Geospatial and multivariate analysis of trace metals in tubewell water using for drinking purpose in the upper Gangetic basin, India: Heavy metal pollution index

Abstract

Groundwater samples via tubewells were collected from the district Saharanpur, Uttar Pradesh (India). The study aimed to analyse groundwater quality and potential sources of trace metal contamination using the multivariate statistical tool, and the level of contamination by applying contamination index (Cd) and heavy metal pollution index (HPI). The groundwater was found to be enriched with Fe and contaminated with the trace and toxic elements like Al, As, B, Cu, Mn and Pb having mean values of 2786, 152, 9, 1033, 107, 199 and 15 µL respectively. Arsenic exceeded the WHO (2011) guidelines and BIS (2012) standard (10 µg/L) for 30% of the groundwater samples. For B, 46% of the samples were found having concentration higher than BIS (2012) permissible limit (1000 µg/L) and 3% to WHO (2011) guideline values (2400 µL). Lead level exceeded the BIS (2012) standard value and WHO (2011) guideline value in 46% of the samples. Multivariate analysis identified three factors responsible for data composition explaining 81% of the total variance in groundwater samples. Factor analysis (PCA and CA) allowed grouping of parameters according to the common features; Fe, Mn and Pb were associated with PC1 and controlled by the mixed origin such as geogenic sources as well as anthropogenic activities. Boron and Cu (PC2) were controlled by anthropogenic activities while As (PC3) was derived from the geogenic sources. The northern part of study area has higher Pb and Mn concentration than the southern part associated with small industrial activities. Degree of contamination and heavy metal pollution index supported the results and higher contamination was found to be in the vicinity of industrial setups. The overall quality (estimated using HPI values) of groundwater in the northern area is poor, and may cause potential health risk from the analyzed tubewells to the local population if the water is consumed for longer time.