On Aug. 26, the U.S. State Dept. issued the final environmental impact statement on TransCanada’s 1,700-mile Keystone XL pipeline, setting the final stage for the hotly contested battle over the line that would move Canadian tar-sands oil from Alberta to the Gulf of Mexico for refining.The final EIS repeats the findings of previous environmental assessments—the construction and operation of the $7-billion pipeline would have “limited adverse environmental impacts.” During the 90-day comment period on the final EIS, the department will hold 13 public meetings. The administration had promised to decide by the end of the year on whether to issue
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.