CONSOLIDATED EDISON CO OF NEW YORK

Incident Narrative

ON TUESDAY, NOVEMBER 2, 2010, THE PUBLIC REPORTED AN OUTSIDE ODOR COMPLAINT AT # 426 E 4 ST (MT. VERNON) TO THE GAS EMERGENCY RESPONSE CENTER. GAS DISTRIBUTION SERVICES (GDS) RESPONDED AND OBTAINED A 60% GAS-IN-AIR READING AT THE 20' LINE OF #426 E 4 ST. THE LEAK WAS CLASSIFIED TYPE-1 DUE TO THE PROXIMITY TO THE 24"" TRANSMISSION MAIN (230 PSI). GAS CONSTRUCTION CREWS AND SUPERVISION RESPONDED, INVESTIGATED AND AT 1536 HRS IT WAS DETERMINED THE LEAK MAY BE COMING FROM THE TRANSMISSION MAIN. THE 12"" 1957 STEEL TRANSMISSION INLET TO GAS REGULATOR GR-514 WAS BELIEVED TO BE THE SOURCE OF THE LEAK IN THE VICINITY OF A DRIP POT AND RISER. GR-514 WAS VALVED OFF AND THE LEAK EXCAVATED AFTER PRESSURE WAS BLED DOWN. THE EXCAVATION DETERMINED THE ACTUAL SOURCE OF THE LEAK WAS ON A 1"" COUPLING IN THE DRIP RISER AT THE INLET PIPING TO GR-514. PRESSURE CONTROL, GAS CONTROL AND GAS ENGINEERING DETERMINED THERE WOULD NOT BE ANY NEGATIVE SYSTEM IMPACT DUE TO THE LOSS OF THIS TRANSMISSION PRESSURE TO HIGH PRESSURE REGULATOR STATION. TRANSMISSION VALVES 25960 AND 28563 WERE CLOSED AT 1705 HRS AND PRESSURE REDUCTION THROUGH GR-514. THE LEAKING COUPLING WAS REMOVED AND A WELDED CAP INSTALLED ON THE DRIP POT WHERE THE RISER CONNECTS TO THE DRIP POT, REMOVING THE HAZARD. THE REGULATOR STATION REMAINED OFFLINE WHILE ADDITIONAL PLANNED WORK REPLACING 70' OF THE AFFECTED SECTION OF INLET PIPING TO THE REGULATOR STATION WAS COMPLETED. THE PIPELINE WORK WAS COMPLETED, AND THE MAIN RESTORED TO FULL SERVICE ON NOVEMBER 9, 2010 AT 23:01 HRS. THE US DOT AND NYS PSC WERE NOTIFIED. NOTE--THIS GAS DISTRIBUTION INCIDENT REPORT IS GENERATED TO REPLACE RECINDED GAS TRANSMISSION INCIDENT REPORT 20100094-15867