As the investigation and cleanup of the ExxonMobil oil spill in the Yellowstone River continues in Montana, plans for a much longer oil line are coming under scrutiny. The State Dept. says it will consider the recent leak from the ExxonMobil pipeline as part of its ongoing review of the international TransCanada's Keystone XL pipeline, parts of which originate in Hardisty, Alberta, and cross through the same river in Montana on its way to oil terminals located in Texas. “Since we're in the decision process, of course we're looking at what's happened in the ExxonMobil case, and we're interested in
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.