Groundwater pollution by nitrate from agricultural fertilizers: The case of Menemen Basin (Aegean Region, Turkey)

Abstract

Groundwater is an essential drinking water source in Menemen sub­basin of İzmir city, Turkey. The aim of this study was to investigate the groundwater contamination by nitrates of agricultural lands. For this purpose, we evaluated variations of groundwater pH, redox potential, electrical conductivity (EC), major anions (NO3, Cl, SO4, HCO3 and CO3) and cations (Na, K, Ca and Mg). A statistical correlation procedure and piper diagram for hydrogeochemistry of groundwater were also applied. Nitrate levels were found to be higher around agricultural areas. Also EC values and Cl­ were measured to be higher as proximity to coastal areas increased, indicating seawater intrusion. Agricultural activities and excessive freshwater withdrawal were shown to impair groundwater quality and quantity at Menemen sub­basin.