ENBRIDGE PIPELINES (OZARK) L.L.C.

Incident Narrative

"ON MARCH 18, 2010, AT APPROXIMATELY 3:30 PM, A COMPANY INSPECTOR DISCOVERED CRUDE OIL ON THE GROUND AT THE CUSHING TERMINAL (NORTH). OPERATIONS WERE IMMEDIATELY NOTIFIED, AND UPON ARRIVAL, FOUND 7 BARRELS OF OIL HAD RELEASED FROM THE 12 INCH E LINE FACILITY PIPING. THE E LINE WAS SHUT DOWN, ISOLATED, AND BYPASSED, AND THE CRUDE OIL RELEASE CONTAINED AND CLEANED UP. THE AFFECTED PIECE OF PIPE HAS BEEN CUT OUT AND SENT TO DET NORSKE VRITAS (DNV), A THIRD PARTY INCIDENT INVESTIGATION COMPANY FOR EXAMINATION/FAILURE ANALYSIS. ENBRIDGE IS CURRENTLY WAITING FOR THE RESULTS OF THE DNV INSPECTION TO FINALIZE THE CAUSE OF THE FAILURE. THE E LINE HAS BEEN REPAIRED, AND WILL BE RETURNED TO SERVICE WHEN ENBRIDGE IS SATISFIED WITH THE CAUSAL ANALYSIS. THE FAILED SEGMENT OF PIPE (ALSO REFERRED TO AS THE SILVER GRILL LINE) WAS SENT TO DET NORSKE VERITAS (DNV) FOR EXAMINATION AND FAILURE ANALYSIS. THE FAILURE ANALYSIS INDICATES THE FAILURE OCCURRED AS A RESULT OF EXTERNAL CORROSION AT A LAP WELD THAT CONTAINED INCLUSIONS AT THE LAP LINE. IT WAS LIKELY THE SYNERGISTIC EFFECT OF THE REDUCED WALL THICKNESS AT THE LAP WELD AND A LOW BOND STRENGTH THAT RESULTED IN THE FAILURE. THE FINDINGS ALSO INDICATED THE MATERIAL MET THE DESIGN SPECIFICATION AT THE TIME OF MANUFACTURE, THE PRESENCE OF BACTERIA, CO2 AND H2S WERE AT MINIMUM LEVELS AND DID NOT CONTRIBUTE SIGNIFICANTLY TO THE FAILURE. ENBRIDGE WILL PERFORM AN INLINE TOOL INSPECTION AND CORRECT ANOMALIES EXCEEDING THE LIMITS OF SAFE OPERATION AND THEN HYDRO TEST THE REMAINING AFFECTED PIPING PRIOR TO RETURNING THE LINE TO SERVICE. UPDATE FOR FINAL REPORT MAY 2011 THE SILVERGRILL DISCHARGE LINE WILL NOT BE RETURNED TO SERVICE FOLLOWING THE INCIDENT ON MARCH 18, 2010. BECAUSE THERE WAS AN ALTERNATIVE FLOWPATH FOR OPERATIONS TO UTILIZE, ENBRIDGE REMOVED APPROXIMATELY 4250 FEET OF THE LINE THAT LEAKED AS PART OF THE DEADLEG PIPING REMOVAL (OPERATIONS) AND STATION PIPING PROJECTS (FACILITIES INTEGRITY)."