EYDAP, always a pioneer in environmental protection, has designed and implemented a high - technology  sewage treatment system in Metamorfosi Attikis and Psyttalia island.

The Metamorfosis Wastewater Treatment Plant  (WWTP) has been in operation since1986.  It is the only plant in Attica Prefecture that can receive and treat septic sewage generated from areas without sewerage system. As a result, environmental protection of surface and ground waters was achieved. The design capacity of the plant is 24,000 m3 per day of septic sewage and 20,000 m3  per day of municipal wastewater . With the full processing of wastewater, the produced water is free from the polluting load at a rate of 90%-95% and ends in the Saronic sea completely harmless for the balance of the marine ecosystem.

The Psyttalia Wastewater Treatment Plant (WWTP) has been in operation since 1994 and is now in full operation. The wastewater treatment in Psyttalia includes pre-treatment,   primary and secondary treatment with advanced biological nitrogen removal, sludge treatment and cogeneration of electrical and thermal energy.

The Psyttalia WWT capacity is 5,600,000 p.e., being one of the biggest WWTPs in Europe and worldwide. The average supply of incoming wastewater is the range of 730, 000  m3 per day.

The First Phase of the project has been in operation since 1994, the Second Phase since 2004, while the Third and final phase of works completed in 2007 with the construction of sludge thermal drying unit.

How is  wastewater treated in Psyttalia WWTP?

  • Pre-treatment process starts  at Akrokeramos, with removal of heavy solids, gridding, removal of sand and deodorizing.
  • The pretreated sewage is transferred with submerged pipelines in Psyttalia.
  • Primary sedimentation tanks collect the primary sludge.
  • Advanced secondary biological treatment with activated sludge system achieves removal of organic load and significant reduction of nitrogen.
  • Digestion, dehydration and thermal drying of sludge are the stage of the wastewater treatment.
  • The processed outflow of WWTP is diffused through pipelines in the Saronic Gulf with reduced organic load of wastewater at a rate of 93% and nitrogen by 80%.

Design and implementation of new Wastewater Treatment Plant at Thriassio Pedio.

Thriassio Pedio and its surrounding marine environment has been for years one of the most environmentally polluted areas of Attica.

EYDAP undertook the construction and operation of the project "Main Collectors and Wastewater Treatment and Disposal in Thriassio Pedio", which is a sensitive environmentally area. The aim is to upgrade the quality of life of 117,000  inhabitants, restoring the balance of the ecosystem of the sea of Eleusis and generally contributing to the sustainable development of the region.

The project  of Thriassio Pedio serves the residential areas of  Eleusis, Aspropyrgos,Magoula and  Mandra, as well as industrial and commercial areas and is a complete solution to a chronic problem of the residents and   professionals who are active in the region. Moreover, most of the collectors  and central sewer system has been completed  in collaboration with the competent Region.

The project is  co-financed  by the Cohesion Fund of the European Union  at a rate of 45%, by the  Public Investment Programme  at a rate of 15% and EYDAP credits  at a rate of 40%.