Csepel, Hungary


With an average daily flow of 300,000 m3/d (1,6 Million people equivalent), the Csepel Waste Water Treatment Plant provides Budapest city with a complete and sophisticated water treatment, compliant with European standards. The plant is able to pre-treat up to 900,000 m3/d in storm conditions.

Enclosed with planted roof and no visible water surface, the plant is completely integrated in its urban environment, Csepel island, a « green belt » located in the north part of District XXI (south of Budapest city). The site is efficiently protected against Danube possible flooding.

The global footprint of the plant has been optimized and reduced thanks to a combination of compact technologies (SEDIPAC pretreatment, space saving implementation of biological treatment equipments, thermophilic digestion of sludge…). Furthermore, the plant benefits from a complete odour and noise treatment.


Water treatment

After passing through fine screening, the wastewater is routed to SEDIPAC compact pretreatment and settling units, where grit and grease are removed, and primary sludge is separated from water. Wastewater is conveyed to the biological line made of 18 units in order to remove carbon, nitrogen and phosphorus. The sludge is then separated from the treated water by settling in rectangular secondary clarifiers (18 tanks). The excess biological sludge is extracted from the bottom of the secondary clarifiers and sent to sludge treatment.


Wastewater treatment plant of Csepel


Sludge treatment

Primary sludge is conveyed to gravitary thickeners, while biological sludge is thickened on draining tables. Primary and biological sludges are sent to pasteurization and thermophilic digestion units. Heat exchangers are used to bring the mixed thickened sludge to the appropriate temperature along the process. It aims at meeting Class A pathogen reduction requirements. Digested sludge is dewatered on 3 centrifuges, in order to reach 26 % dryness.



Energy production by cogeneration


Biogas from sludge digestion process is used for energy production (2,8 MW) and heating (2,8 MW).


Energy production by cogeneration at Csepel            wastewater treatment plant


Recovery of 30% of the total electricity consumption of the plant.


The CSEPEL contract


Signature of contract:

  • Dec 30th, 2005

Start works:

  • Oct 1st, 2006

Plant Hand over and acceptance:

  • July 31st, 2010

O&M contract (4 years) start:

  • August 1st, 2010


  • BKSZT Kft, a company owned by DEGREMONT


The plant has received ISO 9001 and ISO 14001 certifications in June 2010


Contract amount : 249 M€

  • Process (consortium lead by DEGREMONT) : 118 M€
  • Civil works : 131 M€