McNary Drainage, Unwatering, and Equalization System Rehab

Construction project entitled: McNary Drainage, Unwatering, and Equalization System Rehab: construction will occur at McNary Lock and Dam. - Replacing all unwatering and drainage pumps to include all non-embedded intake and discharge piping as well as all isolation valves. Diving in the tailrace will be required to temporary plug the unwatering pump discharge piping while isolation valves are replaced. The three unwatering pumps will be converted from 4160V to 480V with the installation of new transformers and motor control centers. Work within the unwatering and drainage sump will require the setup of temporary pumping to install new pump intakes and seismic bracing. - The blockage in the primary embedded 8-inch drainage header pipe that runs the length of the powerhouse (approx. 1400 feet) will be removed, and the temporary (non-embedded) PVC drainage header removed. - All 56 drain valves are to be replaced. Half of the drain valves are located at the bottom of 30-foot-deep valve pits. Valve work also includes the replacement of stem packing on twenty-six 24-inch equalization valves.

Dam/Tunnel, Renovation.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 22 -	Plumbing, Facility Storm Drainage, Sump Pump Discharge Piping, Sump Pumps.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 33 -	Utilities, Utility Transformers.
Division 35 -	Waterway and Marine Construction, Waterway and Marine Construction and Equipment, Hydraulic Valves, Hydraulic Regulating Valves, Dam Construction and Equipment.