ATMOS PIPELINE - TEXAS

Incident Narrative

ON JUNE 28, 2021, ABOUT 3:35 P.M. LOCAL TIME, A NATURAL GAS IGNITION OCCURRED DURING ROUTINE MAINTENANCE ACTIVITIES AT AN ATMOS ENERGY CORPORATION (ATMOS) FACILITY NEAR FARMERSVILLE, TEXAS. THE NATURAL GAS IGNITED AFTER WORKERS INSERTED AN IN-LINE TOOL (OR PIG) INTO A LAUNCHER. TWO WORKERS FROM ATMOS AND FIVE EMPLOYEES FROM TWO OF ITS CONTRACTORS WERE ON-SITE AT THE TIME OF THE ACCIDENT AND PERFORMING WORK FOR ATMOS. THE IGNITION OCCURRED WHILE THE WORKERS WERE REMOVING THE PIG INSERTION TOOL DURING THE SIXTH OF A SERIES OF IN-LINE INSPECTIONS. A PIG EJECTED FROM THE LAUNCHER. AN ATMOS WORKER CALLED 9-1-1 AT 3:35 P.M. THE COLLIN COUNTY ASSISTANT FIRE MARSHAL WAS THE FIRST EMERGENCY RESPONDER ON THE SCENE, WITH OTHER AGENCIES, INCLUDING THE NATIONAL TRANSPORTATION SAFETY BOARD (NTSB) ARRIVING THEREAFTER FOR ADDITIONAL SUPPORT IN EMERGENCY RESPONSE. THE NTSB LEAD AN INVESTIGATION INTO THE MATTER. THE NTSB'S PIPELINE INVESTIGATION REPORT DETERMINED THAT THE PROBABLE CAUSE OF THE EVENT WAS A LEAKING MAINLINE VALVE THAT ALLOWED NATURAL GAS TO ENTER THE LAUNCHER WHERE IT MIXED WITH AIR, CREATING A FLAMMABLE GAS-AIR MIXTURE THAT WAS IGNITED BY AN UNDETERMINED SOURCE. DUE TO THE CIRCUMSTANCES OF THIS EVENT, THE ESTIMATED VOLUME OF COMMODITY RELEASED IS UNMEASURABLE. THEREFORE, ATMOS ENERGY HAS RESPONDED TO QUESTIONS A7 AND A21C WITH 1.00, WHICH IS THE MINIMUM VALUE ALLOWED. NOTE THAT THE DISTANCE REFLECTED IN RESPONSE TO QUESTION E6, IS ACTUALLY BETWEEN THE VALVE AND THE LAUNCHER DOOR, WHICH IS WHERE THE INCIDENT OCCURRED.