MAGELLAN PIPELINE COMPANY, LP

Incident Narrative

AT 9:10 ON AUGUST 24, 2021, THE IOWA DEPARTMENT OF NATURAL RESOURCES NOTIFIED MAGELLAN OF A SHEEN OBSERVED NEAR THE ROCK RIVER IN SIOUX COUNTY, IOWA. RESPONSE PERSONNEL WERE DISPATCHED AND A LEAK WAS CONFIRMED IN THE CROSSING. CLEANUP ACTIVITIES WERE INITIATED. THE PIPELINE WAS TEMPORARILY REPAIRED WITH A TYPE B SLEEVE AND PLANS FOR AN HDD REPLACEMENT ARE UNDERWAY. THE DEFECT WILL BE CUTOUT AND SENT IN FOR METALLURGICAL TESTING FOLLOWING THE HDD. UPDATE: BASED ON THE METALLURGICAL REPORT, THE FIELD OBSERVATIONS, AND THE CHARACTERISTICS SEEN IN THE WATERWAY SURVEY INFORMATION, THE CRACK INITIATION LIKELY RESULTED FROM FATIGUE STRESS IMPOSED AT THE TOE OF THE FILLET WELD (ACTING AS A STRESS CONCENTRATION POINT) ON THE SLEEVE, ORIGINALLY INSTALLED USING A SINGLE WELDING PASS USING CELLULOSE RODS, DUE TO LACK OF WELD METAL IN THE FILLET WELD. TO PREVENT RE-OCCURRENCE, A PERMANENT PIPELINE REPLACEMENT WAS COMPLETED 11/2021, AND THE WATER CROSSING PROCEDURE WAS AMENDED TO INCLUDE REQUIREMENTS FOR CONTRACTORS TO IDENTIFY AND RECORD OBSERVATIONS OF RIVER WEIGHTS IN SURVEY DATA AND DRAWING DELIVERABLES. ADDITIONALLY, THE PROCEDURE WAS AMENDED TO INCLUDE ADDITIONAL GUIDANCE TO CONSIDER ILI STRESS ANALYSIS ON ANY SURVEYED CROSSING MEETING SPECIFIC CRITERIA, WHICH INCLUDE THE PRESENCE OF RIVER WEIGHTS. PART J NOTE: THE FINAL REPORTS FOR THE 2021 TOOL RUNS HAD NOT BEEN RECEIVED AT THE TIME OF THE RELEASE. SUPPLEMENTAL: (8/2023): PARTS G, H, J