EXXONMOBIL PIPELINE CO

Incident Narrative

THE RELEASE WAS DISCOVERED AND REPORTED TO EMPCO SUPERVISION BY AN EMPCO TECHNICIAN CONDUCTING ROUTINE SITE INSPECTIONS ON SUNDAY, 10/07 AT APPROX. 5:36 PM. EMPCO AND AGENCY NOTIFICATIONS WERE MADE AND RESPONSE RESOURCES DEPLOYED PROMPTLY. TANK OVERFILL PROTECTION ALARM (TOPA) DETECTION DID NOT REACH ALARM STATUS AND THERE WERE NO PRIOR INDICATIONS OF A RELEASE. AT THE TIME OF THE RELEASE THE FAILURE MODE WAS UNDETERMINED. THE RACELAND STATION WAS IMMEDIATELY SHUT-DOWN. AFTER IT WAS DETERMINED THE TANK WAS THE RELEASE SOURCE, THE RACELAND PUMP STATION WAS REACTIVATED TO EMPTY THE TANK INVENTORY AND MINIMIZE ADDITIONAL RELEASE VOLUME. IMPACTED SOIL WAS EXCAVATED AND A SOIL IMPACT ASSESSMENT WILL BE COMPLETED TO DETERMINE ANY ADDITIONAL ACTIONS METHOD OF DISPOSAL. THE TANK WILL BE DEGASSED, CLEANED, INSPECTED AND REPAIRS COMPLETED. A CROSS-FUNCTIONAL INVESTIGATION TEAM WILL BE FORMED AND INCLUDE REPRESENTATIVES FROM OPERATIONS AND ENGINEERING. THE LOSS INVESTIGATION WILL BE COMPLETED AFTER THE TANK INSPECTION SO THE FAILURE MECHANISM CAN BE DETERMINED. THE TANK WAS LAST INSPECTED AND REPAIRED USING API 653 STANDARD IN 2010. FOUNDATION MOVEMENT (SOIL SETTLEMENT) IS BELIEVED TO HAVE CAUSE THE FLOOR TO FAIL IN A SEAM WELD. THE INVESTIGATION TEAM DETERMINED THE RELEASE OCCURRED DUE TO TANK BOTTOM FAILURE AT A LAP PATCH WELD SEAM DUE TO STRESS INDUCED FROM EXCESSIVE EDGE SETTLEMENT. THE TANK WAS RETURNED TO SERVICE ON 9/5/2014.