CONSOLIDATED EDISON CO OF NEW YORK

Incident Narrative

ON JANUARY 13, 2013 AT 22:28 THE RESIDENT AT 1060 KNOLLWOOD RD (TG) REPORTED AN OUTSIDE ODOR AND GAS DISTRIBUTION SERVICES (GDS) RESPONDED, INVESTIGATED AND DETECTED 10% OVER THE 12"" 1948 245 PSI TRANSMISSION MAIN. GAS CONSTRUCTION -EMERGENCY RESPONSE FORCE (ERF) RESPONDED AND INVESTIGATED, DETECTING 95% DIRECTLY OVER THE MAIN. THE 95% READING OVER THE TRANSMISSION MAIN WAS AERATED AND 70% QUICKLY RETURNED. CONTINGENCY CASE 40-C-1 WAS IDENTIFIED AND (2) TRANSMISSION VALVES WERE INITIALLY STAFFED. AN OPERATIONAL PLAN WAS DEVELOPED TO ENSURE NO SYSTEM IMPACT OR CUSTOMER LOSS RESULTED AS A RESULT OF THE PLANNED ISOLATION OF REGULATOR STATIONS GR-484 AND GR-483. AT 12:51 ON JANUARY 14, 2013, TRANSMISSION V-40427 WAS CLOSED ISOLATING THE EFFECTED SEGMENT OF TRANSMISSION MAIN. PRESSURE WAS REDUCED TO APPROX 60 PSI AND EXCAVATION OPERATIONS WERE INITIATED. AROUND-THE-CLOCK OPERATIONS CONTINUED AND ADDITIONAL INVESTIGATION AND EXCAVATION WAS COMPLETED. APPROXIMATELY 21' SOUTH OF THE HIGHEST READING AND INITIAL EXCAVATION, A SECOND EXCAVATION OVER A 12"" COMPRESSION COUPLING WAS COMPLETED AND INVESTIGATION CONTINUED. THE COUPLING WAS FOUND NOT LEAKING. A WELDED REPAIR SLEEVE AND (2) HIGH HATS WERE INSTALLED. ON JANUARY 16, 2013 RESTORATION OPERATIONS WERE INITIATED AT 12:39 AND LEAK SURVEY MONITORED THE SEGMENT AS PRESSURE WAS RESTORED IN 60 PSI INCREMENTS AND NO LEAKS WERE FOUND. THE SEGMENT OF ISOLATED MAIN WAS RETURNED TO NORMAL OPERATING CONDITION AT AT 205 PSI. INVESTIGATION CONTINUED AND AT 14:27 A VISIBLE LEAK ON A 12"" TRANSMISSION COUPLING WAS CONFIRMED AT THE COMPRESSION END SEAL. AN OPERATIONAL PLAN WAS DEVELOPED AND THE LEAK WAS MONITORED AROUND-THE-CLOCK UNTIL SYSTEM CONDITIONS WERE FAVORABLE FOR ISOLATION. THERE WAS NO MIGRATION TOWARD BUILDINGS AND ALL SUBSURFACE STRUCTURES REMAINED GAS FREE DURING THIS PERIOD. ON JANUARY 19, 2013, THE SEGMENT OF MAIN FROM V-40427 TO GR-484 WAS ISOLATED AND PRESSURE REDUCED. THE LEAK WAS FULLY EXCAVATED AND A WELDED REPAIR SLEEVE WAS INSTALLED ON THE LEAKING COUPLING. THE WELDS WERE TESTED AND ALL TESTS PASSED. RESTORATION OPERATIONS WERE INITIATED AT 18:38, AND AT 21:31 THE SEGMENT OF MAIN FROM V-40427 TO GR-484 WAS RESTORED TO FULL LINE PRESSURE AFTER INCREMENTAL INCREASES. NO OTHER TRANSMISSION LEAKS WERE FOUND. THE SUPPLY TO GR-483 WAS RESTORED AT 22:39 AFTER V-34589 WAS OPENED AND LEAK SURVEY DETECTED NO LEAKS. REGULATOR STATION GR-483 WAS RETURNED TO SERVICE. THE US DOT AND NYS PSC WERE NOTIFIED. THIS WAS A SERIOUS LEVEL INCIDENT. NOTE--THIS GAS DISTRIBUTION INCIDENT REPORT WAS GENERATED TO REPLACE GAS TRANSMISSION INCIDENT REPORT 20130011-15731.