ENBRIDGE STORAGE (CUSHING) L.L.C.

Incident Narrative

ON MARCH 11, 2016 AT 8:30 AM, AN OPERATIONS TECHNICIAN DISCOVERED A RELEASE BY THE TANK 1296 MIXER AREA WHILE PERFORMING A ROUTINE INSPECTION. THE MAINTENANCE TECHNICIAN DETERMINED THE LEAK SOURCE TO BE AT THE STEEL TUBING CONNECTION ON THE MIXER. THE RELEASE AMOUNT WAS ESTIMATED TO BE 20 GALLONS AND WAS FULLY CONTAINED WITHIN THE TANK BERM AREA. THE MIXER WAS ISOLATED FOR REPAIRS AND THE STEEL TUBING CONNECTION WAS REPLACED ON MARCH 14, 2016. ALL CLEAN-UP AND REMEDIATION EFFORTS WERE COMPLETED ON MARCH 14, 2016 AND CONTAMINATED SOIL DISPOSED OF AT A DESIGNATED DISPOSAL FACILITY. AFTER FURTHER INVESTIGATION, THE BASIC ROOT CAUSE WAS DETERMINED TO BE DEFECTIVE EQUIPMENT THAT ORIGINATED FROM IMPROPER INSTALLATION OF COMPONENTS DURING CONSTRUCTION (MANUFACTURER FAILED TO PROPERLY SEAT THE TUBING FERRULE ON A COMPRESSION FITTING). JENSEN, THE MIXER MANUFACTURER, IS IN THE PROCESS OF IMPLEMENTING PRESSURE TESTING ON THIS TYPE OF VENT TUBE ASSEMBLY AS A QUALITY ASSURANCE CHECK IN CONJUNCTION WITH THE SENTRY SYSTEM IN ORDER TO PREVENT FUTURE TUBING AND CONNECTION RELATED DEFICIENCIES. IN LIEU OF NO MOP ON THE MIXER TUBING ITSELF, AN ESTIMATE OF HEAD PRESSURE WAS CALCULATED FOR PART E. WHEN TANK 1296 REACHES ITS FULL CAPACITY, THE CALCULATED HEAD PRESSURE IS 20.8 PSIG. AT THE TIME OF THE RELEASE, TANK 1296 WAS FILLED TO 612.0625 INCHES, WHICH CALCULATES TO 18.5 PSIG.