ENBRIDGE ENERGY, LIMITED PARTNERSHIP

Incident Narrative

ON AUGUST 9, 2021 AT APPROXIMATELY 10:38 AM CDT, AN ENVIRONMENTAL CONTRACTOR PERFORMING WORK ALONG THE RIGHT OF WAY NOTICED A SUSPICIOUS AREA WITH DEAD VEGETATION NEAR LINE 1 AT MP 1032. ENBRIDGE OPERATIONS PERSONNEL WERE NOTIFIED AT 11:26 AM CDT AND DISPATCHED PIPELINE MAINTENANCE PERSONNEL TO INVESTIGATE THE AREA. THE EDMONTON CONTROL CENTER WAS CONTACTED AND ALL LINES IN THE RIGHT OF WAY WERE SHUT DOWN AT 11:47 AM CDT. PIPELINE MAINTENANCE PERSONNEL ARRIVED ONSITE AT 12:00 PM CDT AND CONFIRMED DEAD VEGETATION AND A HYDROCARBON SMELL. THERE WAS NO FREE PRODUCT OR GAS ALARMS PRESENT SO ADDITIONAL RESOURCES WERE DISPATCHED TO BEGIN EXCAVATING THE AREA. AT 6:19 PM CDT, NDE DISCOVERED A PINHOLE ON THE GIRTH WELD AT MP 1032. FURTHER EXCAVATION FOUND APPROXIMATELY 1 BARREL OF CRUDE HAD BEEN RELEASED FROM LINE 1. ALL OTHER LINES IN THE AREA WERE RESTARTED AND CLEANUP BEGAN ON THE RELEASE. A CALL TO THE NRC WAS MADE ON AUGUST 9, 2021 AT 7:10 PM CDT BUT ENBRIDGE PERSONNEL WAS PLACED ON HOLD UNTIL 7:24 PM CDT WHICH IS THE TIMESTAMP SHOWN ON THE NRC REPORT (REPORT #1313243). THE 48-HOUR NRC NOTIFICATION WAS MADE ON AUGUST 11, 2021 AT 1:32 PM CDT (REPORT #1313400). A PLIDCO SLEEVE WAS INSTALLED AND LINE 1 WAS RESTARTED ON AUGUST 11, 2021 AT 11:19 AM CDT. APPROXIMATELY 105 CUBIC YARDS OF CONTAMINATED SOIL WAS REMOVED FROM THE RELEASE SITE. A CUTOUT WAS PERFORMED ON AUGUST 30. THE METALLURGICAL ANALYSIS IDENTIFIED A THROUGHWALL GIRTH WELD MANUFACTURING ANOMALY ASSOCIATED WITH A BURN-THROUGH FROM ORIGINAL CONSTRUCTION AS THE CAUSE OF THE RELEASE. SUPPORTING EVIDENCE FOR THIS CONCLUSION INCLUDES THE MORPHOLOGY OF THE LEAK PATH, THE ABSENCE OF A ROOT BEAD, THE PRESENCE OF WELD SLAG ALONG THE LEAK PATH, AND THE ABSENCE FOR ANY OTHER MECHANISM.