COLUMBIA GAS TRANSMISSION, LLC — Gas transmission and gathering — incident on 2015-08-09

Gas transmission and gathering incident in CHESTER SPRING, CHESTER COUNTY County, PA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 6659 NATURAL GAS released, $456,236 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: 20150111.

Operator ID: 2616.

Reported incident date: 8/9/2015 22:20.

Location detail: L-7210

Cause detail: FAILURE OF EQUIPMENT BODY (EXCEPT COMPRESSOR), VESSEL PLATE, OR OTHER MATERIAL

Cause detail: ON AUGUST 9, 2015 AT 22:19 EST, THE COMPRESSION UNITS AT EAGLE COMPRESSOR STATION (CS) LOCATED IN CHESTER SPRINGS, PA DID SHUT DOWN DUE TO AN EMERGENCY SHUTDOWN (ESD) SIGNAL THAT WAS TRIGGERED BY THE FIRE DETECTION/MELT-OUT SENSORS OVER UNIT 3. AT THE TIME OF THE ESD, ALL 4 UNITS AT THE STATION WERE RUNNING. WHEN THE STATION OPERATOR ARRIVED AT THE STATION IN RESPONSE TO A CALLOUT, HE NOTED PRESENCE OF FIRE IN THE COMPRESSOR BUILDING, LINE 1804 BLOWDOWN STACK WAS FOUND TO BE RELEASING NATURAL GAS (MATERIAL) INTO ATMOSPHERE AND LINE 1804 SUCTION HEADER EMERGENCY VALVE (L-7210) NOT FULLY CLOSED ALLOWING MATERIAL TO CONTINUE TO FLOW TO THE STATION AND OUT THE BLOWDOWN STACK. MATERIAL FLOWING INTO THE STATION THROUGH LINE 1804 WAS SHUT-OFF USING UPSTREAM BLOCK VALVES WHICH WERE MANUALLY CLOSED. THE SOURCE OF THE FIRE WAS DETERMINED TO BE A COOLANT LEAK ON A SHORT FLEXIBLE HOSE CONNECTION BETWEEN THE COOLANT HEADER AND HEAD CONNECTION AT CYLINDER NO. 5 ON AN ENGINE/COMPRESSOR PACKAGE. THE OTHER UNITS WERE INSPECTED FOR SIMILAR INDICATIONS ON THE ETHANOL HOSES BEFORE THE OTHER UNITS WERE RETURNED BACK INTO SERVICE. AFTER THE FULL INSPECTION AND SAFETY CHECKS ON THE OTHER UNITS WAS COMPLETED, THEY WERE RETURNED BACK INTO SERVICE IN SEQUENCE. UNIT NO. 3 WAS REPAIRED AND RETURNED BACK TO SERVICE AFTER NECESSARY REPAIRS/REPLACEMENTS WERE PERFORMED. KEY ACTION ITEMS WERE THE REPLACEMENT OF EMERGENCY VALVE(S) AND BLOWDOWN ACTUATORS (THIS PROJECT WAS UNDERWAY AT TIME OF THIS INCIDENT AND NEW VALVE ACTUATORS WERE ONSITE AWAITING INSTALLATION). REPLACEMENT OF THE PNEUMATIC COMPRESSORS WAS COMPLETED BACK IN 2015. ALSO, MODIFICATION TO VALVE INSPECTION PROCEDURE TO INCLUDE METHOD OF TESTING AND MAINTAINING AUXILIARY VALVES AND ACTUATOR HYDRAULICS. ENSURE NO EVIDENCE TO CONTAMINATION IN THE PNEUMATIC SYSTEM TO PREVENT MOISTURE ACCUMULATION IS HAMPERING THE EMERGENCY VALVE ACTUATOR FROM FUNCTIONING. INITIAL INCIDENT REPORT WAS SUBMITTED ON SEPTEMBER 04, 2015.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — FAILURE OF EQUIPMENT BODY.

PHMSA indexed costs: $474,815 reported total cost, $246,105.473 in 1984 dollars, $584,809.368 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.