The Environmental Protection Agency’s top official in the South and Southwest region—the heart of oil and gas country—resigned on April 30 after remarks he made in 2010 about crucifying energy companies that break environmental laws became public and sparked a national controversy. Al Armendariz, appointed to the EPA post by President Obama in 2009, sent a letter to the agency's Administrator, Lisa Jackson, on April 29 apologizing for the comments, which were recorded on video, and part of his description of how he approached enforcing the region’s environmental laws. His resignation became effective on April 30. On the video, Armendariz
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.