EXXONMOBIL OIL CORPORATION

Incident Narrative

AT 7:30AM, EXXONMOBIL PIPELINE COMPANY (EMPCO) HCA PERSONNEL WERE CONDUCTING UNRELATED MAINTENANCE WORK IN THE AREA, WHEN THEY DETECTED LOWER EXPLOSIVE LEVEL (LEL) READINGS AT THE FACILITY FENCE LINE AND NOTICED ICE FORMING ON THE 12"" FLANGE AT THE DEMARCATION OF THE MC-41 CONNECTION SITE. HCA PERSONNEL CONTACTED LOCAL OPERATIONS OF THEIR FINDINGS, RESULTING IN FACILITY PERSONNEL ARRIVAL AT AROUND 7:50AM. LOCAL OPERATIONS INSTRUCTED OCC TO SHUTDOWN, ACCORDINGLY, COORDINATING EFFORTS WITH THE THIRD PARTY OPERATOR. THE AFFECTED PIPELINE SEGMENT WAS COMPLETELY ISOLATED AT 9:06AM. THE RELEASE ORIGINATED FROM A SLIGHT MISALIGNMENT OF FLANGES AT THE INTERFACE WITH THE THIRD PARTY. THE THIRD PARTY FLANGE BOLTS WERE TORQUED TO A LEVEL ABOVE THE TORQUE AT THE FLANGE WHERE THE LEAK OCCURRED. THE EMPCO FLANGE BOLTS WERE TORQUED TO GASKET MANUFACTURER'S SPECIFICATIONS. A SERIES OF ACTIONS WERE CONDUCTED TO RECOMMISSION THE PIPELINE. A TOTAL OF 200 LBS. (1.63 BBLS) OF ETHYLENE WERE RELEASED TO THE ATMOSPHERE. AGENCY NOTIFICATIONS WERE MADE TO THE TEXAS SPILL REPORTING HOTLINE AT 8:07AM (CONFIRMATION # 2019-1672), REACHING TEXAS RAILROAD COMMISSION AND TEXAS COMMISSION OF ENVIRONMENTAL QUALITY, AND THE NATIONAL RESPONSE CENTER (CONFIRMATION #1245579) AT 8:20AM CST.