Ash pond

An ash pond is an engineered structure used at fossil fuel power stations for the disposal of two types of coal combustion products: bottom ash and fly ash. The pond, also called a surface impoundment, uses gravity to settle out large particulates (measured as total suspended solids) from power plant wastewater. This technology does not treat dissolved pollutants. An ash pond is an engineered structure used at fossil fuel power stations for the disposal of two types of coal combustion products: bottom ash and fly ash. The pond, also called a surface impoundment, uses gravity to settle out large particulates (measured as total suspended solids) from power plant wastewater. This technology does not treat dissolved pollutants.