Duke Energy Corp

Duke Energy operates one of the largest coal-fired power generation fleets in the United States, a business activity that inherently produces toxic coal ash as a primary waste byproduct. The company has been the subject of extensive litigation and regulatory enforcement for its handling of this material. In 2014, a coal ash pond at Duke's retired Dan River Steam Station in North Carolina ruptured, spilling approximately 39,000 tons of ash and 27 million gallons of contaminated wastewater into the Dan River. The contaminant plume traveled more than 70 miles downstream. Testing revealed the presence of arsenic, chromium, iron, lead, and other toxic metals. Duke Energy subsequently pleaded guilty to criminal negligence for its handling of the spill.

This incident was part of a broader pattern of coal ash mismanagement. As of 2017, environmental groups identified significant risks at other Duke facilities, such as the East Bend power plant in Kentucky, where 1.4 million tons of toxic coal ash waste were held behind aging earthen dams. The 2014 criminal case was not an isolated failure; the company has faced repeated Clean Air Act enforcement actions. In 2001, the United States brought suit against Duke Energy for failing to obtain permits for major modifications at eight coal-burning plants, a case that reached the Supreme Court. Despite this history of contamination and litigation, Duke Energy continued in 2025 to lobby for the weakening of federal regulations governing coal ash disposal and pollution from coal-fired power plants.