SUNOCO PIPELINE L.P.

Incident Narrative

BEGINNING ON THE MORNING OF AUGUST 29, 2016 THE CONTROL CENTER BEGAN INVESTIGATING LINE IMBALANCE INDICATIONS IDENTIFIED VIA OVER/SHORT CALCULATIONS. UNTIL THE DISCOVERY OF THE RELEASE ON SEPTEMBER 10, 2016 NUMEROUS METHODS WERE EMPLOYED TO DETERMINE THE CAUSE(S) OF THE IMBALANCE. AT NO TIME DURING THE INVESTIGATION PROCESS DID THE IMBALANCE EXCEED ESTABLISHED NORMAL OPERATING TOLERANCES. THE OVER/SHORT CALCULATIONS WERE REVIEWED ALONGSIDE CPM DATA TO ASSESS ALIGNMENT BETWEEN WHAT THE TWO METHODS WERE REPORTING. CPM WAS NOT YET FULLY FUNCTIONAL AND WAS BEING RUN IN PARALLEL WITH NORMAL HOURLY OVER/SHORT LINE BALANCE CALCULATIONS. DURING THE TIMEFRAME BETWEEN AUGUST 29 AND SEPTEMBER 10 THE LINE WAS PATROLLED NUMEROUS TIMES VIA AERIAL, WALKING, DRIVING AND COMBINATIONS OF THESE METHODS. ADDITIONALLY, METERS WERE CHECKED FOR ACCURACY AND FUNCTION WITH ISSUES IDENTIFIED ON SEPTEMBER 3 AND 6 THAT REQUIRED REPAIRS. TANK TO TANK LINE BALANCE CALCULATIONS WERE ALSO EMPLOYED. ON SEPTEMBER 2 A STATIC PRESSURE TEST WAS CARRIED OUT BUT THE RESULTS DID NOT IDENTIFY A LEAK CONDITION. ON THE EVENING OF SEPTEMBER 9 A SECOND STATIC PRESSURE TEST WAS INITIATED. THIS TEST WAS TERMINATED AT 13:16 ON SEPTEMBER 10 WHEN INDICATIONS POINTED TO A SUSPECTED RELEASE. PATROL OF THE PIPELINE CONTINUED THAT DAY UNTIL THE DISCOVERY OF THE RELEASE VIA GROUND PATROL AT APPROXIMATELY 17:15. SUBSEQUENT TO DISCOVERY THE LINE WAS EXCAVATED AND A THROUGH WALL FAILURE WAS OBSERVED AT THE 6 O'CLOCK POSITION. THE FAILED PIPE WAS CUT OUT AND REPLACED. LINE WAS RESTARTED ON SEPTEMBER 23, 2016 UNDER A PHMSA REQUIRED 20% REDUCTION IN OPERATING PRESSURE. METALLURGICAL ANALYSIS OF THE FAILED PIPE CONCLUDED THAT THE CAUSE OF THE THROUGH WALL LEAK WAS EXTERNAL PITTING/CORROSION LOCATED AT THE 6 O'CLOCK ORIENTATION, ADJACENT TO A GIRTH WELD, AT A SINGLE PIT. THE PRIMARY CONTRIBUTING FACTOR TO THE CORROSION RATE WAS DC STRAY CURRENT INTERFERENCE FROM AN ADJACENT PIPELINE. ALL CONTAMINATED SOIL HAS BEEN REMOVED FOR PROPER DISPOSAL OR REMEDIATED ON SITE. PHMSA ISSUED A CORRECTIVE ACTION ORDER (CAO) IN RESPONSE TO THIS ACCIDENT (CPF 4-2016-5030H). A ROOT CAUSE FAILURE ANALYSIS (RCFA) WAS CONDUCTED AND IDENTIFIED RECOMMENDATIONS FOR IMPROVEMENT TO PRE CONSTRUCTION ASSESSMENTS AND CONTROL ROOM PROCEDURES. ACTIONS TO ADDRESS THESE RECOMMENDATIONS AND THE ROOT CAUSE OF THE ACCIDENT WILL BE CARRIED OUT UNDER THE PHMSA ISSUED CAO.