Abu Dhabi Sewerage Services Company (Adssc) is about to formally award the estimated AED2bn ($572m) contract to build a pumping station as part of its strategic tunnels enhancement programme (Step).

The award comes after the contract was approved by Abu Dhabi’s Executive Council in late October, which governs the emirate and oversees major projects.

Brazil’s Odebrecht is understood to be the frontrunner for the contract, for which four groups submitted bids in January 2010 (MEED 7:1:10).

The other bidders were the local/Australian Al-Habtoor Leighton Group; Germany’s Ed Zueblin; and Kuwait’s Kharafi National with Lindenberg-Emirates and the local/Lebanese Arabian Construction Company (ACC).

The contract is a crucial part of the Step scheme, which will overhaul Abu Dhabi’s sewerage system with a network of deep gravity sewers and tunnels.

Construction has already started on the scheme’s three tunnel packages that were awarded by Adssc in 2009 and 2010.

Italy’s Impregilo is working on the AED785m second tunnel contract for Step. It involves the construction of a 10-kilometre long tunnel between Mafraq and Al-Wathba.

Impregilo is also working on the AED891m contract to build the middle section of the 40km-long tunnel from Mussafah to Mafraq.

South Korea’s Samsung C&T is working on the third estimated AED1.1bn tunnel contract, which involves digging a 16.1km, four-metre-diameter tunnel from Abu Dhabi island to the Mussafah area.

US-based CH2M Hill is the programme manager for the overall Step scheme.