DOMINION ENERGY SOUTH CAROLINA, INC.

Incident Narrative

ON JULY 7, 2022, AT APPROXIMATELY 3:30 PM, DOMINION ENERGY SOUTH CAROLINA (DESC) RESPONDED TO A BROKEN GAS MAIN NEAR THE INTERSECTION OF I-20 AND US-1 (AUGUSTA RD), IN LEXINGTON, SC. SHORTLY AFTER THE DESC FIRST RESPONDER ARRIVED, THE FIRE DEPARTMENT ARRIVED AND TOOK CONTROL OF THE AREA. THE THIRD PARTY EXCAVATOR, A SUBCONTRACTOR OF THE COMPANY DOING WORK ON THE INTERSTATE, HAD GOUGED THE 6-IN STEEL, MEDIUM PRESSURE MAIN. THE EXCAVATOR DID NOT HAVE A CLEAR LOCATE TICKET. IN ADDITION, THE EXCAVATOR STATED THEY ASSUMED THE MAIN WAS ABANDONED. THE CONTRACTOR HAD SPOTTED THE MAIN AND FULLY EXPOSED IT BEFORE PROCEEDING TO PULL IT OUT OF THE GROUND. A NEARBY VALVE WAS CLOSED TO REDUCE THE LEAK RATE, THOUGH THE LINE STILL LEAKED AS IT WAS TWO-WAY FED. THE LEAK WAS STOPPED BY INSTALLING A STOPPER FITTING AT APPROXIMATELY 11:30 PM. THE DAMAGED PORTION OF PIPE WAS ALREADY SCHEDULED TO BE ABANDONED AT A LATER DATE. AFTER THE LEAK WAS STOPPED AND REPAIRS WERE MADE ON JULY 8, THIS SECTION OF PIPELINE WAS ABANDONED. DUE TO THE LOCATION OF THE DAMAGE, AND THE AMOUNT OF GAS THAT WAS ESCAPING THE DECISION WAS MADE TO SHUT DOWN AUGUSTA RD AND I-20 (BOTH DIRECTIONS OF TRAFFIC). THE INTERSTATE WAS SHUT DOWN DUE TO CARS DRIVING BY AND SPREADING THE PLUME OF GAS. GAS BLEW FOR APPROXIMATELY 8 HOURS AND THE INTERSTATE WAS SHUT DOWN FOR APPROXIMATELY 7 HOURS. DESC MANAGEMENT DECIDED TO MAKE A PHMSA NOTIFICATION DUE TO THE CONCERN THAT OUR ESTIMATED LOST GAS WOULD EXCEED 3,000 MCF AND THAT THIS EVENT WOULD BE CONSIDERED SIGNIFICANT IN NATURE. THOUGH THIS THRESHOLD WAS NOT EXCEEDED, THE INCIDENT WAS SIGNIFICANT IN THE JUDGMENT OF DESC, BECAUSE OF THE DURATION OF STOPPING TRAFFIC FLOW ON A MAJOR ARTERY AND SIGNIFICANT GOVERNMENT AND MEDIA ATTENTION. NOTE: E.3.B DATE MAOP ESTABLISHED IS ESTIMATED AS JAN 1, 2000. DECADE OF INSTALLATION IS KNOWN, BUT NOT EXACT DATE OF THE PIPELINE TEST. LDF: 517493