430 Water Transmission Pipeline Improvements, Seattle, WA

This Project consists of the following major elements of Work: Base Bid (Bid Schedule 1): Furnish and install 118 linear feet of 12” diameter ductile iron water pipe at Ravenna Ave NE and NE 54th St. Furnish and install access maintenance holes at sites 1 through 12 along the 430 pipeline. Furnish and install pressure relief valve at site 13 and a pressure reducing valve at site 14 along the 430 pipeline, with associated water piping. Furnish and install air gap discharge vault at site 13 along with associated sewer piping. Improvements to the exterior of the 430 Pipeline within the Ship Canal vertical shafts and the Ship Canal tunnel to include: Hold down straps onto the 430 Pipeline within the tunnel Steel angle bracing and straps on the 430 Pipeline in the south shaft. Surface coat and prep a portion of the 430 Pipeline in the south shaft. Install cathodic protection electrical conduit, wire, and anode headers into the shafts and tunnel and cad weld to the 430 Pipeline. Continuously dewater the Ship Canal tunnel and shafts holding the 430 Pipeline and dewater sags in the 430 Pipeline. Excavate and expose 430 Pipeline at the exit of Ship Canal south vertical shaft for Owner assessment. Improvements to the Ship Canal south vertical shaft include: Vertical timber steps to access shaft, Adding an access hatch, Replacing grating, and extending existing handrail. Bonds Required. Prevailing Wages.