TRUNKLINE GAS CO — Gas transmission and gathering — incident on 2011-06-10

Gas transmission and gathering incident in FRESHWATER CITY, VERMILION County, LA. Reported cause: CORROSION FAILURE. Reported consequences: 0 fatalities, 0 injuries, 5000 NATURAL GAS released, $1,452,000 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: 20110227.

Operator ID: 19730.

Reported incident date: 6/10/2011 13:37.

Location detail: 20+29

Cause detail: INTERNAL CORROSION

Cause detail: THIS PIPELINE LEAK WAS REPORTED TO TGC GAS CONTROL CENTER AT 1506 HRS. BY A LOCAL OILFIELD OPERATOR WORKING FOR AN UNIDENTIFIED PRODUCER IN THE AREA. THIS OPERATOR WAS WORKING FROM A FLOAT PLANE AND FLEW OVER THE LEAK LOCATION. GAS CONTROL CONTACTED THE LOCAL OPERATIONS PERSONNEL WHO DISPATCHED A HELICOPTER TO THE LOCATION TO VERIFY THE REPORT. UPON ARRIVAL THE LOCAL PERSONNEL CONFIRMED THE LEAK AND WAS ABLE TO LAND NEAR THE DOWNSTREAM VALVE SETTING AND CLOSE THE ISOLATION VALVE. ONCE ADDITIONAL PERSONNEL ARRIVED ON LOCATION THE HELICOPTER WAS DISPATCHED OFFSHORE TO VR 26B AND THE UPSTREAM ISOLATION VALVE CLOSED AND THE PIPELINE WAS SHUT IN AT 1701 HRS. AND PRESSURIZATION PROCESS COMMENCED. DURING THE DEPRESSURIZATION PROCESS THE PIPELINE BEGAN TO LEAK CONDENSATE. TGC PERSONNEL IMMEDIATELY DISPATCHED AN LOCAL OSRO TO THE LOCATION TO ISOLATE THE RELEASE AND BEGIN CLEAN-UP OPERATIONS. ONCE THE RELEASE WAS CONTAINED PIPELINE REPAIR RESOURCES WERE MOBILIZED AND AN ATTEMPT WAS MADE TO EXCAVATE THE PIPELINE. BECAUSE OF THE DEPTH OF THE PIPE AND THE UNSTABLE SOIL CONDITIONS THE DECISION WAS MADE TO BRING IN A GEOTECHNICAL ENGINEERING CONTRACTOR TO PERFORM SOIL ANALYSIS AND PROVIDE AN EXCAVATION SHORING SYSTEM TO MEET OSHA REGULATIONS. THE INVESTIGATION AND REPAIR OPERATION ARE ON HOLD UNTIL THE SHORING SYSTEM IS AVAILABLE AND CAN BE INSTALLED TO ALLOW SAFE ENTRANCE INTO THE EXCAVATION. THIS LINE WAS ABANDONED FOLLOWING THE INVESTIGATION INTO REPAIRING THE PIPELINE. THE COST AND DIFFICULTY OF REPAIR WERE THE ATTRIBUTING FACTORS FOR THE DECISION.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: CORROSION — INTERNAL.

PHMSA indexed costs: $1,870,973 reported total cost, $1,011,927.554 in 1984 dollars, $2,447,904.911 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.