NESSON GATHERING SYSTEM, LLC — Type R reporting-regulated gas gathering — incident on 2025-12-10

Type R reporting-regulated gas gathering incident in Not Within a Municipality, WILLIAMS County, ND. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 41360 NATURAL GAS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20260001.

Operator ID: 39033.

Reported incident date: 12/10/2025 16:00.

Cause detail: VALVE LEFT OR PLACED IN WRONG POSITION, BUT NOT RESULTING IN AN OVERPRESSURE

Cause detail: EVENT SUMMARY ON DECEMBER 18, AT APPROXIMATELY 11:30 A.M., AN OPEN VALVE WAS DISCOVERED NEAR THE SHOSHONI PAD IN WILLIAMS COUNTY, APPROXIMATELY 50 MINUTES FROM WILLISTON. � THE TEAM ONSITE CLOSED THE VALVE AND STOPPED THE LEAK. � IT�S ESTIMATED THAT THE VALVE HAD BEEN OPEN SINCE APPROXIMATELY DECEMBER 10, WHEN THE TEAM WAS CONDUCTING PIPELINE COMMISSIONING. � REPORTS HAVE BEEN MADE TO THE RELEVANT AUTHORITIES INCLUDING THE NATIONAL RESPONSE CENTER AND THE NORTH DAKOTA DEPARTMENT OF ENVIRONMENTAL QUALITY. � THERE ARE NO INJURIES. INCORRECT OPERATION WE FOLLOW OUR WORK MANAGEMENT PROCESS (USING PERMIT VISION) FOR ENERGY ISOLATION, WHICH SPECIFIES THE VALVES TO BE OPENED FOR VENTING. DURING THE JOB, THE DESIGNATED 2" VENT VALVE WAS FROZEN, AND THE EMPLOYEE OPENED AN ADJACENT VALVE INSTEAD, THIS CONSTITUTED A CHANGE IN THE ISOLATION PROCESS THAT REQUIRED A NEW WORK PERMIT BUT WAS NOT COMPLETED. AS A CORRECTIVE ACTION, WE CONDUCTED REFRESHER TRAINING FOR PIPELINE OPERATORS ON THE PERMITTING PROCESS AND RECOGNIZING WORK SCOPE CHANGES.