ALYESKA PIPELINE SERVICE CO

Incident Narrative

ON JUNE 7, 2019, DURING A SHORT DURATION SHUTDOWN FOR MAINTENANCE OF THE TRANS ALASKA PIPELINE SYSTEM SECURITY DISCOVERED APPROXIMATELY 4 GALLONS OF CRUDE HAD LEAKED FROM CHECK VALVE (CKV) 110 LOCATED AT PIPELINE MILE POST (PLMP) 701.9. ALL OF THE CRUDE WAS CAPTURED IN CONTAINMENT WITH NO LEAK TO GROUND. THE CHECK VALVE WAS LEAKING AT AN ESTIMATED 4 CUPS PER MINUTE AT THE TIME. ALYESKA INITIATED MITIGATIONS AND REPAIRS. THE VALVE CONTINUED TO LEAK AT DIMINISHING RATES WITH CORRECTIVE ACTIONS SUCH AS GREASE PACKING AND VALVE OPERATION UNTIL THURSDAY JUNE 13 WHEN THE ACTUATOR WAS REMOVED. ALL CRUDE WAS CAPTURED AND NO SOIL OR WATER CONTAMINATION OCCURRED. A TEMPORARY REPAIR WAS COMPLETED ON 6/17 TO ENCAPSULATE THE VALVE SHAFT EXTENSION. ALYESKA REMAINED IN COMMUNICATION WITH THE LOCAL PHMSA OFFICE, INSPECTIONS HAVE OCCURRED AND ARE ONGOING. UPDATE: ALYESKA HAS PERMANENTLY REPAIRED THE ACTUATOR AND VALVE SHAFT EXTENSION AS OF AUGUST 9, 2019. FURTHER REVIEW OF OTHER LOCATIONS FOR EXTENT OF CONDITION REVEALED THE POTENTIAL FOR FAILURES AT CHECK VALVES 111, 114, AND 95A. THESE LOCATIONS WERE REPAIRED WITH ALL WORK COMPLETED AUGUST 11, 2019. NO ADDITIONAL ACTION OR REPAIR IS NEEDED.