Posted on February 07, 2016

The construction projects of sewage treatment plants are considered some of the largest and most important projects implemented by the Infrastructure Affairs at the Public Works Authority, in terms of the large volume of implemented works and the projects’ cost that reaches billions of Qatari Riyals. The Doha North Sewage Treatment Works (STW) is one of the most prominent treatment plants; being the first sewage treatment plant in Qatar to use advanced treatment techniques such as ultrafiltration and ultra-violet technologies to produce high quality reclaimed water for reuse in irrigation purposes. The Doha North STW is located in Umm Salal Ali, 25 km to the North of Doha.

The first phase of the project includes the construction of the main treatment plant for the reception and treatment of sewage, which has been designed to treat up to 245,000 m3 of sewage per day, serving a projected population of over 900,000 people by the year 2020. The modern facility features advanced biological treatment processes as well as ultrafiltration, which is an ultra-membrane filtration technique that separates large molecules and small granules from the water. The plant also uses ultra-violet technologies for wastewater treatment.

It is worth mentioning that the STW started receiving sewage flows from the main pumping station in Northern Doha (PS70) located in Al Kheesa. The sewage flows are estimated 46,000 m3 per day. The Doha North STW became fully operational in December 2015, after a full year of inspection and testing processes completed by the Qatari Civil Defense and other entities.

The second phase of the project includes the construction of a Thermal Drying Plant (TDP) within the Doha North STW. The TDP processes sludge, which is the solid materials generated from the sewage treatment process, in order to dispose them according to international standards for safe disposal. The TDP will receive and treat sludge generated from not just Doha North STW but also from all the other sewage treatment works within Qatar. The sludge is dewatered, processed through the thermal dryers to finally produce dried pellets which are bagged and stored for distribution.

The construction of the TDP is substantially completed and is currently going through final commissioning. The TDP includes four thermal dryers which are currently being tested utilising sludge generated at the Doha North STW and the Doha West STW. Two of the thermal dryers are expected to be handed over in Q2 of 2016, while the other two are expected to be handed over in Q3 of 2016.

The Doha North STW is the first facility with comprehensive odour control system to minimise the impact on the surrounding environment. The Buffer Zone surrounding the STW will be carefully landscaped to form a lush-green oasis that includes approximately 95,000 trees and 50 picnic areas with interconnecting roads and a bird watching lagoon which is considered the first of its kind in Qatar. The roads and picnic areas are completed, and the bird watching Lagoon is expected to be completed in Q1 of 2016. The remaining irrigation pipe work and planting are in progress as well as the construction of artificial mounds across the area, which is expected to be completed by mid 2017.

The Doha North Sewage Treatment Works project is worth approximately 3.63 billion Qatari Riyals, including the Design and Build contract, which is worth approximately 2.49 billion Qatari Riyals, and the Operate and Maintain 10-year contract which is worth approximately 1.14 billion Qatari Riyals. The project contracts were awarded to “Keppel Seghers Engineering Singapore LTD”, and it is expected to be completed in Q3 of 2017.