Congress is moving to draft legislation that would cap carbon dioxide emissions and create a carbon allowance trading program to help emitting industries comply. House Energy and Commerce Committee Chairman Henry Waxman (D-Calif.) says he plans to complete a bill by Memorial Day with targets and deadlines for emission reductions. The bill could include energy-efficiency standards and require utilities to generate a specific portion of power with renewable energy sources. A House floor vote could come later this year. In the Senate, Environment and Public Works Committee Chair Barbara Boxer (D-Calif.) says she wants to take a deliberative approach to
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.