VIKING GAS TRANSMISSION CO — Gas transmission and gathering — incident on 2017-03-03

Gas transmission and gathering incident in Not Within a Municipality, POLK County, WI. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 23989 NATURAL GAS released, $0 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: 20170029.

Operator ID: 21252.

Reported incident date: 3/3/2017 20:45.

Location detail: CS 2222

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: THE INITIAL TRIGGER FOR THE EVENT WAS A BLOWN CIRCUIT PROTECTION FUSE. THE LOSS OF POWER ON THE CIRCUIT RESULTED IN AN UNINTENDED EMERGENCY SHUTDOWN OF THE OSCEOLA COMPRESSOR STATION. THE ESD ACTIVATED AND OPERATED AS DESIGNED. OPERATIONS PERSONNEL WERE NOTIFIED IMMEDIATELY AND ARRIVED ON SITE TO FIND GAS BLOWING FROM THE STATION DISCHARGE BLOW OFF. OPERATIONS ASSESSED THE SITUATION ON THE GROUND TO DETERMINE SAFETY OF THE ENVIRONMENT AND DETERMINE CAUSE OF THE ESD. ATTEMPTS WERE MADE TO CLOSE THE DISCHARGE BLOCK VALVE BUT THE ACTUATOR DID NOT FUNCTION. OPERATORS ISOLATED THE ESD SYSTEM TO ALLOW USE OF REVERSING GAS AND CLOSED THE DISCHARGE AND SUCTION BLOW OFF VALVES. THE DISCHARGE BLOCK VALVE ACTUATOR WAS FOUND TO CONTAIN ICE WHICH IMPEDED FUNCTION. THE ACTUATOR WAS THAWED, WATER DRAINED, TESTED AND RETURNED TO SERVICE. THIS REPORT WAS SUBMITTED IN MAY OF 2017 BUT WAS NOT ACCEPTED BY THE SYSTEM FOR UNKNOWN REASON.

PHMSA trend classification: significant incident, not serious.

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

PHMSA indexed costs: $61,000 reported total cost, $57,459.971 in 1984 dollars, $71,155.728 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.