State and federal regulators are closely monitoring conditions at the Trans Alaska Pipeline System following the discovery of a leak and a pair of shutdowns at Booster Pump Station 1. Alyeska Pipeline Service Company, the pipeline operator, says engineers this week re-started the 800-mile pipeline for a second time since the leak was located in the basement of the facility January 8. + Image Image map: Courtesy of Alyeska Pipeline Service Co. The leak happened near pumping station 1 (seen on map as PS1). “The leak was discovered by one of the personnel during routine surveillance of the system,” says
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.