Duke Energy CORP

LEGAL PROCEEDINGS AND MINE SAFETY DISCLOSURES

ITEM 3. LEGAL PROCEEDINGS

MTBE Litigation

In December 2017, the state of Maryland filed suit in Baltimore City Circuit Court against Duke Energy Merchants and other defendants alleging contamination of state waters by MTBE leaking from gasoline storage tanks and is seeking an unspecified amount of monetary damages. MTBE is a gasoline additive intended to increase the oxygen levels in gasoline and make it burn cleaner. The case was removed from Baltimore City Circuit Court to federal District Court. Initial motions to dismiss filed by the defendants were denied by the court in September 2019, and the matter is now in discovery. In December 2020, the plaintiff and defendants selected 50 focus sites, none of which have any ties to Duke Energy Merchants. Discovery will be specific to those sites. At this time, Duke Energy Merchants has not engaged in settlement negotiations with the plaintiff and the plaintiff has not reached a settlement agreement with any defendant. Duke Energy cannot predict the outcome of this matter.

The Town of Carrboro Litigation

On December 4, 2024, the town of Carrboro, North Carolina, filed a lawsuit against Duke Energy in the North Carolina Superior Court, Orange County, alleging that Duke Energy and its predecessor companies knew since the late 1960s that fossil-fuel emissions could cause global climate changes and engaged in a campaign to conceal the dangers of fossil fuel emissions from the public, regulators, legislators, and others, resulting in a delayed transition away from fossil fuel emissions and worsening climate change. The lawsuit also alleges that Duke Energy misled the public regarding Duke Energy’s support for, and actions toward, transitioning its fossil fuel portfolio to renewable energy. The damages alleged range from road and stormwater-system impacts to increased electricity costs and recurring invasions and interferences from extreme weather events. The lawsuit asserts state-law claims for public nuisance, private nuisance, trespass, negligence, and gross negligence, and is seeking an unspecified amount of monetary damages. The case has been transferred to the North Carolina Business Court. Duke Energy cannot predict the outcome of this matter.

In addition, from time to time, the Duke Energy Registrants are parties to various legal, environmental or other regulatory proceedings, including in the ordinary course of business. SEC regulations require disclosure of certain environmental matters when a governmental authority is a party to the proceedings and such proceedings involve potential monetary sanctions that the Duke Energy Registrants reasonably believe will exceed a specified threshold. Pursuant to the SEC regulations, the Duke Energy Registrants use a threshold of $1 million for such proceedings. See Note 4, “Regulatory Matters,” and Note 5, “Commitments and Contingencies,” to the Consolidated Financial Statements, which information is incorporated herein by reference, for discussion of certain legal, environmental and other regulatory proceedings to which the Duke Energy Registrants are a party.