Item 4. Controls and Procedures

Disclosure Controls and Procedures

An evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Securities Exchange Act of 1934, as amended) was carried out under the supervision and with the participation of our management, including our chief executive officer and chief financial officer. Based upon that evaluation, the chief executive officer and chief financial officer concluded that the design and operation of these disclosure controls and procedures were effective as of March 31, 2023, the end of the period covered by this report.

Changes in Internal Control over Financial Reporting

During the quarter ended March 31, 2023, there were no changes in our internal control over financial reporting that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Table of Contents

PART II – OTHER INFORMATION

Item 1. 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.

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 of $1 million for this purpose.

Except as described below, there have been no material changes to the legal matters previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2022.

Martinez Refinery

As previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2022, on July 18, 2016, the U.S. Department of Justice (“DOJ”) lodged a complaint on behalf of EPA and a consent decree in the U.S. Court for the Western District of Texas. Among other things, the consent decree required that the Martinez refinery meet certain annual emission limits for NOx by July 1, 2018. In 2018, Tesoro Refining & Marketing Company LLC (“TRMC”), a wholly owned subsidiary of MPC, informed the EPA that it would need additional time to satisfy requirements of the consent decree. In 2019, TRMC and the United States entered into an agreement to modify the consent decree to resolve these issues. In light of the actions to strategically reposition the Martinez refinery to a renewable diesel facility, we renegotiated the consent decree modification. Under the renegotiated consent decree modification, we have agreed to pay a penalty of $27.5 million, plus interest, and we are no longer required to install a Selective Catalytic Reduction system to control NOx emissions from the now-idled fluid catalytic cracking unit. The modified consent decree was lodged with the court on April 27, 2023, for court approval.

Gathering and Processing

As previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2022, MPLX has been negotiating a consent decree with the EPA with respect to multiple alleged violations of the National Emission Standards for Hazardous Air Pollutants by the Chapita, Coyote Wash, Island, River Bend and Wonsits Valley Compressor Stations in Utah as well as the Robinson Lake Gas Plant in North Dakota. On April 18, 2023, we entered into a consent decree with the EPA pursuant to which MPLX will pay a cash penalty of $2 million, incorporate additional remedial measures and mitigate excess emissions associated with events covering MPLX gas plants and compressor stations located in Utah, North Dakota and Wyoming. The consent decree was lodged with the United States District Court of Utah on April 20, 2023, for court approval.