Evaluating groundwater pollution with emphasizing heavy metal hotspots in an urbanized alluvium watershed of Yamuna River, northern India

Abstract

For the management and prevention of groundwater pollution in the basin, a comprehensive evaluation of groundwater contamination hazards is required. The anthropogenic activities play a vital role in groundwater pollution of the alluvium watershed of Yamuna River in Mathura district through the infiltration process. In this study, several groundwater pollution indices such as pollution index of groundwater (PIG), heavy metal pollution index (HPI), ecological risk index (ERI) and multivariate approach i.e., Principal component analysis (PCA) have been used to detect the contaminated hotspots of the study area. During the study, 110 groundwater samples were collected from shallow hand-pumps to assess the groundwater quality based on selective major ions mainly Chloride, Sulphate, Nitrate, and Fluoride and heavy metals such as Zinc, Lead, Nickel, Cadmium, Iron, Chromium, Manganese and Copper respectively. The results show that the average heavy metal concentrations follow the trend of Ni (2.92 mg/L) > Pb (2.06 mg/L) > Fe (1.73 mg/L) > Zn (0.76 mg/L) > Cr (0.66 mg/L) > Cd (0.45 mg/L) > Mn (0.40 mg/L) > Cu (0.02 mg/L) respectively. Likewise, ERI results indicate a high potential ecological risk in the study area. Based on this, we classify the groundwater samples into good (9.10 %), poor (13.6 %), and very poor quality (77.3 %). The hotspots are found in the Northwestern region of the study area. The findings indicate that the escalation of municipal waste, industrial waste, agriculture applications and practices in the alluvium watershed of Yamuna River, directly and indirectly, affects the groundwater aquifers. This elaborate study helps in designing an appropriate mitigation strategy for pollution containment as well as proper water resources management.