AMERICAN MIDSTREAM (SIGCO INTRASTATE), LLC

Incident Narrative

OPERATIONS CONTROL CENTER NOTICED THROUGH SCADA ON SUNDAY, NOVEMBER 3 AT 15:45 THAT THE CHALMETTE PIPELINE WAS EXPERIENCING A DROP IN PRESSURE, ALONG WITH THE VOLUME OF GAS BEING DELIVERED. THEY IMMEDIATELY NOTIFIED THE OPERATIONS MANAGER FOR THE PIPELINE ASSET AND AERIAL PATROL WAS DISPATCHED TO DETERMINE IF THERE WERE VISIBLE SIGNS OF A LEAK. WITH NONE FOUND AND DUE TO THE LATE TIME, OCC CONTINUED TO MONITOR THE LINE THROUGH THE NIGHT. ON MONDAY, NOVEMBER 4, 2019, A HELICOPTER AND BOAT WERE BOTH DISPATCHED AT 0800 TO MADE ADDITIONAL PATROLS SINCE OCC CONTINUED TO SEE THE SAME INDICATIONS WITH THEIR SYSTEM. NO LEAKS WERE FOUND. AT 15:12, AN OFF DUTY OFFICER FOR THE SAINT BERNARD PARISH NOTICED DIRT AND MUD BEING SPRAYED FROM THE GROUND AND CONTACTED THIRD COAST MIDSTREAM OCC. OCC MADE NOTIFICATIONS PER THE CRM AND OPERATIONS RESPONDED TO THE VERETTE LEVY TO SHUT VALVES AND ENSURE THE BYPASS PORTION OF THE PIPELINE WAS NOT UTILIZED UNTIL REPAIRS COULD BE MADE. REPAIRS BEGAN ON DECEMBER 9, 2019 AND WERE COMPLETED ON MONDAY, DECEMBER 16, 2019 BY REPLACING A 24' SECTION OF CARBON STEEL PIPE. THE PIPE WAS DISCOVERED TO HAVE BEEN INSTALLED IN 1963 CROSSING A CONCRETE PIER BEAM (SIMILAR TO A CURB STOP) AND DUE TO THE PIPE BEING IN A MARSH AREA, APPEARED TO HAVE SETTLED, CAUSING THE PIPE TO FAIL. ANALYSIS PERFORMED BY A THIRD PARTY INDICATED SAMPLE MOST LIKELY FAILED BY CRACKING FROM THE OUTSIDE IN DUE TO COMBINATION OF EXTERNAL WALL THINNING FROM CORROSION, CORROSION FATIGUE AND SHEAR OVERLOAD FROM BENDING.