The Environmental Protection Agency has proposed water-quality standards for Florida that would for the first time set numeric limits on nutrients such as phosphorous and nitrogen in that state. Nitrogen and phosphorous pollution comes from stormwater and agricultural runoff as well as municipal wastewater treatment. Normally, states are responsible for developing their own water-quality standards. EPA says it is taking the action, announced on Jan. 15, as a result of a 2009 consent decree between the EPA and the Florida Wildlife Federation. The wildlife organization filed a lawsuit in 2008 seeking to require EPA to develop numeric water-quality standards for
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.