As prime consultant, EPC is currently providing services as Consultant Construction Manager on behalf of District of Columbia Water and Sewer Authority (DC Water) on the $330M design-build Blue Plains Tunnel project.  The project is the first tunnel contract in the execution of the DC Clean Rivers Project.  The Blue Plains Tunnel is the longest of the four tunnels, and will have a finished internal diameter of 23 feet and will include five shafts between 50-foot and 132-foot-diameter and 110-foot and 170-foot-deep.  Approximately 9,000 feet of the tunnel alignment passes beneath the Potomac and Anacostia Rivers.  The tunnel, which will be constructed using an earth pressure balance machine (EPBM) at depths of 100 feet through ground consisting primarily of clay and silt deposits and will be lined with a fiber reinforced precast segmental liner.  Key components of the project are:

 

• Installation of 24,300 linear feet of tunnel

• Construction of 132 foot- diameter dewatering shaft and 76-foot- diameter screening shaft at BPAWWTP to serve as main access point for the Blue Plains Tunnel construction

• Construction of a 55-foot-diameter drop shaft at the Main Pumping Station to serve as terminus point for the Blue Plains Tunnel construction

• Construction of a 50-foot-diameter drop/overflow shaft at Joint Base Anacostia Bolling (JBAB)

• Construction of a 55-foot-diameter junction/drop shaft at Poplar Point Pumping Station
   

The EPC team is working with the owner to develop a project contingency within the contract that provides the mechanism to address differing site conditions which mitigate DSC and delay claims by the contractor and reduce the impacts of delay to the project schedule.  The team has enhanced delivery and reduced potential changes and claims on the project by providing detailed constructability reviews of the contract documents before bid.