGICAL FAILURE ANALYSIS REPORT OF LINE O-1460 IDENTIFIED THAT THE CAUSE OF THE LEAK IS EROSION-CORROSION. THE CONSTRUCTION OF THE REPLACEMENT SECTION FOR LINE O-1460 WAS COMPLETED BY USING HORIZONTAL DIRECTIONAL DRILLING (HDD) METHOD FOR INSTALLING PIPE UNDER THE TUSCARAWAS RIVER. THE HDD METHOD WILL HELP PROTECT THE PIPE TO AVOID FUTURE EVENTS FROM RE-OCCURRING. RESUBMITTED THE FINAL REPORT PER AN EMAIL FROM PHMSA INVESTIGATOR ON 6/25/2024.