Industry Outreach Meeting for Design-Build Services

Design and construction opportunities for its DC Clean Rivers Project (DCCR) for the District's combined sewer system. DCCR is comprised of a system of deep tunnels, diversion structures and sewers, ancillary facilities and Green Infrastructure (GI) to control combined sewer overflows to the Anacostia and Potomac Rivers and Rock Creek, and to provide flood relief in the Northeast area of Washington, DC. Potomac River Tunnel Contract B - Tunnel System Construction (PRT-B) is a Design-Build project and includes the following: A large diameter tunnel excavated in both rock and soft ground, four (4) inline shafts, three (3) offline drop shafts, four (4) adit connections, six (6) new diversion structures, two (2) emergency overflow structures, internal hydraulic and surge structures, venting facilities, and hydraulic monitoring and data collection system installation. The tunnel is an 18-foot inside diameter tunnel subdivided into north and south reaches. The Northern Drive is approximately 12,800 feet in length and is in rock. The Southern Drive is approximately 16,550 feet (2,350 feet in rock, 1,350 feet in mixed face, and 12,850 feet in soft ground). The tunnel crown will be approximately 75 to 150 feet below the ground surface. The four inline shafts range in diameter from approximately 42 to 60 feet inside diameter. The three (3) offline drop shafts range in diameter from 5 to 8 feet. The four (4) adits range from approximately 60 to 133 feet in length and 7.5 to 18.5 feet inside diameter. The Design-Builder will also be responsible for coordination with DC Water to take the Anacostia Tunnel System out of service to complete the connection of the Potomac River Tunnel to an existing shaft, and the start-up and commissioning of the Potomac River Tunnel.

Dam/Tunnel, Addition.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.