The Public Works Authority (Ashghal) has invited local and international contractors, and consultants to attend a briefing on the Inner Doha Resewerage Implementation Strategy (Idris) on 23 January.

The estimated QR20bn ($5.5bn) project involves building a series of deep tunnels that will serve the Doha South catchment area over the next 50 years. The scheme will eliminate the need for pumping stations in the Doha South area.

The project also involves 76 kilometres of lateral interceptor sewers, 33km of trunk sewer, a terminal pump station, a New Doha South sewerage treatment plant, 92km of treated sewage effluent return facilities and the decommissioning 37 existing pump stations.

Ashghal plans to split the project into six packages, some of which will be split further into individual contracts.

• Package 1: Three design and build contracts for the lateral interceptor sewers
• Package 2: Three design and build contracts for the main trunk sewer
• Package 3: One design, build, operate contract for the terminal pump station
• Package 4: One design, build, operate contract for the New Doha South sewage treatment plant
• Package 5: Three design and build contracts for the treated sewerage effluent return systems
• Package 6: Two contracts for the decommissioning of the pumping stations

Tendering for the first contracts is expected to start this year, with construction work on the project expected to start in mid-2014. Completion is planned for the end of 2018.

Ashghal appointed the US’ CH2M Hill in late 2011 to manage the scheme. The firm has worked on the concept design and preliminary design, and will also manage the design and construction consultants.