Trace elements geochemistry of groundwater: A case study from Patancheru industrial area, Andhra Pradesh, India

Patancheru Industrial Area located about 40 km from Hyderabad in Andhra Pradesh is one of the most contaminated regions identified by central regulatory body in India. About 250 small and large-scale industries manufacture pharmaceuticals, drugs, paints, pesticides and chemicals apart from steel and metallic products in this region. Several small streams drain through the area to join the main Nakkavagu stream which merges into Manjira River, after percolating into the sub-surface. A preliminary study was undertaken in an area of about 65 km² in and around Patancheru to determine the spatial distribution of trace elements in groundwater and to assess the extent of pollution and its impact on human health. Groundwater samples were collected from bore wells for the determination of Li, Be, B, Si, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Ba and Pb by ICP-MS using the standard reference material NIST1640 (Standard for trace elements in natural water) for calibration. Major cations (Ca, Mg, Na, K) were also estimated to characterize the groundwater. Fe was found to exceed the permissible limit in drinking water by about six times. As, Se, Cr, Cu and Mn show high variability in some places indicating heterogenetic characteristic of trace elements transport in groundwater. Contour maps for several trace elements were prepared to identify the source and transport of the contaminant.