LEROS Wastewater Treatment Plant, Agia Marina, Leros, Greece

The LEROS wastewater treatment plant is situated in Agia Marina, on the island of Leros in the South Aegean region of Greece. Serving a population of 6,172, the plant is part of the municipal infrastructure for this island community. The facility operates under Greek national regulations, which transpose the EU Urban Waste Water Treatment Directive (91/271/EEC), requiring appropriate treatment for discharges into coastal waters. As an island plant, LEROS treats wastewater from a small agglomeration. The EU directive mandates secondary treatment for populations between 2,000 and 10,000 in coastal areas, with more stringent requirements if the receiving waters are sensitive. The plant's designed capacity is 1.00 (likely in thousands of cubic meters per day), indicating a modest scale. The treated effluent is discharged into the Aegean Sea, a semi-enclosed sea with limited tidal exchange. The surrounding marine environment supports diverse aquatic life, including seagrass meadows and fish populations. Proper treatment is essential to prevent nutrient enrichment and protect coastal water quality, which is vital for local tourism and fisheries.

The plant discharges into the Aegean Sea, which is connected to the Mediterranean Sea. The local watershed is small due to the island's geography, with runoff flowing directly to the coast. The marine environment around Leros includes sensitive habitats such as seagrass beds, which are important for biodiversity and carbon sequestration. Effective wastewater treatment helps maintain water quality and supports the ecological health of the surrounding sea.