An ash pond, also called a coal ash basin or surface impoundment, is an engineered structure used at coal-fired power stations for the disposal of two types of coal combustion products: bottom ash and fly ash. The pond is used as a landfill to prevent the release of ash into the atmosphere. Although the use of ash ponds in combination with air pollution controls decreases the amount of airborne pollutants, the structures pose serious health risks for the surrounding environment.

A coal-fired power station or coal power plant is a thermal power station which burns coal to generate electricity. Worldwide there are over 2,400 coal-fired power stations, totaling over 2,130 gigawatts capacity. They generate about a third of the world's electricity, but cause many illnesses and the most early deaths, mainly from air pollution. World installed capacity doubled from 2000 to 2023 and increased 2% in 2023.