Seasonal Assessment of Groundwater Contamination in Coal Mining Areas of Balochistan

Abstract

Balochistan is a semi-arid region. The assessment of water quality is very important, as the majority of people depend on groundwater for drinking purposes. The present study involves the quality assessment and mapping of drinking water in the five selected major coal mining sites in the four districts of Balochistan. A total of 50 samples were collected from these five coal mining sites in two seasons: i.e., summer and winter. A physicochemical analysis was carried out for groundwater samples: i.e., pH, electrical conductivity (EC), total dissolved solid (TDS), CO3, HCO3-, Cl-, Ca2+, Mg2+, Na+, K+, Cd, Cr, Co, Cu, Fe, Pb, Mn, Hg, Ni, and Zn. Thematic maps were used to depict the spatial distribution of significant variables and were compared with WHO standards (2011) during both seasons. The majority of parameters crossed the safe permissible limit of WHO standards. The water quality index (WQI) was calculated for the whole monitoring data obtained from both seasons from the perspective of drinking water in each of the selected sites. Moreover, a principle component analysis (PCA) and correlation matrix was carried out for the data analysis in order to identify the source of pollution and correlation among the variables. The results suggested that the overall quality of water from the selected coal mining sites deteriorated due to the overexploitation of coal mines and mining activity. The current investigation provides a comprehensive picture of the current status of water quality in and around the selected coal mines of Balochistan.