Western Midstream Operating, LP

General. Western Midstream Partners, LP (the “Partnership”) is a Delaware master limited partnership formed in September 2012. Western Midstream Operating, LP (together with its subsidiaries, “WES Operating”) is a Delaware limited partnership formed in 2007 to acquire, own, develop, and operate midstream assets. As of December 31, 2025, the Partnership owns, directly and indirectly, a 98.1% limited partner interest in WES Operating, and directly owns all of the outstanding equity interests of Western Midstream Operating GP, LLC, which holds the entire non-economic general partner interest in WES Operating. In addition, Occidental owns the Partnership’s general partner and, as of December 31, 2025, a 1.9% limited partner interest in WES Operating through its ownership of WGR Asset Holding Company LLC (“WGRAH”). See Noncontrolling interests below.

For purposes of these consolidated financial statements, the Partnership refers to Western Midstream Partners, LP in its individual capacity or to Western Midstream Partners, LP and its subsidiaries, including Western Midstream Operating GP, LLC and WES Operating, as the context requires. “WES Operating GP” refers to Western Midstream Operating GP, LLC, individually as the general partner of WES Operating. The Partnership’s general partner, Western Midstream Holdings, LLC (the “general partner”), is a wholly owned subsidiary of Occidental Petroleum Corporation. “Occidental” refers to Occidental Petroleum Corporation, as the context requires, and its subsidiaries, excluding the general partner. “Anadarko” refers to Anadarko Petroleum Corporation, which became a wholly owned subsidiary of Occidental as a result of Occidental’s acquisition by merger of Anadarko in 2019. “Related parties” refers to Occidental (see Note 6), the Partnership’s investments accounted for under the equity method of accounting (see Note 7), and WES Operating for transactions with the Partnership that eliminate upon consolidation (see Note 6).

On October 15, 2025, the Partnership completed its previously announced acquisition of Aris Water Solutions, Inc. (“Aris”), pursuant to the Agreement and Plan of Merger, dated as of August 6, 2025 (the “Merger Agreement”), by and among the Partnership, Aris, and certain Partnership and Aris subsidiaries. Also, immediately following the closing of the Aris acquisition, WES Operating and Aris entered into certain post-closing restructuring transactions through which WES Operating issued preferred units to Aris in exchange for Aris’s operating subsidiaries, and WES Operating was the surviving entity in a merger with Aris Water Holdings, LLC, a subsidiary of Aris that was the issuer of its acquired outstanding senior notes (see Note 3).

The Partnership is engaged in the business of gathering, compressing, treating, processing, and transporting natural gas; gathering, stabilizing, and transporting condensate, natural-gas liquids (“NGLs”), and crude oil; and gathering, transporting, recycling, treating, supplying, and disposing of produced water. In its capacity as a natural-gas processor, the Partnership also buys and sells residue, NGLs, and condensate on behalf of itself and its customers under certain contracts. As of December 31, 2025, the Partnership’s assets and investments consisted of the following:

These assets and investments are located in Texas, New Mexico, and the Rocky Mountains (Colorado, Utah, and Wyoming).

Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and include the accounts of the Partnership and entities in which it holds a controlling or other financial interest, including WES Operating, WES Operating GP, proportionately consolidated interests, and equity investments. All significant intercompany transactions have been eliminated.

The following table outlines the ownership interests and the accounting method of consolidation used in the consolidated financial statements for entities not wholly owned (see Note 7):

(1)The 25% third-party interest in Chipeta Processing LLC (“Chipeta”) is reflected within noncontrolling interests in the consolidated financial statements. See Noncontrolling interests below.

(2)The Partnership proportionately consolidates its associated share of the assets, liabilities, revenues, and expenses attributable to this asset.

(3)Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method of accounting. “Equity-investment throughput” refers to the Partnership’s share of average throughput for these investments.

The consolidated financial results of WES Operating are included in the Partnership’s consolidated financial statements. Throughout these notes to consolidated financial statements, and to the extent material, any differences between the consolidated financial results of the Partnership and WES Operating are discussed separately. The Partnership’s consolidated financial statements differ from those of WES Operating primarily as a result of (i) the presentation of noncontrolling interest ownership (see Noncontrolling interests below), (ii) the elimination of WES Operating GP’s investment in WES Operating with WES Operating GP’s underlying capital account, (iii) the elimination of the preferred unit investment in WES Operating with the Partnership’s underlying preferred capital account (see Note 5), (iv) the general and administrative expenses incurred by the Partnership, which are separate from, and in addition to, those incurred by WES Operating, (v) the inclusion of the impact of Partnership equity balances and Partnership distributions, and (vi) transactions between the Partnership and WES Operating that eliminate upon consolidation.

Use of estimates. In preparing financial statements in accordance with GAAP, management makes informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues, and expenses. Management evaluates its estimates and related assumptions regularly, using historical experience and other reasonable methods. Changes in facts and circumstances or additional information may result in revised estimates, and actual results may differ from these estimates. Effects on the business, financial condition, and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revisions become known. The information included herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the consolidated financial statements.

Noncontrolling interests. The Partnership’s noncontrolling interests in the consolidated financial statements consist of (i) the 25% third-party interest in Chipeta for all periods presented and (ii) the 1.9%,2.0%, and 2.0% limited partner interest in WES Operating as of December 31, 2025, 2024, and 2023, respectively, owned by an Occidental subsidiary. WES Operating’s noncontrolling interest in the consolidated financial statements consists of the 25% third-party interest in Chipeta.

Fair value. The fair-value-measurement standard defines fair value as the price that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The standard characterizes inputs used in determining fair value according to a hierarchy that prioritizes those inputs based on the degree to which the inputs are observable. The three input levels of the fair-value hierarchy are as follows:

Level 1 – Inputs represent unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly (for example, quoted market prices for similar assets or liabilities in active markets or quoted market prices for identical assets or liabilities in markets not considered to be active, inputs other than quoted prices that are observable for the asset or liability, or market-corroborated inputs).

Level 3 – Inputs that are not observable from objective sources, such as management’s internally developed assumptions used in pricing an asset or liability (for example, an estimate of future cash flows used in management’s internally developed present value of future cash flows model that underlies the fair value measurement).

In determining fair value, management uses observable market data when available, or models that incorporate observable market data. When a fair value measurement is required and there is not a market-observable price for the asset or liability or a market-observable price for a similar asset or liability, the cost, income, or market approach is used, depending on the quality of information available to support management’s assumptions. The cost approach is based on management’s best estimate of the current asset-replacement cost. The income approach uses management’s best assumptions regarding expectations of projected cash flows and discounts the expected cash flows using a commensurate risk-adjusted discount rate. Such evaluations involve significant judgment because results are based on expected future events or conditions, such as contractual rates, estimates of future throughput, capital and operating costs and the timing thereof, economic and regulatory climates, and other factors. The market approach uses management’s best assumptions regarding expectations of projected earnings before interest, taxes, depreciation, and amortization (“EBITDA”) and an assumed multiple of that EBITDA that a willing buyer would pay to acquire an asset. Management’s estimates of future net cash flows and EBITDA are inherently imprecise because they reflect management’s expectation of future conditions that are often outside of management’s control. However, the assumptions used reflect a market participant’s view of long-term revenues, costs, and other factors and are consistent with assumptions used in the Partnership’s business plans and investment decisions.

Management uses relevant observable inputs available for the valuation technique employed to estimate fair value. If a fair-value measurement reflects inputs at multiple levels within the hierarchy, the fair-value measurement is characterized based on the lowest level of input that is significant to the fair-value measurement. Non-financial assets and liabilities initially measured at fair value include certain assets and liabilities acquired in a third-party business combination, assets and liabilities exchanged in non-monetary transactions, goodwill and other intangibles, and the initial measurement of asset retirement obligations. Impairment analyses for long-lived assets, goodwill, and equity investments and the initial recognition of asset retirement obligations use Level-3 inputs.

The fair value of debt reflects any premium or discount for the difference between the stated interest rate and the quarter-end market interest rate and is based on quoted market prices for identical instruments, if available, or based on valuations of similar debt instruments. As such, debt fair values as presented in Note 13 use Level-2 inputs.

The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, and outstanding borrowings on the revolving credit facility and commercial paper program reported on the consolidated balance sheets approximate fair value due to the short-term nature of these items.

Cash equivalents. All highly liquid investments with a maturity of three months or less when purchased are considered cash equivalents.

Credit losses. Accounts receivable represent contractual rights for services performed, with, on average, 30-day payment terms from the invoice date. Contract assets primarily relate to revenue accrued but not yet billed under cost-of-service contracts and accrued deficiency fees. Exposure to credit losses is analyzed within collective pools for all of our customers and, if necessary, individual customers may be analyzed separately if their credit quality becomes a concern. The Partnership monitors credit exposure to all customers to ensure exposures are within established credit limits.

As of December 31, 2025, there are no negative indications regarding the collectability of significant receivables, and the Partnership will continue to monitor the credit quality of its customer base and assess collectability of these assets as appropriate. The allowance for expected credit losses was immaterial at December 31, 2025 and 2024.

Imbalances. The consolidated balance sheets include imbalance receivables and payables resulting from differences in volumes received into the Partnership’s systems and volumes delivered by the Partnership to customers. Volumes owed to or by the Partnership that are subject to monthly cash settlement are valued according to the terms of the contract as of the balance sheet dates and generally reflect market index prices. Other volumes owed to or by the Partnership are valued at the Partnership’s weighted-average cost as of the balance sheet dates and are settled in-kind. As of December 31, 2025, imbalance receivables and payables were $12.2 million and $10.8 million, respectively. As of December 31, 2024, imbalance receivables and payables were $7.3 million and $5.2 million, respectively. Net changes in imbalance receivables and payables are reported in Cost of product in the consolidated statements of operations.

Inventory. The cost of NGLs inventory is determined by the weighted-average cost method on a location-by-location basis and is stated at the lower of weighted-average cost or net realizable value. Materials and supplies inventory is valued at weighted-average cost, reviewed periodically for obsolescence, and assessed for impairment together with any associated property, plant, and equipment and other intangible assets.

As of December 31, 2025 and 2024, Other current assets includes (i) $2.7 million and $2.5 million, respectively, of NGLs inventory and (ii) $10.1 million and $0.6 million, respectively, of materials and supplies inventory that are classified as short term on the consolidated balance sheets. As of December 31, 2025 and 2024, Other assets includes (i) $3.2 million and $5.5 million, respectively, of NGLs line-fill inventory, and (ii) $131.6 million and $110.3 million, respectively, of materials and supplies inventory that are classified as long term on the consolidated balance sheets.

Property, plant, and equipment and other intangible assets. Property, plant, and equipment and other intangible assets are stated at historical cost less accumulated depreciation or amortization, or fair value if impaired. Prior long-lived asset acquisitions from Anadarko were transfers of net assets between entities under common control; therefore, the assets acquired were initially recorded at Anadarko’s historical carrying value. Assets acquired in a business combination or non-monetary exchange with a third party are initially recorded at fair value.

All construction-related direct labor and material costs are capitalized. The cost of renewals and betterments that extend the useful life of property, plant, and equipment is also capitalized. The cost of repairs, replacements, and major maintenance projects that do not extend the useful life or increase the expected output of property, plant, and equipment is expensed as incurred.

Depreciation is computed using the straight-line method based on estimated useful lives and salvage values of assets. Subsequent events could cause a change in estimates of remaining useful lives or salvage value, thereby impacting future depreciation amounts. Uncertainties that may impact these estimates include, but are not limited to, changes in laws and regulations relating to environmental matters, including air and water quality, restoration and abandonment requirements, economic conditions, and supply and demand in the area.

Management assesses property, plant, and equipment together with any associated materials and supplies inventory and intangible assets, as described in Note 10, for impairment when events or changes in circumstances indicate their carrying values may not be recoverable. Impairments exist when the carrying value of a long-lived asset exceeds the total estimated undiscounted net cash flows from the future use and eventual disposition of the asset. When alternative courses of action for future use of a long-lived asset are under consideration, estimates of future undiscounted net cash flows incorporate the possible outcomes and probabilities of their occurrence. If an impairment exists, an impairment loss is measured as the excess of the asset’s carrying value over its estimated fair value, such that the asset’s carrying value is adjusted down to its estimated fair value with an offsetting charge to Long-lived asset and other impairments. Refer to Note 9 for a description of impairments recorded during the periods presented.

Capitalized interest. Interest is capitalized as part of the historical cost of constructing assets that are in progress. Capitalized interest is determined by multiplying the Partnership’s weighted-average borrowing cost on debt by the average amount of assets under construction. Cumulative capitalized interest accrued during the year is expensed through depreciation or impairment.

Goodwill. Goodwill is recorded when the purchase price of a business acquired exceeds the fair market value of the tangible and separately measurable intangible net assets. The Partnership has allocated goodwill on its two reporting units: (i) gathering and processing and (ii) transportation. Goodwill is evaluated for impairment at the reporting unit level annually, as of October 1, or more often as facts and circumstances warrant. An initial qualitative assessment is performed to determine the likelihood of whether goodwill is impaired. If management concludes, based on qualitative factors, that it is more likely than not that the fair value of the reporting unit exceeds its carrying value, then no goodwill impairment is recorded and further testing is not necessary. If an assessment of qualitative factors does not result in management’s determination that the fair value of the reporting unit more likely than not exceeds its carrying value, then a quantitative assessment must be performed. If the quantitative assessment indicates that the carrying value of the reporting unit, including goodwill, exceeds its fair value, a goodwill impairment is recorded for the amount by which the reporting unit’s carrying value exceeds its fair value through a charge to Goodwill impairment. See Note 10.

Asset retirement obligations. When tangible long-lived assets are acquired or constructed, the initial estimated asset retirement obligation liability is recognized at fair value, measured using discounted expected future cash outflows of the settlement obligation, with an associated increase in property, plant, and equipment. Over time, the discounted liability is adjusted up to its expected settlement value through accretion expense, which is reported within Depreciation and amortization in the consolidated statements of operations. Estimated asset retirement costs typically extend many years into the future, and estimation requires significant judgment. Subsequent to the initial recognition, the liability is adjusted for any changes in the expected value of the retirement obligation (with a corresponding adjustment to property, plant, and equipment, or depreciation expense if the asset is fully depreciated) until the obligation is settled. Revisions in estimated asset retirement obligations may result from changes in estimated asset retirement costs, inflation rates, discount rates, and the estimated timing of settlement. See Note 12.

Environmental expenditures. The Partnership is subject to various environmental-remediation obligations arising from federal, state, and local laws and regulations. Losses associated with environmental obligations are accrued when the necessity for environmental remediation or other potential environmental liabilities becomes probable and the costs can be reasonably estimated, with the exception of environmental obligations acquired in a business combination, which are recorded at fair value at the time of acquisition. Accruals for estimated losses from environmental-remediation obligations are recognized no later than at the time of the completion of the remediation feasibility study or when the evaluation of response options is complete. These accruals are adjusted as additional information becomes available or as circumstances change. Costs of future expenditures for environmental-remediation obligations are not discounted to their present value. See Note 16.

Revenue and cost of product. The Partnership provides gathering, processing, treating, transportation, and disposal services pursuant to a variety of contracts. Under these arrangements, the Partnership receives fees and/or retains a percentage of products or a percentage of the proceeds from the sale of the customer’s products. These revenues are included in Service revenues and Product sales in the consolidated statements of operations. Payment is generally received from the customer in the month following the service or delivery of the product. Contracts with customers generally have initial terms ranging from 5 to 10 years.

Service revenues – fee based is recognized for fee-based contracts in the month of service based on the volumes delivered by the customer. Producers’ wells or production facilities are connected to the Partnership’s gathering systems for gathering, processing, treating, transportation, and disposal of natural gas, NGLs, condensate, crude oil, and produced water, as applicable. Revenues are valued based on the rate in effect for the month of service when the fee is either the same per-unit rate over the contract term or when the fee escalates and the escalation factor approximates inflation. Deficiency fees charged to customers that do not meet their minimum delivery requirements are recognized as services are performed based on an estimate of the fees that will be billed at the completion of the performance period. Because of its significant upfront capital investment, the Partnership may charge additional service fees to customers for only a portion of the contract term (i.e., for the first year of a contract or until reaching a volume threshold), and these fees are recognized as revenue over the expected period of customer benefit, which is generally the life of the related properties. Timing differences between amounts recognized in Service revenues – fee based and the amounts billed to customers are recognized as contract assets or contract liabilities and are amortized over the related contract period.

The Partnership also receives Service revenues – fee based from contracts that have fees that require periodic rate redeterminations based on the related facility cost of service. The cost-of-service rates are calculated using a contractually specified rate of return and estimates, including long-term assumptions for capital invested, receipt volumes, and operating and maintenance expenses. Certain of these cost-of-service agreements also have minimum-volume-commitment demand fees and guaranteed minimum revenues in addition to cost-of-service rates. Such contracts include fixed and variable consideration that are recognized on a consistent per-unit rate over the term of the contract. Annual adjustments are made to the cost-of-service rates charged to customers, and a cumulative catch-up revenue adjustment related to services already provided to the minimum volumes under the contract may be recorded in future periods, with revenues for the remaining term of the contract recognized on a consistent per-unit rate based on the total expected variable consideration under the contract. If the Partnership determines it is probable that a significant reversal in the cumulative catch-up revenue adjustment could occur, the variable consideration may be constrained up to the amount of the probable significant reversal.

Service revenues – product based includes service revenues from percent-of-proceeds gathering and processing contracts that are recognized net of the cost of product for purchases from the Partnership’s customers since it is acting as the agent in the product sale. Keep-whole agreements, percent-of-product agreements, and certain fee-based contracts that have a fixed-recovery component result in Service revenues – product based being recognized when the natural gas and/or NGLs are received from the customer as non-cash consideration for the services provided. Non-cash consideration for these services is valued at the time the services are provided. Revenue is also recognized in Product sales, along with the cost of product expense related to the sale, when the product received as non-cash consideration is sold.

The Partnership also purchases natural-gas volumes from producers at the wellhead or from a production facility, typically at an index price, and charges the producer fees associated with the downstream gathering and processing services. When the fees relate to services performed after control of the product has transferred to the Partnership, the fees are treated as a reduction of the purchase cost. If the fees relate to services performed before control of the product has transferred to the Partnership, the fees are treated as Service revenues – fee based. Product sales revenue is recognized, along with cost of product expense related to the sale, when the purchased product is sold.

The Partnership receives aid-in-construction reimbursements for certain capital costs necessary to provide services to customers (i.e., connection costs.) under certain service contracts. Aid-in-construction reimbursements are reflected as a contract liability when received and are amortized to Service revenues – fee based over the expected period of customer benefit, which is generally the life of the related properties. See Note 2.

Defined-contribution plan. Employees of the Partnership are eligible to participate in the Western Midstream Savings Plan, a defined-contribution benefit plan maintained by the Partnership. All regular employees may participate in the plan by making elective contributions that are matched by the Partnership, subject to certain limitations. The Partnership also makes other contributions based on plan guidelines. The Partnership recognized expense related to the plan of $29.5 million, $28.9 million, and $24.6 million for the years ended December 31, 2025, 2024, and 2023, respectively.

Partnership income taxes. The Partnership is structured as a publicly traded limited partnership and, therefore, is generally not subject to federal or most state income taxes. The Partnership operates certain business activities through corporate subsidiaries that are subject to federal, state, and local income taxes. These corporate subsidiaries include Arrakis Holdings, Inc, and Aris Water Solutions, Inc.

For federal and most state purposes, the earnings or losses of the Partnership, unless they are attributed to a taxable subsidiary, are reported on the individual tax returns of the partners. The net earnings presented in the Partnership’s consolidated financial statements may differ significantly from the taxable income reported to unitholders. These variations arise from differences in the tax basis versus the financial statement basis of assets and liabilities reported in the Partnership’s consolidated financial statements, as well as the allocation requirements established in the Partnership’s partnership agreement. The Partnership does not have access to information regarding each partner’s individual tax basis in the limited partner interests.

As a publicly traded limited partnership, the Partnership must comply with a statutory requirement that its “qualifying income,” as defined by the Internal Revenue Code, related Treasury Regulations, and Internal Revenue Service pronouncements, exceeds 90% of total gross income on a calendar year basis. Failure to meet this requirement would result in the Partnership being taxed as a corporation for federal and state income tax purposes. For the years ended December 31, 2025, 2024, and 2023, the Partnership’s qualifying income satisfied this statutory threshold.

The Partnership and its corporate subsidiaries utilize the asset and liability method to account for income taxes. Deferred income tax assets and liabilities are recognized to reflect temporary differences between the financial statement basis and the tax basis of assets and liabilities. These amounts are stated at the enacted tax rates expected to apply when the taxes are paid or recovered. If management determines that it is more likely than not that a deferred tax asset will not be realized, a valuation allowance is established. Any changes in tax legislation are incorporated into the relevant computations during the period in which such changes take effect. The Partnership reviews contingent tax liabilities and estimated exposures using a “more likely than not” standard based on its current tax positions.

Consistent with Financial Accounting Standards Board (“FASB”) guidance regarding uncertainty in income taxes, the Partnership may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by tax authorities. This assessment is based on the technical merits of each tax position, as well as the past administrative practices and precedents of the taxing authority. As of December 31, 2025 and 2024, the Partnership had no material uncertain tax positions. See Note 8.

WES Operating income taxes. WES Operating is a limited partnership, generally exempt from federal or state income taxes except for Texas margin tax on Texas-apportioned income. Until August 2024, WES Operating participated in Occidental’s Texas Franchise Tax filings.

Deferred state income tax assets and liabilities are recognized for temporary differences and measured at enacted tax rates. A valuation allowance is set up if deferred tax assets are not likely to be realized. Tax legislation changes are reflected as they take effect. Contingent tax liabilities are assessed using a “more likely than not” threshold.

Pursuant to FASB guidance, WES Operating only recognizes uncertain tax positions if it is more likely than not they will be upheld by authorities. As of December 31, 2025 and 2024, there were no material uncertain tax positions. See Note 8.

Net income (loss) per common unit. The Partnership applies the two-class method in determining net income (loss) per unit applicable to master limited partnerships having multiple classes of securities, including common units and general partner units. The two-class method allocates earnings pursuant to a formula that treats participating securities as having rights to earnings that otherwise would have been available to common unitholders. Under the two-class method, net income (loss) per unit is calculated as if all of the earnings for the period were distributed pursuant to the terms of the relevant contractual arrangement. The accounting guidance provides the methodology for the allocation of undistributed earnings to the general partner and limited partners and the circumstances in which such an allocation should be made. For the Partnership, earnings per unit is calculated based on the assumption that the Partnership distributes cash to its unitholders equal to the net income of the Partnership, notwithstanding the general partner’s ultimate discretion over the amount of cash to be distributed for the period, the existence of other legal or contractual limitations that would prevent distributions of all of the net income for the period, or any other economic or practical limitation on the ability to make a full distribution of the net income for the period. See Note 5.

Net income (loss) per common unit for WES Operating is not calculated because no publicly traded units are outstanding.

Leases. The Partnership determines if an arrangement is a lease based on the rights and obligations conveyed at contract inception. Significant judgment is required when determining whether a customer obtains the right to direct the use of identified property or equipment.

When the Partnership is a lessee at the lease-commencement date, a lease is classified as either operating or finance, and right-of-use (“ROU”) assets and lease liabilities are recognized based on the present value of future lease payments over the lease term. As the rate implicit in the Partnership’s leases is generally not readily determinable, the Partnership discounts lease liabilities using the Partnership’s incremental borrowing rate at the commencement date. Non-lease components associated with leases that began in 2019 or later are accounted for as part of the lease component, and prepaid lease payments are included as ROU assets. Options to extend or terminate a lease are included in the lease term when it is reasonably certain that the Partnership will exercise that option. Leases of 12 months or less are not recognized on the consolidated balance sheets. Lease cost is generally recognized on a straight-line basis over the lease term. For finance leases, interest expense is recognized over the lease term using the effective interest method. Variable lease payments are recognized when the obligation for those payments is incurred.

When the Partnership is a lessor at the lease-commencement date, a lease is classified as operating, sales-type, or direct financing. The underlying assets associated with these agreements are evaluated for future use beyond the lease term. For operating leases, lease income is generally recognized on a straight-line basis over the lease term. Variable lease payments are recognized when the obligation for those payments is performed. The Partnership does not have sales-type or direct financing leases. For the Partnership’s gathering and processing assets, we elected the practical expedient to not separate lease and non-lease components. When the non-lease component is determined to be the predominant component, the combined components are accounted for under Revenue from Contracts with Customers (Topic 606).

Segments. The Partnership’s operations continue to be organized into a single operating segment, the assets of which gather, compress, treat, process, and transport natural gas; gather, stabilize, and transport condensate, NGLs, and crude oil; and gather, transport, recycle, treat, supply and dispose of produced water in the United States.

Accounting Standards Update 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” was adopted on December 31, 2024, using a retrospective approach with no impact to the consolidated financial statements; however, the adoption did result in additional disclosure. See Note 17.

New accounting pronouncements not yet adopted. In November 2024, the Financial Accounting Standards Board issued Accounting Standards Update 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation (Subtopic 220-40): Disaggregation of Income Statement Expenses.” The standard requires additional disclosure and disaggregation of certain income statement expense line items and may be applied prospectively or retrospectively. The Partnership plans to adopt the standard when it becomes effective beginning with the fiscal-year 2027 annual financial statements. The Partnership is assessing the impact of this guidance on its disclosures in the Notes to the Consolidated Financial Statements.

2. REVENUE FROM CONTRACTS WITH CUSTOMERS

The following table summarizes revenue from contracts with customers:

Contract balances. Receivables from customers, which are included in Accounts receivable, net on the consolidated balance sheets, were $737.0 million and $693.9 million as of December 31, 2025 and 2024, respectively.

Contract assets primarily relate to (i) revenue accrued but not yet billed under cost-of-service contracts with fixed and variable fees and (ii) accrued deficiency fees the Partnership expects to charge customers once the related performance periods are completed. The following table summarizes activity related to contract assets from contracts with customers:

2. REVENUE FROM CONTRACTS WITH CUSTOMERS

Contract liabilities primarily relate to (i) fixed and variable fees under cost-of-service contracts that are received from customers for which revenue recognition is deferred, (ii) aid-in-construction payments received from customers that must be recognized over the expected period of customer benefit, and (iii) fees that are charged to customers for only a portion of the contract term and must be recognized as revenues over the expected period of customer benefit.

The following table summarizes activity related to contract liabilities from contracts with customers:

Transaction price allocated to remaining performance obligations. Revenues expected to be recognized from certain performance obligations that are unsatisfied (or partially unsatisfied) as of December 31, 2025, are presented in the table below. The Partnership applies the optional exemptions in Revenue from Contracts with Customers (Topic 606) and does not disclose consideration for remaining performance obligations with an original expected duration of one year or less or for variable consideration related to unsatisfied (or partially unsatisfied) performance obligations. Therefore, the following table represents only a portion of expected future revenues from existing contracts, as most future revenues from customers are dependent on future variable customer volumes and, in some cases, variable commodity prices for those volumes. See Note 18.

Aris. On October 15, 2025, the Partnership closed on the acquisition of Aris by merger in a transaction valued at $2.0 billion, including the cash and equity merger consideration, Aris’s outstanding debt of $80.0 million in revolving credit facility borrowings that were repaid at closing, and $500.0 million in principal amount of senior notes (see Note 13). Based on Aris shareholder consideration elections, the Partnership issued 26.6 million common units and paid $415.0 million in cash, funded with borrowings under the commercial paper program, in exchange for all issued and outstanding shares of Aris common stock. The $368.6 million included as Acquisitions from third parties in the consolidated statements of cash flows includes the cash paid to Aris shareholders net of cash acquired (as presented in the table below).

The Partnership acquired Aris to expand its existing produced-water infrastructure and access additional customers in the area. The assets acquired, located in Lea and Eddy Counties, New Mexico and West Texas, include approximately 830 miles of produced-water pipeline,1,812 MBbls/d of produced-water handling capacity,1,560 MBbls/d of water recycling capacity, and 625,000 dedicated acres.

The Aris acquisition has been accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed in the Aris acquisition were recorded in the consolidated balance sheet at their estimated fair values as of the acquisition date. Results of operations attributable to the Aris acquisition were included in the Partnership’s consolidated statements of operations beginning on the acquisition date in the fourth quarter of 2025. For the year ended December 31, 2025, General and administrative expenses in the consolidated statements of operations include acquisition-related transaction costs consisting primarily of $104.6 million of severance costs and $15.9 million of third-party consulting and legal fees.

The following is the preliminary acquisition-date fair value as of December 31, 2025, for the assets acquired and liabilities assumed in the Aris acquisition. The preliminary fair values are subject to change within the measurement period (up to one year from the acquisition date), pending a final determination of the values assigned to tangible and identifiable intangible assets.

Goodwill recognized in the Aris acquisition relates primarily to enhancing and diversifying the Partnership’s water-asset position, as well as delivering operational synergies, including increasing volumes on its existing processing facilities and increasing revenues on its produced-water systems. See Note 10.

Other intangible assets recognized in the Aris acquisition are related to customer contracts. The basis for determining the value of these intangible assets is estimated future net cash flows to be derived from acquired customer contracts and relationships, offset with appropriate charges for the use of contributory assets and discounted using a risk-adjusted discount rate. These intangible assets are being amortized on a straight-line basis over an initial period of 19 years, which represents the estimated term over which the customer contracts are expected to contribute to the Partnership’s cash flows. See Note 10.

The acquisition-date fair values are based on an assessment of the fair value of the assets acquired and liabilities assumed in the Aris acquisition using inputs that are not observable in the market and thus represent Level 3 inputs. The fair values of the produced-water disposal and recycling systems and related facilities and equipment are based on market and cost approaches.

The following table presents the pro forma condensed financial information of the Partnership as if the Aris acquisition had occurred on January 1, 2024:

The following table presents the pro forma condensed financial information of WES Operating (which is included in the Partnership’s pro forma condensed financial information) as if the Aris acquisition had occurred on January 1, 2024:

The pro forma information is presented for illustration purposes only and is not necessarily indicative of the operating results that would have occurred had the Aris acquisition been completed at the assumed date, nor is it necessarily indicative of future operating results of the combined entity. The pro forma adjustments reflect pre-acquisition results of the Aris acquisition including (i) adjustments of $47.3 million and $41.9 million for the years ended December 31, 2025 and 2024, respectively, to increase revenues and cost of product to apply the Partnership’s revenue recognition policy related to skim-oil received from the customer as non-cash consideration for services provided under certain contracts, (ii) adjustments of $14.0 million and $18.7 million for the years ended December 31, 2025 and 2024, respectively, to increase depreciation and amortization expense based on the acquisition-date fair value and estimated useful lives of property, plant, and equipment, and intangible assets, and (iii) adjustments of $9.1 million and $12.6 million to increase interest expense for the years ended December 31, 2025 and 2024, respectively, related to borrowings under the commercial paper program to finance the cash-funded portion of the Aris acquisition and the acquisition of Aris’s $500.0 million in aggregate principal amount of 7.250% Senior Notes due 2030. The pro forma adjustments include estimates and assumptions based on currently available information. Management believes the estimates and assumptions are reasonable, and the relative effects of the transaction are properly reflected. The pro forma information reflects recurring adjustments, but does not reflect any cost savings or other synergies anticipated as a result of the Aris acquisition, nor any future acquisition-related expenses.

The pro forma information in the table above includes $116.4 million of revenues and $93.2 million of expenses attributable to the assets acquired as part of the Aris acquisition that are included in the Partnership’s and WES Operating’s consolidated statements of operations for the year ended December 31, 2025.

Marcellus Interest systems. During the second quarter of 2024, the Partnership closed on the sale of its 33.75% interest in the Marcellus Interest systems for proceeds of $206.2 million, resulting in a net gain on sale of $63.9 million that was recorded as Gain (loss) on divestiture and other, net in the consolidated statement of operations.

Mont Belvieu JV, Whitethorn LLC, Panola, and Saddlehorn. During the first quarter of 2024, the Partnership closed on the sale of the following equity investments to third parties: (i) the 25.00% interest in Enterprise EF78 LLC, (ii) the 20.00% interest in Whitethorn Pipeline Company LLC, (iii) the 15.00% interest in Panola Pipeline Company, LLC, and (iv) the 20.00% interest in Saddlehorn Pipeline Company, LLC. The combined proceeds received in the first quarter of 2024 of $588.6 million includes $5.9 million in pro-rata distributions through closing, resulting in a net gain on sale of $239.7 million that was recorded as Gain (loss) on divestiture and other, net in the consolidated statement of operations.

Meritage. On October 13, 2023, the Partnership closed on the acquisition of Meritage Midstream Services II, LLC (“Meritage”) for $885.0 million (subject to certain customary post-closing adjustments) funded with cash, including proceeds from the Partnership’s $600.0 million senior note issuance in September 2023 (see Note 13)and borrowings on the senior unsecured revolving credit facility (“RCF”). The cash purchase price, adjusted for working capital and certain customary post-closing adjustments and reduced by the $38.4 million of cash acquired (as presented in the table below), was $878.2 million.

The following is the final acquisition-date fair value for the assets acquired and liabilities assumed in the Meritage acquisition on October 13, 2023.

The acquisition-date fair values were based on an assessment of the fair value of the assets acquired and liabilities assumed in the Meritage acquisition using inputs that are not observable in the market and thus represent Level 3 inputs. The fair values of the processing plants, gathering system, and related facilities and equipment are based on market and cost approaches.

4. PARTNERSHIP DISTRIBUTIONS

Partnership distributions. The Partnership distributes all of its available cash, as defined in the partnership agreement, to unitholders of record on the applicable record date within 55 days following each quarter’s end.

The Board of Directors of the general partner (the “Board”) declared the following cash distributions to the Partnership’s unitholders for the periods presented:

(1)Includes the regular quarterly distribution of $0.500 per unit, or $196.8 million, as well as an enhanced distribution of $0.356 per unit. The enhanced distribution financial policy adopted in 2022, and paid only in the first quarter of 2023, was discontinued in 2025 and will not be used in future periods to calculate the distribution of available cash.

4. PARTNERSHIP DISTRIBUTIONS

WES Operating partnership distributions. WES Operating makes quarterly cash distributions to the Partnership and WGRAH, a subsidiary of Occidental, according to the terms of its limited partnership agreement. WES Operating made and/or declared the following cash distributions to its limited partners for the periods presented:

(1)Includes amounts related to the enhanced distribution discussed above.

In addition to the distributions discussed above, during the year ended December 31, 2023, WES Operating made a distribution of $130.1 million to the Partnership and WGRAH. The Partnership used its portion of the distribution to repurchase common units.

5. EQUITY AND PARTNERS’ CAPITAL

Holdings of Partnership equity. The Partnership’s common units are listed on the New York Stock Exchange under the ticker symbol “WES.” As of December 31, 2025, Occidental held 165,681,578 common units, representing a 39.7% limited partner interest in the Partnership, and through its ownership of the general partner, Occidental indirectly held 9,060,641 general partner units, representing a 2.2% general partner interest in the Partnership. The public held 242,459,788 common units (including the units issued in connection with the Aris acquisition, see Note 3), representing a 58.1% limited partner interest in the Partnership. See Note 18.

Partnership equity repurchases. In February 2025, the Board authorized the Partnership to buy back up to $250.0 million of the Partnership’s common units through December 31, 2026 (the “2025 Purchase Program”). The common units may be purchased from time to time in the open market at prevailing market prices or in privately negotiated transactions. During the year ended December 31, 2025, the Partnership repurchasedno common units. As of December 31, 2025, the Partnership had an authorized amount of $250.0 million remaining under the program.

In 2022, the Board authorized the Partnership to buy back up to $1.25 billion of the Partnership’s common units through December 31, 2024. The common units were purchased from time to time in the open market at prevailing market prices or in privately negotiated transactions. During the year ended December 31, 2023, the Partnership repurchased 5,387,322 common units, which included 5.1 million common units repurchased from Occidental, for an aggregate purchase price of $134.6 million.

Holdings of WES Operating equity. On October 15, 2025, WES Operating issued preferred units to Aris, a wholly owned subsidiary of the Partnership, in connection with the Aris acquisition (see Note 1). As of December 31, 2025, (i) the Partnership, directly and indirectly through its ownership of WES Operating GP, owned a 98.1% limited partner interest and the entire non-economic general partner interest in WES Operating and (ii) Occidental, through its ownership of WGRAH, owned a 1.9% limited partner interest in WES Operating, which is reflected as a noncontrolling interest within the consolidated financial statements of the Partnership (see Note 1).

Partnership’s net income (loss) per common unit. The common and general partner unitholders’ allocation of net income (loss) attributable to the Partnership was equal to their cash distributions plus their respective allocations of undistributed earnings or losses in accordance with their weighted-average ownership percentage during each period using the two-class method.

The following table provides a reconciliation between basic and diluted net income (loss) per common unit:

WES Operating’s net income (loss) per common unit. Net income (loss) per common unit for WES Operating is not calculated because it has no publicly traded units.

Summary of related-party transactions. The following tables summarize material related-party transactions included in the Partnership’s consolidated financial statements:

(1)See Note 7.

(2)Includes related-party natural-gas and NGLs imbalances.

(1)See Note 7.

(2)Includes contract liabilities from contracts with customers. See Note 2.

(1)Represents common and general partner unit distributions paid to Occidental pursuant to the partnership agreement of the Partnership. See Note 4 and Note 5.

(2)Represents distributions paid to Occidental, through its ownership of WGRAH, pursuant to WES Operating’s partnership agreement. See Note 4 and Note 5.

(3)Represents common units repurchased from Occidental. See Note 5.

The following tables summarize material related-party transactions for WES Operating (which are included in the Partnership’s consolidated financial statements) to the extent the amounts differ materially from the Partnership’s consolidated financial statements:

(1)Includes an intercompany service fee between the Partnership and WES Operating.

(1)Includes balances related to transactions between the Partnership and WES Operating.

(1)Represents distributions paid to the Partnership and Occidental, through its ownership of WGRAH, according to the terms of WES Operating’s partnership agreement. The year ended December 31, 2023, included distributions made from WES Operating to the Partnership that were used to repurchase common units. See Note 4 and Note 5.

Related-party revenues. Related-party revenues include amounts earned by the Partnership from services provided to Occidental and from the sale of natural gas, condensate, NGLs, and water solutions volumes to Occidental.

Gathering and processing agreements. The Partnership has significant gathering, treating, processing, stabilization, and produced-water disposal arrangements with affiliates of Occidental on most of its systems. While Occidental is the contracting counterparty of the Partnership, these arrangements with Occidental include not just Occidental-produced volumes, but also, in some instances, the volumes of other working-interest owners of Occidental who rely on the Partnership’s facilities and infrastructure to bring their volumes to market. Natural-gas throughput (excluding equity-investment throughput) attributable to production owned or controlled by Occidental was 36%,34%, and 34% for the years ended December 31, 2025, 2024, and 2023, respectively. Crude-oil and NGLs throughput (excluding equity-investment throughput) attributable to production owned or controlled by Occidental was 91%,91%, and 86% for the years ended December 31, 2025, 2024, and 2023, respectively. Produced-water throughput attributable to production owned or controlled by Occidental was 61%,78%, and 78% for the years ended December 31, 2025, 2024, and 2023, respectively. See Note 18.

The Partnership has discussed varying interpretations of certain contractual provisions with Occidental regarding the calculation of the cost-of-service rates under an oil-gathering contract related to the Partnership’s DJ Basin oil-gathering system. If such discussions are resolved in a manner adverse to the Partnership, such resolution could have a negative impact on the Partnership’s financial condition and results of operations, including a reduction in rates and a non-cash charge to earnings.

Marketing services. While the Partnership markets and sells substantially all of its crude oil, residue gas, and NGLs directly to third parties, it does still have some marketing agreements with affiliates of Occidental, the activity for which is reflected in the related-party statements of operations above.

Operating leases. Certain surface-use and salt-water disposal agreements between an affiliate of Occidental and certain wholly owned subsidiaries of the Partnership are classified as operating leases (see Related-party commercial agreement below). In addition, the Partnership has operating leases for field offices with Occidental as the lessor.

Related-party expenses. Operation and maintenance expense includes amounts accrued for or paid to related parties for field-related costs, field offices, and easements (see Related-party commercial agreement below) supporting the Partnership’s operations at certain assets. General and administrative expense includes amounts accrued for or paid to Occidental for certain reimbursed expenses pursuant to the provisions of the Partnership’s and WES Operating’s agreements with Occidental. Cost of product expense includes amounts related to certain continuing marketing arrangements with affiliates of Occidental, related-party imbalances, and transactions with affiliates accounted for under the equity method of accounting. See Marketing services in the section above. Related-party expenses bear no direct relationship to related-party revenues, and third-party expenses bear no direct relationship to third-party revenues.

Services Agreement. Occidental performed certain centralized corporate functions for the Partnership and WES Operating pursuant to the agreement dated as of December 31, 2019, between WES Operating GP and Occidental (“Services Agreement”). Most of the administrative and operational services previously provided by Occidental fully transitioned to the Partnership by December 31, 2021, with certain limited transition services remaining in place pursuant to the terms of the Services Agreement.

Construction reimbursement agreements and purchases and sales with related parties. From time to time, the Partnership enters into construction reimbursement agreements with Occidental providing that the Partnership will manage the construction of certain midstream infrastructure for Occidental in the Partnership’s areas of operation. Such arrangements generally provide for a reimbursement of costs incurred by the Partnership on a cost or cost-plus basis.

Additionally, from time to time, in support of the Partnership’s business, the Partnership purchases and sells equipment, inventory, and other miscellaneous assets from or to Occidental or its affiliates.

Related-party commercial agreement. During the first quarter of 2021, an affiliate of Occidental and the Partnership amended certain West Texas surface-use and salt-water disposal agreements to reduce usage fees owed by the Partnership in exchange for the forgiveness of certain deficiency fees owed by Occidental and other unrelated contractual amendments. The present value of the reduced usage fees under the amended agreements was $30.0 million at the time the agreement was executed. As a result of the amendments, (i) these agreements are classified as operating leases and (ii) a right-of-use (“ROU”) asset, included in Other assets on the consolidated balance sheets, was recognized during the first quarter of 2021. The ROU asset is being amortized to Operation and maintenance expense through 2038, the remaining term of the agreements.

Customer concentration. Occidental was the only customer from which revenues exceeded 10% of consolidated revenues for all periods presented in the consolidated statements of operations.

The following tables present the financial statement impact of the Partnership’s equity investments:

(1)Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, are calculated on an individual-investment basis.

(1)Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, are calculated on an individual-investment basis.

(2)See Note 3.

During the first quarter of 2024, the Partnership closed on the sale of the following equity investments to third parties: (i) the 25.00% interest in Mont Belvieu JV, (ii) the 20.00% interest in Whitethorn LLC, (iii) the 15.00% interest in Panola, and (iv) the 20.00% interest in Saddlehorn. See Note 3.

The investment balance in White Cliffs at December 31, 2025, is $23.9 million less than the Partnership’s underlying equity in White Cliffs’ net assets primarily due to an impairment loss recognized by the Partnership in 2022 that resulted from a decline in value below the carrying value, which was determined to be other than temporary in nature.

The investment balance in Rendezvous at December 31, 2025, includes $14.1 million for the purchase price allocated to the investment in Rendezvous in excess of the historical cost basis of Western Gas Resources, Inc. (“WGRI”), the entity that previously owned the interest in Rendezvous, which Anadarko acquired in August 2006. This excess balance is attributable to the difference between the fair value and book value of such gathering and treating facilities (at the time WGRI was acquired by Anadarko) and will be amortized to Equity income, net – related parties in the consolidated statements of operations over the remaining estimated useful life of those facilities.

Management evaluates its equity investments for impairment whenever events or changes in circumstances indicate that the carrying value of such investments may have experienced a decline in value that is other than temporary. When evidence of loss in value has occurred, management compares the estimated fair value of the investment to the carrying value of the investment to determine whether the investment has been impaired. Management assesses the fair value of equity investments using commonly accepted techniques and may use more than one method, including, but not limited to, recent third-party comparable sales and discounted cash flow models. If the estimated fair value is less than the carrying value, the excess of the carrying value over the estimated fair value is recognized as an impairment loss in the consolidated statements of operations.

The following tables present the summarized combined financial information for equity investments (amounts represent 100% of investee financial information):

8. INCOME TAXES

Accounting Standards Update 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” was adopted on December 31, 2025, using a retrospective approach with no impact to the consolidated statements or additional disclosures.

The Partnership is not a taxable entity for U.S. federal income tax purposes; therefore, the federal statutory rate is zero percent. However, income apportionable to Texas is subject to Texas margin tax.

For the year ended December 31, 2025, the variance from the federal statutory rate was primarily due to the Texas margin tax liability and federal income tax on activities operated through corporate entities. For the year ended December 31, 2024, the variance from the federal statutory rate was primarily impacted by a state margin tax rate increase associated with no longer being included in Occidental’s affiliated group tax return beginning in September 2024 due to Occidental’s sale of 19.5 million of the Partnership’s common units in August 2024 and the resulting decrease in ownership, inclusive of its ownership in WES Operating. For the year ended December 31, 2023, the variance from the federal statutory rate was primarily due to the Texas margin tax liability.

The components of income tax expense (benefit) are as follows:

Total income taxes differed from the amounts computed by applying the statutory income tax rate to income (loss) before income taxes. The sources of these differences are as follows:

(1)Includes tax expense of $13.1 million for the year ended December 31, 2024, related to an increased Texas margin tax rate resulting from no longer being included in Occidental’s affiliated group tax return beginning in September 2024.

8. INCOME TAXES

The tax effects of temporary differences that give rise to significant portions of deferred tax assets (liabilities) are as follows:

As of December 31, 2025, the Partnership had unused net operating loss carryforwards for federal income tax purposes of $357.3 million, which can be carried forward indefinitely and may be used to offset future taxable income. The federal net operating loss carryforward limit under Internal Revenue Code (“IRC”) Section 382 is $322.1 million. Although the Partnership expects to fully utilize the federal net operating loss allowed under IRC Section 382, the amount utilized in a particular year may be limited.

As of December 31, 2025, the Partnership had unused net operating loss carryforwards for state income tax purposes of $192.3 million, which can be carried forward indefinitely, and $13.0 million, which expire from 2038 through 2040. The Partnership believes that it is more likely than not that the benefit from certain state net operating loss carryforwards will not be realized and have provided a valuation allowance of $0.6 million on the deferred tax assets related to these state net operating loss carryforwards.

9. PROPERTY, PLANT, AND EQUIPMENT

A summary of the historical cost of property, plant, and equipment is as follows:

“Assets under construction” represents property that is not yet placed into productive service as of the respective balance sheet date and is excluded from capitalized costs being depreciated. “Other” property, plant, and equipment primarily represents asset retirement costs, measurement equipment, capitalized interest, electrical distribution equipment, and computer software and equipment.

10. GOODWILL AND OTHER INTANGIBLES

Goodwill. Goodwill is recorded when the purchase price of a business acquired exceeds the fair market value of the tangible and separately measurable intangible net assets. The Partnership’s goodwill has been allocated totwo reporting units: (i) gathering and processing and (ii) transportation. The Partnership recorded $348.5 million of goodwill in connection with the Aris acquisition (see Note 3). As of December 31, 2025, the carrying value of goodwill for the gathering and processing reporting unit was $348.5 million and goodwill allocated to the transportation reporting unit was $4.8 million. The Partnership’s annual goodwill impairment assessment indicatedno impairment for the year ended December 31, 2025.

Other intangible assets. The other intangible assets balance on the consolidated balance sheets includes the fair value, net of amortization, primarily related to (i) contracts assumed in connection with processing plant acquisitions in 2011 that are part of the DJ Basin complex, which are being amortized on a straight-line basis over 38 years, (ii) contracts assumed in connection with the DBM acquisition in November 2014, which are being amortized on a straight-line basis over 30 years, and (iii) contracts assumed in connection with the Aris acquisition, which are being amortized on a straight-line basis over 19 years.

The Partnership assesses other intangible assets for impairment together with the related underlying long-lived assets whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. See Property, plant, and equipment and other intangible assets in Note 1 for further discussion of management’s process to evaluate potential impairment of long-lived assets.

The following table presents the gross carrying value and accumulated amortization of other intangible assets:

Amortization expense for intangible assets was $34.8 million, $31.7 million, and $31.7 million for the years ended December 31, 2025, 2024, and 2023, respectively. Intangible asset amortization to be recorded in each of the next five years is estimated to be $47.4 million per year.

11. SELECTED COMPONENTS OF WORKING CAPITAL

A summary of accounts receivable, net is as follows:

A summary of other current assets is as follows:

A summary of accrued liabilities is as follows:

(1)Includes aid-in-construction reimbursement prepayments, other employee expenses, and as of December 31, 2025, Aris-related accruals.

12. ASSET RETIREMENT OBLIGATIONS

The following table provides a summary of changes in asset retirement obligations:

Liabilities incurred for the year ended December 31, 2025, primarily related to the acquisition of Aris and expansion activity in West Texas. Revisions in estimated liabilities for the year ended December 31, 2025, primarily related to changes in expected settlement timing for assets in West Texas.

Liabilities incurred for the year ended December 31, 2024, primarily related to expansion activity in West Texas. Revisions in estimated liabilities for the year ended December 31, 2024, primarily related to a decrease in expected settlement costs for certain assets in the Rocky Mountains.

WES Operating is the borrower for all outstanding debt and is expected to be the borrower for all future debt issuances. The following table presents the outstanding debt:

(1)Fair value is measured using the market approach and Level-2 fair value inputs.

Debt activity. The following table summarizes the debt activity for the periods presented:

(1)Net of borrowings and repayments related to commercial paper notes with original maturities of 90 days or less.

(2)Includes $29.4 million of premiums related to the 7.250% Senior Notes due 2030.

WES Operating Senior Notes. In January 2020, WES Operating issued the 4.050% Senior Notes due 2030 and 5.250% Senior Notes due 2050. Including the effects of the issuance prices, underwriting discounts, and interest-rate adjustments, the effective interest rates of the Senior Notes due 2030 and 2050 were 4.169% and 5.363%, respectively, at December 31, 2025 and 2024. The effective interest rate of these notes is subject to adjustment from time to time due to a change in credit rating.

During the fourth quarter of 2025, as part of the acquisition of Aris, WES Operating assumed $500.0 million in aggregate principal amount of 7.250% Senior Notes due 2030. See Note 3. Also during the fourth quarter of 2025, WES Operating completed the public offerings of $1.2 billion in aggregate principal amount of Senior Notes. Net proceeds from these public offerings (i) will be used to repay the 4.650% Senior Notes due 2026, (ii) were used to pay amounts outstanding under its commercial paper program (including borrowings incurred to fund the cash consideration of the acquisition of Aris), and (iii) will be used for general partnership purposes, including the funding of capital expenditures.

During the second quarter of 2025, WES Operating retired the total principal amount outstanding of the 3.950% Senior Notes due 2025 at par value. During the first quarter of 2025, WES Operating retired the total principal amount outstanding of the 3.100% Senior Notes due 2025 at par value. See Debt activity above. As of December 31, 2025, the 4.650% Senior Notes due 2026 were classified as short-term debt on the consolidated balance sheet.

During the third quarter of 2024, WES Operating completed the public offering of $800.0 million in aggregate principal amount of 5.450% Senior Notes due 2034. Net proceeds from the offering were used to repay a portion of the 3.100% and 3.950% Senior Notes due 2025, and for general partnership purposes, including the funding of capital expenditures. In addition, during 2024, WES Operating purchased and retired $150.0 million of certain of its senior notes via open-market repurchases with cash from operations.

As of December 31, 2025, WES Operating was in compliance with all covenants under the relevant governing indentures.

Revolving credit facility. In April 2025, WES Operating exercised an option to extend the maturity date of the RCF from April 2029 to April 2030, for each extending lender. The non-extending lenders’ commitments mature in April 2028 and represent $120.0 million out of $2.0 billion of total commitments, which are expandable to a maximum of $2.5 billion, from all lenders.

The RCF bears interest at an Adjusted Term SOFR (as defined in the RCF amendment), plus applicable margins ranging from 1.00% to 1.70%, or an alternate base rate equal to the greatest of (a) the Prime Rate, (b) the Federal Funds Effective Rate plus 0.50%, or (c) Adjusted Term SOFR for a one-month tenor in effect on such day plus 1.00%, in each case plus applicable margins currently ranging from zero to 0.70%, based on WES Operating’s senior unsecured debt rating. A required quarterly facility fee is paid ranging from 0.125% to 0.300% of the commitment amount (whether drawn or undrawn), which also is based on the senior unsecured debt rating.

The RCF contains certain covenants that limit, among other things, WES Operating’s ability, and that of certain of its subsidiaries, to incur additional indebtedness, grant certain liens, merge, consolidate, or allow any material change in the character of its business, enter into certain related-party transactions, and use proceeds other than for partnership purposes. The RCF also contains various customary covenants, certain events of default, and a maximum consolidated leverage ratio as of the end of each fiscal quarter (which is defined as the ratio of consolidated indebtedness as of the last day of a fiscal quarter to Consolidated EBITDA, as defined in the RCF agreement, for the most-recent four-consecutive fiscal quarters ending on such day) of 5.0 to 1.0, or a consolidated leverage ratio of 5.5 to 1.0 with respect to quarters ending in the 270-day period immediately following certain acquisitions. As a result of certain covenants contained in the RCF, our capacity to borrow under the RCF may be limited.

As of December 31, 2025, there wereno outstanding borrowings, resulting in $2.0 billion in effective borrowing capacity under the RCF. Any outstanding commercial paper borrowings (see below) reduce the effective borrowing capacity under the RCF as WES Operating maintains availability under the RCF as support for its commercial paper program. As of December 31, 2025 and 2024, the interest rate on any outstanding RCF borrowings was 4.99% and 5.63%, respectively. The facility-fee rate was 0.20% at December 31, 2025 and 2024. As of December 31, 2025, WES Operating was in compliance with all covenants under the RCF.

Commercial paper program. In November 2023, WES Operating entered into an unsecured commercial paper program under which it may issue (and have outstanding at any one time) an aggregate principal amount up to $2.0 billion. WES Operating intends to maintain a minimum aggregate available borrowing capacity under the RCF equal to the aggregate amount of outstanding commercial paper borrowings. The maturities of the notes may vary but may not exceed 397 days. As of December 31, 2025, there wereno outstanding borrowings under the commercial paper program.

14. LEASES

Lessee. The Partnership has entered into operating leases for equipment supporting the Partnership’s operations, corporate offices, field offices, and easements, with both Occidental and third parties as lessors. The Partnership has also entered into finance leases with third parties for equipment, vehicles, and an NGLs pipeline in Wyoming.

The following table summarizes information related to the Partnership’s leases:

(1)Includes additions to ROU assets and lease liabilities of $24.6 million and $154.1 million related to operating leases for the years ended December 31, 2025 and 2024, respectively. Includes additions to ROU assets and lease liabilities of $3.4 million and $4.3 million related to finance leases for the years ended December 31, 2025 and 2024, respectively.

14. LEASES

The following table summarizes the Partnership’s lease cost:

The following table summarizes cash paid for amounts included in the measurement of lease liabilities:

The following table reconciles the undiscounted cash flows to the operating and finance lease liabilities at December 31, 2025:

15. EQUITY-BASED COMPENSATION

The general partner has the authority to grant equity compensation awards to its outside directors, executive officers, and employees under the Western Gas Partners, LP 2017 Long-Term Incentive Plan (the “2017 LTIP”) and the Western Midstream Partners, LP 2021 Long-Term Incentive Plan (the “2021 LTIP”). In connection with the Merger Agreement, all authorized but unused shares that were previously approved for issuance pursuant to the Aris Water Solutions, Inc. 2021 Equity Incentive Plan were adjusted using the applicable exchange ratio for the Merger, assumed by the Partnership, and added to the common unit pool available under the 2021 LTIP. These plans are collectively referred to as the “WES LTIPs.” The 2017 LTIP and the 2021 LTIP permit the issuance of up to 3,431,251 and 14,403,998 units, respectively, of which 737,749 and 11,655,238 units, respectively, remained available for future issuance as of December 31, 2025.

Common units withheld from an award or surrendered by a participant to satisfy tax withholding obligations or to satisfy the payment of any exercise price with respect to an award will not be considered to be common units delivered under the 2021 LTIP for purposes of the 2021 LTIP Limit. If any award is forfeited, canceled, exercised, settled in cash, or otherwise terminates or expires without the actual delivery of common units, the common units subject to such award will again be available for awards under the 2021 LTIP. The 2021 LTIP provides for the grant of unit options, unit appreciation rights, restricted units, phantom units, other unit-based awards, cash awards, and a unit award or a substitute award to employees and directors of the Partnership and its general partner.

The Board awards phantom units (the “Awards”) to certain members of the leadership team of the Partnership under the WES LTIPs. The Awards include (i) an award of time-vested phantom units that vest ratably over a period ofthree years (“Time-Based Awards”), (ii) a market-based award that vests after a performance period ofthree years based on the Partnership’s relative total unitholder return as compared to a group of peer companies (“TUR Awards”), and (iii) a performance award that vests based on the Partnership’s average return on assets over a performance period ofthree years (“ROA Awards”). At vesting, the number of vested units for the TUR Awards and the ROA Awards will be determined in accordance with the terms of the respective award agreements that provide for payout percentages ranging from 0% to 200% based on results achieved over the applicable performance period. At vesting, the Awards generally will be settled in Partnership common units. Prior to vesting, the Awards granted in 2020 paid in-kind distributions in the form of Partnership common units. During the year ended December 31, 2023, the Partnership issued 3,253 common units as in-kind distributions under such Awards. Prior to vesting, the Time-Based Awards granted after 2020 pay distribution equivalents in cash ratably. The TUR and ROA Awards granted after 2020 pay cash distributions at vesting based on actual performance.

In addition, time-vested phantom units may be awarded under the WES LTIPs to non-executive employees and outside directors of the Partnership, which vest ratably over a period ofthree years andone year from the grant date, respectively. Prior to vesting, the awards to non-executive employees and outside directors pay distribution equivalents in cash.

The equity-based compensation expense attributable to these awards is amortized over the vesting periods applicable to the awards using the straight-line method. Expense is recognized based on the grant-date fair value and recorded, net of actual forfeitures, as General and administrative expense in the consolidated statements of operations. The fair value of the Time-Based Awards and non-executive awards is based on the observable market price of the Partnership’s units on the grant date of the award. The fair value of the TUR Awards is determined using a Monte Carlo simulation at the grant date of the award. The fair value of the ROA Awards is based on the observable market price of the Partnership’s units on the grant date of the award and compensation expense is adjusted quarterly based on the estimated performance rating at vesting. The total fair value of phantom units vested was $54.7 million, $38.2 million, and $23.4 million for the years ended December 31, 2025, 2024, and 2023, respectively, based on the market price at the vesting date. Compensation expense for the WES LTIPs was $50.8 million for the year ended December 31, 2025, of which $7.3 millionwas related to the Merger Agreement. For the years ended December 31, 2024 and 2023, compensation expense for the WES LTIPs was $38.0 million and $32.0 million, respectively. As of December 31, 2025, the Partnership had $59.0 million of estimated unrecognized compensation expense attributable to the WES LTIPs that will be recognized over a weighted-average period of 0.9 years.

15. EQUITY-BASED COMPENSATION

The following table summarizes time-vested award activity under the WES LTIPs:

(1)For the year ended December 31, 2025, includes 513,590 units issued in exchange for Aris equity-based awards.

The following table summarizes TUR Awards activity under the WES LTIPs:

The following table summarizes ROA Awards activity under the WES LTIPs:

16. COMMITMENTS AND CONTINGENCIES

Environmental obligations. The Partnership is subject to various environmental-remediation obligations arising from federal, state, and local regulations regarding air and water quality, hazardous and solid waste disposal, and other environmental matters. As of December 31, 2025 and 2024, the consolidated balance sheets included $10.0 million and $4.0 million, respectively, of liabilities for remediation and reclamation obligations. The current portion of these amounts is included in Accrued liabilities, and the long-term portion of these amounts is included in Other liabilities. The majority of payments related to these obligations are expected to be made over the next year. See Note 11. As of December 31, 2025, the recorded obligations do not include $6.5 million of anticipated insurance recoveries which are included in Accounts receivable, net.

Management regularly monitors the remediation and reclamation process and the liabilities recorded and believes its environmental obligations are adequate to fund remedial actions required to comply with present laws and regulations, and that the ultimate liability for these matters, if any, will not differ materially from recorded amounts nor materially affect the overall results of operations, cash flows, or financial condition. There can be no assurance, however, that current regulatory requirements will not change or past non-compliance with environmental issues will not be discovered.

Litigation and legal proceedings. From time to time, the Partnership is involved in legal, tax, regulatory, and other proceedings in various forums regarding performance, contracts, and other matters that arise in the ordinary course of business. Management is not aware of any such proceeding for which the final disposition could have a material adverse effect on the Partnership’s financial condition, results of operations, or cash flows.

Other commitments. The Partnership has payment obligations, or commitments, that include, among other things, a revolving credit facility, other third-party long-term debt, obligations related to the Partnership’s capital spending programs, pipeline and offload commitments, and various operating and finance leases. The payment obligations related to the Partnership’s capital spending programs, the majority of which is expected to be paid in the next 12 months, primarily relate to expansion, construction, and asset-integrity projects at the DBM water systems, West Texas complex, Powder River Basin complex, and DJ Basin complex.

17. REPORTABLE SEGMENT

Segment overview. The Partnership’s chief operating decision maker (“CODM”) is the Partnership’s President and Chief Executive Officer who assesses performance and allocates resources on a consolidated basis due to the similar nature of services provided to customers across the Partnership’s domestic asset portfolio. The CODM does not assess performance and allocate resources separately for Western Midstream Operating, LP. Accordingly, the Partnership has a single operating and reportable segment, all the assets of which are in the United States and gather, compress, treat, process, and transport natural gas; gather, stabilize, and transport condensate, NGLs, and crude oil; and gather, transport, recycle, treat, supply, and dispose of produced water.

Performance measures. Adjusted EBITDA attributable to Western Midstream Partners, LP (“Adjusted EBITDA”) is used as the performance measure by the Partnership’s CODM in assessing performance and allocating resources to the Partnership’s single operating and reportable segment. Net income (loss) is the most comparable GAAP metric to the performance metric of non-GAAP Adjusted EBITDA. The Partnership defines Adjusted EBITDA as net income (loss), plus (i) distributions from equity investments, (ii) non-cash equity-based compensation expense, (iii) interest expense, (iv) income tax expense, (v) depreciation and amortization, (vi) impairments, and (vii) other expense (including lower of cost or market inventory adjustments recorded in cost of product), less (i) gain (loss) on divestiture and other, net, (ii) gain (loss) on early extinguishment of debt, (iii) income from equity investments, (iv) income tax benefit, (v) other income, (vi) other items impacting comparability with the Partnership’s core operating performance, and (vii) the noncontrolling interest owners’ proportionate share of revenues and expenses.

Adjusted EBITDA is a non-GAAP financial measure that the CODM utilizes to assess (i) the Partnership’s operating performance as compared to other publicly traded partnerships in the midstream industry, without regard to financing methods, capital structure, or historical cost basis, (ii) the ability of the Partnership’s assets to generate cash flow to make distributions, and (iii) the viability of acquisitions and capital expenditures and the returns on investment of various investment opportunities. The Partnership’s calculation of Adjusted EBITDA may or may not be comparable to similarly titled measures used by others.

17. REPORTABLE SEGMENT

Summarized financial information. The following table presents information about the Partnership’s single operating and reportable segment including (i) total revenues and other, (ii) significant expenses, and (iii) other segment items:

(1)Includes Service revenue - fee based, Service revenue - product based, and Product sales.

(2)The significant expense categories and amounts align with the information that is regularly provided to the CODM.

(3)General and administrative expense as presented in the consolidated statements of operations less non-cash equity-based compensation expense and non-cash amortization of cloud-computing arrangements.

(4)Includes interest income earned on cash and cash equivalent balances.

(5)Other includes: (i) Cost of product, (ii) Non-cash equity-based compensation expense, (iii) non-cash amortization of cloud-computing arrangements, (iv) Property and other taxes, (v) Long-lived asset and other impairments, (vi) Gain (loss) on divestiture and other, net, and (vii) Gain (loss) on early extinguishment of debt.

The CODM uses consolidated total assets as the measure of the Partnership’s single reportable segment assets. As of December 31, 2025 and 2024, the consolidated balance sheets included $15.0 billion and $13.1 billion, respectively, of total assets, which includes $504.9 million and $541.4 million of assets related to equity investments as of December 31, 2025 and 2024, respectively.

Capital expenditures for additions to long-lived assets were $728.0 million, $833.9 million, and $735.1 million for the years ended December 31, 2025, 2024, and 2023, respectively.

18. SUBSEQUENT EVENT

Subsequent to December 31, 2025, Delaware Basin Midstream LLC (“DBM”), a subsidiary of the Partnership, entered into an amendment (the “GGA Amendment”) to its Delaware Basin gas gathering agreement with Anadarko E&P Onshore LLC (“AEP”), a subsidiary of Occidental, which agreement was originally dated effective January 1, 2018, to, among other things, (i) replace its cost-of-service-based gathering fee structure with a fixed-fee structure, (ii) add a new minimum-volume commitment through the end of 2027, and (iii) modify the process for certain dedication-related acreage transfers and releases. On January 16, 2026, and in connection with the GGA Amendment and related transactions, including an agreement between DBM and a subsidiary of ConocoPhillips pursuant to which DBM will gather and process certain volumes of natural gas already existing on the Partnership’s system, and conforming modifications to the terms of the associated processing arrangements between subsidiaries of the Partnership and Occidental, the Partnership and subsidiaries of Occidental also entered into a unit redemption agreement (“Unit Redemption Agreement”) providing for the transfer to, and redemption by the Partnership, on February 3, 2026, of approximately 15.3 million common units of the Partnership.

Occidental indirectly holds all of the equity interests of the general partner and, following the consummation of the transactions contemplated by the Unit Redemption Agreement, indirectly holds 38.3% of the Partnership’s outstanding common units. The Unit Redemption Agreement and the GGA Amendment and related transactions were reviewed and approved by the Special Committee of the Board of Directors of the general partner, consisting entirely of independent members of the Board of Directors, and, based upon the recommendation of the Special Committee, the full Board of Directors.