Nevşehir Wastewater Treatment Plant (WWTP)




Project purpose


The purpose of the Nevşehir wastewater treatment plant project is a reduction of the pollution loads to the Kızılırmak River in order to improve water quality of the river.


The Kızılırmak River is used for fresh water supply to the city of Ankara as of May 2008 and also used for irrigation, energy production, fishing and recreational activities and eventually flows into the Black Sea. The untreated wastewater from numerous municipalities and industries is the major pollution factor for the Kızılırmak River.


Background on wastewater problem in Nevşehir


The wastewater from Nevsehir City and nearby municipalities is collected and was being discharged directly into the Karaagaç Creek, without any treatment. The extension of this creek reaches the Kızılırmak River. The Karaagaç Creek is heavily polluted by wastewater, and in fact the water flow in the creek is at times almost entirely wastewater. Approx. 5 km downstream of the discharge point of untreated wastewater, the creek runs through the village Sulusaray which has a population of approx. 2,275. According to information from the Mayor of Sulusaray, the village is severely affected by the untreated wastewater in the creek, resulting in environmental and health problems for the inhabitants. The water from Karaagaç Creek is used for irrigation purposes although it is heavily polluted. This constitutes a high potential risk of water related diseases in the area.


Selection of Nevşehir


Within the framework of the EU Pre-accession Programme, a long list of projects was established, which was then prioritized with objective criteria. From more than 260 investment project packages, the Nevşehir Wastewater Treatment Plant (WWTP) project was ranked as third among all projects and first in wastewater treatment plant projects.

Treatment System


The population of Nevşehir central district was 81,000 according to 2007 census.

The WWTP project serves Nevşehir center as well as tree adjacent municipalities (Nar, Göre and Uçhisar) and two villages (Çardak and Güvercinlik)

The treatment plant is an extended aeration activated sludge plant with physical and biological stages servicing a population of 125,000 persons and 9,000 industrial p.e.(population equivalent) (stage one).  The discharge meets the effluent requirements of the EU directives as well as Turkish effluent requirements.


The wastewater first goes through a physical treatment where the coarse material as well as grit and grease is removed.  Following the physical treatment, wastewater flows into the aeration tanks, in which the pollution of Carbon and Nitrogen is consumed by the bacteria-rich sludge that is present in the tank.  These bacteria require an important amount of oxygen, therefore dissolved oxygen levels are maintained via blowers trough diffusers that are located at the bottom of the tank.  Finally the wastewater/sludge mixture is taken to the final sedimentation tanks in which the sludge is settled and the treated effluent is discharged to the river.  The sludge extracted from the settling tanks are further dried and will either be properly deposited or used for forest application.  Please see Annex 2 for plant schematics.

Budget and components: Total: € 6.65 M with 75 % EU contribution


Service: Contract Signature Date:         30 January 2008

Contract Value:                1,233,656 €

   Commencement Date:   17 March 2008

   Consultant:                                   Sweco-Tempo Consortium (Sweden-Turkey)


The technical assistance included training and institutional strengthening to the municipality and the supervision of the WWTP construction


Works: Contract Signature Date:         04 February 2008

  Contract Value:                 5,419,700 €

  Commencement Date:                17 March 2008

  Contractor:                                    Hidrotek-OTV SA JV (Turkey-France)


The works tender was implemented with FIDIC Yellow Book (Design and Built) contract conditions.  Therefore the design works were carried out by the Contractor.

Current status of implementation


The whole project was completed by the end of 2011.  The treatment plant is in operation and already in full capacity.  An extension will be needed sooner than originally anticipated (which was 2019) possibly due to population increasing faster than anticipated and increased tourism activities.