The Milwaukee Metropolitan Sewerage District has awarded a $116.8 million contract to the J.F. Shea Construction, Inc./Kenny Construction Co. jv to build a 11.4 km sewer at the northwest side of Milwaukee County. The tunnel, with a finished diameter of 6.1 m and an excavation diameter of 6.7 m, will be lined with 30.5 cm of cast-in-place concrete. There will also be a 6.1 m-diameter access shaft, a 7.3 m-diameter valve shaft, and three diversion structures with approach channel, drop shaft, vent shaft, deaeration chamber, and access shaft. The sewer is between 36 m and 50 m deep. Excavation in Niagaran age dolomite with average unconfined compressive strength and indirect tensile strength of 30,000 psi and 2,000 psi, respectively. The overlying soils are generally described as heterogeneous, complex, and interbedded layers of Holocene (recent) and glacial deposits. One Robbins TBM will be used from a single heading (south). All muck will be removed from the south shaft. Initial rock support will be primarily by rockbolts although there are provisions for steel channels and ribs if necessary. Preliminary engineering was performed by the jv of Rust Environment & Infrastructure/Harza Engineering with final design being completed by Black & Veatch, Inc. Financing by the MMSD through the local tax base with some assistance from the State of Wisconsin Clean Water Loan Fund. A notice to proceed is expected on 1st April, 2002 and construction time is 44 months. Visit www.mmsd.com, www.jfshea.com or www.bv.com/bv/index.htm 10/02.The Milwaukee Metropolitan Sewerage District (MMSD) announced that Affholder was awarded the contract to build the 27th Street deep tunnel, a 3.2 km-long 6.4 m-diameter tunnel about 90 metres underground in bedrock to hold wastewater and help prevent sewer overflows. The USD65.3 million extension, from West Hampton Avenue and North 30th Street in Milwaukee, where it will be connected to the North Shore leg of the tunnel system, to North Sydney Place and West Mill Road in Glendale, is part of MMSD's USD1 billion Overflow Reduction Plan. The tunnel will store up to 102.2 million litres of wastewater when it is completed by 31st December, 2009 boosting the tunnel system's total storage capacity to 2 billion litres.Insituform Technologies, parent of contractor Affholder, said on 29th March, 2007 that it will exit the tunnelling business in an effort to focus on its core operations of rehabilitating, replacing and maintaining sewer and water pipelines primarily for municipal customers. Insituform said it will seek a buyer or buyers for its tunnelling business and associated assets. Read E-News Weekly 15/2007 for more. Visit www.mmsd.com/news/27thStDeepTunnelNR.pdf 15/07.
