DC Water is planning to construct a series of tunnels over the next 15 years to capture excess sewer flow and convey it to the Blue Plains wastewater treatment plant. The major tunnel projects are: the 7.5 km x 7.3 m-diameter Blue Plains Tunnel (23,600 ft x 23 ft-diameter); the 4 km-long x 7.3 m-diameter Anacostia River Tunnel (12,500 ft x 23 ft-diameter); the 5.5 km-long x 7.3 m-diameter NE Boundary Tunnel (17,500 ft x 23 ft-diameter); and the 3.6 km-long x 4.8 m-diameter NE Boundary Branch Tunnels (11,300 ft x 15 ft-diameter). Proposals for the construction management services contract are under appraisal, with award expected in March, 2011. Three design-build companies have qualified for the Blue Plains Tunnels, and price and technical proposals are due 02.12.2010 with award expected in April, 2011 for construction start in July, 2011. A request for proposals for the Anacostia River is expected in early 2012. More from Ronald Bizzarri at DCWASA in Washington, e-mail rbizzarri@dcwasa.com. For project details visit www.dcwater.com/site_archive/news/documents/DC WASAs Long Term Control Plan_2009.pdf. 37/10.
Design/build contract for TBM-driven, segmentally-lined 7.5 km x 7.3 m-diameter Blue Plains Tunnel (23,600 ft x 23 ft-diameter) awarded by DC Water to Traylor/Skanska/JayDee JV with design engineer Halcrow, value EUR235 million. Construction start expected in July, 2011. More from Ronald Bizzarri at DCWASA in Washington, e-mail rbizzarri@dcwasa.com. For full project details visit tunnelbuilder archive us/109 and www.dcwater.com/site_archive/news/documents/DC WASAs Long Term Control Plan_2009.pdf. 13/11.
The JV Impregilo (65 percent)/Healy-Parsons (35 percent) secured the EUR193 million (US$254 million) contract for the design and construction of the second portion of the massive tunnel system that will bring relief from combined sewer overflows (CSOs) to the Anacostia River. Named the Anacostia River Tunnel, this will be 7 m-diameter and 3,810 m-long beneath the Anacostia River. It begins at Poplar Point and ends near RFK Stadium. Construction will start at the north and work south, connecting to the Blue Plains Tunnel in 2017. The contract also includes six shafts with a depth of approximately 30 m and three diversion structures. The first tunnel portion of the Clean Rivers Project is already underway. For more click here. For tunnelbuilder archive click here and us/109. Visit http://www.dcwater.com. 19/13.
The District of Columbia Water and Sewer Authority (DC Water) was won by the Joint-venture of Salini Impregilo (30%) and S.A. Healy. (70%) the EUR506 million (USD580 million) contract is to build the Northeast Boundary Tunnel (NEBT) project in Washington, D.C.
The NEBT is the biggest component of DC Water’s Clean Rivers Project. It will be 50 -160 feet below ground and run 27,000 feet from just south of Robert F. Kennedy Stadium to the intersection of Rhode Island Avenue NW and 6th Street NW. It will be aligned to intersect the existing chronic flood areas along Rhode Island Avenue NW.
In times of flooding, the tunnel will receive flows from the sewer system captured by diversion facilities and convey them to DC Water’s Blue Plains Advanced Wastewater Treatment Plant. The NEBT project will also include the construction of ventilation control facilities, storm water inlets, and green infrastructure.
Once it is connected to the other Clean Rivers Project tunnels, the NEBT will help reduce combined sewer overflows to the Anacostia River by 98 percent and the chance of flooding in the areas it serves from about 50 percent to seven percent in any given year.
Work is expected to begin in September 2017 and be completed in 2023 - two years ahead of the Consent Decree schedule. Visit https://www.dcwater.com, http://www.laneconstruct.com/ and https://www.salini-impregilo.com/en/. 28/17.
DC Water (District of Columbia Water and Sewer Authority) has issued notice to proceed to the CBNA-Halmar Clean Rivers Joint Venture comprising CBNA (a US based subsidiary of Bouygues Construction) and Halmar International for the design-build contract for the Potomac River Tunnel. The tunnel is a project part of DC Water’s USD 2.99bn (EUR 2.76 bn) Clean rivers project designed to control combined sewer overflows and to improve water quality in the Potomac River in Washington D.C. The contract value is USD 819 million (EUR 757.13 million). The main tunnel, which is 5.5 miles (8.9 km) long and approximately 100 feet (30 m) deep with internal diameter of 18 feet (5.5 m), will cross variable geological conditions (clay, alluvium, hard rock) and will pass close to Washington D.C's iconic monuments. It will require the use of two TBMs customized specifically for these soil conditions. Ancillary structures comprise of 9 shafts, adits connecting to the main tunnel, and near surface structures which link the new infrastructure to the existing sewage system. Visit https://www.bouygues.com/ and https://www.dcwater.com/. 49/23.
