Despite a formal protest from the second-place bidder for a 3,000-ton-per-day waste-to-energy facility, the Solid Waste Authority of Palm Beach County awarded a $668-million design-build contract to a team of Babcock & Wilcox and BE&K to design, construct and operate the facility. B&W's design-build estimate of $668 million was roughly $62 million higher than that of Wheelabrator, the division of Waste Management Corp. that placed second. However, SWA factored in the value of electrical generation and recoverable materials that each team guaranteed their respective designs would deliver to the authority for a net present-value calculation. Under that formula, B&W's proposal
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.