ENBRIDGE PIPELINES (OZARK) L.L.C.

Incident Narrative

ON OCTOBER 23, 2012 AT APPROXIMATELY 11:50, AN ENBRIDGE CONTRACTOR OBSERVED OIL IN THE CUSHING CENTRAL TERMINAL IN THE MANIFOLD 212 VICINITY. THE TERMINAL SUPERVISOR WAS NOTIFIED AND DISPATCHED RESOURCES TO INVESTIGATE THE SITUATION. AFTER THREE DAYS OF EXCAVATING AND INVESTIGATING THE SOURCE OF THE LEAK, IT WAS THEN DETERMINED THIS INCIDENT WOULD EXCEED $50,000, THEREFORE MEETING THE REQUIREMENTS OF A CALL TO THE NRC AND A 30 DAY PHMSA REPORT. ALTHOUGH THE ACTUAL CAUSE WAS NOT IDENTIFIED, IT IS SPECULATED THAT THE BOLTS ON THE BOTTOM OF A 16"" FLANGE WERE ELASTICALLY DEFORMED BY THE DEAD LOAD OF OVERBURDEN, ALLOWING OIL TO ESCAPE. WHEN THE BURDEN WAS REMOVED, THE FLANGE WAS ALLOWED TO CLOSE BACK UP AND OIL HAS NOT ESCAPED FROM THE FLANGE SINCE. THE PIPELINE MAINTENANCE SERVICES GROUP CONFIRMED BOLTED CONNECTION INTEGRITY BY CHECKING TORQUE ON THE BURIED FLANGES IN THIS MANIFOLD AND ALL TORQUE VALUES MET THE REQUIRED VALUES. THE BURIED PIPING IN THIS MANIFOLD AREA WAS BACKFILLED WITH FLOWABLE FILL (PORTLAND CEMENT WITH NO AGGREGATE) TO MID-PIPE LEVEL PROVIDING SUPPORT SO THAT FUTURE DEFLECTION OF THE PIPE IS NOT POSSIBLE. THE MANIFOLD WAS RETURNED TO FULL OPERATIONAL SERVICE A FEW DAYS AFTER FINDING OIL.