A new survey finds that nearly 80% of the states say they will be ready to implement the Environmental Protection Agency’s new clean-air “tailoring” regulation by the Jan. 2 deadline or within a few months after that. EPA’s final regulation, published on June 3, focuses states’ greenhouse-gas (GHG) permitting on the largest “stationary” sources of such emissions, such as powerplants and industrial facilities. The study, released on Sept. 15 by the National Association of Clean Air Agencies, analyzed letters that states sent to EPA this summer describing progress toward meeting the permitting deadline. Bill Becker, NACAA’s executive director, says states
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.