March 23, 2005

Idaho Falls, ID—The U.S. Department of Energy (DOE) announced today that CH2M*WG Idaho, LLC, was selected to lead the $2.9-billion Idaho Cleanup Project (ICP). The ICP is a seven-year project focusing on the safe, environmental cleanup of the 890-square-mile Idaho National Laboratory site.

CH2M*WG Idaho combines the capabilities of CH2M HILL and Washington Group International (NASDAQ: WGII), leaders in risk reduction and accelerated cleanup of large, complex nuclear facilities.

"We are honored to be entrusted with this important project. As someone who grew up in the state, I understand how critical this project is to the future of Idaho. We need to safely and effectively perform this work to protect our environment," stated Alan Parker, CH2M*WG Idaho president and chief executive officer.

CH2M*WG Idaho’s scope of work includes treatment and disposal of various radioactive waste streams, management of spent nuclear fuel, disposal or disposition of nuclear materials, demolition of reactor and non-reactor nuclear facilities, and environmental remediation activities currently funded through DOE’s Office of Environmental Management.

"Our team brings a fundamental focus on safety that entails partnering with the workforce and front-line supervisors," said CH2M*WG Idaho Chief Operating Officer, Bill Johnson. "We will tackle the highest risk projects first to reduce or eliminate health and environmental hazards."

Partnering with pre-qualified small businesses to meet aggressive cleanup milestones has been a key component of the teams’ success at both Rocky Flats and Mound, and will be essential at Idaho. For example, CH2M*WG Idaho’s small business partner, Premier Technology, will support project critical path activities. The Pocatello-based company brings expertise in the design-build of specialty fabricated stainless steel equipment.

"As a Boise State graduate with a strong interest in Idaho’s future, I am honored to have the opportunity to work with the local Department of Energy leadership, Idaho delegation, local regulators and other stakeholders to make this project a world-class success," said CH2M HILL Chairman, President and Chief Executive Officer Ralph Peterson. "We have assembled a team with unmatched capability that will do everything possible to deliver results that are protective of the environment and the Snake River Aquifer."

"Washington Group has been a contractor at the site for more than a half-century during which time we either designed, built or operated many of the primary facilities on the site.  We’re thrilled to continue our involvement in work so vital to our state and nation," said Washington Group President and Chief Executive Officer Stephen G. Hanks. "As someone who grew up in nearby Rexburg and is part of a company that was founded in Idaho more than 90 years ago, I am especially proud of being a part of this effort."

CH2M*WG Idaho team members have deep roots in Idaho and have served Idaho communities for more than 140 years. Boise-based Washington Group International has provided integrated engineering, construction, and management solutions for Idaho businesses and governments since 1912 and either designed, built or managed many of the original facilities on the Idaho National Laboratory site. Since the opening of its Boise office in 1950 and its second office in Idaho Falls in 1999, CH2M HILL has provided engineering, planning, construction, and operations services in the areas of energy, water, environment, industrial design and construction, and transportation.

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CH2M*WG Idaho, LLC, a joint venture company combining the capabilities of CH2M HILL and Washington Group International, will lead DOE’s cleanup effort at the Idaho National Laboratory site. CH2M HILL is an employee-owned, global project delivery firm headquartered in Denver, Colorado. The company has more than 14,000 employees working in 200 offices worldwide. Washington Group International, based in Boise, Idaho, delivers integrated engineering, construction, and management solutions to clients worldwide. The company’s 27,000 employees work in over 40 states and more than 30 countries.