Thessaloniki is the second largest city of Greece. Thessaloniki is located on the Thermaic Gulf, at the northwest part of the Aegean Sea. It is bounded on the west by the delta of the Axios river. According to the most recent census data the Thessaloniki Urban Area has a population of 824,676 inhabitants while the Thessaloniki Metropolitan Area has 1,030,338 inhabitants. It has an area of 1,285.61 km2 (metropolitan area) and is part of the Region of Central Macedonia. Although it is an area with high population density it has also a particularly important agricultural sector. Thessaloniki does not face particular water problems although the large population and the water requirements for irrigation make the area sensitive to water management issues. In addition, the environmental concerns of Thessaloniki residents and municipal authorities make sewage treatment a major issue in the area.
The major WWTP in Thessaloniki (Sindos) has a capacity of 165,00 m3/day and covers more than 2,500 ha irrigated land (mainly corn, sugar beet, rice).
The secondary effluent of the city’s Wastewater Treatment Plant (WWTP) is used foragricultural irrigation after mixing with freshwater at a 1:5 ratio.
It was estimated that more than 75% of the population was connected to WWTPs with a total capacity of over 1.50 mm3/day.
Water consumption in Thessaloniki increases 1.4% per year (mainly for irrigation).