TSP Name: Northern Natural Gas Company TSP: 784158214 Notice ID: 108330 Notice Type: TSP Capacity Offering Subject: UPDATE 1: OPEN SEASON FOR FIELD AND FIELD TO DEMARC CAPACITY BEGINNING NOVEMBER 2026 Critical: N Post Date/Time: 06/19/2026 10:46 AM Notice Status: Supersede Prior Notice: 104172 For Gas Day(s): 06/19/2026 - 06/25/2026 Notice Effective Date/Time: 06/19/2026 10:45 AM Notice End Date/Time: 06/25/2026 02:00 PM Required Response Indicator Description: 5-No response required Notice Text: Overview On March 31, 2026, Northern posted an open season for service commencing November 1, 2026. Northern is hereby soliciting binding bids for throughput service from receipt points located in Northern's Field Area for delivery to points in the Field Area, including Demarc (POI 37654). This update provides the awarding parameters that will be used to evaluate bids. Timing Commenced: April 1 ,2026 Closes: June 25, 2025, at 2 p.m. CCT To be considered in the open season, a binding Bid Form must be received by Northern by the close of the open season. Procedures Submit your binding Bid Form to Northern by either: · Facsimile to (402) 398-7413 · Email to NNGOpenSea@nngco.com The Bid Form must include: · Requested rate · Receipt point(s) · Delivery point(s) · Volume · Term · Minimum amount of capacity willing to accept, if applicable · Increments of capacity willing to accept, if applicable · Paths, if applicable · Contingencies, if applicable Capacity All receipt and delivery points within the Field Area including Demarc will be considered.Depending on the delivery point(s) selected in the open season, availability of a particular receipt point may be limited. The table below provides notable available group and point capacities. Beginning November 1, 2026 Groups Winter Annual 464D - FIELD TO DEMARC 288,037 288,037 177R - BEAVER C AND BEAVER SYSTEM SOUTH 454,848 454,848 13R - BEAVER SYSTEM SOUTH 16,000 16,000 14R - ROGER MILLS HEMPHILL SYSTEM 125,000 125,000 19R - PAMPA SOUTH 16,000 16,000 998R - BROWNFIELD SOUTH 0 0 598R - SEMINOLE-SUBSYSTEM 20,300 7,337 598D - SEMINOLE-SUBSYSTEM 100,000 100,000 824R - JAL TO GAINES 46,376 39,513 605R - JAL-HOBBS-PLAINS SYSTEM 0 0 825R - MITCHELL TO GAINES 56,000 50,000 600R - SPRABERRY 23,000 13,000 601D - SPRABERRY 12-INCH 61,000 61,000 1112D - SPRABERRY 16-inch 60,000 60,000 602R - SPRABERRY STATION 26,000 26,000 31R - BEAVER C SYSTEM 404,936 389,436 32R - SUNRAY HIGH 317,336 291,836 10R - SUNRAY LOW 60,722 60,722 Points 173R - PEPL/NNG MULLINVILLE 29,467 29,467 186R - EL PASO/NNG DUMAS 220,000 220,000 1504R - ONEOK WESTEX SEAGRAVES 22,363 22,363 1504D - ONEOK WESTEX SEAGRAVES 10,000 10,000 60667R - TW/NNG GRAY ITE 127,050 127,050 Rates Customers may bid the maximum tariff rate or a negotiated rate that is fixed or index-based formula. Fixed rates may be 2-part fixed rate[1] or 1-part fixed rate. All bids other than the maximum tariff rate will be subject to the additional charges, detailed in the General Terms and Conditions, when alternate points are used, which would impact the rate paid by customer resulting in the entire bid being a negotiated rate. As previously communicated, Northern filed a Section 4 rate case on July 1, 2025. In an Order dated February 25, 2026, the Chief Judge granted a motion to implement interim settlement rates effective February 01, 2026. For evaluation purposes, Northern's interim settlement rates shall be used as the maximum applicable tariff rates. Index-Based Formula Rates Index-based formula rates will be accepted using the formulas described in the General Terms and Conditions. Northern will evaluate formula-based rate bids that use Platts Gas Daily Indices by using the Platts Gas Daily index price assumptions in the table below with the following fuel percentage: · 1.54% for primary receipts in MIDs 8-16A to Demarc (Section 2 Fuel) · 0.90% for Primary receipts in MIDs 1-7 to MIDs 1-7 · 2.44% for Primary receipts in MIDs 8-16A to MIDs 1-7 Northern,demarc ICE ONEOK,WestexPool El Paso, Permian Waha Panhandle,Tx.-Okla. NGPL, Midcontinent (D) (D) (R) (R) (R) (R) $4.14 $3.20 $2.70 $2.65 $3.66 $3.55 Note: If necessary, Northern will provide an updated table with the final pricing assumptions that will be used in the NPV analysis prior to 9 a.m. of the open season close date. Bids and Bid Evaluation 1) Except for maximum tariff rate bids, the rate bid must be uniform across the term of the bid and will be evaluated for revenue generated from November 1, 2026, through March 31, 2027 (Evaluation Period). Customers may bid any term with a start date of November 1, 2026, for annual or seasonal service; however, the end date must be March 31, or October 31. Northern reserves the right to reject any non-maximum tariff rate bids that extend past the Evaluation Period. Customers bidding terms past March 31, 2027, should clarify if they are willing to take the bid quantity for the Evaluation Period only should Northern not award service past the Evaluation Period. 2) Bids are subject to the General Terms and Conditions incorporated herein by reference. 3) Northern's Bid Evaluation: o The capacity will be awarded to the highest bid(s) based on a determination of the best bid, or combination of bids that result in the highest net present value (NPV) of reservation revenue, on a per unit of capacity basis, using revenues from the Evaluation Period. o Northern has the right to aggregate bids, or portions of bids, that generate the highest NPV to Northern. o Northern reserves the right to reject any bid, or portion thereof, that contains a discounted or negotiated rate. o The NPV per unit will be determined by discounting the cash flow (using the FERC interest rate) generated from the reservation rate multiplied by the volume for each month, by bid, and then dividing the NPV by the maximum daily quantity bid. For bid evaluation purposes, the assumed reservation component for fixed 1-part rate bids will be the 1-part rate less: o $0.010/Dth/day for receipt points south of the Brownfield compressor station for delivery to points south of the Brownfield compressor station o $0.035/Dth/day for receipt points north of the Brownfield compressor station for delivery to points south of the Brownfield compressor station o $0.024/Dth/day for receipt points north of the Brownfield compression station for delivery to points north of the Plainview compressor station These reductions will be applied to one path of a contiguous 1-part bid. 4) Realignments without an incremental rate bid will have no NPV. 5) For bid evaluation purposes, Northern will use the sum of the NPVs from all contiguous paths bid, using points defined within the bid form, to calculate the total NPV. 6) Northern may consider contingencies in the bids. 7) 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. 8) Bidder(s) must meet the creditworthiness provisions of Northern's tariff. Upon request by Northern, Bidder shall provide appropriate credit assurance within ten (10) calendar days of Northern's request. If a non-creditworthy Bidder fails to provide the appropriate security, Northern may award the capacity to the next best bid(s) or proceed to remarket the capacity, and Bidder will be liable for any difference in value of the bids, in addition to any other remedies available by law. 9) Transportation service agreements are to be executed by customer within 30 calendar days of tender by Northern. 10) Northern is not considering any construction with this open season. 11) The reservation rate bid is binding for throughput service. 12) Northern will evaluate and award capacity for incremental bids based on the terms of this open season. Any remaining capacity will be released as generally available capacity. However, in accordance with Northern's tariff, Northern will process any requests for realignment without an incremental rate in the order they were received within seven (7) workdays of the close of the open season. 13) Northern and customer may agree to amend the service agreement, as allowed by Northern's Tariff, at any time after award of the capacity. If you have questions, please contact your marketing representative. [1] In addition to the reservation rate, customer will pay the commodity rate.