COLUMBIA GULF TRANSMISSION, LLC — Gas transmission and gathering — incident on 2017-12-09

Gas transmission and gathering incident in HOLLOWAY, RAPIDES County, LA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 5229 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: 20180002.

Operator ID: 2620.

Reported incident date: 12/9/2017 20:44.

Location detail: BLOWDOWN VLV

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON DECEMBER 9TH, 2017, ALEXANDRIA COMPRESSOR STATION (CS) WAS SUBJECT TO AN UNINTENTIONAL RELEASE OF NATURAL GAS (MATERIAL) RESULTING IN MATERIAL LOSS EXCEEDING 3,000 MCF. ALEXANDRIA IS A TRANSMISSION CS THAT IS MAINTAINED BY COLUMBIA GULF TRANSMISSION, LLC (TRANSCANADA) AND IS LOCATED IN RAPIDES PARISH, NEAR THE TOWN OF HOLLOWAY, LOUISIANA. AT APPROXIMATELY 20:44 CST TRANSCANADA'S GAS CONTROL PERSONNEL NOTED VIA A SCADA ALARM OF A POTENTIAL PRESSURE DROP ON THE TURBINE PIPING ASSOCIATED WITH THE SUCTION SIDE OF LINE 200 AND 300 OF ALEXANDRIA'S CS. OPERATIONS PERSONNEL WERE IMMEDIATELY DISPATCHED TO INVESTIGATE THE EVENT. AT 21:03 CST, OPERATIONS PERSONNEL ARRIVED ON SITE WHERE THE UNINTENDED RELEASE OF MATERIAL WAS IDENTIFIED AND ISOLATED AT APPROXIMATELY 21:05 CST. ONCE OPERATIONS PERSONNEL ISOLATED THE LEAK AND MADE THE AREA SAFE, GAS CONTROL WAS NOTIFIED TO FOLLOW-UP ON THE NECESSARY FOLLOW-UP ACTIONS AND REQUIRED INVESTIGATIONS. THE PRELIMINARY MATERIAL LOSS CALCULATIONS WERE DETERMINED TO BE GREATER THAN 3,000 MCF, HENCE, THE EVENT WAS REPORTED TO THE NATIONAL RESPONSE CENTER AS AN INCIDENT. FURTHER INVESTIGATION DETERMINED THE PROBABLE CAUSE OF THE EVENT THAT LED TO A REPORTABLE INCIDENT INCLUDED CORRODED WIRES ON A VERSA VALVE SOLENOID CONNECTION IN CONJUNCTION WITH THE ASSOCIATED PLC LOGIC, IN WHICH WERE REMEDIATED BEFORE THE VALVE WAS RETURNED TO OPERATION. A 48-HR. UPDATE NOTICE WAS CALLED-IN TO THE NRC WHERE THE UPDATE REPORT NO. WAS 1199309.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $16,437 reported total cost, $15,261.721 in 1984 dollars, $19,191.784 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.