Related Links: Text of the legislation NTSB San Bruno Explosion Report Centers on Pipeline Seam Welds PG&E Faces Blast Aftermath Under a newly enacted pipeline safety bill, oil and gas pipeline companies could face additional safety requirements, and pipeline operators that violate federal rules will have to pay stiffer fines. But the legislation’s impact on safety and industry won’t be clear for many months because its implementation deadlines for key regulations are not until 2013 or 2014. Further, the law gives the U.S. Dept. of Transportation substantial leeway to consider the economic impact of the new rules.Other provisions call for federal
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.