TENNESSEE GAS PIPELINE COMPANY — Gas transmission and gathering — incident on 2013-05-17

Gas transmission and gathering incident in NATCHITOCHES, NATCHITOCHES County, LA. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 3632 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: 20130048.

Operator ID: 19160.

Reported incident date: 5/17/2013 16:55.

Location detail: 40

Cause detail: VALVE LEFT OR PLACED IN WRONG POSITION, BUT NOT RESULTING IN AN OVERPRESSURE

Cause detail: TENNESSEE GAS PIPELINE (TGP) EMPLOYEES WERE TAKING DISCHARGE PIPING OUT OF SERVICE AT THE TGP NATCHITOCHES COMPRESSOR STATION (STATION 40) MAY 17, 2013 IN ORDER TO PREPARE FOR IMP HYDROSTATIC TESTING. THE EMPLOYEES FAILED TO ISOLATE A RELIEF VALVE DURING THE DEPRESSURIZATION SUCH THAT WHEN THE RELIEF VALVE'S SENSING LINE LOST PRESSURE, THE RELIEF VALVE ACTIVATED AS IT WAS DESIGNED TO DO. THE RELIEF VALVE RELEASED NATURAL GAS TO THE ATMOSPHERE IN A VOLUME THAT EXCEEDED THE INCIDENT REPORTABILITY LEVEL OF 3,000 MCF. UPON HEARING THE NOISE OF THE RELEASE, THE RELIEF VALVE'S ISOATION VALVE WAS CLOSED TO STOP THE RELEASE. THE RELIEF WAS RESET FOR NORMAL OPERATION.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: INCORRECT OPERATION — INCORRECT VALVE POSITION.

PHMSA indexed costs: $14,700 reported total cost, $11,810.908 in 1984 dollars, $14,693.612 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.