CONSOLIDATED EDISON CO OF NEW YORK — Gas transmission and gathering — incident on 2011-12-14

Gas transmission and gathering incident in NEW YORK, BRONX County, NY. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 364 NATURAL GAS released, $33,369 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: 20110399.

Operator ID: 2704.

Reported incident date: 12/14/2011 9:02.

Cause detail: THREADED CONNECTION/COUPLING FAILURE

Cause detail: ON DECEMBER 14, 2011 A CON EDISON PUBLIC IMPROVEMENT INSPECTION SUPERVISOR ON LOCATION FOR AN UNRELATED SEWER PROJECT WAS APPROACHED BY A CUSTOMER FROM 1710 VICTOR ST., BRONX, N.Y. REPORTING A GAS ODOR OUTSIDE. THE GAS EMERGENCY RESPONSE CENTER (GERC) WAS CONTACTED AND GAS DISTRIBUTION SERVICES (GDS) WAS DISPATCHED. UPON INVESTIGATING, GDS REPORTED A 20% GAS-IN-AIR READING 32' WEST OF THE BUILDING ALONG THE CURBLINE AND 60% GAS-IN-AIR READING IN A STREET PATCH IN CLOSE PROXIMITY. THE LEAK WAS CLASSIFIED A TYPE 1 DUE TO A 24" 1948 245 PSI TRANSMISSION MAIN ON THE STREET APPROXIMATELY 2' AWAY FROM A 6" LOW PRESSURE CAST IRON DISTRIBUTION MAIN. GAS CONSTRUCTION RESPONDED AND PERFORMED AN INVESTIGATION. AT 18:48 HRS., CONSTRUCTION SUPERVISION REPORTED TO THE GERC A PROBABLE TRANSMISSION MAIN LEAK WAS SUSPECTED OVER A 24" COUPLING WITH A 57% READING OVER SAME. AN OPERATIONAL PLAN WAS INITIATED AND ALL OPERATING AREAS, TRANSMISSION ENGINEERING, PRESSURE CONTROL, GAS CONTROL, LEAK SURVEY, GERC AND SENIOR MANAGEMENT PARTICIPATED. A PLAN TO ISOLATE THE SECTION OF TRANSMISSION AND REDUCE PRESSURE TO APPROXIMATELY 60 PSI WAS IDENTIFIED AND ONCE REDUCED, EXCAVATION OVER THE SUSPECTED LEAKING COUPLING WOULD BEGIN. CONSTRUCTION, GDS AND PRESSURE CONTROL CREWS PROCEEDED WITH THE TRANSMISSION MAIN ISOLATION AND PRESSURE REDUCTION. OPERATIONS CONTINUED AROUND-THE-CLOCK UNTIL THE 24" TRANSMISSION MAIN WAS EXPOSED AND A VISIBLE LEAK ON A 24" COUPLING WAS DETECTED. A WELDED REPAIR SLEEVE WAS INSTALLED TO SECURE THE LEAK. A SECOND WELDED REPAIR SLEEVE WAS INSTALLED ON THE COUPLING NORTH OF THE LEAK AS A PRECAUTION. ALL WELDS WERE X-RAYED AND APPROVED. ON SATURDAY DECEMBER 17, 2011 AT 01:30 HRS. PRESSURE RESTORATION BEGAN AND AT 05:00 HRS. NORMAL SYSTEM CONDITIONS RESUMED. THERE WERE NO EVACUATIONS OR INJURIES. THE NYS PSC, US DOT AND NYC DEP WERE NOTIFIED. THIS WAS A SERIOUS LEVEL INCIDENT.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — THREADED CONNECTION/COUPLING FAILURE.

PHMSA indexed costs: $41,413 reported total cost, $22,392.986 in 1984 dollars, $54,198.364 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.