ENBRIDGE ENERGY, LIMITED PARTNERSHIP

Incident Narrative

ON DECEMBER 3 THE PIPELINE MAINTENANCE (PLM) CREW WAS WORKING IN THE SUPERIOR TERMINAL BOOSTER PUMP 8 AND 9 DISCHARGE PIPING NEAR THE 225 MANIFOLD. THEY WERE INSTALLING A BRASS PLUG IN A 2 INCH TDW THREAD O-RING (TOR) FITTING WITH A TDW T-101 PLUGGING/TAPPING UNIT IN ORDER TO REMOVE A VALVE FOR REPLACEMENT. THE PLUG IN THE TOR WAS NOT PROPERLY SEATED AND WHEN THE VALVE WAS REMOVED, THE PLUG RELEASED WHICH CAUSED APPROXIMATELY 250 GALLONS OF CRUDE OIL TO SPILL ON THE GROUND. THE VALVE AND CAP WERE REINSTALLED TO STOP THE FLOW OF OIL. AN OUTAGE WAS SCHEDULED FOR FRIDAY DECEMBER 5 TO ISOLATE THE MANIFOLD PIPE TO ALLOW FOR INSPECTION AND PLUG INSTALLATION. IN ORDER FOR THE PLUG TO BE PROPERLY SEATED THE SHOULDER OF THE NEW BRASS PLUG NEEDED TO BE SANDED DOWN. ONCE SANDED DOWN, THE PLUG WAS FULLY INSERTED TO THE REQUIRED COMPLETION DISTANCE, AND THE VALVE REMOVED. IT WAS DISCOVERED THAT THE DEPTH MEASUREMENTS BEFORE INSTALLING THE PLUG WERE NOT CALCULATED (PER THE ENBRIDGE OPERATIONS AND MAINTENANCE MANUAL). IT WAS ALSO DETERMINED THAT THE THREADS ON THE TOR FITTING HAD BECOME DEFORMED WHICH PROHIBITED THE BRASS PLUG FROM BEING FULLY INSERTED AND ALLOWING FULL THREAD ENGAGEMENT. APPROXIMATELY 45 CUBIC YARDS OF CONTAMINATED SOIL HAS BEEN REMOVED FROM THE LEAK SITE. THE CONTAMINATED SOIL IS WAITING PROPER DISPOSAL FACILITY APPROVAL.