CITGO PETROLEUM CORPORATION (TERMINALS)

Incident Narrative

05/09/2022 AFTER COMPLETION OF A TANK TO TANK TRANSFER AT THE CITGO EAST CHICAGO TERMINAL, A LEAK WAS DISCOVERED AT TANK 30 ON TERMINAL IN-PLANT PIPING. TRANSFER BEGAN AT 02:00AM, THE OPERATOR PERFORMED HIS LINEUP AND WALKAROUND OF THE EQUIPMENT AND DID NOT OBSERVE DIESEL ON THE GROUND DURING THAT TIME. THE TRANSFER WAS SHUT DOWN AT 10:30AM, THE VALVE WAS CLOSED AT 11:30AM WHEN THE DIESEL WAS INITIALLY DISCOVERED NEAR THE TANK CHIME AND VALVE-FLANGE CONNECTION. AFTER INVESTIGATION OF THE SYSTEM AND TANK CONNECTIONS, IT WAS DISCOVERED THAT THE LEAK SOURCE WAS THE FLANGE CONNECTION ON THE TANK VALVE. AT THAT TIME, NO FURTHER ACTIVE LEAKAGE WAS OBSERVED. AT 12:35PM, THE MAINTENANCE TEAM ISOLATED THE LEAK AND TIGHTENED DOWN THE FLANGE TO REMEDIATE ANY POTENTIAL OF FURTHER LEAKAGE. 05/19/2022 THE PIPING LEADING TO TANK-30 WAS DRAINED TO REMOVE AND REPLACE THE DAMAGED GASKET. AFTER REMOVAL OF THE GASKET, IT WAS FOUND THAT IT WAS PINCHED IN MULTIPLE LOCATIONS WHICH IS EVIDENCE THAT IT WAS INSTALLED IMPROPERLY. THE REPLACED GASKET WAS TESTED UNDER MAXIMUM TANK HEAD PRESSURE AND THE SYSTEM RETURNED TO NORMAL OPERATION AT 11:00AM. 06/02/2023 UPDATED INCIDENT CAUSE, PART G TO ""INCORRECT OPERATION"" PER PHMSA AID REQUEST. NO OTHER CHANGES MADE.