TSP Name: Northern Natural Gas Company TSP: 784158214 Notice ID: 106849 Notice Type: Planned Service Outage Subject: PLANNED SERVICE OUTAGES - MAY 2026 THROUGH OCTOBER 2026 Location: MARKET AND FIELD AREA Critical: N Post Date/Time: 05/20/2026 10:25 AM Notice Status: Supersede Prior Notice: 106034 For Gas Day(s): 05/20/2026 - 10/31/2026 Notice Effective Date/Time: 05/20/2026 10:25 AM Notice End Date/Time: 11/01/2026 08:59 AM Required Response Indicator Description: 5-No response required Notice Text: Northern has scheduled the service outages that will affect operating capacity within the months of May 2026 through October 2026. Please review the Planned Service Outage Summaryfor detailed information related to each outage. A brief description of the most recent change(s) to the Planned Service Outage Summary follows. Market/Field Area Combined Allocation Group(s)/Point(s): Field to Demarc (Group 831) and Beatrice North (Group 832) Location: Northern's pipelines and compressor stations located between the Mullinville, Kansas, and Ogden, Iowa, compressor stations Project Description: Compressor station and pipeline maintenance Month: May 2026 through October 2026 Direction of Flow: Delivery: Field to Demarc (Group 831) and Beatrice North (Group 832) Capacity Impact: Northern does not anticipate primary firm service will be impacted for Beatrice North (Group 832) and Field to Demarc (Group 831). Revision: Capacity impacts for Field to Demarc (Group 831) and Beatrice North (Group 832) have been updated for August 2026. Market Area Allocation Group(s)/Point(s): North Branch (Group 835) and North Branch Receipt Points (Group 1151) Location: Northern's pipeline between Hugo, Minnesota, and North Branch, Minnesota. Project Description: Pipeline maintenance Month: June 2026 and July 2026 Direction of Flow: Receipt: North Branch (Group 835) and North Branch Receipt Points (Group 1151) Capacity Impact: Northern does not anticipate primary firm service will be impacted for North Branch (Group 835) and North Branch Receipt Points (Group 1151). Allocation Group(s)/Point(s): Waterloo East (Group 773), Earlville East (Group 487), Galena East (Group 463) and Belleville East (Group 488) Location: Northern's pipelines and compressor stations between Waterloo, Iowa, and Belleville, Iowa Project Description: Compressor station and pipeline maintenance Month: May 2026 through October 2026 Direction of Flow: Delivery: Waterloo East (Group 773), Earlville East (Group 487), Galena East (Group 463) and Belleville East (Group 488) Capacity Impact: Northern does not anticipate primary firm service will be impacted for Waterloo East (Group 773), Earlville East (Group 487), Galena East (Group 463) and Belleville East (Group 488). Revision: Capacity impacts for Waterloo East (Group 773), Earlville East (Group 487), Galena East (Group 463) and Belleville East (Group 488) have been updated for June 2026 through August 2026. Allocation Group(s)/Point(s): TBPL/NNG Beatrice (POI 1318) Location: Northern's compressor station located in Beatrice, Nebraska Project Description: Compressor station maintenance Month: June 2026 Direction of Flow: Receipt: TBPL/NNG Beatrice (POI 1318) Capacity Impact: Primary firm service will not be impacted for TBPL/NNG Beatrice (POI 1318). Allocation Group(s)/Point(s): Ventura South (Group 735) Location: Northern's pipelines and compressor stations between Ventura, Iowa, and Ogden, Iowa Project Description: Compressor station and pipeline maintenance Month: May 2026 through August 2026 Direction of Flow: Delivery: Ventura South (Group 811) Capacity Impact: Northern does not anticipate primary firm service will be impacted for Ventura South (Group 735). Revision: Capacity impacts for Ventura South (Group 735) have been included for August 2026. Field Area Allocation Group(s)/Point(s): Beaver North (Group 1025), Beaver C & Beaver North (Group 1080), Brownfield North (Group 1022), Pampa North (Group 1023), Beaver C System (Group 31) and Mitchell to Gaines (Group 825) Location: Northern's compressor stations and pipeline between Florey, Texas, and Mullinville, Kansas Project Description: Compressor station and pipeline maintenance Month: May 2026 through July 2026 Direction of Flow: Delivery: Beaver North (Group 1025), Beaver C & Beaver North (Group 1080), Brownfield North (Group 1022) and Pampa North (Group 1023) Receipt: Beaver C System (Group 31) and Mitchell to Gaines (Group 825) Capacity Impact: Primary firm service will be impacted for Brownfield North (Group 1022) and Mitchell to Gaines (Group 825). Primary firm service will not be impacted for Beaver North (Group 1025) and Beaver C System (Group 31). Northern does not anticipate primary firm service will be impacted for Beaver C and Beaver System North (Group 1080) and Pampa North (Group 1023). Revision: Capacity impacts for Beaver C System (Group 31) have been updated for July 2026. Allocation Group(s)/Point(s): Spraberry 12-inch (Group 601), Spraberry 16-inch (Group 1112) and Spraberry Station (Group 602) Location: Northern's compressor station located in Spraberry, Texas Project Description: Compressor station and pipeline maintenance Month: May 2026 through July 2026 Direction of Flow: Delivery: Spraberry 12-inch (Group 601) and Spraberry 16-inch (Group 1112) Receipt: Spraberry Station (Group 602) Capacity Impact: Primary firm service will be impacted for Spraberry 12-inch (Group 601), Spraberry 16-inch (Group 1112) and Spraberry Station (Group 602). Revision: Capacity impacts for Spraberry 12-inch (Group 601) has been updated for May 2026. Allocation Group(s)/Point(s): Enterprise Midland Basin Newberry Plant (POI 79313) Location: Northern's compressor station located in Spraberry, Texas Project Description: Compressor station maintenance Month: June 2026 Direction of Flow: Receipt: Enterprise Midland Basin Newberry Plant (POI 79313) Capacity Impact: Northern anticipates primary firm service will be impacted for Enterprise Midland Basin Newberry Plant (POI 79313). Please see Operationally Available Capacityon Northern's website for current flow information and the Field Area Group Allocation Mapsand Market Area Group Allocation Mapsfor a list of impacted points. If you have any questions, contact your customer service or marketing representative.