ENBRIDGE ENERGY, LIMITED PARTNERSHIP

Incident Narrative

ON APRIL 23 AT APPROXIMATELY 10:10 AM CST, WHILE IN THE PROCESS OF REMOVING DRAIN LINE PIPING AT THE CLEARBROOK TERMINAL MANIFOLD AREA, OIL LEAKED PAST A 3"" DRAIN VALVE ON THE BOOSTER PUMP 3 AND 4 MANIFOLD HEADER, CAUSING AN ESTIMATED 10 BARRELS OF OIL TO LEAK OUT OF THE OPEN END OF THE PIPING AND THE COLD CUT THAT HAD BEEN MADE. THE TERMINAL GAUGER CONTACTED THE CONTROL CENTER AND REQUESTED THAT LINES 3 AND 4 ALONG WITH THE ASSOCIATED BOOSTER PUMPS 3 AND 4 BE SHUT DOWN. AS A PRECAUTION, ALL INCOMING LINES INTO THE CLEARBROOK TERMINAL WERE SHUT DOWN UNTIL THE SOURCE OF THE OIL COULD BE DETERMINED. THE INVESTIGATION REVEALED THAT THE 3"" DRAIN VALVE DID NOT PROPERLY SEAL, ALLOWING OIL TO FLOW PAST IT, ONTO THE GROUND. THE RESULTS OF THE FAILURE ANALYSIS REVEALED THAT A VARIETY OF DEBRIS WAS RESPONSIBLE FOR JAMMING THE DISC AND PREVENTING IT FROM BEING COMPLETELY CLOSED. THE ITEMS CONSISTED OF STAINLESS STEEL NUTS, BOLTS, AND WASHERS, A STAINLESS STEEL BRACKET, AND SOME IRON SULFIDE DEBRIS. THE SOURCE OF THE ITEMS AND HOW LONG THEY WERE STUCK IN THE VALVE IS UNKNOWN. AFTER REMOVING THE DEBRIS, THE VALVE WAS ABLE TO BE COMPLETELY CLOSED. APPROXIMATELY 40 CUBIC YARDS OF CONTAMINATED SOIL WAS DISPOSED OF TO AN APPROVED LANDFILL.