Greece advances Psyttaleia wastewater reuse plan as water scarcity intensifies

Reclaimed water gains urgency

Greece is taking a formal step toward expanding wastewater reuse as prolonged dry periods, falling groundwater reserves and rising demand increase pressure on the country’s water system. According to iefimerida.gr, reclaimed water produced through suitable treatment of municipal wastewater could become a supplementary source for agriculture, industry, cooling systems and urban green spaces.

The European Environment Agency estimates that reclaimed water could theoretically replace about 10% of current agricultural water abstraction in Greece if technical and financing barriers are resolved. The wider European context is also tightening: about 30% of Europe’s population and 20% of its territory experience water scarcity annually, while as much as 70% of Southern Europe’s population can face water stress during summer. Yet reuse remains close to 2.4%, and European networks lose approximately 23.5% of treated water before it reaches consumers.

EYDAP commissions the Psyttaleia roadmap

Greek water utility EYDAP has opened an electronic tender for studies covering new works at the Psyttaleia wastewater treatment center. The contract, described as Psyttaleia Phase 3 and associated with the “Psyttaleia 3.0” roadmap, is valued at approximately €9.3 million excluding VAT and nearly €11.5 million including VAT. Its duration is 35 months from signing, and electronic bids are due by 10:00 on October 16, 2026.

The tender covers studies rather than construction. According to iefimerida.gr, the eventual investment could approach €500 million, although its final value, scope and structure have not been determined. The work will proceed in four phases: assessment of the existing facility; a feasibility study comparing technologies and investment priorities; topographical, geotechnical, geological, preliminary engineering and environmental studies; and support for the later contractor-selection process.

From treatment plant to resource hub

The strategy would expand Psyttaleia beyond conventional wastewater treatment. Tertiary-plus treatment is expected to be central, raising effluent quality sufficiently for reuse in irrigation, industrial processes, cooling and green-space maintenance. EYDAP will also examine whether reclaimed water can help replenish groundwater in Attica, where levels have declined after long-term over-extraction.

Distribution is one of the largest constraints. Psyttaleia is at sea level, while several potential users are at higher elevations. Supplying them would require new pipelines, reservoirs and pumping stations, as well as substantial energy consumption. A cost-benefit analysis will therefore determine which destinations and applications are viable. Pricing will also be decisive: reclaimed water must be materially cheaper than drinking water while still covering production and transport costs. Discussions with the Regulatory Authority for Waste, Energy and Water are intended to establish that framework.

Agriculture, industry and data centers

Potential demand includes farmers, industrial users and large facilities, including data centers being developed in Eastern Attica. Depending on their cooling technology, data centers require a stable water supply. Reclaimed water could reduce their dependence on the drinking-water network and improve resilience to future restrictions.

The roadmap also targets net-zero energy through sludge utilization, biogas or biomethane, electricity generation and photovoltaic systems. A second pillar covers net-zero carbon dioxide, including assessment of carbon capture, management, transport, utilization and storage options. The study must determine whether these ambitions can be combined with affordable reclaimed-water delivery. For contractors and technology providers, the immediate opportunity is a complex engineering mandate; for water users, the larger issue is whether Greece can build a reliable second-use supply at a commercially workable price.