Italian firm wins wastewater tunnel deal
Abu Dhabi hands out US $243m STEP contract
Italian construction major Impregilo has won a US $243 million contract to build the first 15-kilometre section of Abu Dhabi’s Strategic Tunnel Enhancement Programme (STEP).
The STEP project, which is controlled by Abu Dhabi Sewerage Services Company (ADSSC) will consist of a 40-kilometre long gravity tunnel that will collect wastewater on Abu Dhabi island and transport it to a treatment plant in Al Wathba.
Work will begin by the end of the year and should be completed in the second half of 2013.
“Technically and organisationally, STEP is a particularly complex project. It will involve simultaneous use of three earth pressure balance tunnel boring machines, to excavate and at the same time case the tunnel with precast concrete sections,” an Impregilo statement said.
“This is the first time this advanced mechanised excavation technology has been used in Abu Dhabi. The hydraulic tunnel and the access shafts will be lined with a special membrane to keep the concrete sections fully protected against the aggressive environment, for a minimum duration of one hundred years.”