ONEOK GAS TRANSPORTATION, LLC — Gas transmission and gathering — incident on 2019-02-07

Gas transmission and gathering incident in EDMOND, LOGAN County, OK. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 6736 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: 20190044.

Operator ID: 31286.

Reported incident date: 2/7/2019 3:00.

Location detail: EDMONDSTORAGE

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: THURSDAY FEBRUARY 7TH AT 3:00 AM THE 8' RELIEF VALVE PROTECTING A-4002 FROM A-1129 WENT OFF AT 729 PSI WITH A 740 PSI SET POINT. MERCER VALVE HAD TESTED THE RELIEF VALVE WEDNESDAY FEBRUARY 4TH. THE EVENT LASTED FOR 15 MINUTES AT 729 PSI THROUGH A 8' RELIEF WITH AN APPROX. 6MMCF GAS LOSS. MERCER HAS RETESTED THE RELIEF VALVE AND FOUND TO BE SET AT 740 PSI SET POINT. THE FREEZING COLD TEMPERATURES AND PRESSURES WITHIN 11 PSI OF MAOP MAY HAVE BEEN THE LEADING CAUSE OF EVENT.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $19,537 reported total cost, $20,254.895 in 1984 dollars, $24,869.934 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.