TSP Name: Northern Natural Gas Company TSP: 784158214 Notice ID: 101850 Notice Type: Force Majeure Subject: UPDATE 6: FORCE MAJEURE - CARLTON AREA Location: MARKET AREA Critical: Y Post Date/Time: 01/30/2026 08:21 AM Notice Status: Supersede Prior Notice: 101764 For Gas Day(s): 01/30/2026 - 03/30/2026 Notice Effective Date/Time: 01/30/2026 09:00 AM Notice End Date/Time: 03/31/2026 08:59 AM Required Response Indicator Description: 5-No response required Reason: Force Majeure Notice Text: Update 6: Effective with the Intraday 1 nomination cycle for Gas Day Friday, January 30, 2026, the operational capacities at the Carlton South Receipt Allocation Group (811) and the five receipt points will be as posted in update five. Northern will provide an update once the permanent pipeline is placed into service and approval is received from the Pipeline and Hazardous Materials Safety Administration to return the pipeline to normal operating capacity. Update 5: With construction and testing of the temporary bypass pipeline near Willow River, Minnesota, nearing completion, Northern is providing the following information to help customers prepare for the pipeline segment's return to service. Once construction of the temporary bypass pipeline is placed in-service, the affected mainline will operate at a reduced pressure until final repairs are completed and a return to normal operating pressure is approved by the Pipeline and Hazardous Materials Safety Administration (PHMSA). As a result, the operational capacity of the Carlton South Receipt Allocation Group (811) will be reduced. The reduced group operational capacity shown below may be adjusted based on actual system performance. Upon completion of the temporary bypass pipeline, operational capacities at the five receipt points listed below will return to normal levels. The Carlton Obligation will remain in effect when called. Provided Northern continues to receive the called-upon supply, any Carlton penalties resulting from a Force Majeure allocation will be waived. Group Name Group Number Flow Direction Normal Operational Capacity (Dth) Reduced Operational Capacity (Dth) Carlton South 811 Receipt 306,926 260,000 POI Point Name Normal Operational Capacity (Dth) 388 GRLKS/NNG Carlton 550,000 21972 GRLKS/NNG Wakefield 36,915 78994 GRLKS/NNG Grand Rapids 24,000 79374 Semco Marquette M-35 88,000 79379 Semco Marquette Emergency Receipt 0 Northern will provide an update when the temporary bypass pipeline is placed in-service or if any material changes occur. If you have any questions, please contact your marketing or customer service representative. Update 4: Northern continues to make strong progress and is ahead of the original schedule for the completion of the temporary bypass pipeline being constructed near Willow River, Minnesota. A pressure test of the bypass is planned for the week of January 26, 2026. If the test is successful, Northern expects to revise its estimate and place the line in service for Gas Day Sunday, February 1, 2026. Northern will continue to provide updates as the project advances or if any material changes to the schedule occur. Update 3: Northern continues its work on the impacted pipeline segment of its mainline near Willow River, Minnesota. The cause of the incident remains under investigation and is currently unknown. The repair plan requires the replacement of more than 2,000 feet of 20-inch-diameter mainline pipe. Northern is constructing a 2,400-foot temporary bypass around the incident site to support the ongoinginvestigation by Northern and the Department of Transportation. The necessary materials, equipment and personnel are being mobilized as quickly as possible, despite challenging weather conditions. Based on current projections, this work is estimated to be completed mid-February. Update 2: Northern has isolated the impacted pipeline segment of its mainline near Willow River, Minnesota, and has begun executing a repair plan. Northern is proceeding as quickly as possible under challenging weather conditions to mobilize the necessary materials, equipment and personnel to provide a temporary replacement of the impacted pipeline. At this time, Northern estimates that this work will be completed by mid-February. Updates will be provided as the repairs progress, with the next update coming no later than Wednesday, January 21, 2026. The operating capacity at the points outlined below remains unchanged at this time. Northern has called a Carlton Obligation at 50% for Gas Day Wednesday, January 21, 2026. Provided Northern continues to receive adequate supply at the points listed below, any Carlton penalty resulting from an allocation at the points listed below will be waived. To help ensure system integrity, Northern will not accept any incremental SMS requests for less than an annual term, the remaining term of an existing agreement or five years until otherwise noted. Update 1: Inspection of the impacted pipeline segment is ongoing. Northern is conducting an investigation into the cause of the incident and developing a return to service plan. At this time, a return to service date is not known. Updates will be provided as the repair plan develops, with the next update coming no later than Monday, January 19, 2026. At this time, the capacity impacts at the five points described below remain unchanged. Original Notice: Northern has experienced a Force Majeure event between the Hinckley, Minnesota, and Carlton, Minnesota, compressor stations located near Willow River, Minnesota, which requires operating capacity to be lowered to a combined 225,000 Dth/day effective immediately and until further notice at the following points. · GRLKS/NNG Carlton (POI 388) · GRLKS/NNG Wakefield (POI 21972) · GRLKS/NNG Grand Rapids (POI 78994) · Semco Marquette M-35 (POI 79374) · Semco Marquette Emergency Receipt (POI 79379) Incremental nominations at these points may not be accepted for the Intraday 3 nomination cycle for Gas Day Friday, January 16, 2026. Northern will be required to allocate the points to the reduced combined operating capacity of 225,000 Dth/day beginning with the Evening nomination cycle for Gas Day Saturday, January 17, 2026, and continuing until resolved. Northern has called a Carlton Obligation beginning with Gas Day Saturday, January 17, 2026. The Carlton Obligation will remain in effect. Provided Northern continues to receive the 225,000 Dth of supply at the points listed above, any Carlton penalty resulting from an allocation at the points listed above will be waived. Please continue to monitor Northern's website for updates. Please see Operationally Available Capacity on Northern's website for current flow information and the Market Area Group Allocation Maps for a list of impacted points.