AWWA ACE94291

Everett, Washington, has been using a direct filtration process to treat a high-quality low-turbidity surface water source from the western slopes of the Cascade Mountains for approximately 10 years. Rapid population growth in Snohomish County and plant reliability issues required modification and expansion of Everett's water filtration facilities. This paper describes several aspects of the design and construction of the Phase I Expansion of the City of Everett's Water Filtration Facilities. It focuses on the design and construction challenges faced during the project and presents the solutions implemented to overcome these challenges. The relative success of the various elements of the project is also discussed for the benefit of those who may be facing challenges similar to those at Everett. It is not possible to convey the entire construction and design experience in this paper. This text is limited to issues that are likely to be experienced at other water treatment facilities.