GRAYVILLE GAS DEPT, CITY OF

Incident Narrative

AT APPROXIMATELY 10:30 PM LOCAL TIME ON 5/4/2011 THE 6 INCH MAIN OWNED AND OPERATED BY THE CITY OF GRAYVILLE, ILLINOIS THAT SERVES GRAYVILLE, IL , CONSUMERS GAS COMPANY'S NORTH SYSTEM, AND MT. CARMEL PUBLIC UTILITY COMPANY RUPTURED IN A FLOOD PLAIN OF THE WABASH RIVER. THE PRESSURE MONITOR ON THE MT. CARMEL UTILITY SYSTEM INDICATED LOW PRESSURE AT APPROXIMATELY 11:00 PM. THE CITY OF GRAYVILLE WAS NOTIFIED AND THE INVESTIGATION REVEALED THAT THE PRESSURE AT THE GRAYVILLE STATION, WHICH NORMALLY OPERATES AT 400 PSIG, WAS IN THE NEIGHBORHOOD OF 100 PSIG. FURTHER INVESTIGATION REVEALED THAT THE 6 INCH TRANSMISSION MAIN HAD FAILED IN THE FLOOD PLAIN. THE 6 INCH MAIN WAS SHUT OFF AT THE GRAYVILLE STATION AT APPROXIMATELY 12:00 AM. THE SYSTEMS WERE KEPT IN OPERATION THROUGH THE 4 INCH TRANSMISSION MAIN THAT PARALLELS THE 6 INCH TRANSMISSION MAIN. THE 6 INCH VALVE AT THE TEXAS EASTERN DELIVERY POINT WAS STILL OPEN AND IT WAS DECIDED TO LEAVE THE VALVE OPEN UNTIL DAYLIGHT DUE TO THE DANGER OF TRAVERSING THE FLOOD PLAIN IN THE DARK. AT DAYLIGHT TWO BOATS WERE TAKEN TO THE DELIVERY POINT WHERE THE 6 INCH VALVE IS LOCATED. THE 6 INCH VALVE WAS CLOSED AT APPROXIMATELY 8:30 AM. THE 6 INCH MAIN IS UNDER SEVERAL FEET OF WATER AND THE DECISION ON REPAIRS WILL BE MADE WHEN THE WATER RECEDES AND THE SITE CAN BE ACCESSED.