"ENBRIDGE ENERGY, LIMITED PARTNERSHIP"

Incident Narrative

"ON DECEMBER 31, 2024, AT APPROXIMATELY 9:30 AM CST, OPERATIONS WAS PREPARING TO DRAIN WATER FROM THE ROOF OF TANK 17 AT FLANAGAN TERMINAL. UPON INSPECTION OF THE ROOF PRIOR TO DRAINAGE, PRODUCT WAS OBSERVED ON THE WATER. IT APPEARED THAT PRODUCT HAD SEEPED OUT OF SEVERAL LEG SLEEVES AND WAS SUBSEQUENTLY SPREAD ACROSS A LARGE SURFACE AREA OF THE TANK ROOF BY WIND AND WATER. A VAC TRUCK AND THIRD-PARTY CONTRACTORS WERE MOBILIZED TO THE SITE TO PUMP THE PRODUCT/WATER MIXTURE OFF THE ROOF AND BEGIN CLEANUP ACTIVITIES. THE INITIAL COST ESTIMATE FOR THE CLEANUP WAS PROJECTED TO BE LESS THAN $50,000. ON JANUARY 2, 2025, AT 11:22 AM CST, IT WAS CONFIRMED THAT THE COSTS HAD INCREASED DUE TO THE AMOUNT OF RAINWATER ON THE ROOF AND THE ADDITIONAL OVERTIME EXPENSES INCURRED RESULTING FROM THE INCIDENT OCCURRING ON A HOLIDAY. THE NRC WAS NOTIFIED ON JANUARY 2, 2025, AT 11:39 AM CST (NRC #1420275). A 48-HOUR UPDATE TO THE NRC WAS MADE ON JANUARY 4, AT 10:27 AM CST (NRC #1420399). APPROXIMATELY 10 GALLONS OF CRUDE OIL WAS RELEASED AND CONTAINED ON THE ROOF. AN INTERNAL INVESTIGATION DETERMINED THE CAUSE OF THE RELEASE WAS LIKELY DUE TO A DIFFERENCE IN BATCH QUALITY. SINCE THERE WAS ONLY ONE BATCH INTO AND OUT OF THE TANK BETWEEN THIS INCIDENT AND INSPECTION, IT IS POSSIBLE THAT THIS BATCH WAS OFF-SPEC AND MORE VOLATILE, INCREASING THE LIKELIHOOD OF VAPOR FORMATION AND BURPING, WHICH CAUSED PRESSURE TO PUSH THE PRODUCT ONTO THE ROOF. TO ADDRESS THIS, OPERATIONS WILL CONDUCT WEEKLY ROOF CHECKS AND DAILY DRONE FLYOVERS TO HELP NARROW DOWN THE RANGE OF MOVEMENTS THAT COULD BE CAUSING THESE ISSUES."