NORTHWEST PIPELINE LLC

Incident Narrative

IN APRIL OF 2020 WILLIAMS CONTRACTED WITH AN IN-LINE INSPECTION VENDOR TO COMPLETE TOOL RUNS ON THE WILLIAMS NORTHWEST PIPELINE 1400 POCATELLO TO BURLEY SEGMENT. HIGH-RES MFL TOOL RUNS WERE CONDUCTED, AND A PRELIMINARY REPORT WAS PROVIDED TO WILLIAMS WITH CERTAIN HIGH-PRIORITY ANOMALIES ON THE WEEK OF 5/25/2020. A PROJECT WAS INITIATED TO ADDRESS PRELIMINARY HIGH-PRIORITY ANOMALIES. IN PREPARATION TO EXCAVATE, WILLIAMS OPERATIONS CONDUCTED A LEAK SURVEY OF THE EXCAVATION AREA AND IDENTIFIED GAS READINGS AT THREE ANOMALIES WITHIN AN APPROXIMATE 350FT. SPAN ON 6/10/2020 NEAR M.P. 626.8. IN RESPONSE, THE LINE SEGMENT BETWEEN VALVES 9-1 AND 9-2 WAS SHUT-IN AND BLOWN DOWN ON THE SAME DATE. EXCAVATIONS OF THE ANOMALIES CONFIRMED PIN-HOLE LEAKS RESULTING FROM CORROSION. AFTER ASSESSING REPAIR OPTIONS WILLIAMS PROJECT MANAGEMENT DETERMINED THAT REPAIRS WOULD BE BEST ACCOMPLISHED THROUGH PIPE REPLACEMENT OF APPROXIMATELY 400'. THE PRELIMINARY COST OF REPAIRS EXCEEDS $50,000, WITH COST OF CONTRACTOR AND INTERNAL LABOR APPROACHING $600,000. IT WAS DETERMINED THAT THIS QUALIFIED AS A DOT REPORT-ABLE INCIDENT BASED ON COST WHEN WILLIAMS MANAGEMENT SETTLED ON PIPE REPLACEMENT AS THE PREFERRED REPAIR OPTION ON 6/12/2020. THE NRC WAS INITIALLY NOTIFIED OF THE INCIDENT ON 6/12/2020. AT THE TIME OF THIS REPORT THE LINE IS SHUT-IN AND BLOWN-DOWN. THE ANTICIPATED START DATE FOR THE REPLACEMENT PROJECT IS 7/13/2020 WITH ANTICIPATED PROJECT COMPLETION 8/1/2020. ON 8/12/2020 ALL REPAIRS ON THE LINE WERE COMPLETED, AND THE PIPELINE WAS RETURNED TO SERVICE.