Item 3. Legal Proceedings

We are the subject of, or a party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. While it is possible that an adverse result in one or more of the lawsuits or proceedings in which we are a defendant could be material to us, based upon current information and our experience as a defendant in other matters, we believe that these lawsuits and proceedings, individually or in the aggregate, will not have a material adverse effect on our consolidated results of operations, financial position or cash flows. See “Climate Change Litigation,” “Tesoro High Plains Pipeline,” and “Dakota Access Pipeline” of Note 27 in Item 8. Financial Statements and Supplementary Data for additional information regarding Legal Proceedings and other regulatory matters.

ENVIRONMENTAL ENFORCEMENT MATTERS

Item 103 of Regulation S-K promulgated by the SEC requires disclosure of certain environmental matters when a governmental authority is a party to the proceedings and such proceedings involve potential monetary sanctions, unless we reasonably believe that the matter will result in no monetary sanctions, or in monetary sanctions, exclusive of interest and costs, of less than a specified threshold. We use a threshold of $1 million for this purpose.

In March 2022, the State of Illinois brought an action in Madison County Circuit Court in Illinois against Marathon Pipe Line LLC, an indirect wholly owned subsidiary of MPLX, asserting various violations and demanding a permanent injunction and civil penalties in connection with a release of crude oil on the Wood River to Patoka 22-inch line near Edwardsville, Illinois. In September 2023, the U.S. Department of Justice and the EPA confirmed they will be pursuing federal enforcement for alleged Clean Water Act violations arising from this incident as well as three pipeline incidents in Illinois and Indiana in 2018, 2020 and 2021. We cannot currently estimate the timing of the resolution of this matter, but do not believe any civil penalty will have a material impact on our consolidated results of operations, financial position or cash flows.

On December 18, 2023, the EPA Region 6 issued a Notice of Violation and Opportunity to Confer alleging violations of the National Emission Standard for Benzene Waste Operations at 40 C.F.R. Part 61, Subpart FF (“BWON”) and of the New Source Performance Standards for Volatile Organic Compounds from Petroleum Wastewater Systems at 40 C.F.R. Part 60, Subpart QQQ (“NSPS QQQ”) at our Garyville refinery. On January 10, 2024, the EPA Region 5 issued a Finding of Violation alleging violations of BWON and NSPS QQQ at our St. Paul Park refinery. In addition, the EPA has conducted a compliance inspection at our Anacortes refinery. In February 2024, the EPA published an enforcement alert noting its ongoing efforts to evaluate petroleum refineries’ compliance with BWON and NSPS QQQ. We cannot currently estimate the amount of any civil penalty or the timing of the resolution of these matters, but do not believe any civil penalty will have a material impact on our consolidated results of operations, financial position or cash flows.

On August 30, 2012, MPC entered into a consent decree with the EPA regarding the operation of flares at six of our refineries. The consent decree was modified on September 15, 2016. On December 20, 2023, MPC formally submitted a request to the EPA to terminate the consent decree. The EPA may seek payment of stipulated penalties for violations of the consent decree as a condition of termination. Based on negotiations with the EPA in the third quarter of 2024, we believe resolution of the stipulated penalty demands may result in the payment of $1 million or more, but do not believe any stipulated penalties will have a material impact on our consolidated results of operations, financial position or cash flows.

On August 4, 2025, the Washington Department of Ecology (“Washington DOE”) commenced an enforcement action against Tesoro Refining & Marketing Company LLC, a subsidiary of the Company, for allegedly violating provisions of the Washington Hazardous Waste Management Act and associated regulations. We are finalizing resolution of this matter with the Washington DOE and do not believe the final resolution will have a material impact on our consolidated results of operations, financial position or cash flows.

On August 29, 2025, MPLX acquired Northwind Delaware Holdings LLC (“Northwind Midstream”), including its subsidiary Northwind Midstream Partners LLC, which owns and operates a sour gas treating facility in Lea County, New Mexico. We have disclosed to the New Mexico Environment Department (“NMED”) excess air emissions from the facility flares. We initiated discussions with NMED to resolve this matter and have entered into a new owner audit agreement with NMED as result of those discussions. We do not believe any civil penalty will have a material impact on our consolidated results of operations, financial position or cash flows.