Qatar’s Public Works Authority (Ashghal) is finalising documents with selected contractors for three design, build contracts for main trunk sewers in the Inner Doha Resewerage Implementation Strategy (Idris) deep sewerage system.

The award for the 45 kilometres of 3,500mm and 4,000mm pipeline, divided into northern, central and southern sections is expected to be announced imminently with construction work starting on 1 June 2015.

All other contracts are in the tender process for prequalified bidders and will be awarded by the end of 2015, according to Terry Krause, Idris Programme Manager at CH2M Hill, speaking at MEED’s Qatar Projects Conference today.

However, the TSE pipelines design build contract will be issued as an open tender in late March or early April, as it will take advantage of existing treated sewage effluent (TSE) pipelines. The bulk transfer system package has therefore been delayed until after 2022.

Two design build bids for the lateral trunk sewers have passed technical evaluation, and commercial bids are due to be opened. An award is expected in quarter two of 2015. The 65km of 400mm to 2,400mm pipeline are split into three sections in Doha Central, al-Wakrah and Messaied Industrial City.

The bid deadline for the terminal pump station, which represents around half the value of the project, is in April 2015. The only pumping station on the project will have a capacity of 12 cubic metres a second and be located 65 metres underground.

It will pump sewage to the state-of-the art 500,000cm/d waste treatment plant. A design build operate contract covering 20 years has the same deadline.

Post-contract consultancy services for the MTS and LTS packages are under evaluation. The construction supervision contracts for the pumping and WTP contracts will be issued in April, with the TSE pipelines following in the second quarter.