WASHINGTON GAS LIGHT CO

Incident Narrative

ON 7/21/21 AT 1118 HRS, WASHINGTON GAS RECEIVED A REPORT OF A NATURAL GAS BROKEN LINE AT JOHN MARSHALL HIGHWAY AND TRADING SQUARE HAYMARKET, VA. 20169 FROM PRINCE WILLIAM COUNTY FIRE BOARD. 1119 HRS WASHINGTON GAS DISPATCHED FIELD OPS CREWS FOR RESPONSE. 1120 HRS WASHINGTON GAS RECEIVED AN ALARM ON SCADA OF PRESSURE DROPPING AND PRESSURE OPERATIONS CREWS WERE DISPATCHED. THE FIRST FIELD OPS CREW ARRIVED AT 1200 HRS AND WORKED WITH THE FIRE DEPARTMENT TO SECURE THE SCENE AND RELAY INFORMATION TO WASHINGTON GAS DISPATCH FOR ADDITIONAL SUPPORT. THE FIRST ARRIVING CREWS BEGAN TO LOCATE THE CLOSEST DISTRIBUTION VALVE. THE AREA OF THIS VALVE #1 HAD BEEN RECENTLY REGRADED AND HAD EXTENSIVE VEGETATION GROWTH. THE CREWS LOCATED A BROKEN PORTION OF A LINE MARKER (IT HAD RECENTLY BEEN BUSHED HOGGED AND BROKEN OFF) AND FOUND THE VALVE COVER WAS FOUND UNDER 3-4"" OF SOIL. CUSTOMER IMPACT THROUGH THE UTILIZATION OF CRITICAL VALVES TO STOP GAS, AND AREA OF THE DAMAGE (NATURAL GAS VENTING INTO THE ATMOSPHERE IN AN OPEN LOT AND THE CLOSEST STRUCTURE APPROXIMATELY 300FT. AWAY) WERE FACTORS CONSIDERED AS PART OF THE RESPONSE PLANNING. AT APPROXIMATELY 1445 HRS WASHINGTON GAS PRESSURE OPS BEGAN TO CONTROL THE FLOW OF NATURAL GAS, REDUCING THE PRESSURE TO 5PSIG BY USE OF VALVE #1. ONCE THE PRESSURE WAS STABILIZED CREWS BEGAN TO EXCAVATE UPSTREAM AND DOWNSTREAM OF THE BREAK AREA TO INSTALL (2) 2"" BYPASSES. THESE BYPASSES WERE INSTALLED TO MAINTAIN THE DOWNSTREAM CUSTOMERS AND TO USE THE EXPOSED 12' PLASTIC TO DOUBLE SQUEEZE THE PIPE. GAS WAS SQUEEZED OFF AT 0400 HRS ON 7/22/2021. FURTHER INVESTIGATION AND REPAIRS COMMENCED. CURRENT VALVE ASSIGNMENTS WERE REVALUATED NETTING AN INCREASE OF CRITICAL VALES ON THE EXISTING INFRASTRUCTURE.