Implementing a DBO project

The city of Seattle, Wash., used an innovative public-private partnership to develop its first water filtration plant. The new Tolt treatment facilities will increase system reliability and flexibility by allowing continuous operation of Seattle's Tolt source through periods of high turbidity. It will also improve system yield and allow long-range compliance with anticipated regulations. As an alternative to the conventional public works procurement process, Seattle created a design-build-operate (DBO) model to provide reliable, cost-effective project development while maintaining public ownership of the facility. The DBO contract is valued at $101 million, which represents a savings of $70 million over the $171-million estimated cost of developing the same facility using conventional design-bid-build procurement with city operations for 25 years. The Tolt facility, expected to be operational in late 2000, will be a 120-mgd (45 x 106-m3/d) 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 its 26 regional wholesale customers.