Evaluation of Groundwater Contamination Caused by Extraction of Sand and Gravel in Pools

Assessing the effect of sand and gravel harvesting on groundwater resources is of great importance due to being situated of underground aquifers below the surface of mines and sand production factories. The main objective of this study is to identify and evaluate the pollution of the groundwater caused by the extraction of sand and gravel in sedimented pools located in the mines of Shahriar and Qods cities. Our research indicated that so far no study has been carried out on groundwater contamination caused by the extraction as well as washing of sand and gravel. The present study was conducted in three phases: data preparation, creation of a continuous map of groundwater contamination by Simple Kriging method, and the detection of relationships and spatial correlations between qualitative parameters and gravel mines. The results indicated that levels of bicarbonate, carbonate, nitrate, sodium, potassium, chlorine, magnesium, and acidity pollution parameters of groundwater are desirable, whereas the amount of sulfate, electrical conductivity, and Total Dissolved Solids (TDS) of groundwater in the study area are higher than the standard level. The values obtained from the spatial correlation between the distance from the sand and gravel harvesting region and sulfate, electrical conductivity, as well as TDS were -0.53, -0.56, and -0.66, respectively. These values demonstrate the high correlation between these three parameters and the extraction of sand and gravel.