Toxic trace element pollution in ground waters around Patancheru and Bolaram industrial areas, Andhra Pradesh, India: A graphical approach

Patancheru and Bolaram are satellite industrial towns near Hyderabad with over 300 large and medium scale pharmaceutical, heavy engineering, paints, paper and chemical factories. The industries of the area generate a cumulative 8 x 10 super(6) l/day of effluents which are being directly discharged on to surrounding land, irrigation fields, and surface water bodies which finally enter into the Nakkavagu River a tributary of the Manzira River. The present study on abundance and distribution pattern of toxic trace elements indicates the quantitative aspect of pollution in the Nakkavagu Basin. Migration patterns drawn for TDS, toxic elements such as Cu, As, Se, Zn, B, Cr and iron indicate that pollutants discharged by the industries are entering the surface and groundwater system (aquifers) and are also migrating towards the Manzira River further deteriorating the entire hydrological setup of the area. Entry and dispersion of pollutants in the hydrological system is shown by distribution diagrams. A conservative estimate indicates that the effect of pollutants on the agricultural lands and water bodies extends 0.25 to 0.5 km to either side of the Nakkavagu River over a length of 25 km. In addition to this, the movement of pollutants with ground water in the downstream direction worsened the hydrological system and increased the possibility of geo-accumulation of pollutants in biota. Open wells, dug wells and tanks have become useless and redundant as the concentrations of Cu, Se, As, B, Cr and Fe have increased to 5 to 10 times the permissible limits. Several villages have been affected by the toxic pollutants in the area. The groundwater system is polluted over a large area as shown in elemental migration diagrams and is not potable. Tentatively an area of 20 sq km can be categorized as the worst affected by various pollutants.