Construction method: pipe bursting

King County’s contractor will install another pipeline in the existing pipe corridor. Crews will work at an entry pit on 32nd Avenue West and an exit pit in the south end of the Smith Cove Park athletic fields. Prior to installing the pipe, King County’s contractor will fuse the pipe, first in sections and then in one long string. Fusion activity will require the closure of 32nd Avenue West between 33rd Avenue West and Clise Place West, and the closure of the parking lane on Clise Place West from 32nd Avenue West to 33rd Avenue West.

King County's contractor will use a method called pipe bursting. Pipe bursting uses a drill rig to pull a series of tools and another pipe through the existing pipeline from the entry pit to the exit pit in Smith Cove Park (shown in the graphic and diagram). The pipe material is high density polyethylene (HDPE), which works well for this method.

Graphic updated on 2/27/2018 to clarify that the four activities in pipe bursting occur in one step.

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The pipe bursting process takes place in one step. It is expected to take three days. The pipe cutter tool breaks and expands the existing pipe while pulling another pipe through the same path as the current pipe.