EAST TENNESSEE NATURAL GAS, LLC (SPECTRA ENERGY PARTNERS, LP)

Incident Narrative

ORIGINAL REPORT: AT APPROXIMATELY 2:15 A.M. ON APRIL 20, 2017 AT ETNG'S BOWATER METER AND REGULATING STATION, A REGULATOR FAILURE CAUSED AN INCREASE IN PRESSURE RESULTING IN THE ACTIVATION OF A RELIEF VALVE. AN ALARM WAS TRIGGERED IN THE CONTROL ROOM, WHICH WAS ACKNOWLEDGED BY THE CONTROL ROOM OPERATOR. THE CONTROL ROOM OPERATOR ASSUMED IT WAS AN ERRONEOUS READING, AND THUS DID NOT FOLLOW PROCEDURES WHICH REQUIRED AN IMMEDIATE NOTIFICATION TO FIELD PERSONNEL TO CONDUCT A FOLLOW-UP FIELD INVESTIGATION. CONTROL ROOM SHIFT CHANGE OCCURRED AT APPROXIMATELY 7:00 A.M. , AND THE CONTROL ROOM OPERATOR LEAVING DID NOT VERBALLY DISCUSS THE ALARM WITH THE ONE COMING ON SHIFT, THOUGH IT WAS IN THE SHIFT LOG. AT APPROXIMATELY 6:45 A.M., THE LOCAL FIRE DEPARTMENT CALLED THE CONTROL ROOM TO REPORT THE GAS VENTING FROM THE RELIEF VALVE. THE CONTROL ROOM OPERATOR NOW ON SHIFT CALLED FIELD OPERATIONS, AND A TECHNICIAN WAS DISPATCHED TO THE SITE, SHUTTING OFF THE FLOW OF GAS. THE ESTIMATED GAS LOSS WAS 9 MMSCF DUE TO THE EXTENDED DURATION OF THE RELEASE. SUPPLEMENTAL REPORT: CONTROL ROOM SHIFT CHANGE OCCURRED AT APPROXIMATELY 5:10 A.M., AND THE CONTROL ROOM OPERATOR LEAVING DID NOT VERBALLY DISCUSS THE ALARM WITH THE ONE COMING ON SHIFT, THOUGH IT WAS IN THE SHIFT LOG.