Impacts of human activities on groundwater quality of an alluvial aquifer: A case study of the eskişehir plain, Turkey

Abstract

Groundwater in an alluvial aquifer in the Eski?cehir plain, Turkey, has been polluted by means of municipal and industrial wastewaters and agricultural activities. This pollution is of concern because a large amount of groundwater is abstracted by drilled water wells, mostly located in the urban area, to supply municipal and industrial water for Eskişehir city. Hydrochemical water-quality (except biological) data obtained through a two-year sampling and analysis program indicate that the highest concentrations of groundwater pollution occur in the central and eastern parts of Eskişehir city. Groundwater quality degradation outside the urban area results from agricultural activities. The most serious pollution of groundwater in the Eskişehir plain is from nitrogen compounds (ammonia, nitrite, and nitrate). The concentrations of ammonia, nitrite, and nitrate of the 51 surveyed water wells range from 0.01-1.65 mg/L, 0.01-1.80 mg/L, and 1.1-257.0 mg/L, respectively. Orthophosphate concentrations in groundwater range from 0.01-1.25 mg/L. Considerable seasonal fluctuation in the groundwater quality was observed. In general, the groundwater quality in wet seasons was better than the quality in dry seasons.