"WBI ENERGY TRANSMISSION, INC."

Incident Narrative

"MONTANA DAKOTA UTILITIES (MDU) EMPLOYEE RESPONDED TO A NO-HEAT/GAS ODOR CALL AT THE FARMHOUSE NEAR THE LEAK AT 3:49 AM MT/ 4:49 AM CT AM MONDAY 2/17/25. CUSTOMER'S FURNACE WOULD RUN FOR A SHORT PERIOD OF TIME AND THEN SHUT DOWN. MDU EMPLOYEE SAID THE PRESSURE AT THE CUSTOMER'S HOUSE WAS ZERO. CUSTOMER ALSO SAID SHE HEARD A LOUD HISSING, FIRST HEARING THE HISSING ABOUT 3:00 PM MT/4:00 PM CT SUNDAY 2/16/25. MDU EMPLOYEE WENT TO THE FARM TAP TAKE-OFF AND PRESSURE WAS ZERO ON THE MDU SIDE THERE AS WELL. THE SOUND OF HISSING WAS LOUD, AND MDU EMPLOYEE CALLED WBI GAS CONTROL AND REQUESTED WBI EMPLOYEES TO ASSIST, WBI EMPLOYEES RESPONDED TO THE SCENE. MDU EMPLOYEE ALSO SAID THAT HE WAS RESPONDING TO GAS ODOR CALLS IN SIDNEY ON 2-16-25, HIS FIRST CALL WAS 2:00 AM MT/3:00 AM CT. THE GAS ODOR/LEL AND CALLS VARIED IN NUMBER WITH WIND DIRECTION; WHEN THE WIND WAS BLOWING TOWARD TOWN CALLS INCREASED. WBI EMPLOYEES RESPONDED TO THE LOCATION AND CONFIRMED SUSPECTED AREA OF THE LEAK TO WBI GAS CONTROL AT 7:30AM MST ON 2/17/25. PIPELINE WAS CONTINUALLY MONITORED UNTIL IT WAS SHUT IN AND BLOWN DOWN AT 2:00PM MST ON 2/17/25. LINE WAS REPAIRED AND RETURNED TO SERVICE BY 12:30AM MST ON 2/18/25. SUPPLEMENTAL INFORMATION 6/13/2025: THE FAILED SECTION WAS SENT INTO A LAB FOR METALLURGICAL ANALYSIS. THE RESULTS FROM THIS ANALYSIS CONFIRMED THAT THE CAUSE OF THE FAILURE WAS LACK OF PENETRATION AND MISALIGNMENT OF THE WELD WHEN THE WELD WAS MADE DURING THE INITIAL CONSTRUCTION OF THE PIPELINE IN 1947."