SOUTHERN NATURAL GAS CO — Gas transmission and gathering — incident on 2014-06-17

Gas transmission and gathering incident in CATAHOULA, ST. MARTIN County, LA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 1 NATURAL GAS released, $1,010,000 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: 20140075.

Operator ID: 18516.

Reported incident date: 6/17/2014 9:45.

Location detail: 11.688

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: AT 9:45 AM ON JUNE 17, 2014, A LEAK WAS DISCOVERED ON SOUTHERN NATURAL GAS COMPANY'S 20-INCH SOUTH SECTION 28 PIPELINE. THE LEAK IS LOCATED IN THE ATCHAFALAYA BASIN, ST. MARTIN PARISH, LOUISIANA, AND IS LOCATED IN A LAND LOCKED POND APPROXIMATELY 750 FEET FROM BAYOU L'EMBARRAS. TECHNICIANS WERE AT THE LOCATION, PERFORMING VALVE MAINTENANCE, WHEN THEY NOTICED BUBBLES COMING FROM THE WATER BENEATH THE PLATFORM WHERE A 20-INCH MAIN LINE VALVE OPERATOR IS LOCATED. THE LEAK WAS ISOLATED AND THE PIPING WAS DEPRESSURIZED. EXCAVATION TO EXPOSE THE LEAK SITE WAS DIFFICULT DUE TO THE FACILITY'S DEPTH AND THE PRESENCE OF WATER. AFTER A COFFER DAM WAS CONSTRUCTED IN ORDER TO GAIN ACCESS, THE LEAK WAS FOUND TO BE COMING FROM AROUND THE O-RING IN A CHECK VALVE IMMEDIATELY UPSTREAM OF THE MAIN LINE VALVE. THE LEAKING CHECK VALVE WAS REPAIRED AND THE LINE WAS PLACED BACK INTO SERVICE.

PHMSA trend classification: significant incident, not serious.

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

PHMSA indexed costs: $1,014,861 reported total cost, $515,117.578 in 1984 dollars, $1,267,840.571 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.