The Public Works Authority ‘Ashghal’ starts excavation works for the main trunk sewer, part of Doha south Sewage Infrastructure Project.

The project comprises the construction of a 16 kilometer main trunk sewer, divided into three segments, Eastern, Northern and Western. This is in addition to the design and construction of 11 shafts that will be used to excavate the main tunnel. The main trunk sewer will convey the sewage flows through pumping stations to the existing Doha south treatment works.

The project also includes the construction of seven lateral interceptor sewers with a length of about 24 kilometers, which will convey flows from areas in the centre of Doha to the main tunnel.

The Doha South Sewage Infrastructure Project is designed to serve areas in the south of Doha and the expected population growth over a hundred years to come. The project can be linked to future infrastructure projects, and when completed, it will enable the decommissioning of more than twenty old pumping stations currently located in the residential and commercial areas in the south of Doha.

One of the important benefits of the project is the gravity based main trunk sewer that will link a number of areas in the south of Doha to the sewage network. As a result, it will reduce the environmental impacts through the full control of odours in sewage treatment works and conveying system, and reduce other environmental problems arising from sewage overflow due to excess hydraulic pressure on the existing drainage network, where sewage flows exceed its capacity.

The main trunk sewer will be excavated using two Tunnel-Boring Machines designed specifically for the geological features encountered in Doha. To minimise the footprint within the city of Doha, five shafts will be excavated using a Vertical Shaft Machine.

The project will be complete by Q1 2019. The Doha South Sewage Infrastructure Project is the first project in the region to implement the ‘CEEQUAL’ an international evidence-based sustainability assessment, rating and awards scheme for civil engineering, infrastructure, landscaping and works in public spaces. The Joint Venture “Bouygues Travaux Publics” and “UCC” is the project contractor and “CH2M” is the Project Management Consultant.