The 3B phase of the project consisted of the installation of 4,255 feet of 54-inch steel welded water pipeline with the associated blow-off chamber, air gap, manholes, concrete blocking, and electrolysis test stations. The final aspect of the project included construction of a maintenance road.
Additionally, slip lining of 840 feet of 46-inch steel welded pipe inside the existing 54-inch potable water line and grouting of the annular space between the 46-inch carrier pipe and the existing 54-inch potable water line beneath the Snoqualmie River was required.
Due to the environmental sensitivity of the project site, erosion and sedimentation control and site restoration including wetland vegetation, hydro-seeding, and fences and gates was required.