BRIDGER PIPELINE LLC

Incident Narrative

ON JULY 27, 2022 A COMPANY AREA SUPERVISOR AND TWO OTHER COMPANY EMPLOYEES WERE CONDUCTING FIELD SITE VISITS ON THE SUSSEX DIESEL LINE WHEN A LEAK WAS DISCOVERED AT GPS COORDINATES - LAT: 43.92226, LONG: -106.01862. THE LINE WAS NOT OPERATING AT THE TIME THE LEAK WAS DISCOVERED; HOWEVER, UPON DISCOVERING THE LEAK, THE AREA SUPERVISOR INSTRUCTED ONE OF THE OTHER EMPLOYEES ON SITE TO CALL THE CONTROL CENTER AND ASK THEM TO LOCKOUT THE PIPELINE SO IT COULDN'T BE RESTARTED. THE AREA SUPERVISOR THEN CALLED OPERATIONS MANAGEMENT AND INFORMED THEM OF THE LEAK AND DISCUSSED MOBILIZING RESOURCES TO THE SITE TO EXPOSE THE LINE AND DETERMINE THE LOCATION AND CAUSE OF THE LEAK. THE AREA SUPERVISOR THEN ISOLATED THE SEGMENT BY CLOSING THE NEAREST UPSTREAM AND DOWNSTREAM VALVES. WHEN THE COMPANY PIPELINE MAINTENANCE CREW ARRIVED ON SITE THEY BEGAN EXCAVATING AND EXPOSED THE PIPELINE IN THE AREA WHERE THE LEAK WAS SUSPECTED. AFTER THE LINE WAS EXPOSED, THEY DETERMINED THE LEAK WAS THE RESULT OF A CRACKED GIRTH WELD AND APPLIED A TEMPORARY LEAK CLAMP UNTIL THE LINE COULD BE FULLY EXPOSED AND THE SEGMENT DRAINED UP AND CUT OUT. THE LINE WAS THEN SUBSEQUENTLY DRAINED, FULLY EXPOSED, AND THE SEGMENT THAT LEAKED REMOVED. A METALLURGICAL ANALYSIS ON THE FAILED GIRTH WELD DETERMINED THE CAUSE OF RELEASE WAS DUE TO MULTIPLE ORIGIN FATIGUE FRACTURE INITIATED AT THE ID SURFACE OF THE FAILED PIPELINE WITH ALL CRACKS PROPAGATING RADIALLY OUTWARD TOWARDS THE OD. THE INITIATION AND PROGRESSION OF FATIGUE WAS VERY SLOW AND MOST LIKELY OCCURRED OVER MANY YEARS PRIOR TO THE FAILURE EVENT. A ROOT CAUSE ANALYSIS INVESTIGATION SUBSEQUENTLY DETERMINED THE GIRTH WELD FAILURE EVENT MOST LIKELY OCCURRED ON JUNE 11, 2022. UPON ASSESSING THE LEAK SITE, IT WAS DETERMINED IT WOULD BE BEST TO INSTALL A NEW PIPE SEGMENT AROUND THE LEAK AREA TO ALLOW FOR SAFE EXCAVATION OF CONTAMINATED SOILS AND APPROXIMATELY 2,750 FT. OF NEW 6"" PIPE WAS INSTALLED TO THE SOUTHEAST OF THE EXISTING PIPELINE. NO SURFACE WATER, GROUND WATER OR WILDLIFE WAS IMPACTED BY THE RELEASE; HOWEVER, SOIL IN THE LEAK AREA WAS CONTAMINATED AND WILL BE REMOVED AND MANAGED IN ACCORDANCE WITH WYOMING DEQ REQUIREMENTS. WHEN THE LEAK WAS DISCOVERED IT WAS QUICKLY DETERMINED IT MET STATE AND FEDERAL REPORTING THRESHOLDS; THEREFORE, NOTIFICATIONS WERE MADE TO THE WYOMING DEQ SPILL COORDINATOR AND THE NRC. IN ADDITION, COURTESY NOTIFICATIONS WERE MADE TO THE PHMSA ACCIDENT INVESTIGATION DIVISION AND THE PHMSA WESTERN REGION DIRECTOR.