COLUMBIA GAS TRANSMISSION, LLC

Incident Narrative

ON JUNE 7, 2019, AT APPROXIMATELY 13:00 EASTERN STANDARD TIME (EST), A COLUMBIA GAS TRANSMISSION, LLC. (COLUMBIA) OPERATIONS PERSONNEL WAS PERFORMING NORMAL ROUTINE MAINTENANCE TASKS ON LINE Z-215 AND ASSOCIATED SIDE LINES. AT THE LAWRENCEVILLE MEASURING STATION, THE OPERATIONS PERSONNEL NOTICED A WEAK SMELL OF ODOR OF GAS. BASED ON THE LOCATION AND THE AMOUNT OF GAS, THE LEAK WAS GRADED AS A GRADE 2 LEAK. ON JUNE 10, 2019, OPERATIONS PERSONNEL CONDUCTED ADDITIONAL SURVEYS FOR FURTHER INVESTIGATIONS. AFTER EXPOSING THE PIPE, IT WAS DISCOVERED THAT NATURAL GAS WAS LEAKING FROM AN UNMAPPED CASING ON LINE Z-228 UNDER SHRINE ROAD. AT APPROXIMATELY 14:00 EST OPERATIONS TEAM DECIDED TO UPGRADE THE LEAK TO A GRADE 1 AND CONTINUED MONITORING THE LEAK THROUGH THE NIGHT. ON JUNE 11, 2019 AT APPROXIMATELY 08:00 EST AFTER ESTIMATING THE COST OF THE PIPELINE REPAIR, IT WAS DECIDED TO REPORT THIS EVENT TO THE NATIONAL RESPONSE CENTER AS AN INCIDENT DUE TO COST OF THE REPAIRS. PIPELINE Z-228 IS A 2.375-INCH IN DIAMETER WITH0.154-INCH WALL THICKNESS. IT IS 164-FEET LATERAL PIPELINE FROM LINE Z-215 LOCATED IN CLARK COUNTY ON 3735 SHRINE RD, SPRINGFIELD, OHIO. ON JUNE 11, 2019, AT 16:35 EST A COMPRESSED NATURAL GAS TANKER WAS CONNECTED AND STARTED FEEDING THROUGH LAWRENCEVILLE POINT OF DELIVERY TO CONTINUE DELIVERABILITY TO THE DOWNSTREAM TOWN. AT 16:45 LINE Z-228 WAS BLOWN DOWN. ON JUNE 13, 2019, THE CONSTRUCTION CREW WAS DISPATCHED TO THE SITE AND ON JUNE 14, 2019 THE CASING AND PIPE WERE REMOVED AND SENT TO A COLUMBIA STORAGE FACILITY. AFTER INVESTIGATION, IT WAS IDENTIFIED THE INCIDENT WAS CAUSED DUE TO EXTERNAL CORROSION PITTING. THE INITIAL NRC REPORT NO.1248488 AND THE NRC 48-HOUR REPORT NO. 1248650 HAVE BEEN CALLED-IN ON JUNE 11TH AND JUNE 12TH RESPECTIVELY.