NORTHERN BORDER PIPELINE COMPANY — Gas transmission and gathering — incident on 2015-02-09

Gas transmission and gathering incident in Not Within a Municipality, DUNN County, ND. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 4000 NATURAL GAS released, $40,572 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: 20150029.

Operator ID: 13769.

Reported incident date: 2/9/2015 10:18.

Location detail: ND 272

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: A COMPRESSOR STATION EMERGENCY SHUTDOWN (ESD) WAS INITIATED BY THE FAILURE OF A BATTERY CHARGER IN THE STATION CONTROL SYSTEM. THE STATION BLOCK VALVES (SUCTION AND DISCHARGE) WERE COMMANDED CLOSED, AND THE STATION VENT VALVE WAS COMMANDED OPEN. THE DISCHARGE AND VENT VALVES OPERATED AS DESIGNED, BUT THE STATION SUCTION VALVE REMAINED OPEN. GAS VENTED THROUGH THE STATION VENT VALVE AND VENT STACK FOR 3 MINUTES BEFORE OPERATOR PERSONNEL CLOSED THE STATION VENT VALVE TO CONTROL THE GAS RELEASE. THIS VENTED AN AMOUNT OF GAS THAT EXCEEDED THE LEVEL REQUIRED FOR REPORTING AS AN INCIDENT. THE STATION SUCTION VALVE FAILED TO OPERATE DUE TO THE FAILURE OF A RUBBER DIAPHRAGM IN THE CONTROL SYSTEM FOR THE VALVE OPERATOR.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $55,320 reported total cost, $31,990.818 in 1984 dollars, $67,379.494 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.