ENABLE MIDSTREAM PARTNERS, LP

Incident Narrative

ON 10-14-18 A LEAK WAS FOUND BY A LAND OWNER IN HARRISON COUNTY, TEXAS. THE LANDOWNER IMMEDIATELY NOTIFIED ENABLE GAS TRANSMISSION SYSTEM CONTROL. AN O&M TECHNICIAN WAS DISPATCHED TO VERIFY IF THE LEAK AND IT WAS CONFIRMED THAT LINE AJ-3 WAS LEAKING. THE RESPONDING EMPLOYEES THEN CONTACTED GAS CONTROL AND THE HARRISON CO SHERIFF'S OFFICE. THE LINE WAS TAKEN OUT OF SERVICE AND A REPAIR WAS MADE. DURING THE RELEASE, THE LIQUID ETHANE IMMEDIATELY VAPORIZED WHEN EXPOSED TO AIR RESULTING IN A LARGE ICE CRATER AT THE LEAK SITE. FIELD EXAMINATION OF THE LINE SHOWED LOCALIZED PITTING WITH A PINHOLE IN THE PIPELINE. THE DEFECT WAS REMOVED AND SENT FOR ANALYSIS. THE RESULTS OF THE ANALYSIS HAVE NOT BEEN COMPLETED AND A SUPPLEMENTAL REPORT WILL BE SUBMITTED WHEN THE ANALYSIS IS RECEIVED. THE INCIDENT WAS REPORTED TO THE NRC ON 10/14/2018 AT 19:29 CST (NRC #1227477) AND THE 48 HOUR FOLLOW UP (1227588) WAS PROVIDED ON 10/16/2018 09:15. ENABLE RECEIVED THE METALLURGICAL REPORT FROM THE LAB. THE LAB CONFIRMED THE CAUSE OF THE PINHOLE WAS STRAY CURRENT CORROSION, BUT COULD NOT IDENTIFY SPECIFICALLY AC OR DC. ENABLE FIELD INVESTIGATIONS AND MEASUREMENTS LEAD US TO BELIEVE THAT IT WAS STRAY AC CURRENT. SUPPLEMENTAL 3/20/2019 PART H NARRATIVE