Characteristics of industrial effluents and their possible impacts on quality of underground water

This study was conducted to evaluate various industrial effluents of Hayatabad Industrial Estate (HIE), Peshawar, and assess the possible impacts of such effluents on quality of underground water. A total of 12 samples including 7 from industrial effluents at the discharge point of each industry (marble, matches, steel, aluminum, pharmaceutical, beverages, ghee industries), 1 from main drain receiving effluents of all industries and 4 from tube or dug wells in the vicinity of the Estate were collected in March, 2003 and analyzed for temperature, pH, electrical conductivity, total dissolved salts, total suspended solids, biological oxygen demand and heavy metal contents (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn). The characteristics of effluents varied with the industry. The pH of one effluent (from aluminum industry) was beyond the limit and of the remaining within the permissible limit whereas TSS of one effluent (Pepsi industry) was within and of the remaining beyond the permissible limits comparing with the National Environmental Quality Standards (NEQS). The BOD was above the permissible limit in almost all of the effluents. Among heavy metals, Cd, Cr, Cu, Fe and Zn were within the permissible limits in all but Mn, Ni and Pb were beyond the permissible limits in one or more effluents. Variable results were also obtained for various parameters in underground water samples. The pH, TSS, TDS, Fe and Zn were within the permissible limits in all but Cd, Cr, Cu, Mn, Ni and Pb were above the permissible limits in one or more water samples compared with the WHO and US- EPA standards established for drinking water. These results suggested that effluents discharged from various industries showed variable characteristics and are potential threat to underground water contamination. It is thus recommended that wastewater treatment plants must be established with each industry. Further, efficient environmental laws and social awareness program must be undertaken for inhabitants of the estate and in the surrounding area with respect to potential threat of industrial effluents to the environment.