NORTHERN BORDER PIPELINE COMPANY — Gas transmission and gathering — incident on 2013-11-30

Gas transmission and gathering incident in ARNEGARD, MCKENZIE County, ND. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 11450 NATURAL GAS released, $1,508 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20130121.

Operator ID: 13769.

Reported incident date: 11/30/2013 14:30.

Location detail: 36.2

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: AT 13:51 ON 11/30/2013 THE STATION CONTROL PANEL PROGRAMMABLE LOGIC CONTROLLER (PLC) FAILED DUE TO A DIGITAL INPUT CARD FAILURE. THE PLC FAILURE CAUSED THE STATION TO SHUT DOWN AND BLOW DOWN. THE STATION ISOLATION VALVES AND BLOWDOWN VALVE OPERATED CORRECTLY AND VENTED THE STATION MAIN GAS PIPING. AT THE SAME TIME, THE FUEL GAS VENT VALVES OPENED, BUT THE FUEL GAS ISOLATION VALVES, HV-1014 AND HV-1036 FAILED TO CLOSE. THE ON-CALL TECHNICIAN ARRIVED AT THE STATION AT 16:15 AND DISCOVERED GAS VENTING THROUGH THE FUEL GAS VENT VALVES. AT 16:25 THE FUEL GAS VENT VALVES WERE MANUALLY CLOSED. THE STATION WAS RESTORED TO SERVICE AT 01:15 12/01/2013.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $47,302 reported total cost, $37,759.197 in 1984 dollars, $47,517.335 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.