COMMITMENTS AND CONTINGENCIES	9 Months Ended
Sep. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES From time to time, we are subject to legal, administrative and environmental proceedings before various courts, arbitration panels and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits and pending judicial matters. We cannot predict the final disposition of such proceedings. We regularly review legal matters and record provisions for claims that we can estimate and are considered probable of loss. The amount or range of reasonably possible losses is not anticipated to, either individually or in the aggregate, materially adversely affect our business, financial condition and results of operations. Guarantees In certain limited circumstances, we enter into contractual guarantees. We may guarantee another entity's obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. We did not have any guarantees of other parties' obligations as of September 30, 2026. Surety Bonds In certain limited circumstances, we enter into contracts that require us to obtain external surety bonds to secure our payment and performance. We agree to indemnify the issuers of these surety bonds for amounts, if any, paid by them under these agreements. In the event that any surety bonds are called for non-performance, we would be obligated to reimburse the issuer of the surety bond. The maximum potential indemnification under our surety bond agreements as of September 30, 2026 is $11 million. Vector Line of Credit We are the lender under a revolving term credit facility to Vector, the borrower, in the amount of CAD $70 million. The credit facility was executed in response to the passage of Canadian regulations requiring oil and gas pipelines to demonstrate their financial ability to respond to a catastrophic event and exists for the sole purpose of satisfying these regulations. Vector may only draw upon the facility if the funds are required to respond to a catastrophic event. The maximum potential payout as of September 30, 2026 is USD $49 million. The funding of a loan under the terms of the revolving term credit facility is considered remote. Clean Fuels Gathering Contingent Payments A gas supply agreement at Clean Fuels Gathering requires contingent payments from DT Midstream of up to $34 million upon the completion of certain milestones, including cumulative production and income tax credits, and variable payments under a sharing mechanism. One milestone was achieved in 2024 related to verification of gas production volumes and $10 million was paid and recorded as a prepaid asset. No additional milestones have been achieved as of September 30, 2026. The remaining unamortized prepaid asset is $1 million and $7 million in current and long-term other assets, respectively, in DT Midstream's Consolidated Statements of Financial Position as of September 30, 2026. Contingent Liability In order to comply with certain state environmental regulations, we have an obligation to restore pipeline right-of-way slope failures that may arise in the ordinary course of business in the Utica and Marcellus formations. We completed evaluations of all locations, which were prioritized based on the severity and proximity of the slope failures, and used updated cost information to assess the adequacy of the estimate for the contingent liability accrual. As of December 31, 2025, the Company had accrued contingent liabilities of $2 million for future slope restoration expenditures, which were included in other current liabilities in the Consolidated Statements of Financial Position. Based on evaluations during the three months ended June 30, 2026, we determined that the remaining contingent liability for future slope restoration expenditures was no longer required. As a result, there is no remaining accrued contingent liability for future slope restorations as of September 30, 2026. Stonewall Litigation On November 27, 2024, Antero Resources Corporation ("Antero") filed a lawsuit against Stonewall regarding the application of certain rate provisions under the Agreement between the parties dated June 20, 2014. On December 12, 2025, the Eleventh Division of the Business Court of Texas issued an Order granting Antero’s Motion for Summary Judgment related to one aspect of the dispute. On January 12-16, 2026, trial was held on the remaining issues. On April 2, 2026, an Order was issued related to the application of the aforementioned rate provisions resulting in no damages awarded to Antero. Both parties have the right to appeal this Order. On October 28, 2026, the Eleventh Division of the Business Court of Texas issued a Final Order Assessing Attorney’s Fees awarding Antero a portion of its requested attorney’s fees and costs. Stonewall intends to continue to defend against Antero’s claim and intends to appeal this award of attorney’s fees and costs. The Company deems the probability of loss related to the award of attorney’s fees and costs to be reasonably possible, and the range of estimated loss to be $0 to $4.9 million. No contingent liability has been recorded in the accompanying Consolidated Financial Statements related to this matter. While the ultimate outcome cannot be predicted with certainty, the Company does not believe an unfavorable resolution would have a material adverse effect on the Company’s financial position, results of operations, or cash flows.

From time to time, we are subject to legal, administrative and environmental proceedings before various courts, arbitration panels and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits and pending judicial matters. We cannot predict the final disposition of such proceedings. We regularly review legal matters and record provisions for claims that we can estimate and are considered probable of loss. The amount or range of reasonably possible losses is not anticipated to, either individually or in the aggregate, materially adversely affect our business, financial condition and results of operations.

In certain limited circumstances, we enter into contractual guarantees. We may guarantee another entity's obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. We did not have any guarantees of other parties' obligations as of September 30, 2026.

In certain limited circumstances, we enter into contracts that require us to obtain external surety bonds to secure our payment and performance. We agree to indemnify the issuers of these surety bonds for amounts, if any, paid by them under these agreements. In the event that any surety bonds are called for non-performance, we would be obligated to reimburse the issuer of the surety bond. The maximum potential indemnification under our surety bond agreements as of September 30, 2026 is $11 million.

We are the lender under a revolving term credit facility to Vector, the borrower, in the amount of CAD $70 million. The credit facility was executed in response to the passage of Canadian regulations requiring oil and gas pipelines to demonstrate their financial ability to respond to a catastrophic event and exists for the sole purpose of satisfying these regulations. Vector may only draw upon the facility if the funds are required to respond to a catastrophic event. The maximum potential payout as of September 30, 2026 is USD $49 million. The funding of a loan under the terms of the revolving term credit facility is considered remote.

A gas supply agreement at Clean Fuels Gathering requires contingent payments from DT Midstream of up to $34 million upon the completion of certain milestones, including cumulative production and income tax credits, and variable payments under a sharing mechanism. One milestone was achieved in 2024 related to verification of gas production volumes and $10 million was paid and recorded as a prepaid asset. No additional milestones have been achieved as of September 30, 2026. The remaining unamortized prepaid asset is $1 million and $7 million in current and long-term other assets, respectively, in DT Midstream's Consolidated Statements of Financial Position as of September 30, 2026.

In order to comply with certain state environmental regulations, we have an obligation to restore pipeline right-of-way slope failures that may arise in the ordinary course of business in the Utica and Marcellus formations. We completed evaluations of all locations, which were prioritized based on the severity and proximity of the slope failures, and used updated cost information to assess the adequacy of the estimate for the contingent liability accrual. As of December 31, 2025, the Company had accrued contingent liabilities of $2 million for future slope restoration expenditures, which were included in other current liabilities in the Consolidated Statements of Financial Position. Based on evaluations during the three months ended June 30, 2026, we determined that the remaining contingent liability for future slope restoration expenditures was no longer required. As a result, there is no remaining accrued contingent liability for future slope restorations as of September 30, 2026.

On November 27, 2024, Antero Resources Corporation ("Antero") filed a lawsuit against Stonewall regarding the application of certain rate provisions under the Agreement between the parties dated June 20, 2014. On December 12, 2025, the Eleventh Division of the Business Court of Texas issued an Order granting Antero’s Motion for Summary Judgment related to one aspect of the dispute. On January 12-16, 2026, trial was held on the remaining issues. On April 2, 2026, an Order was issued related to the application of the aforementioned rate provisions resulting in no damages awarded to Antero. Both parties have the right to appeal this Order. On October 28, 2026, the Eleventh Division of the Business Court of Texas issued a Final Order Assessing Attorney’s Fees awarding Antero a portion of its requested attorney’s fees and costs.

Stonewall intends to continue to defend against Antero’s claim and intends to appeal this award of attorney’s fees and costs. The Company deems the probability of loss related to the award of attorney’s fees and costs to be reasonably possible, and the range of estimated loss to be $0 to $4.9 million. No contingent liability has been recorded in the accompanying Consolidated Financial Statements related to this matter. While the ultimate outcome cannot be predicted with certainty, the Company does not believe an unfavorable resolution would have a material adverse effect on the Company’s financial position, results of operations, or cash flows.