NORTHWEST PIPELINE LLC

Williams’ Consolidated Overview

The following table and discussion is a summary of Williams’ consolidated results of operations for the three and six months ended June 30, 2025, compared to the three and six months ended June 30, 2024, and should be read in conjunction with the results of operations by segment, as discussed in further detail following this consolidated overview discussion.

•Higher revenues associated with expansion projects and increased transportation and storage rates that became effective March 1, 2025 at the Transmission & Gulf of America segment;

•Higher volumes from the August 2024 Discovery Acquisition at the Transmission & Gulf of America segment (See Note 3 – Acquisitions and Divestitures), the January 2025 Rimrock Asset Purchase, the Haynesville Shale region at the West segment, and the Northeast JV at the Northeast G&P segment;

•Higher revenues associated with reimbursable expenses primarily in the Northeast G&P segment, which is offset by similar changes in the charges reflected in Operating and maintenance expenses; partially offset by

•Lower revenues in the Eagle Ford Shale region due to lower MVC revenue at the West segment.

The Product sales and service revenues – commodity consideration increase primarily consists of:

•Higher equity NGL sales and commodity consideration revenues associated with equity NGL production activity primarily driven by the Discovery Acquisition at the Transmission & Gulf of America segment;

•Higher product sales from upstream operations primarily related to higher volumes from the November 2024 Crowheart Acquisition at Other (See Note 3 – Acquisitions and Divestitures); partially offset by

•Lower marketing sales activities primarily related to lower NGLs marketing sales prices and lower net natural gas marketing sales activity at the Gas & NGL Marketing Services segment.

As Williams is acting as agent for natural gas marketing customers, its natural gas marketing product sales are presented net of the related costs of those activities within the Gas & NGL Marketing Services segment.

Net gain (loss) from commodity derivatives includes realized and unrealized gains and losses from derivative instruments reflected within Total revenues primarily in the Gas & NGL Marketing Services segment, as well as at Other (see Note 9 – Commodity Derivatives).

Williams experiences significant earnings volatility from the fair value accounting required for the derivatives used to hedge a portion of the economic value of the underlying transportation and storage capacity portfolios as well as upstream-related production. However, the unrealized fair value measurement gains and losses are generally offset by valuation changes in the economic value of the underlying production or transportation and storage capacity contracts, which are not recognized until the underlying transaction occurs.

The Product costs and net processing commodity expenses increase primarily consists of:

•Higher shrink natural gas purchases and commodity consideration costs associated with Williams’ equity NGL production activities primarily due to the Discovery Acquisition at the Transmission & Gulf of America segment; partially offset by

•Lower marketing activities primarily related to lower NGLs marketing purchases at the Gas & NGL Marketing Services segment, including from the Discovery Acquisition.

Operating and maintenance expenses increased primarily due to operating costs of the assets acquired at the Transmission & Gulf of America and West segments, as well as at Other and higher electricity and fuel primarily in the Northeast G&P segment (substantially offset by higher Service revenues discussed above).

Depreciation, depletion, and amortization expenses increased primarily related to the increase in depreciation rates effective March 1, 2025 at the Transmission & Gulf of America segment and assets acquired at the Transmission & Gulf of America and West segments, as well as at Other.

Other (income) expense – net within Operating income (loss)includes an unfavorable change in the amortization of regulatory assets and liabilities at the Transmission & Gulf of America segment.

The unfavorable change in Other investing income (loss) – net includes lower interest income earned on lower cash and cash equivalent balances.

Interest expense was primarily impacted by Williams’ 2024 and 2025 debt issuances, partially offset by 2024 and 2025 debt retirements (see Note 7 – Debt and Banking Arrangements) and the absence of imputed interest on deferred consideration obligations related to previous acquisitions.

The unfavorable change in Other income (expense) – netbelow Operating income (loss) includes a decrease in equity AFUDC primarily as a result of the timing of capital projects at Williams’ regulated businesses.

Provision (benefit) for income taxes changed unfavorably primarily due to higher pre-tax income. See Note 6 – Provision (Benefit) for Income Taxes for a discussion of the effective tax rate compared to the federal statutory rate for both periods.

•Higher revenues associated with expansion projects and increased transportation and storage rates that became effective March 1, 2025, at the Transmission & Gulf of America segment;

•Higher volumes from the August 2024 Discovery Acquisition at the Transmission & Gulf of America segment (See Note 3 – Acquisitions and Divestitures), January 2025 Rimrock Asset Purchase at the West segment, and the Northeast JV at the Northeast G&P segment;

•Higher revenues associated with reimbursable expenses primarily in the Northeast G&P segment, which is offset by similar changes in the charges reflected in Operating and maintenance expenses; partially offset by

•Lower revenues in the Eagle Ford Shale region due to lower MVC revenue at the West segment.

The Product sales and service revenues – commodity consideration increase primarily consists of:

•Higher equity NGL sales and commodity consideration revenues associated with equity NGL production activity primarily due to the Discovery Acquisition at the Transmission & Gulf of America segment and higher prices at the West segment;

•Higher marketing sales activities primarily related to higher NGLs marketing sales at the Gas & NGL Marketing Services segment and higher sales prices at the West segment;

•Higher product sales from upstream operations primarily related to higher volumes from the November 2024 Crowheart Acquisition at Other (See Note 3 – Acquisitions and Divestitures).

Net gain (loss) from commodity derivatives includes realized and unrealized gains and losses from derivative instruments reflected within Total revenues primarily in the Gas & NGL Marketing Services segment, as well as at Other (see Note 9 – Commodity Derivatives).

The Product costs and net processing commodity expenses increase primarily consists of:

•Higher marketing activities primarily related to higher NGLs marketing purchases at the Gas & NGL Marketing Services segment;

•Higher shrink natural gas purchases and commodity consideration costs associated with Williams’ equity NGL production activities primarily due to the Discovery Acquisition at the Transmission & Gulf of America segment.

Operating and maintenance expenses increased primarily due to operating costs of the assets acquired at the Transmission & Gulf of America and West segments, as well as at Other and higher electricity and fuel primarily in the Northeast G&P segment (substantially offset by higher Service revenues discussed above).

Depreciation, depletion, and amortization expenses increased primarily related to the increase in depreciation rates effective March 1, 2025 at the Transmission & Gulf of America segment and assets acquired at the Transmission & Gulf of America and West segments, as well as at Other.

Other (income) expense – net within Operating income (loss)includes an unfavorable change in the amortization of regulatory assets and liabilities and deferral of ARO-related depreciation at the Transmission & Gulf of America segment.

The unfavorable change in Other investing income (loss) – net includes lower interest income earned on lower cash and cash equivalent balances.

Interest expense was primarily impacted by Williams’ 2024 and 2025 debt issuances, partially offset by 2024 and 2025 debt retirements (see Note 7 – Debt and Banking Arrangements) and the absence of imputed interest on deferred consideration obligations related to previous acquisitions.

The unfavorable change in Other income (expense) – netbelow Operating income (loss) includes a decrease in equity AFUDC primarily as a result of the timing of capital projects at Williams’ regulated businesses.

Provision (benefit) for income taxes changed unfavorably primarily due to higher pre-tax income.

Period-Over-Period Operating Results – Williams’ Segments

Williams’ CODM evaluates segment operating performance based upon Modified EBITDA. Note 11 – Segment Disclosures includes a reconciliation of this non-GAAP measure to Income (loss) before income taxes. Management uses Modified EBITDA because it is an accepted financial indicator used by investors to compare company performance. In addition, management believes that this measure provides investors an enhanced perspective of the operating performance of Williams’ assets. Modified EBITDA should not be considered in isolation or as a substitute for a measure of performance prepared in accordance with GAAP.

(1)Included as a component of Commodity margins.

Transmission & Gulf of America Modified EBITDA increased primarily due to higher Service revenues, partially offset by higher Other segment costs and expenses.

•A $76 million increase in Transco’s revenues primarily associated with expansion projects placed in-service, notably Regional Energy Access in August 2024, Southside Reliability Enhancement in November 2024, Texas Louisiana Energy Pathway in April 2025, and Southeast Energy Connector in April 2025; and transportation and storage rate increases effective during the second quarter of 2024 and March 1, 2025;

•A $34 million increase in the Gulf Coast region primarily due to higher gathering and transportation volumes from the Whale expansion project that went in-service in January 2025 and production handling volumes from a new well at Gulfstar One in the Pickerel field;

•A $24 million increase primarily in gathering revenues due to the Williams’ Discovery Acquisition in August 2024 (see Note 3 – Acquisitions and Divestitures);

•A $9 million increase in Gulf Coast Storage’s revenues primarily associated with higher storage rates.

Commodity margins increased primarily due to the Discovery Acquisition.

Other segment costs and expenses increased primarily due to:

•Higher operating expenses and administrative costs including increased operating costs resulting from Williams’ Discovery Acquisition and the absence of a gain associated with MountainWest cash-out sales in 2024;

•Unfavorable change in equity AFUDC primarily as a result of the timing of capital projects at Williams’ regulated businesses;

•Unfavorable change in the amortization of regulatory assets and liabilities at Transco;

•Unfavorable change in the deferral of ARO-related depreciation at Transco.

Proportional Modified EBITDA of equity-method investments decreased primarily due to lower proportional results as Discovery was consolidated.

Transmission & Gulf of America Modified EBITDA increased primarily due to higher Service revenues, partially offset by higher Other segment costs and expenses.

•A $120 million increase in Transco’s revenues primarily associated with expansion projects placed in service, notably Regional Energy Access in August 2024, Southside Reliability Enhancement in November 2024, Texas Louisiana Energy Pathway in April 2025, and Southeast Energy Connector in April 2025; and transportation and storage rate increases effective during the second quarter of 2024 and March 1, 2025;

•A $46 million increase primarily in gathering revenues due to the Discovery Acquisition;

•A $44 million increase in the Gulf Coast region primarily due to higher gathering and transportation volumes from the Whale expansion project that went in-service in January 2025 and production handling volumes from a new well at Gulfstar One in the Pickerel field, partially offset by shut-ins for maintenance activities at Devil’s Tower impacting the Taggart and Kodiak fields;

•A $22 million increase in Gulf Coast Storage’s revenues primarily associated with higher storage rates.

Commodity margins increased primarily due to the Discovery Acquisition.

Other segment costs and expenses increased primarily due to:

•Higher operating expenses and administrative costs including increased operating costs resulting from Williams’ Discovery Acquisition, corporate allocations, and employee-related costs; as well as the absence of a gain associated with MountainWest cash-out sales in 2024; partially offset by the absence of acquisition and transition costs related to Williams’ Gulf Coast Storage Acquisition in January 2024 (see Note 3 – Acquisitions and Divestitures);

•Unfavorable change in equity AFUDC primarily as a result of the timing of capital projects at Williams’ regulated businesses;

•Unfavorable change in the amortization of regulatory assets and liabilities at Transco;

•Unfavorable change in the deferral of ARO-related depreciation at Transco.

Proportional Modified EBITDA of equity-method investments decreased primarily due to lower proportional results as Discovery was consolidated.

Northeast G&P

(1)Included as a component of Commodity margins.

Northeast G&P Modified EBITDA increased primarily due to higher Service revenues, partially offset by higher Other segment costs and expenses.

•A $17 million increase in revenues at the Northeast JV primarily related to higher gathering, processing, and fractionation volumes, and higher gathering and processing rates;

•A $9 million increase in revenues associated with reimbursable expenses, which is offset by similar changes in the charges reflected in Other segment costs and expenses.

Other segment costs and expenses increased primarily due to higher operating expenses, including higher electricity and fuel (substantially offset by higher Service revenues discussed above).

Proportional Modified EBITDA of equity-method investments increased at Appalachia Midstream Investments primarily driven by higher gathering volumes and escalated rates. The increase was partially offset by a decrease at Aux Sable Liquid Products LP due to the sale of Williams’ investment in the third quarter of 2024.

Northeast G&P Modified EBITDA increased primarily due to higher Service revenues, partially offset by higher Other segment costs and expenses.

•A $29 million increase in revenues at the Northeast JV primarily related to higher gathering, processing, and fractionation volumes, and higher gathering and processing rates;

•A $17 million increase in revenues associated with reimbursable expenses, which is offset by similar changes in the charges reflected in Other segment costs and expenses.

Other segment costs and expenses increased primarily due to higher operating expenses, including higher electricity and fuel (substantially offset by higher Service revenues discussed above).

Proportional Modified EBITDA of equity-method investments increased at Blue Racer primarily due to annual rate escalations and at Laurel Mountain Midstream, LLC primarily due to higher commodity-based gathering rates. Additionally, Appalachia Midstream Investments increased primarily driven by escalated gathering rates. The increase was partially offset by a decrease at Aux Sable Liquid Products LP due to the sale of Williams’ investment in the third quarter of 2024.

West

(1) Included as a component of Commodity margins.

West Modified EBITDA increased primarily due to higher Service revenues.

•A $21 million increase in the DJ Basin region primarily associated with the Rimrock Asset Purchase;

•A $15 million increase in the Haynesville Shale region primarily due to higher gathering volumes;

•An $8 million increase in the Wamsutter region associated with higher gathering volumes;

•An $8 million increase in the Barnett Shale region primarily due to higher gathering rates driven by favorable commodity pricing; partially offset by

•A $16 million decrease in the Eagle Ford Shale region primarily due to lower MVC revenue.

Net realized gain (loss) from commodity derivatives relating to service revenues is unfavorable due to the absence of realized hedge positions in second-quarter 2025.

West Modified EBITDA increased primarily due to higher Service revenues and Commodity margins.

•A $30 million increase in the DJ Basin region primarily due to higher gathering volumes associated with the Rimrock Asset Purchase;

•A $16 million increase in the Haynesville Shale region primarily due to higher gathering volumes;

•A $14 million increase in the Barnett Shale region primarily due to higher gathering rates driven by favorable commodity pricing;

•An $8 million increase in other NGL operations primarily associated with higher fractionation revenue due to higher volumes and higher rates driven by favorable commodity pricing; partially offset by

•A $29 million decrease in the Eagle Ford Shale region primarily due to lower MVC revenue.

Net realized gain (loss) from commodity derivatives relating to service revenues reflects an unfavorable change in settled commodity prices relative to our natural gas hedge positions.

Commodity margins increased $21 million primarily due to $14 million higher margins from equity NGLs associated with higher net realized NGL sales prices and a $10 million increase in marketing margins from increased sales activities associated primarily with higher prices.

Other segment costs and expenses increased primarily due to higher operating expenses associated with the Rimrock Asset Purchase.

Proportional Modified EBITDA of equity-method investments increased primarily due to higher volumes at OPPL.

Gas & NGL Marketing Services

(1) Included as a component of Commodity margins.

Gas & NGL Marketing Services Modified EBITDA increased primarily due to a favorable change in Net unrealized gain (loss) from commodity derivative instruments, partially offset by lower Commodity margins.

Commodity margins decreased $19 million primarily due to an $11 million decrease in natural gas marketing margins, including $27 million of lower natural gas transportation capacity marketing margins due to unfavorable net realized pricing spreads. The decrease in natural gas marketing margins was partially offset by $16 million of higher natural gas storage marketing margins primarily driven by favorable realized derivative gains, partially offset by higher storage fees.

The change in Net unrealized gain (loss) from commodity derivative instruments within Segment revenues and Net processing commodity expenses relates to derivative contracts that are not designated as hedges for accounting purposes. The change from 2024 is primarily due to a change in forward commodity prices relative to hedge positions in 2025 compared to 2024.

Gas & NGL Marketing Services Modified EBITDA increased primarily due to a favorable change in Net unrealized gain (loss) from commodity derivative instruments, partially offset by lower Commodity margins.

Commodity margins decreased $64 million primarily due to:

•A $49 million decrease in natural gas marketing margins, including $51 million of lower natural gas transportation capacity marketing margins due to unfavorable net realized pricing spreads. The decrease in natural gas marketing margins was partially offset by $2 million of higher natural gas storage marketing margins primarily driven by higher withdrawals in 2025 compared to 2024, partially offset by less favorable realized derivative gains.

•A $15 million decrease in NGL marketing margins including an unfavorable change in net realized gains and losses on sale of inventory in 2025 compared to 2024 driven by an unfavorable change in NGL prices.

Net unrealized gain (loss) from commodity derivative instruments within Segment revenues and Net processing commodity expenses changed from 2024 primarily due to a change in forward commodity prices relative to hedge positions in 2025 compared to 2024.

Proportional Modified EBITDA of equity-method investments increased due to the March 2025 investment in Cogentrix.

Other

(1) Included as a component of Net realized product sales.

Modified EBITDA from upstream operations, corporate, and other business activities increased primarily due to:

•A $65 million favorable change in Net unrealized gain (loss) from derivative instruments due to a change in forward commodity prices relative to hedge positions;

•A $37 million increase in Net realized product sales from our upstream operations primarily due to higher production volumes associated with Williams’ Wamsutter region production, including the Crowheart Acquisition. The second quarter 2025 also benefited from higher net realized gas prices, which were partially offset by lower net realized oil prices compared to second quarter 2024; partially offset by

•A $31 million unfavorable change in other costs and expenses primarily related to upstream operations, including an increase from the Crowheart Acquisition in November 2024.

Modified EBITDA from upstream operations, corporate, and other business activities increased primarily due to:

•A $77 million increase in Net realized product sales from upstream operations primarily due to higher production volumes and higher net realized commodity prices associated with Williams’ Wamsutter region production, including the Crowheart Acquisition. The first half of 2025 also benefited from higher net realized commodity prices associated with Williams’ South Mansfield production in the Haynesville Shale region;

•A $33 million favorable change in Net unrealized gain (loss) from derivative instruments due to a change in forward commodity prices relative to hedge positions; partially offset by

•A $40 million unfavorable change in other costs and expenses primarily related to upstream operations, including an increase from the Crowheart Acquisition in November 2024.