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Construction, Operation and Maintenance of the Psyttalia Wastewater Treatment Plant


Psyttalia Wastewater Treatment Plant (WWTP), the main wastewater treatment plant in the greater Athens area, is an exemplary project of the expertise and the leading position AKTOR holds in the field of wastewater treatment projects, being one of the largest, the most complex and technologically advanced constructions in the field at an international level.

With a treatment capacity of 5,600,000 Equivalent Population and an hydraulic capacity of 27 m³/s, the Psyttalia WWTP is an infrastructure project which has managed to completely transform the image of the Saronic Gulf and the coastline of Athens.

The facilities of the Psyttalia WWTP include pre-treatment of wastewater in the area of Akrokeramos, with removal of heavy solids, gridding, removal of sand and deodorizing, as well as a smaller pretreatment unit at Kynosoura, on Salamina Island. Pretreated wastewater is then piped, by means of submerged pipes, to the island of Psyttalia, 2 km west of Piraeus Harbor. On a surface of 560,000 sq.m., the island of Psyttalia hosts the main wastewater treatment units, operating with an activated sludge system and achieving removal of organic load (advanced secondary treatment), sludge treatment units (thickening, hydrolysis, anaerobic digestion, dehydration and thermal drying of sludge), as well as thermal and electric power generation stations, operating with biogas and natural gas.

As one of the biggest environmental projects in Greece, Psyttalia WWTP contributes vitally to the environmental protection of the area, while enhancing biodiversity in the ecosystem of the Saronic Gulf.  Moreover, the important sustainability elements of the Plant (biosolids utilisation, biogas utilisation, reuse of treated effluent etc.) are of vital importance for Greece.

AKTOR provides Operation and Maintenance services to Psyttalia WWTP, including works for the improvement of the facility’s energy management towards maximum possible increase of the plant’s energy self-sufficiency rate.



Psyttalia Wastewater Treatment Plant


Infrastructure Project


Attica, Greece