CONSUMERS ENERGY CO

Incident Narrative

ON SEPTEMBER 3, 2020 AT APPROXIMATELY 08:45 HOURS CONSUMERS ENERGY WAS NOTIFIED BY THE LEAK SURVEY CONTRACTOR OF A POSSIBLE GAS LEAK ON W. GRAND RIVER AVENUE, BETWEEN HILTON AND CHALLIS BRIGHTON, MICHIGAN (LIVINGSTON COUNTY). A GAS SERVICE WORKER (GSW) ARRIVED ONSITE AT 09:01 HOURS AND BEGAN A LEAK INVESTIGATION. DURING THE INVESTIGATION, MULTIPLE UNDERGROUND READS WERE DISCOVERED AS WELL AS READS IN NEARBY MANHOLES. THE GSW REQUESTED ADDITIONAL RESOURCES, GAS SERVICE AND GAS DISTRIBUTION, TO ASSIST WITH LEAK PROSPECTING AND TO CHECK NEARBY STRUCTURES TO ENSURE PUBLIC SAFETY. THE GAS DISTRIBUTION CREW ARRIVED ONSITE AT 10:40 HOURS AND BEGAN VENTING TRAFFIC SIGNAL MANHOLES WHERE GAS READS WERE DISCOVERED AND PROCEEDED WITH LEAK PROSPECTING TO IDENTIFY THE SOURCE OF THE GAS RELEASE. TRAFFIC CONTROL WAS SET UP AND EMERGENCY RESPONDERS (POLICE AND FIRE) WERE ONSITE TO ASSIST WITH TRAFFIC CONTROL. THERE WERE NO FATALITIES OR INJURIES AS A RESULT OF THE INCIDENT. THE DISTRIBUTION CREW CONTINUED EXPOSING A 6"" STEEL HIGH-PRESSURE PIPELINE AND LEAK PINPOINTING THROUGH THE NIGHT DISCOVERING A FROST BALL ON THE PIPELINE NEAR 8580 W. GRAND RIVER AVENUE. GAS OPERATIONS ISOLATED THE HIGH-PRESSURE PIPELINE FROM THE VALVE CLUSTER AT HOWELL RS 402 (HILTON ROAD) BY CLOSING DESIGNATED VALVE H140 AND ENSURING H138 WAS OPEN. THIS RESULTED IN A LOSS OF SERVICE TO 13 CUSTOMERS. THE GAS MECHANICS PROCEEDED TO CLOSED IN BOTH HP STATIONS TO ISOLATE THE LINE. THE VALVE STOPPAGE WAS UNSUCCESSFUL AND REQUIRED THE INSTALLATION OF CONTROL FITTINGS TO OBTAIN A COMPLETE SHUT-DOWN. THE PIPELINE WAS ISOLATED, CUT AND CAPPED ON SEPTEMBER 5, 2020 AT APPROXIMATELY 21:30 THE SOURCE OF THE LEAK WAS DETERMINE TO BE A 4"" HP BOLTED FLANGE FITTING OFF OF A MUELLER HP BOTTOM-OUT FITTING. THE FLANGE GASKET FAILED CAUSING GAS TO BE RELEASED. ON SEPTEMBER 10, 2020, APPROXIMATELY 390'-2"" PLASTIC MEDIUM-PRESSURE PIPELINE WAS INSTALLED AND SERVICE RESTORE TO THE 13 CUSTOMERS PREVIOUSLY SERVED BY THE HP PIPELINE. THE ISOLATED SEGMENT OF THE HIGH-PRESSURE PIPELINE HAS BEEN SCHEDULE FOR REPLACED AT A LATER DATE. A CONSTRUCTION PROJECT REPLACING 884 FEET OF 6-INCH STEEL HIGH PRESSURE PIPELINE WAS COMPLETED AND NORMAL OPERATIONS RESUMED ON NOVEMBER 20, 2020.