WILLIAMS FIELD SERVICES

Incident Narrative

ON MAY 14TH 2020 AT 6:50AM MST OPERATION PERSONNEL COMPLETING PREVENTIVE MAINTENANCE TASK DROVE UP TO THE SITE GATE AT PGX TANKAGE AND NOTICED A VAPOR CLOUD OF NGL AND ESD STATION. IT WAS DETERMINED A LEAK OCCURRED ON P-4267. THE LEAK LOCATION WAS WITHIN THE SECONDARY CONTAINMENT FOR THE NGL STORAGE TANKS AND 69 OUT OF 70 GALLONS THAT WAS RELEASED ON THE GROUND WERE RECOVERED FROM A VAC TRUCK. THE VALVE COVER GASKET WAS REPLACED SAME DAY AND WITH NO LEAKS DETECTED AT THAT POINT IN TIME. SECONDARY CONTRIBUTING FACTOR TO LEAK WAS PUMP SEAL IS ATTACHED TO A DRAIN LINE THAT IS CONNECTED TO A DRAIN TANK AND DURING THE PUMP SEAL LEAK THE DRAIN LINE WAS WORKING PROPERLY AND CONTINUED TO FILL TK-4813 UNTIL STATIC HEAD WAS GREAT ENOUGH TO CAUSED THE DIRECTION OF FLOW FROM THE TK-4813 BACK TO THE LEAK POINT ON P-4627 IN WHICH THE NGL DISCHARGED ONTO THE GROUND. TK-4813 CURRENTLY ONLY HAS A LOCAL LEVEL GAUGE WITH NO TRANSMITTING CAPACITY TO SCADA. ON MAY 18TH PUMP WAS IDLE AND DETERMINED LEAK WAS STILL PRESENCE FROM ANOTHER PERSONNEL PERFORMING PM TASK, PUMP WAS RE-ISOLATED AND PUT OUT OF SERVICE AS A PART OF MAINTENANCE ACTIVITY TO REPLACE A PUMP SEAL PACKING. ISSUED WAS RESOLVED AND PUT BACK INTO SERVICE WITHOUT ANY ADDITIONAL ISSUES. ACTIONS TAKEN TO REDUCE LIKELIHOOD OF FUTURE RELEASE. 1) DRAIN LINE HAS A PRESSURE SWITCH HIGH HIGH (PSHH4627) THAT WAS SET AT 30 PSI AND HAS BEEN DECREASED TO 10 PSI TO BE ABLE TO DETECT FUTURE BACK FLOW CONDITION.