CITGO REFINING & CHEMICAL CO. L.P.

Incident Narrative

AT APPROXIMATELY 1830 ON JUNE 28, 2023, CITGO PERSONAL OBSERVED A STAIN ON THE GROUND AT N27.8177 / W-97.43118 APPROXIMATELY 30 FEET NORTH OF CITGO'S 204 AREA FENCE LINE. THIS LOCATION IS OFTEN FREQUENTED BY TRACTOR TRAILERS AND OTHER HEAVY EQUIPMENT PRIOR TO ENTERING THE FACILITY WHICH MADE DETERMINING THE SOURCE OF THE STAIN QUESTIONABLE. THIS LOCATION IS ALSO A MAJOR RIGHT OR WAY FOR OTHER THIRD-PARTY PIPELINES. ON THE MORNING OF THE JUNE 29, 2023, IT WAS DECIDED TO EXCAVATE FOR FURTHER INVESTIGATION. AT 0900 AN 811 CALL WAS SUBMITTED TO INFORM THE OTHER PIPELINE OPERATORS IN THE AREA OF A POSSIBLE LEAK IN THE AREA AND OF OUR INTENTIONS FOR FURTHER INVESTIGATION. THE INITIAL CALL TO THE NRC WAS PLACED AT 1115 AND EXCAVATION OPERATIONS COMMENCED. AT 1348 THE DIESEL TRANSFER WAS HALTED AND THE CITGO'S PO3 CASA PIPELINE WAS ISOLATED UPSTREAM AND DOWNSTREAM. EXCAVATION AND INVESTIGATION OPERATIONS PROCEEDED THROUGHOUT THE NIGHT TO DETERMINE A LEAK SOURCE. ON JUNE 30, 2023 AT 1745 THE PO3 CASA PIPELINE WAS IDENTIFIED AS THE SOURCE OF THE LEAK. A 48-HOUR UPDATE TO THE NRC WAS CALLED SOON AFTER AT 2046. THE LEAK WAS IDENTIFIED TO BE, ISOLATED EXTERNAL CORROSION WITH A PINHOLE THROUGH-WALL FAILURE. THIS WAS DUE TO A COATING FAILURE, THE PO3 PIPELINE HAD THE ORIGINAL BITUMASTIC COATING. THE CAUSE OF THE COATING FAILURE WAS CONTRIBUTED TO THE AGE OF THE COATING. A PRESSURE TEST WAS CONDUCTED ON SEPTEMBER 29, 2019. AN INITIAL SPIKE TEST OF 139% (405 PSIG), OF THE MOP WAS HELD FOR AT LEAST 30 MINUTES. FOLLOWING THE SPIKE TEST, A TEST PRESSURE OF 125% (365 PSIG), OF THE MOP WAS HELD FOR AT LEAST 4 CONTINUOUS HOURS. SINCE THE ENTIRE LINE IS NOT VISIBLE, THE PRESSURE WAS HELD AT 110% (360 PSIG), OF THE MOP FOR AT LEAST 4 ADDITIONAL HOURS. THE PO3 IS UNDER CATHODIC PROTECTION. POTENTIALS FROM PREVIOUS ANNUAL REPORTS WERE DEPRESSED BUT STILL IN ACCEPTABLE RANGE ABOVE THE -850 MV PIPE TO SOIL THRESHOLD. RESULTS OF THE CLOSE INTERVAL SURVEY, PRIOR TO WRAP BEING INSTALLED, SHOWED A DROP BELOW THE -850MV THRESHOLD AT THE INCIDENT SIGHT AND NO INDICATION OF STRAY CURRENT. AS A RESULT A CURRENT REQUIREMENT TEST WAS REQUIRED TO DETERMINE ADDITIONAL CURRENT REQUIREMENTS. RESULTS OF THE CURRENT REQUIREMENT TEST, AFTER WRAP WAS INSTALLED, DETERMINED THAT PIPE TO SOIL POTENTIALS HAD ROSE ABOVE THE -850MV THRESHOLD AND ADDITIONAL CURRENT WAS NOT NEEDED. THE SCADA SYSTEM WAS FUNCTIONAL AND OPERATING AT THE TIME OF THE EVENT, HOWEVER, DID NOT INDICATE ANY ISSUE DUE TO THE SMALL LEAK. THE INCIDENT RESULTED IN AN UNINTENTIONAL RELEASE OF .66 BARRELS TO SOIL. THE VOLUME WAS CALCULATED BASED ON TIME DISCOVERED, PRESSURE OF THE PIPELINE, AND SIZE OF THE PINHOLE. THICKNESS READINGS WERE TAKEN AROUND THE LEAK LOCATION, ALL READINGS WERE NOMINAL. AS PER ASME B31.4 AN ENGINEERED CLAMP WAS INSTALLED ON JULY 1, 2023. THE PIPELINE WAS LEAK TESTED AND PUT BACK INTO SERVICE AT 1436.