Evaluation of the factors affecting chemical quality and nitrate pollution of groundwater resources, Case study: Zeidoun plain

This research investigates the factors affecting the quality and nitrate pollution of groundwater of Zeidoun plain in Khuzestan province. To this purpose, 25 agricultural wells were sampled and then the chemical parameters of water samples (including total dissolved solids, temperature, and cations and major anions) were measured. To investigate the factors influencing groundwater quality, compositiondiagrams, mineral saturation index and factor analysis method have been used.The results of this study showed that the groundwater has an unsuitable quality in the vast part of the study area. So that the salinity of groundwater is more than 3000 µmohs/cm in the middle and northern parts of the plain. Also, the concentration of sodium and chloride ions in these areas is more than 400 and 550 mg/l respectively. From the Nitrate pollution view point, groundwater contamination and pollution was occurred in central and northern parts of the study area. The concentration of nitrate in these regions varies from 15 to 100 mg/l. According to the results, the most important factors influencing the groundwater quality are water- rock interaction and pollution by agricultural activities and municipal wastes.