TSP Name: Northern Natural Gas Company TSP: 784158214 Notice ID: 086933 Notice Type: TSP Capacity Offering Subject: CENTRAL MAINLINE CORRIDOR 2026 EXPANSION OPEN SEASON Critical: N Post Date/Time: 03/04/2025 11:15 AM Notice Status: Terminate For Gas Day(s): 03/04/2025 - 04/08/2025 Notice Effective Date/Time: 03/04/2025 11:15 AM Notice End Date/Time: 04/08/2025 05:00 PM Required Response Indicator Description: 5-No response required Notice Text: Open Season Overview Northern Natural Gas Company (Northern) is hereby soliciting binding bids for firm TFX throughput service from NNG Field/Market Demarcation-16B (POI 37654) and NBPL/NNG Ventura (POI 192) to delivery points located in the central mainline corridor of Northern's Market Area within the area highlighted on the attached map (Open Season Area) (LINK TO MAP) for service commencing on or after November 1, 2026. Receipts from Demarc are limited to delivery points located south of the Palmyra, Nebraska compressor station. Northern anticipates that the construction of facilities will be required to provide requested service (Project). Depending on the Project scope and capital, a section 7 filing could be required, which could result in a delay in the start date of the Project to November 1, 2027, or later. Interested customers may request firm TFX throughput service by submitting a signed binding Bid Form. Customers requesting service are responsible for ensuring arrangements have been made for any capacity necessary on any upstream or downstream pipeline for their volumes to be confirmed during the nomination and scheduling process. If sufficient customer interest indicates a Project is feasible, Northern will develop the Project subject to certain conditions including, securing contractual commitments for incremental firm throughput service with rates and terms sufficient to justify the Project economics, and receipt of all necessary regulatory approvals. The actual in-service date of a Project, or any portion thereof, is subject to the timing of regulatory approvals and the subsequent construction required. Northern reserves the right to include in the Project only service and facilities that Northern determines can reasonably be approved and in service on a timely basis.Open Season Timing The open season commences on Tuesday, March 4, 2025, and ends at 5:00 p.m. CCT on Tuesday, April 8, 2025. To be considered in the open season, customer's signed binding Bid Form must be received by the close of the open season at 5:00 p.m. CCT on Tuesday, April 8, 2025. If you have any questions, please contact your Account Manager or Mike Barry at (402) 398-7105. Open Season Procedures Submit your binding Bid Form to Northern either via facsimile to (402) 398-7413 or e-mail to NNGOpenSea@nngco.com. The Bid Form must include the requested volume, receipt point, delivery point(s), rate and term. The following receipt points will be considered in this open season: NNG Field/Market Demarcation-16B (POI 37654), and NBPL/NNG Ventura (POI 192). Receipts from Demarc are limited to delivery points located south of the Palmyra, Nebraska compressor station. Depending on the delivery points selected in the open season, availability of a particular receipt point may be limited. Northern will work with participants to allocate receipt point capacity among the requests in order to optimize the amount of service that can be provided and the associated value to Northern. Depending on the delivery points requested, other receipt points within the Open Season Area may be available. The reservation rate bid is binding at rates up to and including Northern's maximum tariff rates for firm TFX throughput service. The term of service for any bid must end on a March 31 or October 31. The bid quantity must be equal for each month across the winter season (November-March) and each month across the summer season (April-October) for the term of the bid. Northern reserves its right not to accept any bid at less than its maximum rates. The rates necessary for service may change based on the actual cost of the Project. The actual costs will include any reservation charge credits paid by Northern to other customers as a result of the construction of the Project. A reservation rate higher than the reservation rate bid for firm service may be necessary to justify the Project economics. The term of service may be extended to cover construction costs. Alternatively, customers may pay an agreed-upon reservation rate and provide a contribution in aid of construction for its proportionate share of the construction costs. In the event a higher reservation rate than the reservation rate bid or a longer term is required, the customer will be informed in writing of such reservation rate and term. Within 10 calendar days upon receipt of the notification from Northern of a higher reservation rate or longer term, customer shall provide written notice to Northern whether it is terminating its participation in the Project or agreeing to proceed with the Project at the higher reservation rate or longer term. If the customer fails to respond, the customer will be deemed to have terminated its participation. Customer must sign an agreement for construction of the necessary facilities for the Project within 30 calendar days after tender by Northern. The agreement will be designed for the service requested by each customer and obligates customer for its allocated share of capital costs. Northern and customer may agree to other terms specific to the facilities or service provided pursuant to this open season. Northern may consider contingencies in the bids but reserves the right to reject any bid(s) which are subject to contingencies. Transportation contracts are to be executed by customers within 30 calendar days of tender by Northern. Northern and customer may agree to amend the service agreement, as allowed by Northern's Tariff, at any time after award of the capacity. Customer(s) must meet the creditworthiness provisions of Northern's Tariff. Upon request by Northern, customer shall provide appropriate credit assurance, including credit assurance for the construction of facilities, within 10 calendar days of Northern's request. The results of this open season will be posted on Northern's website. Solicitation of Turn Back Capacity Firm customers who currently hold capacity in Northern's Market Area that may be used to reduce construction must notify Northern in writing if they wish to permanently relinquish their capacity. The written notification must be received by Northern prior to the expiration of the open season in order for Northern to determine the need for, extent and feasibility of the use of such capacity for the proposed Project.