U.S. investigators have found the engineering giant Bechtel National failed on more than half of projects assigned under its $1.8 billion contract in Iraq. The failed efforts include a sewage treatment facility, an electrical plant and a massive landfill. Bechtel was one of the first U.S. companies to benefit from the post-invasion contracting boom in Iraq. The special inspector general for Iraq reconstruction says State Department officials assigned just two staffers to oversee Bechtel’s work.