COLUMBIA GAS TRANSMISSION, LLC — Gas transmission and gathering — incident on 2015-03-25

Gas transmission and gathering incident in MATHIAS, HARDY County, WV. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 5446 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: 20150056.

Operator ID: 2616.

Reported incident date: 3/25/2015 6:00.

Location detail: 8-IN BO VALVE

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON MARCH 25TH, 2015, AN 8-IN BLOW-OFF VALVE RELEASED INADVERTENTLY MATERIAL INTO ATMOSPHERE AT LOST RIVER COMPRESSOR STATION LOCATED IN THE TOWN OF MATHIAS, HARDY COUNTY, WV. THE COMPRESSOR STATION HEADER WAS ISOLATED AND THE SECTION WAS BLOWN DOWN TO STOP THE UNINTENDED RELEASE. PRELIMINARY INVESTIGATIONS INDICATED THAT THE SUPPLY TUBING HAD A LOW POINT THAT ALLOWED FOR THE COLLECTION OF MOISTURE WHICH, APPARENTLY, FROZE AND ISOLATED THE ACTUATOR FROM THE EMERGENCY SHUTDOWN (ESD) TRIGGER AIR SUPPLY. THEN, A NUISANCE LEAK WAS FOUND IN THE LAST TUBING CONNECTION TO THE ACTUATOR. THE COMBINATION OF THESE TWO FINDINGS, ALLOWED THE ESD TRIGGER PRESSURE ON THIS VALVE ACTUATOR TO LEAK DOWN TO THE POINT THE VALVE ACTUATED INADVERTENTLY, RELEASING MATERIAL INTO ATMOSPHERE. AS A RECOMMENDATION, (I) AN INSPECTION TO ESD VALVES WITH SIMILAR INSTALLATIONS WAS TO BE PERFORMED, (II) RE-ROUTING TO THE TUBING WAS INTRODUCED TO PREVENT THE COLLECTION OF THIS MOISTURE COLLECTION AND (III) RESEARCH THE INTRODUCTION OF AN ALARM WHENEVER ANY UPSET CONDITIONS DO EXIST TO SIMILAR VALVE INSTALLATIONS. THESE STEPS WILL NOT ALLOW THE CHAIN OF EVENTS LEADING TO THE ACTIVATION OF THE BLOW-OFF VALVE FROM FUTURE RE-OCCURRENCE.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $15,359 reported total cost, $14,241.326 in 1984 dollars, $17,486.185 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.