The Qatar Authority for Public Works (Ashghal) has signed three contracts worth QR3.212bn ($882m) the Inner Doha Resewerage Implementation Strategy (Idris) project.

The contracts are for the design and build of three main trunk sewer (MTS) projects.

A joint venture of French Bouygues Construction and local UrbaCon Trading and Contracting won two contracts for package one, the northern segments, and package three, the southern segment.

They are worth QR965m and QR1,235m respectively.

Idris SHP, a joint venture of German Hochtief and local/Austrian Al-Sraiya Strabag, won package two, the 14.7 kilometre central segment, worth QR1,066m.

The MTS will be approximately 45 kilometres long, with internal diameters ranging from 3-4.5 metres, and depths ranging from 20-55 metres.

Work is scheduled to start in mid-2015, and be completed by the end of 2019.

The $2.7bn Idris project will have a catchment area of 680 square kilometres. It replaces the current, overloaded sewerage system, and its more than 35 pumping stations. Including a 500,000 cubic-metre-a-day sewage treatment plant, it will serve Doha’s needs for the next 50 years.

Two bids for the lateral trunk sewers have passed technical evaluation. An award is expected in the second quarter of 2015. The 65km of pipeline with diameters of 400-2,400mm are split into three sections in Doha Central, Al-Wakrah and Mesaieed Industrial City.

The bid deadline for the terminal pump station, which represents about half the value of the project, was in April. The only pumping station on the scheme will have a capacity of 12 cubic metres a second (cm/s) and be located 65 metres underground.

It will pump sewage to the New Doha South sewage treatment works. The client has also tendered the contract for the sewage treatment plant, which will be built under a 20-year design, build and operate deal.

An open tender was issued for the design and build of a treated sewage effluent (TSE) distribution system in April 2015.

Post-contract consultancy services for the main trunk sewer and lateral trunk sewer packages are under evaluation. The construction supervision contracts for the pumping and wastewater treatment plant contracts will be issued shortly, followed by supervision on the TSE pipelines.

The programme manager is US firm CH2M.