TRANSCONTINENTAL GAS PIPE LINE COMPANY, LLC — Gas transmission and gathering — incident on 2012-06-09

Gas transmission and gathering incident in LA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 0.1 NATURAL GAS released, $100,000 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: 20120065.

Operator ID: 19570.

Reported incident date: 6/9/2012 12:00.

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: 6/8/12 @ 7:40AM- STONE ENERGY VERM 131 OBSERVED A SHEEN NW OF THEIR PRODUCTION PLATFORM, THE OBSERVED A SHEEN ALONG WITH BUBBLES. STONE ENERGY REPORTED LEAK TO ES&H, THEY MADE NOTIFICATIONS TO USCG, NRC. NRC #1013919. 6/8/12 @ 9:40AM STONE ENERGY NOTIFIED WGP OPERATIONS OF BUBBLES AND SHEEN NW OF VERM 131 PLATFORM. 6/8/12- WGP OPERATIONS NOTIFIED WGP DISTRICT MANAGER OF BUBBLES AND SHEEN NEAR VERM 131 PLATFORM. 6/8/12- WGP OPERATIONS NOTIFIED WGP AREA ENGINEER OF POSSIBLE LEAK AT VERM 131, AREA ENGINEER STARTED LOOKING FOR DIVE BOAT TO RESPOND TO BUBBLES. 6/9/12@2:00AM- DIVE BOAT MOBBED OUT OF CAMERON AT 2:00AM, ARRIVED ON LOCATION AT VERM 131 AT 12:40PM. 6/9/12@ 4:30AM- MADE NOTIFICATION TO WGP GAS CONTROL LEAD OF LEAK ON OUR 16' PIPELINE, WGP GAS CONTROL MADE NOTIFICATIONS TO NRC, USCG AND EXTERNAL NOTIFICATIONS. NEW NRC# 1014068 6/9/12@ 6:30AM- 3 PRODUCERS ON 16' PIPELINE HAVE BEEN NOTIFIED AND SHUT IN. VERM 131, VERM 129 & VERM 87. 6/9/12@ 8:40PM- CONFIRMED THAT LEAK WAS COMING FROM 16' CHECK VALVE ON 16' PIPELINE SEGMENT #1584. LEAK WAS ON FLANGE ON TOP OF CHECK VALVE. CURRENTLY, WGP AREA ENGINEER WORKING ON A REPAIR PLAN TO MAKE REPAIRS TO 16' CHECK VALVE. ***UPDATE 10/30/2012*** PRODUCER STILL WORKING TO FIX LEAK AT CHECK VALVE. PRODUCER HAS GONE TO VALVE SITE TWICE TO TRY TO FIX CHECK VALVE BOTH TIMES VALVE HAS LEAKED. THE PIPE IS FILLED WITH WATER. NEXT OPTION WILL BE REPLACING CHECK VALVE WITH BLIND FLANGE AND BRING THE PIPELINE BACK TO SERVICE BY THE END OF NOVEMBER. ***REPAIR COMPLETED*** THE LEAKING CHECK VALVE WAS REPAIRED BY REPLACING A DAMAGED GASKET. THE LINE RESUMED ACTIVE STATUS ON JANUARY 1, 2013

PHMSA trend classification: significant incident, not serious.

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

PHMSA indexed costs: $102,500 reported total cost, $54,757.738 in 1984 dollars, $132,273.425 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.