ENBRIDGE ENERGY, LIMITED PARTNERSHIP

Incident Narrative

ON AUGUST 25, 2022 AT APPROXIMATELY 11:36 CDT, A CONTRACTOR WAS CONDUCTING SANDBLASTING ON THE 36"" TANK HEADER AT AN INTEGRITY DIG NEAR TANK 23 AT THE SUPERIOR TERMINAL. CONTRACTOR NOTICED OIL APPEARING ON THE BOTTOM OF THE PIPE, AND NOTIFIED ENBRIDGE EMPLOYEE. THE EDMONTON CONTROL CENTER WAS CONTACTED AND THE PIPING WAS ISOLATED. APPROXIMATELY ONE GALLON OF CRUDE OIL WAS RELEASED INTO THE CONTAINMENT TUB THAT WAS UNDER THE TANK PIPING WITH NO IMPACT TO SOIL. THE AREA OF CONCERN WAS TEMPORARILY PLUGGED UNTIL FURTHER REPAIRS COULD BE MADE. IT WAS DETERMINED AT 14:10 CDT THAT THE REPAIR WOULD EXCEED THE $50,000 NRC REPORTING THRESHOLD. THE NRC WAS NOTIFIED AT 14:54 CDT (REPORT # 1345537). A SPLIT SLEEVE PLIDCO REPAIR CLAMP WAS INSTALLED TO COMPLETE THE REPAIR AND NDE TESTING WAS CONDUCTED ON THE TANK LINE PRIOR TO IT BEING RETURNED TO SERVICE AT 17:00 CDT. THE NRC 48-HOUR UPDATE NOTIFICATION WAS COMPLETED ON AUGUST 26, 2022 AT 14:47 CDT (REPORT# 1345633). THE CAUSE OF THE RELEASE HAS BEEN ATTRIBUTED TO INTERNAL CORROSION. THE LOCATION OF THE FAILURE WAS ON A DEAD LEG SECTION OF PIPING THAT DOES NOT SEE FLOW, CAUSING WATER TO SEPARATE AND POOL AT THE BOTTOM OF THE PIPE RESULTING IN A PINHOLE WHEN SANDBLASTED. THIS SECTION OF PIPING WAS SPECIFICALLY IDENTIFIED FOR THE INTEGRITY DIG AND ASSESSMENT DUE TO THESE CHARACTERISTICS. FURTHER INSPECTION AND PLANNING IS REQUIRED TO DEVELOP A PATH FORWARD ON A PERMANENT REPAIR. THE ACTUAL VOLUME RELEASED AT SUPERIOR TERMINAL WAS 0.02 BARRELS OF CRUDE OIL. THE PHMSA PORTAL DOES NOT RECOGNIZE VOLUMES LESS THAN 0.1 BARRELS THEREFORE THAT IS THE VOLUME ENTERED.