Cleanup of the worst spill of its kind the history of the United States continues this week in east Tennessee, where an earthen retention wall at the Tennessee Valley Authority’s Kingston coal plant failed on Dec. 22 and covered 300 acres with 5.4 million cubic yards and water—or more than one billion gallons—of a sludge-like byproduct of coal combustion called fly ash. Photo: AP/Wide world House knocked off it foundation near site of Tennessee spill. Photo: AP/Wideworld Impoundment pond retention wall failure on Dec. 22 covered 300 acres with 5.4 million cu yd of coal-combustion waste from TVA’s Kingston powerplant.
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.