WASHINGTON GAS LIGHT CO

Incident Narrative

WASHINGTON GAS WAS NOTIFIED OF A POSSIBLE EXPLOSION AND FIRE AT 7806 EAGLE CT., ALEXANDRIA, VIRGINIA AT 9:42 AM ON 4/17/2014. UPON ARRIVAL, THE FAIRFAX COUNTY FIRE DEPARTMENT WAS ON SITE AND CONTROLLING THE SCENE. NATURAL GAS APPEARED TO BE RELEASING IN THE GENERAL AREA OF THE GAS METER. THE GAS WAS CONTROLLED BY SQUEEZE-OFF OF THE PLASTIC SERVICE LINE AT 11:08 AM. WASHINGTON GAS PERSONNEL CONDUCTED BAR/TEST IN THE AREA OF THE INCIDENT AND OBSERVED NO EVIDENCE OF GAS MIGRATION. AN ODORANT SAMPLE WAS TAKEN AND THE LEVEL OF ODORANT WAS DETERMINED TO BE ACCEPTABLE. A PRESSURE TEST WAS CONDUCTED ON THE PLASTIC SERVICE LINE FROM THE SQUEEZE-OFF POINT TO THE UPPER END OF THE STEEL SERVICE RISER. THE PRESSURE TEST WAS CONDUCTED AT OPERATING PRESSURE FOR 15 MINUTES. THE SERVICE HELD THE PRESSURE TEST. A FRACTURE WAS OBSERVED AT THE THREADED END OF THE RISER IMMEDIATELY BELOW THE STOPCOCK. FOLLOW-UP ANALYSIS OF THE THREADED END OF THE RISER INDICATED THAT THE FRACTURE OF THE STEEL PIPE WAS CAUSED BY THE APPLICATION OF A SINGLE HIGH LOAD EXCEEDING THE FRACTURE STRENGTH OF THE STEEL. THERE WAS NO INDICATION THAT ENVIRONMENT OR FATIGUE LOADING CONTRIBUTED TO THIS FAILURE. UPON GAINING ACCESS TO THE MOBILE HOME ON 5/5/2014, WASHINGTON GAS CONDUCTED A PRESSURE TEST ON THE REMAINING HOUSE LINES UNDER THE OBSERVATION OF THE FAIRFAX COUNTY FIRE MARSHAL. THE HOUSE LINE TO THE STOVE WAS FRACTURED AND THE STOVE WAS FOUND ON THE GROUND BENEATH THE FLOOR LEVEL OF THE MOBILE HOME. THIS LINE WAS CAPPED TO PERFORM THE PRESSURE TEST. THE TEST WAS CONDUCTED AT 10 INCHES OF WATER COLUMN FOR 13 MINUTES. THE HOUSE LINES HELD THE PRESSURE TEST. THE FRACTURED LINE TO THE STOVE WAS REMOVED FOR ANALYSIS. FAIRFAX COUNTY FM REPORT, IGNITION SOURCE CAN NOT BE DETERMINED BUT IS SUSPECTED AS INVOLVING THE GAS FURNACE. BASED UPON ALL KNOWN INFORMATION, THE CAUSE OF THE INCIDENT IS UNDETERMINED.