The City of Seattle executed a Design-Build-Operate (DBO) agreement with CDMPhilip to procure their new 120 MGD Tolt Treatment Facility. Design of this ozonation/direct filtration treatment plant was completed in May 1998, and contruction is underway. Innovative designs for many of the treatment process units were necessary to deliver both the stringent treated water quality specified and the cost savings anticipated from the DBO approach. This paper will discuss the raw water quality, treated water performance requirements, treatment process challenges, pilot testing program, and design innovation aspects of the project.