Construction of Bismil Wastewater Treatment Plant and Collectors, Turkey

[Translate to englisch:] Bismil Wastewater Treatment Plant

The overall objective of the Project of which this Contract is part is to accelerate Turkey's accession to the EU by enabling Turkey to achieve a high level of environmental protection and compliance with the EU wastewater sector directives. Its specific aim is to provide a modern and sustainable wastewater system for the inhabitants of Bismil (indirect Project beneficiary) and the service provider DİSKİ (direct Project beneficiary), and the protection of the environment, in particular the Tigris (Dicle) River, which receives the untreated wastewater of the city’s population in the existing situation.

Within the scope of the project, a new wastewater collection infrastructure in Bismil district and some other nearby villages is designed and constructed. This collected wastewater is then treated with the newly built Wastewater Treatment Plant (WWTP) which was also part of this project. Collected and treated water is then discharged into the Tigris River which is an important water supply in the region for irrigation purposes. Thus, implementation of the project plays an important role in preservation and general improvement of public health.

This project consists of two sections which are:

  • Section 1 (WWTP): Bismil Wastewater Treatment Plant consists of overflow manholes to bypass excessive wastewater at inlet, coarse and fine screens, inlet pumping station, aerated grit and grease removal tanks, inlet flow measurement chamber, anaerobic Bio‑P removal tank, aeration tanks with extended aeration CNP (Carbon, Nitrogen, Phosphorous) biological treatment process, turbo blowers, secondary sedimentation tanks, service and irrigation water pumping station, treated water discharge structure, mechanical thickening of treatment sludge using belt press, mechanical dewatering of treatment sludge using centrifuge decanter, solar sludge drying plant.
  • Section 2 (Wastewater Collectors): Construction of wastewater collectors: 25,591 m in trench (corrugated HDPE, concrete, and RC pipes) and 48 m by horizontal drilling (steel pipe), construction of 502 standard inspection manholes (Type‑1: 450 nos., Type‑2: 16 nos., Type‑3: 36 nos.) and 15 special inspection manholes, construction of 4,694 m house connection lines and 469 parcel manholes.

Location (Google Earth)

Bismil WWTP


  • Review of Contractor’s design, calculations, and equipment specifications
  • Technical Assistance, contract management and construction supervision, financial administration, testing, commissioning, performance tests on completion and certification (as per FIDIC Yellow Book)
  • Supervision of 12 months of defects liability period for the construction contracts and supervision of the first year of the Bismil WWTP operations contract
  • Accompanying services (sludge management plan, awareness raising program for visibility and others)

Technical Data

Section 1 (WWTP)

  • Capacity: 12.453 m3/day (2.802 kg BOD/day)
  • Treatment Process: Advanced Biological Treatment with Extended Aeration Process
  • Sludge Treatment: Mechanical dewatering and Solar Drying
  • Project Horizon: Stage 1 – 2032

Section 2 (WW Collectors)

  • Length: approx. 25.6 km of wastewater collector lines
  • Manholes: approx. 517 inspection manholes
  • House Connection: 4,694 m house connection lines and 469 parcel manholes

Client / Financing Agency

General Directorate of Diyarbakır Water and Sewerage Administration (DİSKİ) / General Directorate of European Union and Foreign Relations (GDEUFR) within the Ministry of Environment, Urbanization and Climate Change (MEUCC)

Services Period



May 17th, 2024

GKW Consult at the IFAT Munich 2024

From May 13th to 17th, GKW Consult GmbH and GFA Consulting Group, both members of the GFA Group,…

April 18th, 2024

We are excited to be part of #IFAT Munich

We are excited to be part of #IFAT Munich – the World's Leading Trade Fair for #Water, #Sewage,…

April 1st, 2024

Transition in management at GKW Consult

After a long career of almost 40 years, Dr. Christoph Theune retires on 31st of March 2024.…