A Maryland environmental agency and the state's Public Service Commission staff have recommended the once problem-plagued 755-MW Keys Energy Center be built near Brandywine in Prince George’s County.The natural-gas-fired plant was first proposed in 2012 as a 735-MW unit that would use recycled water for cooling. Problems siting the water line and the natural-gas pipeline delayed the project.Developer Genesis Power resolved the pipeline issues last spring in an agreement with Pepco to follow Pepco's right-of-way for most of the route. The firm also fixed the cooling issues by changing the unit to include an air-cooled system, says President Robert Place.In
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.