US-based Parsons has been awarded the consultancy contract for the AED12.5bn ($3.4bn) Dubai deep sewer tunnels project.

The consultant will provide a number of consultancy services for the duration of the project, including feasibility studies, preliminary design, tender preparation and support. Following the appointment of contractors, Parsons will provide programme management of the detailed design and construction phases and supervision of the construction of the primary tunnels.

MEED reported in November last year that Parsons had submitted the low bid for the consultancy contracts.

The Dubai Strategic Sewerage Tunnels project will contain two main tunnels with a total length of 75km. The Bur Dubai deep tunnel will have a total length of 50km and the Deira tunnel with have a total length of 25km. The tunnels will be supported by about 140km of link sewers and two major pump stations. The tunnels will reach depths of up to 90m below ground level.

The deep tunnel sewerage network and 2 major pump station will replace 11 major pump stations and more than 100 other pump stations that currently serve Dubai’s wastewater network.

Speaking at the signing of the contract with Parsons, Dubai Municipality representatives said that they expected the prequalification process to be completed and for the main construction packages to be tendered within the next 12 months. The representatives said that the number and scope of construction packages will not be clear until Parsons had completed the preliminary designs.

Municipality representatives said that the prequalification process was underway for the planned deep-tunnel stormwater network, and that some of the companies prequalified for the stormwater network would likely be prequalified to participate in the deep tunnel sewer tunnel project.

Construction of the deep tunnel project will take five years to complete, according to the municipality representatives.