CONSOLIDATED EDISON CO OF NEW YORK

Incident Narrative

ON THE EVENING OF MAY 8, 2015, CON EDISON WAS NOTIFIED THAT NEW YORK CITY DEPARTMENT OF TRANSPORTATION (NYCDOT) EMPLOYEES WERE INJURED WHILE REPAIRING A POTHOLE NEAR A NEW YORK CITY DEPARTMENT OF ENVIRONMENTAL PROTECTION (NYCDEP) WATER VALVE BOX AT THE INTERSECTION OF EAST 54TH STREET AND LEXINGTON AVENUE. FIRE DEPARTMENT CITY OF NEW YORK (FDNY) INITIALLY REPORTED TO CON EDISON THAT THERE WAS A SMOKING MANHOLE AT THE LOCATION. THE ELECTRIC CREW THAT RESPONDED FOUND THAT THE WATER VALVE COVER HAD BEEN BLOWN OFF ITS CASTING. THEY DETERMINED THAT THERE WAS NO ELECTRIC INVOLVEMENT, CONDUCTED A PRELIMINARY INVESTIGATION WHICH DETECTED TRACE METHANE, AND REQUESTED A GAS CREW TO RESPOND. A GAS EMERGENCY MECHANIC WAS DISPATCHED AT 22:52 HOURS TO INVESTIGATE AND FOUND NO INDICATIONS OF GAS IN THE WATER VALVE BOX. ON MAY 9, 2015 AT 1:18 HOURS, ANOTHER GAS EMERGENCY MECHANIC WAS DISPATCHED TO INVESTIGATE AND ALSO FOUND NO INDICATIONS OF NATURAL GAS IN THE WATER VALVE BOX. AT 13:37 HOURS, THE NYCDEP REPORTED TO THE GAS EMERGENCY RESPONSE CENTER (GERC) THAT THEY WERE RECEIVING GAS READINGS IN THE WATER VALVE BOX, WHICH HAD BEEN SUBSEQUENTLY BACKFILLED. A GAS EMERGENCY MECHANIC RESPONDED, INVESTIGATED AND REPORTED A 7% GAS READING IN THE WATER VALVE BOX. CON EDISON'S CHEMICAL LAB PERSONNEL WERE DISPATCHED TO THE LOCATION AND AT 20:32 HOURS THEY REPORTED FINDING A CONCENTRATION OF 5.9% NATURAL GAS-IN-AIR IN THE WATER VALVE BOX. CON EDISON DISPATCHED AN EMERGENCY CONSTRUCTION CREW TO RESPOND, VENTILATE AND INVESTIGATE FOR A POSSIBLE GAS LEAK. THE LEAK INVESTIGATION REVEALED POSITIVE GAS READINGS OVER A 16"" LOW PRESSURE CAST IRON GAS MAIN, LOCATED IN THE ROADWAY APPROXIMATELY 50' WEST AND 15' SOUTH OF THE WATER VALVE BOX. A LEAKING HUB ON THE 16"" MAIN WAS EXPOSED AND SEALED. A RETIRED, OUT-OF-SERVICE 8"" STEEL GAS MAIN ON THE NORTH SIDE OF EAST 54TH STREET BETWEEN LEXINGTON AND THIRD AVENUES WAS EXPOSED AND FOUND TO CONTAIN 90% GAS-IN-AIR. THE LEAK INVESTIGATION FOUND POSITIVE GAS READINGS NEAR THE NORTHWEST CORNER OF EAST 54 STREET AND THIRD AVENUE IN THE AREA OF A 16"" LOW PRESSURE CAST IRON GAS MAIN. THREE HUB CONNECTIONS ON THAT 16"" LOW PRESSURE GAS MAIN WERE EXCAVATED, FOUND TO BE LEAKING AND WERE REPAIRED. THE AREA WAS MONITORED, CONFIRMED CLEAR AND NO ADDITIONAL READINGS WERE DETECTED. THE FDNY FIRE MARSHAL INVESTIGATED, AND CONCLUDED THIS WAS A NATURAL GAS EVENT WITH AN UNKNOWN SOURCE OF IGNITION. CIG, PSC, DOT AND DEP WERE NOTIFIED. THIS WAS A SERIOUS LEVEL INCIDENT.