LAUSR

The present study investigated seven physico‐chemical parameters (depth, pH, chloride, and hardness) and trace elements (arsenic [As], copper [Cu], and iron [Fe]) in the shallow aquifers of Barak River valley in Assam, India. All the physico‐chemical parameters were within the guideline value except pH; approximately 37.5% of the samples were below the guideline value (6.5–8.5). As ranged from 0 to 270 µg/L, Fe ranged from 1.43 to 61.03 mg/L, and Cu concentration ranged from 0 to 0.25 mg/L. All the samples for Fe, 83.33% for Cu and 70.84% for As were above the guideline value as prescribed by WHO or BIS. Further, the data were subjected to multivariate statistical analysis (MSA), including principal component analysis (PCA) and cluster analysis (CA), to investigate pollution sources. PCA identified three components, accounting for 72.42% of the total variance. The R‐mode CA identified two clusters, while the Q‐mode identified six clusters. The MSA results signified that human activities were more responsible than natural or geogenic processes for the deterioration of groundwater quality in the study area.