OSAGE PIPE LINE COMPANY, LLC

Incident Narrative

**UPDATE** 08/28/2020 ON SEPTEMBER 13, 2019, ENBRIDGE SOUTH TANK FARM PERSONNEL RESPONDED TO AN UNINTENDED MOVEMENT ALARM ON ENBRIDGE TANK 3010. ONCE ENBRIDGE PERSONNEL ARRIVED ON LOCATION, THEY DISCOVERED CRUDE OIL IN CONTAINMENT, INSIDE THE BERM OF TANK 3011. ENBRIDGE CHECKED THE TANK LEVEL ON TANK 3011, WHICH WAS UNCHANGED. ENBRIDGE THEN BLOCKED THE RELIEF LINE TO TANK 3010 AND OPENED UP THE LINE TO TANK 3013. THE LEVEL ON TANK 3010 STABILIZED AFTER THE RELIEF LINE WAS CLOSED. ENBRIDGE MADE INITIAL NOTIFICATIONS TO THE NRC. CLEAN-UP BEGAN IMMEDIATELY, WITH ENBRIDGE HANDLING INITIAL EFFORTS. ON SEPTEMBER 14, 2019 AT 13:21, HOLLY ENERGY PARTNERS (HEP) AND ENBRIDGE DETERMINED THAT THE LEAK ORIGINATED AT A CORROSION FAILURE ON A RELIEF LINE. HEP TOOK OVER CLEAN-UP EFFORTS ON SEPTEMBER 14 AND NOTIFIED THE NATIONAL RESPONSE CENTER (NRC) AT 13:47. HEP FILED A WRITTEN F 7000.1 ACCIDENT REPORT ON OCTOBER 14, 2019. HEP HAS COMPLETED A METALLURGICAL ANALYSIS OF THE FAILED PIPE SEGMENT AND HAS RESOLVED JURISDICTIONAL AND OWNERSHIP UNCERTAINTIES. AT THE TIME OF THE RELEASE, HEP DID NOT BELIEVE THAT IT OWNED THE RELIEF LINE. HEP THEN INVESTIGATED THE DOCUMENTATION RELATED TO ITS 2015 ACQUISITION OF THE NEARBY OSAGE PIPELINE FOR MORE INFORMATION. WHILE OUR REVIEW DID NOT CONCLUSIVELY DEMONSTRATE THAT THE RELIEF LINE CONVEYED IN THAT ACQUISITION, HEP HAS DECIDED TO RESOLVE THE UNCERTAINTY BY TAKING RESPONSIBILITY FOR THE RELIEF LINE. HEP ALSO EVALUATED THE JURISDICTIONAL STATUS OF THE RELIEF LINE AND HAS DETERMINED THAT THE LINE PROVIDES SURGE RELIEF TO AN OSAGE PIPELINE HEADER THAT RECEIVES OIL FROM THIRD PARTY, PART 195 REGULATED PIPELINES. HEP'S THIRD PARTY METALLURGICAL CONTRACTOR EVALUATED TWO PIPE SAMPLES FROM THE RELIEF LINE. THE CONTRACTOR OBSERVED INTERNAL CORROSION PITTING, CHARACTERIZED ITS MORPHOLOGY, AND CONCLUDED THAT MICROBIAL INDUCED CORROSION (MIC) WAS A CONTRIBUTING FACTOR FOR THE INTERNAL CORROSION. HEP HAS EVALUATED AVAILABLE INFORMATION ABOUT THE RELIEF LINE AND DETERMINED THAT IT WAS A DEAD LEG, THAT CONTAINED CRUDE OIL WITHOUT REGULAR FLOW. IT IS LIKELY THAT THIS LOW-FLOW ENVIRONMENT CONTRIBUTED TO THE MIC THAT LED TO THE FAILURE. CONSIDERING THESE FINDINGS, HEP HAS TAKEN A NUMBER OF STEPS TO IMPROVE SAFETY OF THE RELIEF LINE AND REDUCE THE LIKELIHOOD OF FUTURE FAILURES, INCLUDING: REPLACED A SUBSTANTIAL PORTION OF THE RELIEF LINE WITH INTERNALLY-COATED STEEL PIPE. THE INTERNAL COATING (SHERWIN WILLIAMS NOVA-PLATE 360) IS A PTFE BASE THAT LINES THE ENTIRE PIPE. INTERNAL SLEEVES WERE USED AT FIELD JOINTS, AND WERE PROTECTED DURING WELDING WITH BACKING STRIPS, AND WERE BONDED TO THE INTERIOR OF THE LINE. HEP HAS INSTALLED AND IS MONITORING ONE CORROSION COUPON ON THE RELIEF LINE. DEVELOPED A LINE FLUSHING AND CHEMICAL INJECTION PROCEDURE FOR THE RELIEF LINE. THE PURPOSE OF THE PROCEDURE IS TO PERIODICALLY SWEEP THE LINE OF STAGNANT CRUDE AND INJECT CORROSION INHIBITOR AS NECESSARY. INSTALLED A CHECK VALVE IMMEDIATELY DOWNSTREAM FROM THE ENBRIDGE RELIEF TANK (TANK 3010), TO PREVENT BACK-FLOW FROM THE TANK.