AWWA ACE56226

The City of Seattle has utilized the design-build-operate contracting approach for development of two major treatment facilities. As an alternative to the conventional public works procurement process, Seattle has sought to create situations where integrated teams of designers, constructors, and operators would innovate in order to provide the most reliable and cost effective proposal for development of the projects, while maintaining public ownership of the facilities. The two projects will provide 99% of the water to about 1.3 million people in Seattle and the surrounding cities. The Tolt Treatment Facility is a 120 million gallon per day (MGD) filtration and ozonation plant for treatment of Seattle's Tolt River source of supply, which provides about a third of the water for Seattle and it's 26 regional wholesale customers. The Tolt facility has been operational since early 2001. The Cedar Treatment facility will be a 180 MGD ozonation and UV disinfection plant for treatment of the Cedar source of supply, which provides about two-thirds of the water for the region. The Cedar facility is scheduled to begin construction in spring of 2002, and be operational by late 2004. If operational today, the Cedar facility would be the world's largest UV drinking water treatment facility. This paper discusses issues and options related to project definition, and real project examples of risk allocation during implementation of these projects. Includes 2 references, figures.