CONSOLIDATED EDISON CO OF NEW YORK

Incident Narrative

ON SATURDAY OCTOBER 15, 2011 AT 08:46 HRS A LEAK SURVEY CREW REPORTED TO THE GAS EMERGENCY RESPONSE CENTER (GERC) A TYPE-1 LEAK ALONG THE ROUTE OF THE TRANSMISSION SYSTEM AT 200' NORTH OF HAMILTON AVE ON BRONX ST., WHITE PLAINS. THE ONLY MAIN AT THIS LOCATION IS A 12"" 1948 TRANSMISSION PRESSURE MAIN OPERATING AT 237 PSI AT THE TIME OF DISCOVERY. ALL CONTINGENCY VALVES WERE IDENTIFIED AND BRONX GAS OPERATIONS ASSISTED IN MANNING THESE VALVES. WESTCHESTER GAS DISTRIBUTION SERVICES, GAS CONSTRUCTION, GAS CONTROL, PRESSURE CONTROL AND CENTRAL OPERATIONS RESPONDED. OPERATIONAL PLANNING INVOLVING ALL OPERATING AREAS, PRESSURE CONTROL, GAS CONTROL, LEAK SURVEY, TRANSMISSION ENGINEERING AND MAJOR PROJECTS WAS CONDUCTED. GAS CONSTRUCTION INVESTIGATED AND IDENTIFIED THE LOCATION OF THE LEAK. GAS CONTROL REDUCED OPERATING PRESSURE TO 68 PSI. GAS CONSTRUCTION EXCAVATED AND EXPOSED A 12"" COMPRESSION COUPLING LEAKING AT BOTH END RINGS. THE COUPLING WAS TIGHTENED TO TEMPORARILY SECURE THE LEAK. GAS CONSTRUCTION INSTALLED A PRE-FABRICATED WELDED REPAIR SLEEVE. WELDING OPERATIONS WERE COMPLETED ON OCTOBER 16, 2011 AT 09:15 HRS. THE REPAIR SLEEVE WAS PRESSURE TESTED AND FOUND OK . CORROSION OPERATIONS INSPECTED THE MAIN AND SAME WAS CLEANED AND COATED. LEAK SURVEY CONDUCTED A MOBILE SURVEY OF ISOLATED SECTION OF MAIN AND NO LEAKS WERE FOUND. GAS CONTROL RETURNED ROV-32717 TO THE FULLY OPENED POSITION AT 108 HRS AND PRESSURE RETURNED TO 234 PSI. AT 14:04 HRS., VALVES 25978 AND 25979 WERE FULLY OPENED. LEAK SURVEY COMPLETED THEIR SURVEY OF THE AREA AND DETECTED NO LEAKS. BACKFILLING OPERATIONS STARTED AT 14:58 HRS AND THE INCIDENT COMMAND STRUCTURE WAS TERMINATED. THE NYS PUBLIC SERVICE COMMISSION AND THE US DEPARTMENT OF TRANSPORTATION WERE NOTIFIED. THE NATIONAL TRANSPORTATION SAFETY BOARD CALLED FOR INFORMATION. THIS WAS A SERIOUS LEVEL INCIDENT. NOTE--THIS GAS DISTRIBUTION INCIDENT REPORT IS GENERATED TO REPLACE RESCINDED GAS TRANSMISSION INCIDENT REPORT 20110381-15383