Harbor Island Southwest Yard Habitat Restoration

This 2.7-acre project benefits natural resources including fish, shorebirds, and other wildlife that were injured from direct or indirect exposure to releases of hazardous substances and/or discharges of oil in this industrial waterway over decades. The habitat construction project involved demolition of upland  and overwater shipyard infrastructure, then excavating over 50,000 cubic yards of clean sediments and soils for reuse to create a new off-channel intertidal and marsh aquatic habitat with a perimeter berm to protect the habitat from Puget Sound wave action and tie-up locations for tribal fishing. The project also included shipyard infrastructure upgrades for facility access, drydock moorage, and stormwater treatment.    

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Upland utilities consisted of five ground water pump stations that included  new motors, installation of ten underground electrical vaults and remotely located control stations for each. All of the wiring and installation coordination was completed without causing disruption to the operating facility. The main waste water tank farm was provided with a new power source that included a 600A panel and coordination with Seattle City Light to remove power via a defined shutdown to be wired to an existing sub-station. Additional scope included removal of existing and placement of new low voltage controls at this location to provide ground water monitoring. During reconstruction of the two pier locations, multiple existing power runs were removed or relocated with a new 2500A underground and under pier multi-conduit raceway  built for future use.