Hydrochemical characteristics of the Gallikos River water, Prefecture of Kilkis, Greece

The Gallikos river basin is located in the northern part of Greece and discharges into the
Thermaikos Gulf, North Aegean sea. Three main tributaries contribute to the river, the basin
of which has a total areal extent of 930 km2. The basin of Gallikos river is formed of
metamorphic rocks, limestones, Neogene and Quaternary deposits. Groundwater resources
are mainly located within the carbonate rocks and the quaternary deposits.
Water quality deterioration is documented based on the performed hydrochemical analyses of
samples collected along the river course and its tributaries during the end of the wet and the
dry seasons of year 2004. Results were correlated to the groundwater quality as this is
reflected by analyses conducted on samples collected from wells adjacent to the river over
the same periods. Samples were analyzed for major ions, nitrates, BOD5, COD, heavy metals
and boron, whilst in situ measurements of pH, electrical conductivity and water temperature
were performed.
River water quality is related to the flow regime and is influenced by the geological structure,
agricultural activities, as well as by untreated waste effluent that is discharged from villages
and small industrial units that are scattered along the river basin.