"COLUMBIA GAS TRANSMISSION, LLC"

Incident Narrative

"ON MAY 20, 2024, AN INCIDENT OCCURRED ON PIPELINE SR- 538 IN BENTON, OHIO, DURING A SCHEDULED MAINTENANCE PROJECT. AS PART OF THE PROJECT, FOUR (4) TC ENERGY TECHNICIANS AND TWO (2) THIRD PARTY CONTRACTORS WERE WORKING TO INSTALL A SKILLET BLIND FLANGE TO ISOLATE THE AFFECTED PIPELINE SEGMENT. THE CREW OBSERVED A GAS LEAK FROM A 6-INCH VALVE AT THAT TIME AND DECIDED TO GREASE THE VALVE TO REMEDIATE THE LEAK USING A MOTORIZED GREASE GUN. AN IGNITION/FLASH FIRE ENSUED THAT INJURED TWO (2) OF THE TC ENERGY TECHNICIANS AND BOTH OF THE THIRD-PARTY CONTRACTORS. THE INJURED WORKERS WERE IMMEDIATELY TAKEN FOR MEDICAL EVALUATION AND TREATMENT. TC ENERGY COMPLETED AN INVESTIGATION TO IDENTIFY THE FACTORS THAT MAY HAVE CAUSED OR CONTRIBUTED TO THE INCIDENT. THE RESULTS OF THAT INVESTIGATION IDENTIFIED THE FOLLOWING PROPOSED RECOMMENDATIONS: 1. DEVELOP AND PUBLISH AN OPERATING PROCEDURE, OR UPDATE EXISTING PROCEDURES, TO OUTLINE THE REQUIREMENTS FOR INSTALLING A SKILLET BLIND. 2. CONDUCT A CONTROL OF WORK ASSESSMENT FOR INSTALLING SKILLET BLINDS TO PRODUCE A HAZARD CONTROLS DIAGRAM FOR REVIEW BY PERSONNEL WITH THE JOB SAFETY ANALYSIS (JSA). 3. IMPLEMENT IMPROVEMENTS TO PERSONNEL TRAINING MATERIALS TO PROVIDE MORE EMPHASIS ON THE ADEQUATE RESPONSE TO UNEXPECTED LEAKS. 4. CONDUCT RISK ASSESSMENT ON THE USAGE OF CSN SOLUTIONS BLACK WIDOW 20V GREASE GUNS. 5. UPDATE THE JSA FORM TO HAVE OPERATOR CONFIRM THE SPECIFIC PERSONAL PROTECTIVE EQUIPMENT (PPE) NEEDED FOR THE TASK (E.G., FLAME-RESISTANT CLOTHING, ETC.) 6. UPDATE APPLICABLE PROCEDURES TO REQUIRE A HOT WORK PERMIT TO BE COMPLETED WHEN INSTALLING A SKILLET BLIND DOWNSTREAM OF A SINGLE POINT OF ISOLATION REGARDLESS OF WHETHER A GAS LEAK OCCURS. 7. COMPLETE ONGOING EFFORT TO ISSUE PERSONAL DIFFUSIVE 4-GAS MONITOR GAS MONITORS TO ALL TC ENERGY FIELD TECHNICIANS AND OPERATIONS SPECIALISTS. 8. UPDATE JSA FORM TO CLARIFY THAT CONTRACTORS MUST ALSO SIGN THE JSA IF THEY ARE ALSO INVOLVED IN THE TASK BEING COVERED. 9. SHARE ADDITIONAL DETAILS AND LEARNINGS FROM THE INCIDENT TO THE ORGANIZATION. 10. UPDATE GAS HANDLING PROCEDURES TO CLARIFY THE AMOUNT OF TIME SINCE THE LAST VALVE INSPECTION / SERVICING THAT WOULD TRIGGER ADDITIONAL INSPECTION / SERVICING BEFORE COMPLETING A LOCKOUT TAG OUT ACTIVITY. TC ENERGY SENT THE VALVE ASSOCIATED WITH THE INCIDENT TO A LABORATORY FOR FURTHER ANALYSIS. THE LAB RESULT CONFIRMED THE SOURCE OF THE GAS LEAK WAS THE VALVE. THE FOLLOWING ARE THE RESULT OF TESTS; 1-THE SEAT TESTS CONDUCTED IN GENERAL ACCORDANCE WITH THE 24TH EDITION OF API 6D, SPECIFICATION FOR PIPELINE AND PIPING VALVES, SHOWED THAT THERE WAS A DETECTABLE LEAK AT THE VALVE SEAT OF THE SUBJECT PLUG VALVE AT PRESSURES AS LOW AS 70 PSI. 2-THE SHELL TESTS CONDUCTED IN GENERAL ACCORDANCE WITH THE 24TH EDITION OF API 6D SHOWED THAT THERE WAS A DETECTABLE LEAK AT THE FLANGED CONNECTION BETWEEN THE ROTATING SHAFT OF THE PLUG AND THE SHELL OF THE VALVE AT PRESSURES AS LOW AS 800 PSI."