CITGO REFINING & CHEMICAL CO. L.P.

Incident Narrative

AT 3:00 AM ON NOVEMBER 12, 2018, LYONDELL PERSONNEL REPORTED A POTENTIAL PIPELINE LEAK JUST SOUTH OF LYONDELL VALVE STATION CLOSE TO CITGO VALVE STATION C (LATITUDE:27.80514; LONGITUDE: 097.47093). THE POTENTIAL LEAK WAS DISCOVERED DUE TO BUBBLING WATER IN THE DITCH. NO VISIBLE HYDROCARBON SHEEN WAS NOTED, INDICATING A PROBABLE NON-HYDROCARBON GAS LEAK. THE MORNING OF NOVEMBER 12TH, LYONDELL TESTED THEIR AREA GAS PIPELINES AND DETERMINED THAT LYONDELL WAS NOT THE SOURCE OF THE LEAK. LATER THAT DAY, CITGO TESTED THE N11 (PURCHASED H2) PIPELINE, NB7 (AIR LIQUIDE) PIPELINE, AND FINALLY THE N02 (#5 PLAT H2) PIPELINE. THE N02 PIPELINE WAS DETERMINED TO BE THE SOURCE OF THE LEAK. WHEN THE N02 LINE WAS DE-PRESSURED, THE BUBBLING IN THE DITCH SUBSIDED. THE SCADA SYSTEM WAS FUNCTIONAL AND OPERATING UNDER NORMAL CONDITIONS AT THE TIME OF THE INCIDENT. THE PIPELINE PRESSURE DROP DUE TO THE FAILURE WAS SO SMALL THAT IT DID NOT INDICATE ON THE CONTROL ROOM SCADA SCREEN AT THE PRESSURE POINT ADJACENT TO THE LEAK AREA. THE TEXAS RAILROAD COMMISSION WAS CALLED AND NOTIFIED OF THE LEAK AT 12:55 AM ON NOVEMBER 13, 2018. THE N02 LINE WAS DE-PRESSURED TO THE POINT WHERE THE BUBBLING STOPPED (NOON ON NOVEMBER 13TH) AND A PLAN WAS DEVELOPED TO ISOLATE THE LINE WHILE MINIMIZING EMISSIONS FROM THE WEST PLANT DUE TO H2 CONTAINMENT FROM THE #5 REFORMER. AN ADDITIONAL ISOLATION VALVE ON THE N02 LINE AT CITGO VALVE STATION C WAS INSTALLED IN ORDER TO ISOLATE THE N02 LINE FROM THE N11 LINE. HYDRO-EXCAVATION WAS ATTEMPTED TO UNCOVER THE LEAK LOCATION BUT, DUE TO SOIL INSTABILITY, THE DEPTH OF THE EXCAVATION (OVER 25 FOOT), AND ITS PROXIMITY TO I-37, THE DECISION WAS MADE TO ABANDON THIS ACTIVITY AND BACKFILL THE EXCAVATION. QUEST INTEGRITY WAS CONTRACTED TO SMART PIG THE N02 LINE. RESULTS FROM THE UT ILI SMART PIG IDENTIFIED 5 AREAS OF CONCERN. ALL LOCATIONS WERE AT THE BOTTOM OF THE PIPE AND AT LOW LYING AREAS. NO PROPERTY DAMAGE OCCURRED DUE TO THE INCIDENT, EITHER CITGO OR PROPERTY OF OTHERS. THE LEAK RESULTED IN 1.7 MMSCF OF GAS RELEASED TO ATMOSPHERE AN NRC CALL (REPORT #1242400) WAS MADE ON 4/10/19 AT 16:23 AN NCR 48-HOUR UPDATE (RENEWED REPORT #1242587) WAS MADE ON 4/12/19 AT 13:38 THE RE-ROUTE OF A PORTION OF THE N02 LINE IS NOW ALMOST COMPLETE. MAINTENANCE COSTS INCURRED DUE TO THE PARTIAL REPLACEMENT OF THE LINE ARE YET TO BE FINALIZED BUT COST ESTIMATES HAVE BEEN REPORTED HEREIN AS REQUESTED. ESTIMATED COMPLETION OF THE N02 PIPELINE REPAIR IS EXPECTED BY THE END OF NOVEMBER 2019; THE LINE CONTINUES TO BE ISOLATED AND DEPRESSURED AT THIS TIME.