Characterization and Assessment of Hydrogeological and Hydrogeochemical Processes in Torbalı-Fetrek Sub-basin, Türkiye

Abstract:The Torbalı-Fetreksub-basin is an area of significant agricultural and industrial importancelocated in the Izmir Province of Türkiye. The region’s industrial,agricultural, and domestic water consumption relies exclusively on groundwaterresources, attributing to the existing pollution and limited seasonal flow ofthe Fetrek Stream. The water budget of the region for the year 2021 wascalculated separately for three primary consumption components: industrial,domestic, and agricultural usage. Groundwater consumption was calculated as 9.52%,10.87% and 79.61%, respectively. There is no tourism activity in the region,and livestock is limited. Paleozoic aged marbles in Menderes Massif, UpperCretaceous limestone, Neogene, limestone/claystone intercalations andQuaternary alluvium units represent the characteristic aquifers. Surface andgroundwater sampling was done from 36 different points in the region. Accordingto the results of the major ions (Na, K, Ca, Mg, HCO3, Cl and SO4),the dominant cation was Ca and the dominant anion was HCO3 ingroundwater. According to the results of minor ions (Al, Sb, As, Cu, Ba, B, Hg,Zn, Fe, P, Ag, Cd, Cr, Pb, Li, Mg, Mn, Ni, Se, Sr, U and Si), most of thegroundwater is suitable for domestic, irrigation and industrial usage. In thewater samples taken from the Fetrek River, a significant increase in totaldissolved solids and pollution loads is observed, particularly in areas wherewastewater is discharged into the river. Due to the region's regular populationgrowth and industrial development, it is necessary to impose restrictions onunplanned groundwater abstraction. The river's water quality should beprotected and evaluated as an alternative to groundwater. Moreover, it isadvised to employ appropriate treatment procedures to re-use industrialwastewater for agricultural purposes.