Pepco, the electric utility that serves Washington, D.C., and its Maryland suburbs, will spend $256.5 million over the next five years to accelerate planned improvements to its distribution system after it struggled to recover from a severe thunderstorm in late July. More than 322,000 Pepco customers lost power after the storm; the company took five days to restore the power. The utility added $115 million to a planned system reliability upgrade after executives were grilled by the Maryland Public Service Commission about their response to the July storm and back-to-back snowstorms in February. Earlier this month, Pepco asked state regulators
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.