ASSESSMENT OF HEAVY METAL CONTAMINANTS IN GROUNDWATER AROUND MINING AREA BY USING METAL POLLUTION INDICES MULTIVARIATE ANALYSIS AND GIS TECHNIQUE

Abstract

An opencast and underground coal mining each have the potential to have a negative impact on the groundwater table in terms of both its quantity and quality. Leachates from overburden dumps and industrial waste are another issue worldwide; they infiltrate into the groundwater and have a negative impact on the quality of it. A concern is that groundwater will become contaminated with heavy metals. Therefore, in the current study, the groundwater sample have been collected systematically from different sources of water in pre monsoon season (May) of 2022 around Korba coalfield (KCF). The collected water samples were examined for 9 different heavy metals by using ICP-MS (Inductively Coupled Plasma Mass Spectrometer-Perkin Elmer, Optima 4300 DV) instrument. In general,
the concentrations of few metals such as Aluminium, Cadmium, Copper, Iron, Lead, and Zinc were found to be well below the acceptable limits of World Health Organization (WHO) and Bureau of Indian Standards (BIS) standard, however Manganese, Barium, and Nickel concentrations were observed to be above to desirable limits of WHO and BIS standard at a few sites which is similar to the results obtained by previous studies. These laboratory data were applied for the calculation of heavy metal pollution indices such as Heavy Metal Pollution Index (HPI), Heavy Metal Evaluation Index (HEI), and Contamination Index (Cd). The multiple approach used to evaluate the metal indices identifies that 80 % of HPI, 85 % of HEI, and 95 % of Cd for groundwater samples mostly classified as “low
to medium” class. The spatial diagram of these different indices showed a higher value in the south east part of the region suggesting that the heavy metal leaching from mining activities has little impact on the groundwater in the south east of the examined area. Multivariate statistical studies, like principal component analysis (PCA) analysis reveals that Fe, Pb, and Zn originate from anthropogenic sources like coal mining, while Al and Cd originate from both lithogenic and anthropogenic sources.